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Lyimo BM, Bakari C, Popkin-Hall ZR, Giesbrecht DJ, Seth MD, Pereus D, Shabani ZI, Moshi R, Boniface R, Mandara CI, Madebe R, Juliano JJ, Bailey JA, Ishengoma DS. Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity. Malar J 2024; 23:139. [PMID: 38720288 PMCID: PMC11080125 DOI: 10.1186/s12936-024-04974-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND In 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (PfCSP), but polymorphisms in the gene raise concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission intensities in Mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. METHODS The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of Mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright's inbreeding coefficient (Fws), Wright's fixation index (FST), principal component analysis, nucleotide diversity, and Tajima's D were used to assess within-host parasite diversity, population structure and natural selection. RESULTS Based on Fws (< 0.95), there was high polyclonality (ranging from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST = 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima's D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences revealed 50 different haplotypes (H_1 to H_50), with only 2% of sequences matching the 3D7 strain haplotype (H_50). Conversely, with the NF54 strain, the Pfcsp C-terminal sequences revealed 49 different haplotypes (H_1 to H_49), with only 0.4% of the sequences matching the NF54 strain (Hap_49). CONCLUSIONS The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima's D values, consistent with balancing selection for variants within Th2R and Th3R regions. The study observed differences between the intended haplotypes incorporated into the design of RTS,S and R21 vaccines and those present in natural parasite populations. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.
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Affiliation(s)
- Beatus M Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania.
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Misago D Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Zulfa I Shabani
- Dar Es Salaam University College of Education, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth Boniface
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Celine I Mandara
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Rashid Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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Rogier E, Battle N, Bakari C, Seth MD, Nace D, Herman C, Barakoti A, Madebe RA, Mandara CI, Lyimo BM, Giesbrecht DJ, Popkin-Hall ZR, Francis F, Mbwambo D, Garimo I, Aaron S, Lusasi A, Molteni F, Njau R, Cunningham JA, Lazaro S, Mohamed A, Juliano JJ, Bailey JA, Udhayakumar V, Ishengoma DS. Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions among patients enrolled at 100 health facilities throughout Tanzania: February to July 2021. Sci Rep 2024; 14:8158. [PMID: 38589477 PMCID: PMC11001933 DOI: 10.1038/s41598-024-58455-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/29/2024] [Indexed: 04/10/2024] Open
Abstract
Plasmodium falciparum with the histidine rich protein 2 gene (pfhrp2) deleted from its genome can escape diagnosis by HRP2-based rapid diagnostic tests (HRP2-RDTs). The World Health Organization (WHO) recommends switching to a non-HRP2 RDT for P. falciparum clinical case diagnosis when pfhrp2 deletion prevalence causes ≥ 5% of RDTs to return false negative results. Tanzania is a country of heterogenous P. falciparum transmission, with some regions approaching elimination and others at varying levels of control. In concordance with the current recommended WHO pfhrp2 deletion surveillance strategy, 100 health facilities encompassing 10 regions of Tanzania enrolled malaria-suspected patients between February and July 2021. Of 7863 persons of all ages enrolled and providing RDT result and blood sample, 3777 (48.0%) were positive by the national RDT testing for Plasmodium lactate dehydrogenase (pLDH) and/or HRP2. A second RDT testing specifically for the P. falciparum LDH (Pf-pLDH) antigen found 95 persons (2.5% of all RDT positives) were positive, though negative by the national RDT for HRP2, and were selected for pfhrp2 and pfhrp3 (pfhrp2/3) genotyping. Multiplex antigen detection by laboratory bead assay found 135/7847 (1.7%) of all blood samples positive for Plasmodium antigens but very low or no HRP2, and these were selected for genotyping as well. Of the samples selected for genotyping based on RDT or laboratory multiplex result, 158 were P. falciparum DNA positive, and 140 had sufficient DNA to be genotyped for pfhrp2/3. Most of these (125/140) were found to be pfhrp2+/pfhrp3+, with smaller numbers deleted for only pfhrp2 (n = 9) or only pfhrp3 (n = 6). No dual pfhrp2/3 deleted parasites were observed. This survey found that parasites with these gene deletions are rare in Tanzania, and estimated that 0.24% (95% confidence interval: 0.08% to 0.39%) of false-negative HRP2-RDTs for symptomatic persons were due to pfhrp2 deletions in this 2021 Tanzania survey. These data provide evidence for HRP2-based diagnostics as currently accurate for P. falciparum diagnosis in Tanzania.
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Affiliation(s)
- Eric Rogier
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Catherine Bakari
- National Institute for Medical Research, Dar Es Salaam, Tanzania
| | - Misago D Seth
- National Institute for Medical Research, Dar Es Salaam, Tanzania
| | - Douglas Nace
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Camelia Herman
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Achut Barakoti
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
- CDC Foundation, Atlanta, GA, USA
| | - Rashid A Madebe
- National Institute for Medical Research, Dar Es Salaam, Tanzania
| | - Celine I Mandara
- National Institute for Medical Research, Dar Es Salaam, Tanzania
| | - Beatus M Lyimo
- National Institute for Medical Research, Dar Es Salaam, Tanzania
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | | | | | | | | | - Issa Garimo
- National Malaria Control Programme, Dodoma, Tanzania
| | | | | | | | - Ritha Njau
- World Health Organization, Country Office, Dar Es Salaam, Tanzania
| | | | - Samwel Lazaro
- National Malaria Control Programme, Dodoma, Tanzania
| | - Ally Mohamed
- National Malaria Control Programme, Dodoma, Tanzania
| | | | | | | | - Deus S Ishengoma
- National Institute for Medical Research, Dar Es Salaam, Tanzania.
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia.
- Harvard T.H Chan School of Public Health, Boston, MA, USA.
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Lyimo BM, Bakari C, Popkin-Hall ZR, Giesbrecht DJ, Seth MD, Pereus D, Moshi R, Boniface R, Mandara CI, Madebe R, Juliano JJ, Bailey JA, Ishengoma DS. Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.23.24301587. [PMID: 38343796 PMCID: PMC10854334 DOI: 10.1101/2024.01.23.24301587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Background In 2021 and 2023, the World Health Organization approved RTS, S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (Pfcsp) but polymorphisms in this gene raises concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission in mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. Methods The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright's inbreeding coefficient (Fws), Wright's fixation index (FST), principal component analysis, nucleotide diversity, and Tajima's D were used to assess within-host parasite diversity, population structure and natural selection. Results Based on Fws (< 0.95), there was high polyclonality (ranged from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST= 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima's D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences had 50 different haplotypes (H_1 to H_50) and only 2% of sequences matched the 3D7 strain haplotype (H_50). Conclusions The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima's D values for parasite populations, consistent with balancing selection for variants within Th2R and Th3R regions. This data is consistent with other studies conducted across Africa and worldwide, which demonstrate low 3D7 haplotypes and little population structure. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.
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Affiliation(s)
- Beatus M. Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Misago D. Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth Boniface
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | | | - Rashid Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Deus S. Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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Mwalimu CD, Kiware S, Nshama R, Derua Y, Machafuko P, Gitanya P, Mwafongo W, Bernard J, Emidi B, Mwingira V, Malima R, Githu V, Masanja B, Mlacha Y, Tungu P, Kabula B, Sambu E, Batengana B, Matowo J, Govella N, Chaki P, Lazaro S, Serbantez N, Kitau J, Magesa SM, Kisinza WN. Dynamics of malaria vector composition and Plasmodium falciparum infection in mainland Tanzania: 2017-2021 data from the national malaria vector entomological surveillance. Malar J 2024; 23:29. [PMID: 38243220 PMCID: PMC10797900 DOI: 10.1186/s12936-024-04849-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 01/10/2024] [Indexed: 01/21/2024] Open
Abstract
BACKGROUND In 2015, Tanzania National Malaria Control Programme (NMCP) established a longitudinal malaria vector entomological surveillance (MVES). The MVES is aimed at a periodical assessment of malaria vector composition and abundance, feeding and resting behaviours, and Plasmodium falciparum infection in different malaria epidemiological strata to guide the NMCP on the deployment of appropriate malaria vector interventions. This work details the dynamics of malaria vector composition and transmission in different malaria epidemiological strata. METHODS The MVES was conducted from 32 sentinel district councils across the country. Mosquitoes were collected by the trained community members and supervised by the NMCP and research institutions. Three consecutive night catches (indoor collection with CDC light trap and indoor/outdoor collection using bucket traps) were conducted monthly in three different households selected randomly from two to three wards within each district council. Collected mosquitoes were sorted and morphologically identified in the field. Thereafter, the samples were sent to the laboratory for molecular characterization using qPCR for species identification and detection of P. falciparum infections (sporozoites). ELISA technique was deployed for blood meal analysis from samples of blood-fed mosquitoes to determine the blood meal indices (BMI). RESULTS A total of 63,226 mosquitoes were collected in 32 district councils from January 2017 to December 2021. Out of which, 39,279 (62%), 20,983 (33%) and 2964 (5%) were morphologically identified as Anopheles gambiae sensu lato (s.l.), Anopheles funestus s.l., and as other Anopheles species, respectively. Out of 28,795 laboratory amplified mosquitoes, 13,645 (47%) were confirmed to be Anopheles arabiensis, 9904 (34%) as An. funestus sensu stricto (s.s.), and 5193 (19%) as An. gambiae s.s. The combined average entomological inoculation rates (EIR) were 0.46 (95% CI 0.028-0.928) for An. gambiae s.s., 0.836 (95% CI 0.138-1.559) for An. arabiensis, and 0.58 (95% CI 0.165-0.971) for An. funestus s.s. with variations across different malaria transmission strata. Anopheles funestus s.s. and An. arabiensis were predominant in the Lake and South-Eastern zones, respectively, mostly in high malaria transmission areas. Monthly mosquito densities displayed seasonal patterns, with two peaks following the rainy seasons, varying slightly across species and district councils. CONCLUSION Anopheles arabiensis remains the predominant vector species followed by An. funestus s.s. in the country. Therefore, strengthening integrated vector management including larval source management is recommended to address outdoor transmission by An. arabiensis to interrupt transmission particularly where EIR is greater than the required elimination threshold of less than one (< 1) to substantially reduce the prevalence of malaria infection.
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Affiliation(s)
- Charles D Mwalimu
- National Malaria Control Programme (NMCP), Dodoma, United Republic of Tanzania
| | - Samson Kiware
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania.
- Pan African Mosquito Control Association (PAMCA), Dar es Salaam, Tanzania.
| | - Rosemary Nshama
- National Malaria Control Programme (NMCP), Dodoma, United Republic of Tanzania
| | - Yahya Derua
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Pendael Machafuko
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Peter Gitanya
- National Malaria Control Programme (NMCP), Dodoma, United Republic of Tanzania
| | - Winfred Mwafongo
- National Malaria Control Programme (NMCP), Dodoma, United Republic of Tanzania
| | - Jubilate Bernard
- National Malaria Control Programme (NMCP), Dodoma, United Republic of Tanzania
| | - Basiliana Emidi
- National Institute for Medical Research (NIMR), Mwanza, Tanzania
| | - Victor Mwingira
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Robert Malima
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
- University of Dar es Salaam, Mbeya College of Health and Allied Sciences, Mbeya, Tanzania
| | | | - Brian Masanja
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania
| | - Yeromin Mlacha
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania
- Pan African Mosquito Control Association (PAMCA), Dar es Salaam, Tanzania
| | - Patrick Tungu
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Bilali Kabula
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Edward Sambu
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Bernard Batengana
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - Johnson Matowo
- Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Nicodem Govella
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania
- Population Services International (PSI), Dar es Salaam, Tanzania
| | - Prosper Chaki
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania
- Pan African Mosquito Control Association (PAMCA), Dar es Salaam, Tanzania
| | - Samwel Lazaro
- National Malaria Control Programme (NMCP), Dodoma, United Republic of Tanzania
| | - Naomi Serbantez
- U.S. President's Malaria Initiative, Dar es Salaam, Tanzania
| | - Jovin Kitau
- World Health Organization, Country Office, Dar es Salaam, Tanzania
| | - Stephen M Magesa
- Pan African Mosquito Control Association (PAMCA), Dar es Salaam, Tanzania
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
| | - William N Kisinza
- National Institute for Medical Research (NIMR), Amani Centre, Muheza, Tanzania
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Jongo S, Church LP, Milando F, Qassim M, Schindler T, Rashid M, Tumbo A, Nyaulingo G, Bakari BM, Athuman Mbaga T, Mohamed L, Kassimu K, Simon BS, Mpina M, Zaidi I, Duffy PE, Swanson PA, Seder R, Herman JD, Mendu M, Zur Y, Alter G, KC N, Riyahi P, Abebe Y, Murshedkar T, James ER, Billingsley PF, Sim BKL, Richie TL, Daubenberger C, Abdulla S, Hoffman SL. Safety and protective efficacy of PfSPZ Vaccine administered to HIV-negative and -positive Tanzanian adults. J Clin Invest 2024; 134:e169060. [PMID: 38194272 PMCID: PMC10940097 DOI: 10.1172/jci169060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 12/20/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUNDSanaria PfSPZ Vaccine, composed of attenuated Plasmodium falciparum (Pf) sporozoites (SPZ), protects against malaria. We conducted this clinical trial to assess the safety and efficacy of PfSPZ Vaccine in HIV-positive (HIV+) individuals, since the HIV-infection status of participants in mass vaccination programs may be unknown.METHODSThis randomized, double-blind, placebo-controlled trial enrolled 18- to 45-year-old HIV-negative (HIV-) and well-controlled HIV+ Tanzanians (HIV viral load <40 copies/mL, CD4 counts >500 cells/μL). Participants received 5 doses of PfSPZ Vaccine or normal saline (NS) over 28 days, followed by controlled human malaria infection (CHMI) 3 weeks later.RESULTSThere were no solicited adverse events in the 9 HIV- and 12 HIV+ participants. After CHMI, 6 of 6 NS controls, 1 of 5 HIV- vaccinees, and 4 of 4 HIV+ vaccinees were Pf positive by quantitative PCR (qPCR). After immunization, anti-Pf circumsporozoite protein (anti-PfCSP) (isotype and IgG subclass) and anti-PfSPZ antibodies, anti-PfSPZ CD4+ T cell responses, and Vδ2+ γδ CD3+ T cells were nonsignificantly higher in HIV- than in HIV+ vaccinees. Sera from HIV- vaccinees had significantly higher inhibition of PfSPZ invasion of hepatocytes in vitro and antibody-dependent complement deposition (ADCD) and Fcγ3B binding by anti-PfCSP and ADCD by anti-cell-traversal protein for ookinetes and SPZ (anti-PfCelTOS) antibodies.CONCLUSIONSPfSPZ Vaccine was safe and well tolerated in HIV+ vaccinees, but not protective. Vaccine efficacy was 80% in HIV- vaccinees (P = 0.012), whose sera had significantly higher inhibition of PfSPZ invasion of hepatocytes and enrichment of multifunctional PfCSP antibodies. A more potent PfSPZ vaccine or regimen is needed to protect those living with HIV against Pf infection in Africa.TRIAL REGISTRATIONClinicalTrials.gov NCT03420053.FUNDINGEquatorial Guinea Malaria Vaccine Initiative (EGMVI), made up of the Government of Equatorial Guinea Ministries of Mines and Hydrocarbons, and Health and Social Welfare, Marathon Equatorial Guinea Production Limited, Noble Energy, Atlantic Methanol Production Company, and EG LNG; Swiss government, through ESKAS scholarship grant no. 2016.0056; Intramural Research Program of the National Institute of Allergy and Infectious Diseases, NIH; NIH grant 1U01AI155354-01.
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Affiliation(s)
- Said Jongo
- Ifakara Health Institute (IHI), Bagamoyo, Tanzania
| | | | | | | | - Tobias Schindler
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Anneth Tumbo
- Ifakara Health Institute (IHI), Bagamoyo, Tanzania
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | | | | | | | | | | | - Maxmillian Mpina
- Ifakara Health Institute (IHI), Bagamoyo, Tanzania
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Irfan Zaidi
- Laboratory of Malaria Immunology and Vaccinology and
| | | | | | - Robert Seder
- Vaccine Research Center, NIH, Bethesda, Maryland, USA
| | - Jonathan D. Herman
- Division of Infectious Disease, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Maanasa Mendu
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Yonatan Zur
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Galit Alter
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Natasha KC
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential LLC, Rockville, Maryland, USA
| | | | | | | | | | | | - B. Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential LLC, Rockville, Maryland, USA
| | | | - Claudia Daubenberger
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Bisanzio D, Sudathip P, Kitchakarn S, Kanjanasuwan J, Gopinath D, Pinyajeerapat N, Sintasath D, Shah JA. Malaria Stratification Mapping in Thailand to Support Prevention of Reestablishment. Am J Trop Med Hyg 2024; 110:79-82. [PMID: 38081047 PMCID: PMC10793033 DOI: 10.4269/ajtmh.23-0595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/06/2023] [Indexed: 01/05/2024] Open
Abstract
Thailand aims to eliminate malaria by 2026, with 46 of the country's 77 provinces already verified as malaria free. However, these provinces remain susceptible to the reestablishment of indigenous transmission that would threaten the national goal. Thus, the country is prioritizing national and subnational prevention of reestablishment (POR) planning while considering the spatial heterogeneity of the remaining malaria caseload. To support POR efforts, a novel nonmodeling method produced a malaria stratification map at the tambon (subdistrict) level, incorporating malaria case data, demographic data, and environmental factors. The stratification analysis categorized 7,425 tambons into the following four risk strata: Local Transmission (2.9%), At Risk for Transmission (3.1%), High Risk for Reintroduction (2.9%), and Low Risk for Reintroduction (91.1%). The stratification map will support the national program to target malaria interventions in remaining hotspots and mitigate the risk of transmission in malaria-free areas.
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Affiliation(s)
- Donal Bisanzio
- Inform Asia: USAID’s Health Research Program, RTI International, Bangkok, Thailand
| | - Prayuth Sudathip
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Suravadee Kitchakarn
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Jerdsuda Kanjanasuwan
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | | | - Niparueradee Pinyajeerapat
- U.S. President’s Malaria Initiative, United States Agency for International Development (USAID), Regional Development Mission for Asia, Bangkok, Thailand
| | - David Sintasath
- U.S. President’s Malaria Initiative, United States Agency for International Development (USAID), Regional Development Mission for Asia, Bangkok, Thailand
| | - Jui A. Shah
- Inform Asia: USAID’s Health Research Program, RTI International, Bangkok, Thailand
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Adhikari B, Bayo M, Peto TJ, Callery JJ, Tripura R, Dysoley L, Mshamu S, Gesase S, von Seidlein L, Dondorp AM. Comparing the roles of community health workers for malaria control and elimination in Cambodia and Tanzania. BMJ Glob Health 2023; 8:e013593. [PMID: 38070880 PMCID: PMC10729139 DOI: 10.1136/bmjgh-2023-013593] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/12/2023] [Indexed: 12/18/2023] Open
Abstract
The reduction of deaths from malaria in sub-Saharan Africa (SSA) is stalling, whereas many countries in Southeast Asia are approaching malaria elimination. We reviewed the role of community health worker (CHW) programmes in malaria control and elimination between regions, with a more detailed description of the programmes in Tanzania and Cambodia. Compared with Tanzania, Cambodia has a much more developed CHW network, which has been pivotal in the near elimination of malaria. In Tanzania, the malaria burden has remained similar over the last decade and treatment continues to rely on healthcare facilities, which provide more limited access to early diagnosis and treatment. Overall, the proportion of malaria cases treated by CHWs is substantially lower in SSA than in Southeast Asia. Even though networks of CHWs are resource intensive and malaria epidemiology differs substantially between countries, there is a strong case for expanding CHW networks in rural SSA to improve early access to effective malaria treatment and reduce the malaria burden.
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Affiliation(s)
- Bipin Adhikari
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
| | - Makhily Bayo
- Faculty of Medicine, University of Amsterdam, Amsterdam, The Netherlands
| | - Thomas J Peto
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
| | - James J Callery
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
| | - Rupam Tripura
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
| | - Lek Dysoley
- C.N.M National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
- School of Public Health, National Institute of Public Health, Phnom Penh, Cambodia
| | - Salum Mshamu
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
- CSK Research Solutions, Mtwara, Tanzania
| | - Samwel Gesase
- Korogwe Research Laboratory, National Institute for Medical Research, Tanga, Tanzania
| | - Lorenz von Seidlein
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK, Oxford, UK
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8
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Mkali HR, Lalji SM, Al-Mafazy AW, Joseph JJ, Mwaipape OS, Ali AS, Abbas FB, Ali MH, Hassan WS, Reaves EJ, Kitojo C, Serbantez N, Kabula BI, Nyinondi SS, McKay M, Cressman G, Ngondi JM, Reithinger R. How Real-Time Case-Based Malaria Surveillance Helps Zanzibar Get a Step Closer to Malaria Elimination: Description of Operational Platform and Resources. GLOBAL HEALTH, SCIENCE AND PRACTICE 2023; 11:e2200522. [PMID: 37903584 PMCID: PMC10615242 DOI: 10.9745/ghsp-d-22-00522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 09/26/2023] [Indexed: 11/01/2023]
Abstract
Testing and treating asymptomatic populations have the potential to reduce the population's parasite reservoir and reduce malaria transmission. Zanzibar's malaria case notification (MCN) platform collects detailed sociodemographic and epidemiological data from all confirmed malaria cases to inform programmatic decision-making. We describe the design and operationalization process of the platform and other malaria surveillance resources that are enabling Zanzibar's progress toward malaria elimination.The MCN platform consists of an interactive short message service (SMS) system for case notification, a software application for Android mobile devices, a visual question set and workflow manager, a back-end database server, and a web browser-based application for data analytics, configuration, and management. Malaria case data were collected from August 2012 to December 2021 and reported via SMS from all public and private health facilities to a central database and then to district malaria surveillance officers' mobile devices. Data included patient names, shehia (administrative area), and date of diagnosis, enabling officers to track patients, ideally within 24 hours of reporting. Patients' household members were tested for malaria using conventional rapid diagnostic tests (RDTs). Treatment using artemisinin-based combination therapy was provided for persons testing positive.Between 2012 and 2021, a total of 48,899 index malaria cases were confirmed at health facilities, 22,152 (45.3%) within 24 hours of reporting; 41,886 (85.7%) cases were fully investigated and followed up to the household level. A total of 111,811 additional household members were tested with RDTs, of whom 10,602 (9.5%) were malaria positive.The MCN platform reports malaria case data in near real time, enabling prompt follow-up of index cases and prompt testing and treatment of members in index case households. Along with routine testing and treatment and other preventive interventions, the MCN platform is foundational to the programmatic efforts in further reducing malaria and ultimately eliminating autochthonous malaria transmission in Zanzibar.
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Affiliation(s)
| | - Shabbir M Lalji
- RTI International, Dar es Salaam, United Republic of Tanzania
| | | | - Joseph J Joseph
- RTI International, Dar es Salaam, United Republic of Tanzania
| | - Osia S Mwaipape
- RTI International, Dar es Salaam, United Republic of Tanzania
| | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Faiza B Abbas
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Mohamed H Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Wahida S Hassan
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Erik J Reaves
- U.S. President's Malaria Initiative, U.S. Centers for Disease Control and Prevention, Dar es Salaam, United Republic of Tanzania
| | - Chonge Kitojo
- U.S. President's Malaria Initiative, U.S. Agency for International Development, Dar es Salaam, United Republic of Tanzania
| | - Naomi Serbantez
- U.S. President's Malaria Initiative, U.S. Agency for International Development, Dar es Salaam, United Republic of Tanzania
| | - Bilali I Kabula
- RTI International, Dar es Salaam, United Republic of Tanzania
| | | | - Mike McKay
- RTI International, Research Triangle Park, USA
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9
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Kihwele F, Gavana T, Makungu C, Msuya HM, Mlacha YP, Govella NJ, Chaki PP, Sunguya BF. Exploring activities and behaviours potentially increases school-age children's vulnerability to malaria infections in south-eastern Tanzania. Malar J 2023; 22:293. [PMID: 37789435 PMCID: PMC10548596 DOI: 10.1186/s12936-023-04703-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 09/02/2023] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND Strengthening malaria control activities in Tanzania has dramatically declined human malaria infections. However, there is an increasing epidemiological shift in the burden on school-age children. The underlying causes for such an epidemiological shift remain unknown in this context. This study explored activities and behaviours that could increase the vulnerability of school-age children to transmission risk to provide insight into protection gap with existing interventions and opportunities for supplementary interventions. METHODS This cross-sectional study conducted twenty-four focus group discussions (FGDs) in three districts of Rufiji, Kibiti and Kilwa in south-eastern Tanzania. Sixteen FGDs worked with school-age children (13 to 18 years) separating girls and boys and eight FGDs with their parents in mixed-gender groups. A total of 205 community members participated in FGDs across the study area. Of them, 72 participants were parents, while 133 were school-age children (65 boys and 68 girls). RESULTS Routine domestic activities such as fetching water, washing kitchen utensils, cooking, and recreational activities such as playing and watching television and studying were the reported activities that kept school-age children outdoors early evening to night hours (between 18:00 and 23:00). Likewise, the social and cultural events including initiation ceremonies and livelihood activities also kept this age group outdoors from late evening to early night and sometimes past midnight hours. Parents migrating to farms from December to June, leaving behind school-age children unsupervised affecting their net use behaviour plus spending more time outdoors at night, and the behaviour of children sprawling legs and hands while sleeping inside treated bed nets were identified as potential risks to infectious mosquito bites. CONCLUSION The risky activities, behaviours, and social events mostly occurring outdoors might increase school-age children's vulnerability to malaria infections. The findings provide preliminary insight on potential risk factors for persisting transmission. Further studies to quantify the risk behaviour and activities are recommended to establish the magnitude and anticipated impact on supplementary control strategies to control infection in school-age children.
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Affiliation(s)
- Fadhila Kihwele
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania.
- Muhimbili University of Health and Allied Sciences, P.O. Box 65001, Dar es Salaam, United Republic of Tanzania.
| | - Tegemeo Gavana
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania
- Muhimbili University of Health and Allied Sciences, P.O. Box 65001, Dar es Salaam, United Republic of Tanzania
| | - Christina Makungu
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania
| | - Hajirani M Msuya
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania
| | - Yeromin P Mlacha
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania
| | - Nicodem James Govella
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania
- School of Life Sciences and Bioengineering (LISBE), Nelson Mandela African Institution of Science and Technology, P.O. BOX 447, Tengeru, Arusha, United Republic of Tanzania
| | - Prosper Pius Chaki
- Environmental Health and Ecological Sciences Department, #5 Ifakara Street, Plot 463 Mikocheni, P.O. Box 78373, Dar Es Salaam, United Republic of Tanzania
- The Pan African Mosquito Control Association (PAMCA), KEMRI Headquarters, Mbagathi Road Nairobi, Nairobi, 54840-00200, Kenya
| | - Bruno Fokas Sunguya
- Muhimbili University of Health and Allied Sciences, P.O. Box 65001, Dar es Salaam, United Republic of Tanzania
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10
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Fakih BS, Holzschuh A, Ross A, Stuck L, Abdul R, Al-Mafazy AWH, Irema I, Mbena A, Thawer SG, Shija SJ, Aliy SM, Ali A, Fink G, Yukich J, Hetzel MW. Risk of imported malaria infections in Zanzibar: a cross-sectional study. Infect Dis Poverty 2023; 12:80. [PMID: 37641152 PMCID: PMC10464242 DOI: 10.1186/s40249-023-01129-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/11/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND Zanzibar has made substantial progress in malaria control with vector control, improved diagnosis, and artemisinin-based combination therapy. Parasite prevalence in the population has remained around 1% but imported infections from mainland Tanzania contribute to sustained local transmission. Understanding travel patterns between mainland Tanzania and Zanzibar, and the risk of malaria infection, may help to control malaria importation to Zanzibar. METHODS A rolling cross-sectional survey linked to routine reactive case detection of malaria was carried out in Zanzibar between May 2017 and October 2018. Households of patients diagnosed with malaria at health facilities were surveyed and household members were tested for malaria using rapid diagnostic tests and a sub-sample by quantitative PCR (qPCR). Interviews elicited a detailed travel history of all household members who had travelled within the past two months, including trips within and outside of Zanzibar. We estimated the association of malaria infection with travel destinations in pre-defined malaria endemicity categories, trip duration, and other co-variates using logistic regression. RESULTS Of 17,891 survey participants, 1177 (7%) reported a recent trip, of which 769 (65%) visited mainland Tanzania. Among travellers to mainland Tanzania with travel destination details and a qPCR result available, 241/378 (64%) reported traveling to districts with a 'high' malaria endemicity and for 12% the highest endemicity category was 'moderate'. Travelers to the mainland were more likely to be infected with malaria parasites (29%, 108/378) than those traveling within Zanzibar (8%, 16/206) or to other countries (6%, 2/17). Among travellers to mainland Tanzania, those visiting highly endemic districts had a higher odds of being qPCR-positive than those who travelled only to districts where malaria-endemicity was classified as low or very low (adjusted odd ratio = 7.0, 95% confidence interval: 1.9-25.5). Among travellers to the mainland, 110/378 (29%) never or only sometimes used a mosquito net during their travel. CONCLUSIONS Strategies to reduce malaria importation to Zanzibar may benefit from identifying population groups traveling to highly endemic areas in mainland Tanzania. Targeted interventions to prevent and clear infections in these groups may be more feasible than attempting to screen and treat all travellers upon arrival in Zanzibar.
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Affiliation(s)
- Bakar S Fakih
- Ifakara Health Institute, Dar es Salaam, Tanzania.
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Aurel Holzschuh
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA
| | - Amanda Ross
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Logan Stuck
- Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
- Amsterdam Institute for Global Health and Development, Amsterdam, Netherlands
| | - Ramadhan Abdul
- Ifakara Health Institute, Dar es Salaam, Tanzania
- Amsterdam Institute for Global Health and Development, Amsterdam, Netherlands
| | | | - Imani Irema
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | | | - Sumaiyya G Thawer
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Shija J Shija
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Safia M Aliy
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Günther Fink
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Joshua Yukich
- Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
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11
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Hussein AK, Tarimo D, Reaves EJ, Chacky F, Abade AM, Mwalimu CD, Mohamed A, Nasser A, Kishimba RS. The quality of malaria case management in different transmission settings in Tanzania mainland, 2017-2018. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0002318. [PMID: 37603541 PMCID: PMC10441786 DOI: 10.1371/journal.pgph.0002318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 07/31/2023] [Indexed: 08/23/2023]
Abstract
Tanzania is undergoing an epidemiological transition for malaria transmission with some areas of the country having <10% (hypoendemic) and other areas 10% - 50% malaria prevalence (mesoendemic). It is not known whether there is a difference in the quality of malaria case management based on endemicity in Tanzania mainland. We examined the influence of endemicity on the quality of malaria case management at health facilities. We conducted a cross-sectional analysis of 1713 health facilities in Tanzania mainland, using data collected by the National Malaria Control Program through an assessment tool to evaluate quality of malaria case management. The data was gathered from September 2017 to December 2018. Using standard quality factors, mean scores from facilities in the different endemicity regions were compared by a Student's t-test. Simple and multiple linear regression analyses were performed to determine the association between facility performance (score) and endemicity (mesoendemic vs. hypoendemic). Facilities in mesoendemic regions scored higher than those in hypoendemic regions on the overall quality of services [difference in mean scores ([Formula: see text]) = 2.52; (95% Confidence Interval (CI) 1.12, 3.91)], site readiness [[Formula: see text] = 2.97; (95% CI 1.30, 4.61)], availability of malaria reference materials [[Formula: see text] = 4.91; (95% CI 2.05, 7.76)], availability of Health Management Information System tools [[Formula: see text] = 5.86; (95% CI 3.80, 7.92)] and patient satisfaction [[Formula: see text] = 6.61; (95% CI 3.75, 9.48)]. Predictors associated with lower facility scores included; being located in a hypoendemic region [β: -2.49; (95% CI -3.83, -1.15)] and urban area [β: -3.84; (95% CI -5.60, -2.08)]. These findings highlight the differences in quality of malaria case management based on endemicity, but there is still a need to target improvement efforts in underperforming facilities, regardless of endemicity.
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Affiliation(s)
- Ally Kassim Hussein
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, United Republic of Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, United Republic of Tanzania
| | - Donath Tarimo
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, United Republic of Tanzania
| | - Erik J. Reaves
- U.S. President’s Malaria Initiative, U.S. Centers for Disease Control and Prevention, Dar es Salaam, United Republic of Tanzania
| | - Frank Chacky
- National Malaria Control Program, Dodoma, United Republic of Tanzania
- Ministry of Health, Dodoma, United Republic of Tanzania
| | - Ahmed Mohamed Abade
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, United Republic of Tanzania
| | | | - Ally Mohamed
- National Malaria Control Program, Dodoma, United Republic of Tanzania
- Ministry of Health, Dodoma, United Republic of Tanzania
| | - Ahlam Nasser
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, United Republic of Tanzania
| | - Rogath Saika Kishimba
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, United Republic of Tanzania
- Ministry of Health, Dodoma, United Republic of Tanzania
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12
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Thawer SG, Golumbeanu M, Lazaro S, Chacky F, Munisi K, Aaron S, Molteni F, Lengeler C, Pothin E, Snow RW, Alegana VA. Spatio-temporal modelling of routine health facility data for malaria risk micro-stratification in mainland Tanzania. Sci Rep 2023; 13:10600. [PMID: 37391538 PMCID: PMC10313820 DOI: 10.1038/s41598-023-37669-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 06/26/2023] [Indexed: 07/02/2023] Open
Abstract
As malaria transmission declines, the need to monitor the heterogeneity of malaria risk at finer scales becomes critical to guide community-based targeted interventions. Although routine health facility (HF) data can provide epidemiological evidence at high spatial and temporal resolution, its incomplete nature of information can result in lower administrative units without empirical data. To overcome geographic sparsity of data and its representativeness, geo-spatial models can leverage routine information to predict risk in un-represented areas as well as estimate uncertainty of predictions. Here, a Bayesian spatio-temporal model was applied on malaria test positivity rate (TPR) data for the period 2017-2019 to predict risks at the ward level, the lowest decision-making unit in mainland Tanzania. To quantify the associated uncertainty, the probability of malaria TPR exceeding programmatic threshold was estimated. Results showed a marked spatial heterogeneity in malaria TPR across wards. 17.7 million people resided in areas where malaria TPR was high (≥ 30; 90% certainty) in the North-West and South-East parts of Tanzania. Approximately 11.7 million people lived in areas where malaria TPR was very low (< 5%; 90% certainty). HF data can be used to identify different epidemiological strata and guide malaria interventions at micro-planning units in Tanzania. These data, however, are imperfect in many settings in Africa and often require application of geo-spatial modelling techniques for estimation.
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Affiliation(s)
- Sumaiyya G Thawer
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Monica Golumbeanu
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Samwel Lazaro
- Ministry of Health, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Frank Chacky
- Ministry of Health, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Khalifa Munisi
- Ministry of Health, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Sijenunu Aaron
- Ministry of Health, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- National Malaria Control Programme, Dodoma, Tanzania
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Clinton Health Access Initiative, New York, USA
| | - Robert W Snow
- Population Health Unit, KEMRI-Welcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Victor A Alegana
- World Health Organization, Regional Office for Africa, Brazzaville, Republic of Congo
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13
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Hofer LM, Kweyamba PA, Sayi RM, Chabo MS, Maitra SL, Moore SJ, Tambwe MM. Malaria rapid diagnostic tests reliably detect asymptomatic Plasmodium falciparum infections in school-aged children that are infectious to mosquitoes. Parasit Vectors 2023; 16:217. [PMID: 37391770 DOI: 10.1186/s13071-023-05761-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/29/2023] [Indexed: 07/02/2023] Open
Abstract
BACKGROUND Asymptomatic malaria infections (Plasmodium falciparum) are common in school-aged children and represent a disease transmission reservoir as they are potentially infectious to mosquitoes. To detect and treat such infections, convenient, rapid and reliable diagnostic tools are needed. In this study, malaria rapid diagnostic tests (mRDT), light microscopy (LM) and quantitative polymerase chain reaction (qPCR) were used to evaluate their performance detecting asymptomatic malaria infections that are infectious to mosquitoes. METHODS One hundred seventy asymptomatic school-aged children (6-14 years old) from the Bagamoyo district in Tanzania were screened for Plasmodium spp. infections using mRDT (SD BIOLINE), LM and qPCR. In addition, gametocytes were detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for all qPCR-positive children. Venous blood from all P. falciparum positive children was fed to female Anopheles gambiae sensu stricto mosquitoes via direct membrane feeding assays (DMFAs) after serum replacement. Mosquitoes were dissected for oocyst infections on day 8 post-infection. RESULTS The P. falciparum prevalence in study participants was 31.7% by qPCR, 18.2% by mRDT and 9.4% by LM. Approximately one-third (31.2%) of asymptomatic malaria infections were infectious to mosquitoes in DMFAs. In total, 297 infected mosquitoes were recorded after dissections, from which 94.9% (282/297) were derived from infections detected by mRDT and 5.1% (15/297) from subpatent mRDT infections. CONCLUSION The mRDT can be used reliably to detect children carrying gametocyte densities sufficient to infect high numbers of mosquitoes. Subpatent mRDT infections contributed marginally to the pool of oocyts-infected mosquitoes.
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Affiliation(s)
- Lorenz M Hofer
- Vector Biology Unit, Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Kreuzstrasse 2, 4123, Allschwil, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania
| | - Prisca A Kweyamba
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania
| | - Rajabu M Sayi
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania
| | - Mohamed S Chabo
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania
| | - Sonali L Maitra
- Vector Biology Unit, Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Kreuzstrasse 2, 4123, Allschwil, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania
| | - Sarah J Moore
- Vector Biology Unit, Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Kreuzstrasse 2, 4123, Allschwil, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania
- The Nelson Mandela African Institution of Science and Technology (NM-AIST), 447, Tengeru, Arusha, Tanzania
| | - Mgeni M Tambwe
- Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, 74, Bagamoyo, Tanzania.
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14
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Holzschuh A, Lerch A, Gerlovina I, Fakih BS, Al-Mafazy AWH, Reaves EJ, Ali A, Abbas F, Ali MH, Ali MA, Hetzel MW, Yukich J, Koepfli C. Multiplexed ddPCR-amplicon sequencing reveals isolated Plasmodium falciparum populations amenable to local elimination in Zanzibar, Tanzania. Nat Commun 2023; 14:3699. [PMID: 37349311 PMCID: PMC10287761 DOI: 10.1038/s41467-023-39417-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023] Open
Abstract
Zanzibar has made significant progress toward malaria elimination, but recent stagnation requires novel approaches. We developed a highly multiplexed droplet digital PCR (ddPCR)-based amplicon sequencing method targeting 35 microhaplotypes and drug-resistance loci, and successfully sequenced 290 samples from five districts covering both main islands. Here, we elucidate fine-scale Plasmodium falciparum population structure and infer relatedness and connectivity of infections using an identity-by-descent (IBD) approach. Despite high genetic diversity, we observe pronounced fine-scale spatial and temporal parasite genetic structure. Clusters of near-clonal infections on Pemba indicate persistent local transmission with limited parasite importation, presenting an opportunity for local elimination efforts. Furthermore, we observe an admixed parasite population on Unguja and detect a substantial fraction (2.9%) of significantly related infection pairs between Zanzibar and the mainland, suggesting recent importation. Our study provides a high-resolution view of parasite genetic structure across the Zanzibar archipelago and provides actionable insights for prioritizing malaria elimination efforts.
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Affiliation(s)
- Aurel Holzschuh
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Indiana, IN, USA.
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
| | - Anita Lerch
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Indiana, IN, USA
| | - Inna Gerlovina
- EPPIcenter Research Program, Division of HIV, ID and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Bakar S Fakih
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Ifakara Health Institute, Dar es Salaam, United Republic of Tanzania
| | | | - Erik J Reaves
- U.S. Centers for Disease Control and Prevention, President's Malaria Initiative, Dar es Salaam, United Republic of Tanzania
| | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Faiza Abbas
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Mohamed Haji Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Mohamed Ali Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Joshua Yukich
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Cristian Koepfli
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Indiana, IN, USA.
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Farnham A, Loss G, Lyatuu I, Cossa H, Kulinkina AV, Winkler MS. A roadmap for using DHIS2 data to track progress in key health indicators in the Global South: experience from sub-saharan Africa. BMC Public Health 2023; 23:1030. [PMID: 37259137 DOI: 10.1186/s12889-023-15979-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 05/23/2023] [Indexed: 06/02/2023] Open
Abstract
High quality health data as collected by health management information systems (HMIS) is an important building block of national health systems. District Health Information System 2 (DHIS2) software is an innovation in data management and monitoring for strengthening HMIS that has been widely implemented in low and middle-income countries in the last decade. However, analysts and decision-makers still face significant challenges in fully utilizing the capabilities of DHIS2 data to pursue national and international health agendas. We aimed to (i) identify the most relevant health indicators captured by DHIS2 for tracking progress towards the Sustainable Development goals in sub-Saharan African countries and (ii) present a clear roadmap for improving DHIS2 data quality and consistency, with a special focus on immediately actionable solutions. We identified that key indicators in child and maternal health (e.g. vaccine coverage, maternal deaths) are currently being tracked in the DHIS2 of most countries, while other indicators (e.g. HIV/AIDS) would benefit from streamlining the number of indicators collected and standardizing case definitions. Common data issues included unreliable denominators for calculation of incidence, differences in reporting among health facilities, and programmatic differences in data quality. We proposed solutions for many common data pitfalls at the analysis level, including standardized data cleaning pipelines, k-means clustering to identify high performing health facilities in terms of data quality, and imputation methods. While we focus on immediately actionable solutions for DHIS2 analysts, improvements at the point of data collection are the most rigorous. By investing in improving data quality and monitoring, countries can leverage the current global attention on health data to strengthen HMIS and progress towards national and international health priorities.
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Affiliation(s)
- Andrea Farnham
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Georg Loss
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Isaac Lyatuu
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Herminio Cossa
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Manhiça Health Research Centre, Maputo, Mozambique
| | - Alexandra V Kulinkina
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Mirko S Winkler
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Mategula D, Mitambo C, Sheahan W, Masingi Mbeye N, Gumbo A, Kwizombe C, Kawonga J, Banda B, Hamuza G, Kalanga A, Kamowa D, Kafulafula J, Banda A, Twaibi H, Musa E, Kapito-Tembo A, Ntwere T, Chirombo J, Kalonde PK, Masambuka M, Munthali L, Sakala M, Bangoura A, Gichuki J, Chipeta MG, Galatas Adrade B, Kayange M, Terlouw DJ. Malaria Burden Stratification in Malawi- A report of a consultative workshop to inform the 2023-2030 Malawi Malaria Strategic Plan. Wellcome Open Res 2023; 8:178. [PMID: 37600585 PMCID: PMC10432890 DOI: 10.12688/wellcomeopenres.19110.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2023] [Indexed: 08/22/2023] Open
Abstract
Background: Malawi's National Malaria Control Programme (NMCP) is developing a new strategic plan for 2023-2030 to combat malaria and recognizes that a blanket approach to malaria interventions is no longer feasible. To inform this new strategy, the NMCP set up a task force comprising 18 members from various sectors, which convened a meeting to stratify the malaria burden in Malawi and recommend interventions for each stratum. Methods: The burden stratification workshop took place from November 29 to December 2, 2022, in Blantyre, Malawi, and collated essential data on malaria burden indicators, such as incidence, prevalence, and mortality. Workshop participants reviewed the malaria burden and intervention coverage data to describe the current status and identified the districts as a appropriate administrative level for stratification and action. Two scenarios were developed for the stratification, based on composites of three variables. Scenario 1 included incidence, prevalence, and under-five all-cause mortality, while Scenario 2 included total malaria cases, prevalence, and under-five all-cause mortality counts. The task force developed four burden strata (highest, high, moderate, and low) for each scenario, resulting in a final list of districts assigned to each stratum. Results: The task force concluded with 10 districts in the highest-burden stratum (Nkhotakota, Salima, Mchinji, Dowa, Ntchisi, Mwanza, Likoma, Lilongwe, Kasungu and Mangochi) 11 districts in the high burden stratum (Chitipa, Rumphi, Nkhata Bay, Dedza, Ntcheu, Neno, Thyolo, Nsanje, Zomba, Mzimba and Mulanje) and seven districts in the moderate burden stratum (Karonga, Chikwawa, Balaka, Machinga, Phalombe, Blantyre, and Chiradzulu). There were no districts in the low-burden stratum. Conclusion: The next steps for the NMCP are to review context-specific issues driving malaria transmission and recommend interventions for each stratum. Overall, this burden stratification workshop provides a critical foundation for developing a successful malaria strategic plan for Malawi.
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Affiliation(s)
- Donnie Mategula
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
- Malawi-Liverpool Wellcome Programme,, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | | | | | - Nyanyiwe Masingi Mbeye
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
- PATH, Seatle, Washington, USA
| | - Austin Gumbo
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Collins Kwizombe
- U.S. President's Malaria Initiative, United States Agency for International Development (USAID), Lilongwe, Malawi
| | - Jacob Kawonga
- Country Health Information Systems and Data Use (CHISU) Program, Lilongwe, Malawi
| | - Benard Banda
- Country Health Information Systems and Data Use (CHISU) Program, Lilongwe, Malawi
| | - Gracious Hamuza
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | | | - Dina Kamowa
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Akuzike Banda
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Halima Twaibi
- Department of Mathematical Sciences, School of Natural and Applied Sciences,, University of Malawi, Zomba, Malawi
| | - Esloyn Musa
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Atupele Kapito-Tembo
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Tapiwa Ntwere
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Patrick, Ken Kalonde
- Malawi-Liverpool Wellcome Programme,, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | | | - Lumbani Munthali
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Melody Sakala
- Malawi-Liverpool Wellcome Programme,, Blantyre, Malawi
| | | | - Judy Gichuki
- Strathmore University, Institute of Healthcare Management, Nairobi, Malawi
| | | | | | - Michael Kayange
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Dianne J Terlouw
- Malawi-Liverpool Wellcome Programme,, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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17
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Women attending antenatal care as a sentinel surveillance population for malaria in Geita region, Tanzania: feasibility and acceptability to women and providers. Malar J 2023; 22:66. [PMID: 36829200 PMCID: PMC9951145 DOI: 10.1186/s12936-023-04480-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/02/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Measurement of malaria prevalence is conventionally estimated through infrequent cross-sectional household surveys that do not provide continuous information regarding malaria parasitaemia. Recent studies have suggested that malaria parasitaemia prevalence among women attending antenatal care (ANC) correlates with prevalence among children under 5 years old and that pregnant women could be a sentinel population for tracking malaria prevalence. In mainland Tanzania, 97% of women are tested for malaria parasitaemia during first ANC visits. However, acceptability among pregnant women and healthcare providers of collecting malaria risk factor data during ANC visits is limited. METHODS A tablet-based questionnaire including 15 questions on insecticide-treated net ownership and use and care-seeking for febrile children was introduced at 40 healthcare facilities in Geita Region, Tanzania. Facilities were randomly selected from among those with 15-120 first ANC visits per month. To assess perspectives regarding introduction of the questionnaire, 21 semi-structured interviews were held with providers and facility in-charges at 12 facilities. Thirty pregnant and recently delivered women participated in focus group discussions at seven facilities to assess the acceptability of spending additional time answering questions about malaria risk. RESULTS All pregnant women reported that introduction of ANC surveillance and spending 10 more minutes with providers answering questions about their health would be neutral or beneficial. They perceived being asked about their health as standard of care. Providers and in-charges reported that introduction of ANC surveillance was within their scope of practice. Nine of 21 indicated it could potentially benefit women's health. Six providers expressed concern about staffing shortages and need for reimbursement for extra time and noted that data management occurs after hours. CONCLUSIONS Pregnant women and providers generally perceived ANC surveillance for malaria as acceptable and positive. Pregnant and recently delivered women saw this as a reasonable and even helpful intervention. To be seen as a part of standard practice, efforts are needed to ensure providers perceive a benefit for ANC clients and that staffing concerns are addressed. In addition, staff should receive feedback related to data submissions regarding malaria prevalence and risk factors among women at their facility, with actions to take.
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18
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Implementation research of a cluster randomized trial evaluating the implementation and effectiveness of intermittent preventive treatment for malaria using dihydroartemisinin-piperaquine on reducing malaria burden in school-aged children in Tanzania: methodology, challenges, and mitigation. Malar J 2023; 22:7. [PMID: 36609279 PMCID: PMC9816525 DOI: 10.1186/s12936-022-04428-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 12/23/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND It has been more than 20 years since the malaria epidemiologic shift to school-aged children was noted. In the meantime, school-aged children (5-15 years) have become increasingly more vulnerable with asymptomatic malaria prevalence reaching up to 70%, making them reservoirs for subsequent transmission of malaria in the endemic communities. Intermittent Preventive Treatment of malaria in schoolchildren (IPTsc) has proven to be an effective tool to shrink this reservoir. As of 3rd June 2022, the World Health Organization recommends IPTsc in moderate and high endemic areas. Even so, for decision-makers, the adoption of scientific research recommendations has been stifled by real-world implementation challenges. This study presents methodology, challenges faced, and mitigations used in the evaluation of the implementation of IPTsc using dihydroartemisinin-piperaquine (DP) in three councils (Handeni District Council (DC), Handeni Town Council (TC) and Kilindi DC) of Tanga Region, Tanzania so as to understand the operational feasibility and effectiveness of IPTsc on malaria parasitaemia and clinical malaria incidence. METHODS The study deployed an effectiveness-implementation hybrid design to assess feasibility and effectiveness of IPTsc using DP, the interventional drug, against standard of care (control). Wards in the three study councils were the randomization unit (clusters). Each ward was randomized to implement IPTsc or not (control). In all wards in the IPTsc arm, DP was given to schoolchildren three times a year in four-month intervals. In each council, 24 randomly selected wards (12 per study arm, one school per ward) were chosen as representatives for intervention impact evaluation. Mixed design methods were used to assess the feasibility and acceptability of implementing IPTsc as part of a more comprehensive health package for schoolchildren. The study reimagined an existing school health programme for Neglected Tropical Diseases (NTD) control include IPTsc implementation. RESULTS The study shows IPTsc can feasibly be implemented by integrating it into existing school health and education systems, paving the way for sustainable programme adoption in a cost-effective manner. CONCLUSIONS Through this article other interested countries may realise a feasible plan for IPTsc implementation. Mitigation to any challenge can be customized based on local circumstances without jeopardising the gains expected from an IPTsc programme. Trial registration clinicaltrials.gov, NCT04245033. Registered 28 January 2020, https://clinicaltrials.gov/ct2/show/NCT04245033.
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19
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Koenker H, Worges M, Yukich J, Gitanya P, Chacky F, Lazaro S, Mwalimu CD, Aaron S, Ibrahim R, Abbas F, Khamis M, Mwingizi D, Dadi D, Selby A, Serbantez N, Msangi L, Loll D, Kamala B. Estimating population ITN access at council level in Tanzania. Malar J 2023; 22:4. [PMID: 36604693 PMCID: PMC9815063 DOI: 10.1186/s12936-022-04432-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/24/2022] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Since 2013, the National Malaria Control Programme in mainland Tanzania and the Zanzibar Malaria Elimination Programme have implemented mass insecticide-treated net (ITN) distribution campaigns, routine ITN distribution to pregnant women and infants, and continuous distribution through primary schools (mainland) and community leaders (Zanzibar) to further malaria control efforts. Mass campaigns are triggered when ITN access falls below 40%. In this context, there is a need to monitor ITN access annually to assess whether it is below threshold and inform quantification of ITNs for the following year. Annual estimates of access are needed at the council level to inform programmatic decision-making. METHODS An age-structured stock and flow model was used to predict annual net crops from council-level distribution data in Tanzania from 2012 to 2020 parameterized with a Tanzania-specific net median lifespan of 2.15 years. Annual nets-per-capita (NPC) was calculated by dividing each annual net crop by mid-year council projected population. A previously fit nonparametric conditional quantile function for the proportion of the population with access to an ITN (ITN access) as a function of NPC was used to predict ITN access at the council level based on the predicted NPC value. These estimates were compared to regional-level ITN access from large household surveys. RESULTS For regions with the same ITN strategy for all councils, predicted council-level ITN access was consistent with regional-level survey data for 79% of councils. Regions where ITN strategy varied by council had regional estimates of ITN access that diverged from the council-specific estimates. Predicted ITN access reached 60% only when "nets issued as a percentage of the council population" (NPP) exceeded 15%, and approached 80% ITN access when NPP was at or above 20%. CONCLUSION Modelling ITN access with country-specific net decay rates, council-level population, and ITN distribution data is a promising approach to monitor ITN coverage sub-regionally and between household surveys in Tanzania and beyond.
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Affiliation(s)
- Hannah Koenker
- USAID Tanzania Vector Control Activity, Tropical Health, Baltimore, MD USA
| | - Matt Worges
- USAID Tanzania Vector Control Activity, Tropical Health, New Orleans, LA USA
| | - Joshua Yukich
- USAID Tanzania Vector Control Activity, Tropical Health, New Orleans, LA USA ,grid.265219.b0000 0001 2217 8588Tulane University, New Orleans, LA USA
| | - Peter Gitanya
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | - Frank Chacky
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | - Samwel Lazaro
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | | | - Sijenunu Aaron
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | - Raya Ibrahim
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - Faiza Abbas
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - Mwinyi Khamis
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - Deodatus Mwingizi
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programs, Dar Es Salaam, Tanzania
| | - David Dadi
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programs, Dar Es Salaam, Tanzania
| | - Ato Selby
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programs, Dar Es Salaam, Tanzania
| | - Naomi Serbantez
- U.S. President’s Malaria Initiative, Dar Es Salaam, Tanzania
| | - Lulu Msangi
- U.S. President’s Malaria Initiative, Dar Es Salaam, Tanzania
| | - Dana Loll
- grid.21107.350000 0001 2171 9311USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programs, Baltimore, MD USA
| | - Benjamin Kamala
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programs, Dar Es Salaam, Tanzania
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20
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Katusi GC, Hermy MRG, Makayula SM, Ignell R, Govella NJ, Hill SR, Mnyone LL. Seasonal variation in abundance and blood meal sources of primary and secondary malaria vectors within Kilombero Valley, Southern Tanzania. Parasit Vectors 2022; 15:479. [PMID: 36539892 PMCID: PMC9768911 DOI: 10.1186/s13071-022-05586-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 08/20/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Existing control tools have significantly reduced malaria over the past two decades. However, progress has been stalled due to increased resistance in primary vectors and the increasing role of secondary vectors. This study aimed to investigate the impact of seasonal change on primary and secondary vector abundance and host preference. Understanding the impact of seasonal dynamics of primary and secondary vectors on disease transmission will inform effective strategies for vector management and control. METHODS Vector abundance was measured through longitudinal collection of mosquitoes, conducted monthly during the wet and dry seasons, in Sagamaganga, a village in the Kilombero Valley, Tanzania. Mosquitoes were collected indoors using CDC light traps and backpack aspirators, and outdoors using resting buckets baited with cattle urine. In addition, a direct measure of host preference was taken monthly using human- and cattle-baited mosquito electrocuting traps. A host census was conducted to provide an indirect measure of host preference together with monthly blood meal source analysis. All collected mosquitoes were assayed for Plasmodium sporozoites. RESULTS A total of 2828 anophelines were collected, of which 78.5% and 21.4%, were primary and secondary vectors, respectively. The abundance of the primary vectors, Anopheles arabiensis and Anopheles funestus, and of the secondary vectors varied seasonally. Indirect measures of host preference indicated that all vectors varied blood meal choice seasonally, with the direct measure confirming this for An. arabiensis. All anopheline mosquitoes tested negative for sporozoites. CONCLUSIONS At the study location, the abundance of both primary and secondary vectors changed seasonally. Indirect and direct measures of host preference demonstrated that An. arabiensis varied from being zoophilic to being more opportunistic during the wet and dry seasons. A similar trend was observed for the other vectors.
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Affiliation(s)
- Godfrey C. Katusi
- grid.414543.30000 0000 9144 642XDepartment of Environmental Health and Ecological Sciences, Ifakara Health Institute, Off Mlabani Passage, Ifakara, P.O. Box 53, Morogoro, Tanzania ,grid.11887.370000 0000 9428 8105Department of Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, P.O. Box 3019, Morogoro, Tanzania
| | - Marie R. G. Hermy
- grid.6341.00000 0000 8578 2742Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 190, 234 22 Lomma, Sweden
| | - Samwely M. Makayula
- grid.414543.30000 0000 9144 642XDepartment of Environmental Health and Ecological Sciences, Ifakara Health Institute, Off Mlabani Passage, Ifakara, P.O. Box 53, Morogoro, Tanzania
| | - Rickard Ignell
- grid.6341.00000 0000 8578 2742Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 190, 234 22 Lomma, Sweden
| | - Nicodem J. Govella
- grid.414543.30000 0000 9144 642XDepartment of Environmental Health and Ecological Sciences, Ifakara Health Institute, Off Mlabani Passage, Ifakara, P.O. Box 53, Morogoro, Tanzania ,grid.451346.10000 0004 0468 1595School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Sharon R. Hill
- grid.6341.00000 0000 8578 2742Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 190, 234 22 Lomma, Sweden
| | - Ladslaus L. Mnyone
- grid.11887.370000 0000 9428 8105Pest Management Centre, Sokoine University of Agriculture, P.O. Box 3110, Morogoro, Tanzania
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Rogier E, Bakari C, Mandara CI, Chiduo MG, Plucinski M, Nace D, Battle N, Chacky F, Rumisha SF, Molteni F, Mandike R, Mkude S, Njau R, Mohamed A, Udhayakumar V, Ishengoma DS. Performance of antigen detection for HRP2-based malaria rapid diagnostic tests in community surveys: Tanzania, July-November 2017. Malar J 2022; 21:361. [PMID: 36457087 PMCID: PMC9714097 DOI: 10.1186/s12936-022-04383-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/12/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Malaria rapid diagnostic tests (RDTs) based on the detection of the Plasmodium falciparum histidine-rich protein 2 (HRP2) antigen are widely used for detection of active infection with this parasite and are the only practical malaria diagnostic test in some endemic settings. External validation of RDT results from field surveys can confirm appropriate RDT performance. METHODS A community-based cross-sectional survey was conducted between July and November 2017 enrolling participants of all ages in households from 15 villages in four border regions of Tanzania: Geita, Kigoma, Mtwara and Ruvuma. All participants had an RDT performed in the field and provided a blood sample for later laboratory multiplex antigen detection of HRP2. In assessing the continuous HRP2 levels in participant blood versus RDT result, dose-response logistic regression provided quantitative estimates for HRP2 limit of detection (LOD). RESULTS From the 15 study villages, 6941 persons were enrolled that had a RDT at time of enrollment and provided a DBS for later laboratory antigen detection. RDT positive prevalence for the HRP2 band by village ranged from 20.0 to 43.6%, but the magnitude of this prevalence did not have an effect on the estimated LOD of RDTs utilized in different villages. Overall, HRP2 single-target tests had a lower LOD at the 95% probability of positive RDT (4.3 ng/mL; 95% CI 3.4-5.4) when compared to pLDH/HRP2 dual target tests (5.4 ng/mL; 4.5-6.3), though this difference was not significant. With the exception of one village, all other 14 villages (93.3%) showed RDT LOD estimates at 90% probability of positive RDT between 0.5 and 12.0 ng/mL. CONCLUSIONS Both HRP2-only and pLDH/HRP2 combo RDTs utilized in a 2017 Tanzania cross-sectional survey of border regions generally performed well, and reliably detected HRP2 antigen in the low ng/mL range. Though single target tests had lower levels of HRP2 detection, both tests were within similar ranges among the 15 villages. Comparison of quantitative HRP2 detection limits among study sites can help interpret RDT testing results when generating population prevalence estimates for malaria infection.
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Affiliation(s)
- Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30029, USA.
| | - Catherine Bakari
- grid.416716.30000 0004 0367 5636National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania
| | - Celine I. Mandara
- grid.416716.30000 0004 0367 5636National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania
| | - Mercy G. Chiduo
- grid.416716.30000 0004 0367 5636National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Mateusz Plucinski
- grid.416738.f0000 0001 2163 0069Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA 30029 USA
| | - Douglas Nace
- grid.416738.f0000 0001 2163 0069Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA 30029 USA
| | - Nastassia Battle
- grid.416738.f0000 0001 2163 0069Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA 30029 USA ,grid.474959.20000 0004 0528 628XCDC Foundation, Atlanta, GA USA
| | - Franky Chacky
- grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, Tanzania
| | - Susan F. Rumisha
- grid.416716.30000 0004 0367 5636National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania ,grid.414659.b0000 0000 8828 1230Malaria Atlas Project, Geospatial Health and Development, Telethon Kids Institute, Perth, WA Australia
| | | | - Renata Mandike
- grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, Tanzania
| | - Sigsbert Mkude
- grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, Tanzania
| | - Ritha Njau
- World Health Organization Country Office, Dar es Salaam, Tanzania
| | - Ally Mohamed
- grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, Tanzania
| | - Venkatachalam Udhayakumar
- grid.416738.f0000 0001 2163 0069Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA 30029 USA
| | - Deus S. Ishengoma
- grid.416716.30000 0004 0367 5636National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania ,grid.38142.3c000000041936754XHarvard T.H Chan School of Public Health, Boston, MA USA ,grid.1002.30000 0004 1936 7857Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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22
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The use of routine health facility data for micro-stratification of malaria risk in mainland Tanzania. Malar J 2022; 21:345. [DOI: 10.1186/s12936-022-04364-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/05/2022] [Indexed: 11/19/2022] Open
Abstract
Abstract
Background
Current efforts to estimate the spatially diverse malaria burden in malaria-endemic countries largely involve the use of epidemiological modelling methods for describing temporal and spatial heterogeneity using sparse interpolated prevalence data from periodic cross-sectional surveys. However, more malaria-endemic countries are beginning to consider local routine data for this purpose. Nevertheless, routine information from health facilities (HFs) remains widely under-utilized despite improved data quality, including increased access to diagnostic testing and the adoption of the electronic District Health Information System (DHIS2). This paper describes the process undertaken in mainland Tanzania using routine data to develop a high-resolution, micro-stratification risk map to guide future malaria control efforts.
Methods
Combinations of various routine malariometric indicators collected from 7098 HFs were assembled across 3065 wards of mainland Tanzania for the period 2017–2019. The reported council-level prevalence classification in school children aged 5–16 years (PfPR5–16) was used as a benchmark to define four malaria risk groups. These groups were subsequently used to derive cut-offs for the routine indicators by minimizing misclassifications and maximizing overall agreement. The derived-cutoffs were converted into numbered scores and summed across the three indicators to allocate wards into their overall risk stratum.
Results
Of 3065 wards, 353 were assigned to the very low strata (10.5% of the total ward population), 717 to the low strata (28.6% of the population), 525 to the moderate strata (16.2% of the population), and 1470 to the high strata (39.8% of the population). The resulting micro-stratification revealed malaria risk heterogeneity within 80 councils and identified wards that would benefit from community-level focal interventions, such as community-case management, indoor residual spraying and larviciding.
Conclusion
The micro-stratification approach employed is simple and pragmatic, with potential to be easily adopted by the malaria programme in Tanzania. It makes use of available routine data that are rich in spatial resolution and that can be readily accessed allowing for a stratification of malaria risk below the council level. Such a framework is optimal for supporting evidence-based, decentralized malaria control planning, thereby improving the effectiveness and allocation efficiency of malaria control interventions.
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Joseph JJ, Mkali HR, Reaves EJ, Mwaipape OS, Mohamed A, Lazaro SN, Aaron S, Chacky F, Mahendeka A, Rulagirwa HS, Mwenesi M, Mwakapeje E, Ally AY, Kitojo C, Serbantez N, Nyinondi S, Lalji SM, Wilillo R, Al-mafazy AW, Kabula BI, John C, Bisanzio D, Eckert E, Reithinger R, Ngondi JM. Improvements in malaria surveillance through the electronic Integrated Disease Surveillance and Response (eIDSR) system in mainland Tanzania, 2013-2021. Malar J 2022; 21:321. [PMID: 36348409 PMCID: PMC9641756 DOI: 10.1186/s12936-022-04353-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tanzania has made remarkable progress in reducing malaria burden and aims to transition from malaria control to sub-national elimination. In 2013, electronic weekly and monthly reporting platforms using the District Health Information System 2 (DHIS2) were introduced. Weekly reporting was implemented through the mobile phone-based Integrated Disease Surveillance and Response (eIDSR) platform and progressively scaled-up from 67 to 7471 (100%) public and private health facilities between 2013 and 2020. This study describes the roll-out and large-scale implementation of eIDSR and compares the consistency between weekly eIDSR and monthly DHIS2 malaria indicator data reporting, including an assessment of its usefulness for malaria outbreak detection and case-based surveillance (CBS) in low transmission areas. METHODS The indicators included in the analysis were number of patients tested for malaria, number of confirmed malaria cases, and clinical cases (treated presumptively for malaria). The analysis described the time trends of reporting, testing, test positivity, and malaria cases between 2013 and 2021. For both weekly eIDSR and monthly DHIS2 data, comparisons of annual reporting completeness, malaria cases and annualized incidence were performed for 2020 and 2021; additionally, comparisons were stratified by malaria epidemiological strata (parasite prevalence: very low < 1%, low 1 ≤ 5%, moderate 5 ≤ 30%, and high > 30%). RESULTS Weekly eIDSR reporting completeness steadily improved over time, with completeness being 90.2% in 2020 and 93.9% in 2021; conversely, monthly DHIS2 reporting completeness was 98.9% and 98.7% in 2020 and 2021, respectively. Weekly eIDSR reporting completeness and timeliness were highest in the very low epidemiological stratum. Annualized malaria incidence as reported by weekly eIDSR was 17.5% and 12.4% lower than reported by monthly DHIS2 in 2020 and 2021; for both 2020 and 2021, annualized incidence was similar across weekly and monthly data in the very low stratum. CONCLUSION The concurrence of annualized weekly eIDSR and monthly DHIS2 reporting completeness, malaria cases and incidence in very low strata suggests that eIDSR could be useful tool for early outbreak detection, and the eIDSR platform could reliably be expanded by adding more indicators and modules for CBS in the very low epidemiological stratum.
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Affiliation(s)
| | | | - Erik J. Reaves
- U.S. President’s Malaria Initiative, U.S. Center for Disease Control and Prevention, Dar es Salaam, United Republic of Tanzania
| | | | - Ally Mohamed
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Samwel N. Lazaro
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Sijenunu Aaron
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Frank Chacky
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Anna Mahendeka
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Hermes S. Rulagirwa
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania
| | - Mwendwa Mwenesi
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania
| | - Elibariki Mwakapeje
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania
| | - Ally Y. Ally
- grid.415734.00000 0001 2185 2147Ministry of Health, Dodoma, United Republic of Tanzania
| | - Chonge Kitojo
- U.S. President’s Malaria Initiative, U.S. Agency for International Development, Dar es Salaam, United Republic of Tanzania
| | - Naomi Serbantez
- U.S. President’s Malaria Initiative, U.S. Agency for International Development, Dar es Salaam, United Republic of Tanzania
| | - Ssanyu Nyinondi
- RTI International, Dar es Salaam, United Republic of Tanzania
| | | | | | | | | | - Claud John
- U.S. President’s Malaria Initiative, U.S. Center for Disease Control and Prevention, Dar es Salaam, United Republic of Tanzania
| | - Donal Bisanzio
- grid.62562.350000000100301493RTI International, Washington, DC USA
| | - Erin Eckert
- grid.62562.350000000100301493RTI International, Washington, DC USA
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24
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Matowo NS, Tanner M, Temba BA, Finda M, Mlacha YP, Utzinger J, Okumu FO. Participatory approaches for raising awareness among subsistence farmers in Tanzania about the spread of insecticide resistance in malaria vectors and the possible link to improper agricultural pesticide use. Malar J 2022; 21:277. [PMID: 36180865 PMCID: PMC9524312 DOI: 10.1186/s12936-022-04289-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Background Insecticide resistance is a key barrier to long-term malaria control, and it may be exacerbated by poor agricultural pesticide use. Current practices, however, do not link public health and agricultural pesticide use. This study investigated the perspectives of farmers and other stakeholders regarding the integration of agricultural and public health measures to address resistance. Additionally, the feasibility of participatory workshops to increase the farmers’ understanding and participation in pesticide stewardship was assessed. Methods Four themes were investigated: pesticide awareness, practices, and opinions of; insecticide resistance in malaria vectors; the effectiveness of current malaria prevention tools; and the links between agricultural and public health pesticide usage. Participatory workshops and field training were held with entomologists, farmers, and agricultural specialists, focusing on agro-ecosystem practices related to pest control; and local farmers were involved in live-testing for insecticides resistance of local Anopheles mosquitoes. Results Most farmers (94%) considered pesticides effective, and nearly half of them (n = 198, 46.4%) could identify and name crop pests and diseases, mostly using local names. Three quarters were unaware of mosquito larvae in their fields, and only 7% considered their fields as potential sources of mosquitoes. Two thirds were uninformed of any effects that agricultural pesticides may have on mosquitoes, and three quarters had never heard of resistance in malaria mosquitoes. Experts from various sectors acknowledged that agricultural pesticides might impact malaria control through increasing resistance. They did, however, emphasize the importance of crop protection and advocated for the use of pesticides sparingly and non-chemical approaches. Farmers learnt how to discriminate between malaria vectors and non-vectors, identify agricultural pests and diseases, choose and use pesticides effectively, and conduct resistance tests during the participatory workshops. Conclusion This study emphasizes the significance of enhancing subsistence farmers’ awareness of mosquito ecology as well as merging public health and agricultural pest management measures. Participatory techniques have the potential to raise stakeholder awareness and engagement, resulting in more effective resistance management.
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Affiliation(s)
- Nancy Stephen Matowo
- Environmental and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania. .,Swiss Tropical and Public Health Institute, Allschwil, Switzerland. .,University of Basel, Basel, Switzerland. .,Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.,University of Basel, Basel, Switzerland
| | - Benigni Alfred Temba
- Department of Veterinary Physiology, Pharmacology and Toxicology, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Marceline Finda
- Environmental and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Yeromin Paul Mlacha
- Environmental and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania.,Swiss Tropical and Public Health Institute, Allschwil, Switzerland.,University of Basel, Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.,University of Basel, Basel, Switzerland
| | - Fredros Oketch Okumu
- Environmental and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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25
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Bohle LF, Abdallah AK, Galli F, Canavan R, Molesworth K. Knowledge, attitudes and practices towards malaria diagnostics among healthcare providers and healthcare-seekers in Kondoa district, Tanzania: a multi-methodological situation analysis. Malar J 2022; 21:224. [PMID: 35864543 PMCID: PMC9306200 DOI: 10.1186/s12936-022-04244-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 07/08/2022] [Indexed: 12/04/2022] Open
Abstract
Background Despite the large-scale rollout of malaria rapid diagnostic tests (RDTs) in Tanzania, many healthcare providers (HCPs) continue using blood film microscopy (BFM) and clinical examination to diagnose malaria, which can increase the risk of mal-diagnosis and over-prescribing of anti-malarials. Patients disregarding negative test results and self-treating exacerbate the problem. This study explored the knowledge, attitudes and practices of HCPs and healthcare-seekers regarding RDTs in comparison to BFM testing. Methods A situational analysis was, therefore, conducted in Kondoa District, Dodoma Region, Tanzania. A multi-methodological approach was adopted including (i) a health facility inventory and screening of logbooks from May 2013 to April 2014 with 77,126 patient entries from 33 health facilities; (ii) a survey of 40 HCPs offering malaria services; and iii) a survey of 309 randomly selected household members from the facilities’ catchment area. Surveys took place in April and May 2014. Results Health facility records revealed that out of 77,126 patient entries, 22% (n = 17,235) obtained a malaria diagnosis. Of those, 45% were made with BFM, 33% with RDT and 22% with clinical diagnosis. A higher rate of positive diagnoses was observed with BFM compared with RDT (71% vs 14%). In the HCP survey, 48% preferred using BFM for malaria testing, while 52% preferred RDT. Faced with a negative RDT result for a patient presenting with symptoms typical for malaria, 25% of HCPs stated they would confirm the result with a microscopy test, 70% would advise or perform a clinical diagnosis and 18% would prescribe anti-malarials. Interviews with household members revealed a preference for microscopy testing (58%) over RDT (23%), if presented with malaria symptoms. For participants familiar with both tests, a second opinion was desired in 45% after a negative microscopy result and in 90% after an RDT. Conclusions Non-adherence to negative diagnostics by HCPs and patients continues to be a concern. Frequent training and supportive supervision for HCPs diagnosing and treating malaria and non-malaria febrile illnesses is essential to offer quality services that can instil confidence in HCPs and patients alike. The introduction of new diagnostic devices should be paired with context-specific behaviour change interventions targeting healthcare-seekers and healthcare providers. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04244-0.
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Affiliation(s)
- Leah F Bohle
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Ally-Kebby Abdallah
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Health Promotion and System Strengthening Project (HPSS), Dodoma, Tanzania
| | - Francesco Galli
- Veterinary Public Health Institute, University of Bern, Bern, Switzerland
| | - Robert Canavan
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Kate Molesworth
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
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26
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Okumu F, Gyapong M, Casamitjana N, Castro MC, Itoe MA, Okonofua F, Tanner M. What Africa can do to accelerate and sustain progress against malaria. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000262. [PMID: 36962314 PMCID: PMC10021840 DOI: 10.1371/journal.pgph.0000262] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
After a longstanding global presence, malaria is now largely non-existent or suppressed in most parts of the world. Today, cases and deaths are primarily concentrated in sub-Saharan Africa. According to many experts, this persistence on the African continent reflects factors such as resistance to insecticides and drugs as well as insufficient access to essential commodities such as insecticide-treated nets and effective drugs. Crucially, however, this narrative ignores many central weaknesses in the fight against malaria and instead reinforces a narrow, commodity-driven vision of disease control. This paper therefore describes the core challenges hindering malaria programs in Africa and highlights key opportunities to rethink current strategies for sustainable control and elimination. The epidemiology of malaria in Africa presents far greater challenges than elsewhere and requires context-specific initiatives tailored to national and sub-national targets. To sustain progress, African countries must systematically address key weaknesses in its health systems, improve the quality and use of data for surveillance-responses, improve both technical and leadership competencies for malaria control, and gradually reduce overreliance on commodities while expanding multisectoral initiatives such as improved housing and environmental sanitation. They must also leverage increased funding from both domestic and international sources, and support pivotal research and development efforts locally. Effective vaccines and drugs, or other potentially transformative technologies such as genedrive modified mosquitoes, could further accelerate malaria control by complementing current tools. However, our underlying strategies remain insufficient and must be expanded to include more holistic and context-specific approaches critical to achieve and sustain effective malaria control.
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Affiliation(s)
| | - Margaret Gyapong
- Centre for Health Policy and Implementation Research, Institute of Health Research, University of Health and Allied Sciences, Ho, Ghana
| | - Núria Casamitjana
- Barcelona Institute for Global Health (ISGlobal), Hospital Clinic–University of Barcelona, Barcelona, Spain
| | - Marcia C. Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Maurice A. Itoe
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Friday Okonofua
- Department of Obstetrics and Gynaecology, School of Medicine, University of Benin, Benin City, Nigeria
| | - Marcel Tanner
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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27
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Stratification at the health district level for targeting malaria control interventions in Mali. Sci Rep 2022; 12:8271. [PMID: 35585101 PMCID: PMC9117674 DOI: 10.1038/s41598-022-11974-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 04/22/2022] [Indexed: 01/13/2023] Open
Abstract
Malaria is the leading cause of morbidity and mortality in Mali. Between 2017 and 2020, the number of cases increased in the country, with 2,884,827 confirmed cases and 1454 reported deaths in 2020. We performed a malaria risk stratification at the health district level in Mali with a view to proposing targeted control interventions. Data on confirmed malaria cases were obtained from the District Health Information Software 2, data on malaria prevalence and mortality in children aged 6-59 months from the 2018 Demographic and Health Survey, entomological data from Malian research institutions working on malaria in the sentinel sites of the National Malaria Control Program (NMCP), and environmental data from the National Aeronautics and Space Administration. A stratification of malaria risk was performed. Targeted malaria control interventions were selected based on spatial heterogeneity of malaria incidence, malaria prevalence in children, vector resistance distribution, health facility usage, child mortality, and seasonality of transmission. These interventions were discussed with the NMCP and the different funding partners. In 2017-2019, median incidence across the 75 health districts was 129.34 cases per 1000 person-years (standard deviation = 86.48). Risk stratification identified 12 health districts in very low transmission areas, 19 in low transmission areas, 20 in moderate transmission areas, and 24 in high transmission areas. Low health facility usage and increased vector resistance were observed in high transmission areas. Eight intervention combinations were selected for implementation. Our work provides an updated risk stratification using advanced statistical methods to inform the targeting of malaria control interventions in Mali. This stratification can serve as a template for continuous malaria risk stratifications in Mali and other countries.
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28
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Rugarabamu S, Rumisha SF, Mwanyika GO, Sindato C, Lim HY, Misinzo G, Mboera LEG. Viral haemorrhagic fevers and malaria co-infections among febrile patients seeking health care in Tanzania. Infect Dis Poverty 2022; 11:33. [PMID: 35462550 PMCID: PMC9036688 DOI: 10.1186/s40249-022-00959-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 03/10/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND In recent years there have been reports of viral haemorrhagic fever (VHF) epidemics in sub-Saharan Africa where malaria is endemic. VHF and malaria have overlapping clinical presentations making differential diagnosis a challenge. The objective of this study was to determine the prevalence of selected zoonotic VHFs and malaria co-infections among febrile patients seeking health care in Tanzania. METHODS This facility-based cross-sectional study was carried out between June and November 2018 in Buhigwe, Kalambo, Kyela, Kilindi, Kinondoni, Kondoa, Mvomero, and Ukerewe districts in Tanzania. The study involved febrile patients seeking health care from primary healthcare facilities. Blood samples were collected and tested for infections due to malaria, Crimean-Congo haemorrhagic fever (CCHF), Ebola virus disease (EVD), Marburg virus disease (MVD), Rift Valley fever (RVF) and yellow fever (YF). Malaria infections were tested using rapid diagnostics tests while exposure to VHFs was determined by screening for immunoglobulin M antibodies using commercial enzyme-linked immunosorbent assays. The Chi-square test was used to compare the proportions. RESULTS A total of 308 participants (mean age = 35 ± 19 years) were involved in the study. Of these, 54 (17.5%) had malaria infection and 15 (4.8%) were positive for IgM antibodies against VHFs (RVF = 8; CCHF = 2; EBV = 3; MBV = 1; YF = 1). Six (1.9%) individuals had both VHF (RVF = 2; CCHF = 1; EVD = 2; MVD = 1) and malaria infections. The highest co-infection prevalence (0.6%) was observed among individuals aged 46‒60 years (P < 0.05). District was significantly associated with co-infection (P < 0.05) with the highest prevalence recorded in Buhigwe (1.2%) followed by Kinondoni (0.9%) districts. Headache (100%) and muscle, bone, back and joint pains (83.3%) were the most significant complaints among those infected with both VHFs and malaria (P = 0.001). CONCLUSIONS Co-infections of VHF and malaria are prevalent in Tanzania and affect more the older than the younger population. Since the overlapping symptoms in co-infected individuals may challenge accurate diagnosis, adequate laboratory diagnosis should be emphasized in the management of febrile illnesses.
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Affiliation(s)
- Sima Rugarabamu
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Susan F Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Malaria Atlas Project, Geospatial Health and Development, Telethon Kids Institute, Perth, WA, Australia
| | - Gaspary O Mwanyika
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- Mbeya University of Science and Technology, Mbeya, Tanzania
| | - Calvin Sindato
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- National Institute for Medical Research, Tabora Research Centre, Tabora, Tanzania
| | - Hee-Young Lim
- Korea Disease Control and Prevention Agency, National Institute of Health, Osong, Chungchungbukdo, Republic of Korea
| | - Gerald Misinzo
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Leonard E G Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.
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29
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Runge M, Thawer SG, Molteni F, Chacky F, Mkude S, Mandike R, Snow RW, Lengeler C, Mohamed A, Pothin E. Sub-national tailoring of malaria interventions in Mainland Tanzania: simulation of the impact of strata-specific intervention combinations using modelling. Malar J 2022; 21:92. [PMID: 35300707 PMCID: PMC8929286 DOI: 10.1186/s12936-022-04099-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/23/2022] [Indexed: 11/21/2022] Open
Abstract
Background To accelerate progress against malaria in high burden countries, a strategic reorientation of resources at the sub-national level is needed. This paper describes how mathematical modelling was used in mainland Tanzania to support the strategic revision that followed the mid-term review of the 2015–2020 national malaria strategic plan (NMSP) and the epidemiological risk stratification at the council level in 2018. Methods Intervention mixes, selected by the National Malaria Control Programme, were simulated for each malaria risk strata per council. Intervention mixes included combinations of insecticide-treated bed nets (ITN), indoor residual spraying, larval source management, and intermittent preventive therapies for school children (IPTsc). Effective case management was either based on estimates from the malaria indicator survey in 2016 or set to a hypothetical target of 85%. A previously calibrated mathematical model in OpenMalaria was used to compare intervention impact predictions for prevalence and incidence between 2016 and 2020, or 2022. Results For each malaria risk stratum four to ten intervention mixes were explored. In the low-risk and urban strata, the scenario without a ITN mass campaign in 2019, predicted high increase in prevalence by 2020 and 2022, while in the very-low strata the target prevalence of less than 1% was maintained at low pre-intervention transmission intensity and high case management. In the moderate and high strata, IPTsc in addition to existing vector control was predicted to reduce the incidence by an additional 15% and prevalence by 22%. In the high-risk strata, all interventions together reached a maximum reduction of 76%, with around 70% of that reduction attributable to high case management and ITNs. Overall, the simulated revised NMSP was predicted to achieve a slightly lower prevalence in 2020 compared to the 2015–2020 NMSP (5.3% vs 6.3%). Conclusion Modelling supported the choice of intervention per malaria risk strata by providing impact comparisons of various alternative intervention mixes to address specific questions relevant to the country. The use of a council-calibrated model, that reproduces local malaria trends, represents a useful tool for compiling available evidence into a single analytical platform, that complement other evidence, to aid national programmes with decision-making processes. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04099-5.
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Affiliation(s)
- Manuela Runge
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Sumaiyya G Thawer
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Frank Chacky
- National Malaria Control Programme, Dodoma, Tanzania.,Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
| | - Sigsbert Mkude
- National Malaria Control Programme, Dodoma, Tanzania.,Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
| | - Renata Mandike
- National Malaria Control Programme, Dodoma, Tanzania.,Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
| | - Robert W Snow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Ally Mohamed
- National Malaria Control Programme, Dodoma, Tanzania.,Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,CHAI, Clinton Health Access Initiative, New York, USA.
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30
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Mitchell CL, Ngasala B, Janko MM, Chacky F, Edwards JK, Pence BW, Mohamed A, Mhamilawa LE, Makene T, Kyaw T, Molteni F, Mkali H, Nyinondi S, Kabula B, Serbantez N, Eckert EL, Kitojo C, Reaves E, Emch M, Juliano JJ. Evaluating malaria prevalence and land cover across varying transmission intensity in Tanzania using a cross-sectional survey of school-aged children. Malar J 2022; 21:80. [PMID: 35264152 PMCID: PMC8905829 DOI: 10.1186/s12936-022-04107-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/24/2022] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Transmission of malaria in sub-Saharan Africa has become increasingly stratified following decades of malaria control interventions. The extent to which environmental and land cover risk factors for malaria may differ across distinct strata of transmission intensity is not well known and could provide actionable targets to maximize the success of malaria control efforts. METHODS This study used cross-sectional malaria survey data from a nationally representative cohort of school-aged children in Tanzania, and satellite-derived measures for environmental features and land cover. Hierarchical logistic regression models were applied to evaluate associations between land cover and malaria prevalence within three distinct strata of transmission intensity: low and unstable, moderate and seasonal, and high and perennial. RESULTS In areas with low malaria transmission, each 10-percentage point increase in cropland cover was associated with an increase in malaria prevalence odds of 2.44 (95% UI: 1.27, 5.11). However, at moderate and higher levels of transmission intensity, no association between cropland cover and malaria prevalence was detected. Small associations were observed between greater grassland cover and greater malaria prevalence in high intensity settings (prevalence odds ratio (POR): 1.10, 95% UI: 1.00, 1.21), and between greater forest cover and reduced malaria prevalence in low transmission areas (POR: 0.74, 95% UI: 0.51, 1.03), however the uncertainty intervals of both estimates included the null. CONCLUSIONS The intensity of malaria transmission appears to modify relationships between land cover and malaria prevalence among school-aged children in Tanzania. In particular, greater cropland cover was positively associated with increased malaria prevalence in areas with low transmission intensity and presents an actionable target for environmental vector control interventions to complement current malaria control activities. As areas are nearing malaria elimination, it is important to re-evaluate environmental risk factors and employ appropriate interventions to effectively address low-level malaria transmission.
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Affiliation(s)
- Cedar L. Mitchell
- grid.410711.20000 0001 1034 1720Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC USA
| | - Billy Ngasala
- grid.25867.3e0000 0001 1481 7466Muhimbili University of Health and Allied Sciences, Dar es Salam, Tanzania
| | - Mark M. Janko
- grid.34477.330000000122986657Institute for Health Metrics and Evaluation, University of Washington, Washington, USA
| | - Frank Chacky
- grid.490706.cGender, Elderly and Children, Ministry of Health, Community Development, Dodoma, Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, Tanzania
| | - Jessie K. Edwards
- grid.410711.20000 0001 1034 1720Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC USA
| | - Brian W. Pence
- grid.410711.20000 0001 1034 1720Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC USA
| | - Ally Mohamed
- grid.490706.cGender, Elderly and Children, Ministry of Health, Community Development, Dodoma, Tanzania ,grid.415734.00000 0001 2185 2147National Malaria Control Programme, Dodoma, Tanzania
| | - Lwidiko E. Mhamilawa
- grid.25867.3e0000 0001 1481 7466Muhimbili University of Health and Allied Sciences, Dar es Salam, Tanzania
| | - Twilumba Makene
- grid.25867.3e0000 0001 1481 7466Muhimbili University of Health and Allied Sciences, Dar es Salam, Tanzania
| | - Thwai Kyaw
- grid.10698.360000000122483208Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, NC USA
| | - Fabrizio Molteni
- grid.490706.cGender, Elderly and Children, Ministry of Health, Community Development, Dodoma, Tanzania ,Tropical and Public Health Institute, Basel, Switzerland
| | | | | | | | - Naomi Serbantez
- US President’s Malaria Initiative (PMI), United States Agency for International Development, Dar es Salaam, Tanzania
| | - Erin L. Eckert
- grid.62562.350000000100301493RTI International, Washington, DC USA
| | - Chonge Kitojo
- US President’s Malaria Initiative (PMI), United States Agency for International Development, Dar es Salaam, Tanzania
| | - Erik Reaves
- President’s Malaria Initiative, U.S. Centers for Disease Control and Prevention, Dar es Salaam, Tanzania
| | - Michael Emch
- grid.410711.20000 0001 1034 1720Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Department of Geography, University of North Carolina, Chapel Hill, NC USA
| | - Jonathan J. Juliano
- grid.10698.360000000122483208Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, NC USA
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Kamau A, Paton RS, Akech S, Mpimbaza A, Khazenzi C, Ogero M, Mumo E, Alegana VA, Agweyu A, Mturi N, Mohammed S, Bigogo G, Audi A, Kapisi J, Sserwanga A, Namuganga JF, Kariuki S, Otieno NA, Nyawanda BO, Olotu A, Salim N, Athuman T, Abdulla S, Mohamed AF, Mtove G, Reyburn H, Gupta S, Lourenço J, Bejon P, Snow RW. Malaria hospitalisation in East Africa: age, phenotype and transmission intensity. BMC Med 2022; 20:28. [PMID: 35081974 PMCID: PMC8793189 DOI: 10.1186/s12916-021-02224-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/21/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Understanding the age patterns of disease is necessary to target interventions to maximise cost-effective impact. New malaria chemoprevention and vaccine initiatives target young children attending routine immunisation services. Here we explore the relationships between age and severity of malaria hospitalisation versus malaria transmission intensity. METHODS Clinical data from 21 surveillance hospitals in East Africa were reviewed. Malaria admissions aged 1 month to 14 years from discrete administrative areas since 2006 were identified. Each site-time period was matched to a model estimated community-based age-corrected parasite prevalence to provide predictions of prevalence in childhood (PfPR2-10). Admission with all-cause malaria, severe malaria anaemia (SMA), respiratory distress (RD) and cerebral malaria (CM) were analysed as means and predicted probabilities from Bayesian generalised mixed models. RESULTS 52,684 malaria admissions aged 1 month to 14 years were described at 21 hospitals from 49 site-time locations where PfPR2-10 varied from < 1 to 48.7%. Twelve site-time periods were described as low transmission (PfPR2-10 < 5%), five low-moderate transmission (PfPR2-10 5-9%), 20 moderate transmission (PfPR2-10 10-29%) and 12 high transmission (PfPR2-10 ≥ 30%). The majority of malaria admissions were below 5 years of age (69-85%) and rare among children aged 10-14 years (0.7-5.4%) across all transmission settings. The mean age of all-cause malaria hospitalisation was 49.5 months (95% CI 45.1, 55.4) under low transmission compared with 34.1 months (95% CI 30.4, 38.3) at high transmission, with similar trends for each severe malaria phenotype. CM presented among older children at a mean of 48.7 months compared with 39.0 months and 33.7 months for SMA and RD, respectively. In moderate and high transmission settings, 34% and 42% of the children were aged between 2 and 23 months and so within the age range targeted by chemoprevention or vaccines. CONCLUSIONS Targeting chemoprevention or vaccination programmes to areas where community-based parasite prevalence is ≥10% is likely to match the age ranges covered by interventions (e.g. intermittent presumptive treatment in infancy to children aged 2-23 months and current vaccine age eligibility and duration of efficacy) and the age ranges of highest disease burden.
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Affiliation(s)
- Alice Kamau
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya.
| | | | - Samuel Akech
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Arthur Mpimbaza
- Child Health and Development Centre, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Cynthia Khazenzi
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Morris Ogero
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Eda Mumo
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Victor A Alegana
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Ambrose Agweyu
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Neema Mturi
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Shebe Mohammed
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Godfrey Bigogo
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Allan Audi
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - James Kapisi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Simon Kariuki
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Nancy A Otieno
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Bryan O Nyawanda
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Ally Olotu
- Ifakara Health Institute, Bagamoyo, Tanzania
| | - Nahya Salim
- Ifakara Health Institute, Bagamoyo, Tanzania
| | | | | | - Amina F Mohamed
- Kilimanjaro Christian Medical Centre/Joint Malaria Programme, Moshi, Tanzania
- London School of Hygiene and Tropical Medicine, London, UK
| | - George Mtove
- National Institute for Medical Research, Amani Research Centre, Muheza, Tanzania
| | - Hugh Reyburn
- London School of Hygiene and Tropical Medicine, London, UK
| | - Sunetra Gupta
- Department of Zoology, University of Oxford, Oxford, UK
| | - José Lourenço
- Department of Zoology, University of Oxford, Oxford, UK
| | - Philip Bejon
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Robert W Snow
- Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
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Seidahmed O, Jamea S, Kurumop S, Timbi D, Makita L, Ahmed M, Freeman T, Pomat W, Hetzel MW. Stratification of malaria incidence in Papua New Guinea (2011-2019): Contribution towards a sub-national control policy. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000747. [PMID: 36962582 PMCID: PMC10022348 DOI: 10.1371/journal.pgph.0000747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 10/20/2022] [Indexed: 11/22/2022]
Abstract
Malaria risk in Papua New Guinea (PNG) is highly heterogeneous, between and within geographical regions, which is operationally challenging for control. To enhance targeting of malaria interventions in PNG, we investigated risk factors and stratified malaria incidence at the level of health facility catchment areas. Catchment areas and populations of 808 health facilities were delineated using a travel-time accessibility approach and linked to reported malaria cases (2011-2019). Zonal statistics tools were used to calculate average altitude and air temperature in catchment areas before they were spatially joined with incidence rates. In addition, empirical Bayesian kriging (EBK) was employed to interpolate incidence risk strata across PNG. Malaria annual incidence rates are, on average, 186.3 per 1000 population in catchment areas up to 600 m, dropped to 98.8 at (800-1400) m, and to 24.1 cases above 1400 m altitude. In areas above the two altitudinal thresholds 600m and 1400m, the average annual temperature drops below 22°C and 17°C, respectively. EBK models show very low- to low-risk strata (<100 cases per 1000) in the Highlands, National Capital District and Bougainville. In contrast, patches of high-risk (>200 per 1000) strata are modelled mainly in Momase and Islands Regions. Besides, strata with moderate risk (100-200) predominate throughout the coastal areas. While 35.7% of the PNG population (estimated 3.33 million in 2019) lives in places at high or moderate risk of malaria, 52.2% (estimated 4.88 million) resides in very low-risk areas. In five provinces, relatively large proportions of populations (> 50%) inhabit high-risk areas: New Ireland, East and West New Britain, Sandaun and Milne Bay. Incidence maps show a contrast in malaria risk between coastal and inland areas influenced by altitude. However, the risk is highly variable in low-lying areas. Malaria interventions should be guided by sub-national risk levels in PNG.
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Affiliation(s)
- Osama Seidahmed
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
- University of Basel, Basel, Switzerland
| | - Sharon Jamea
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Serah Kurumop
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Diana Timbi
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Leo Makita
- National Department of Health, Port Moresby, Papua New Guinea
| | - Munir Ahmed
- Rotarians Against Malaria, Port Moresby, Papua New Guinea
| | - Tim Freeman
- Rotarians Against Malaria, Port Moresby, Papua New Guinea
| | - William Pomat
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
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33
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Alegana VA, Macharia PM, Muchiri S, Mumo E, Oyugi E, Kamau A, Chacky F, Thawer S, Molteni F, Rutazanna D, Maiteki-Sebuguzi C, Gonahasa S, Noor AM, Snow RW. Plasmodium falciparum parasite prevalence in East Africa: Updating data for malaria stratification. PLOS GLOBAL PUBLIC HEALTH 2021; 1:e0000014. [PMID: 35211700 PMCID: PMC7612417 DOI: 10.1371/journal.pgph.0000014] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022]
Abstract
The High Burden High Impact (HBHI) strategy for malaria encourages countries to use multiple sources of available data to define the sub-national vulnerabilities to malaria risk, including parasite prevalence. Here, a modelled estimate of Plasmodium falciparum from an updated assembly of community parasite survey data in Kenya, mainland Tanzania, and Uganda is presented and used to provide a more contemporary understanding of the sub-national malaria prevalence stratification across the sub-region for 2019. Malaria prevalence data from surveys undertaken between January 2010 and June 2020 were assembled form each of the three countries. Bayesian spatiotemporal model-based approaches were used to interpolate space-time data at fine spatial resolution adjusting for population, environmental and ecological covariates across the three countries. A total of 18,940 time-space age-standardised and microscopy-converted surveys were assembled of which 14,170 (74.8%) were identified after 2017. The estimated national population-adjusted posterior mean parasite prevalence was 4.7% (95% Bayesian Credible Interval 2.6-36.9) in Kenya, 10.6% (3.4-39.2) in mainland Tanzania, and 9.5% (4.0-48.3) in Uganda. In 2019, more than 12.7 million people resided in communities where parasite prevalence was predicted ≥ 30%, including 6.4%, 12.1% and 6.3% of Kenya, mainland Tanzania and Uganda populations, respectively. Conversely, areas that supported very low parasite prevalence (<1%) were inhabited by approximately 46.2 million people across the sub-region, or 52.2%, 26.7% and 10.4% of Kenya, mainland Tanzania and Uganda populations, respectively. In conclusion, parasite prevalence represents one of several data metrics for disease stratification at national and sub-national levels. To increase the use of this metric for decision making, there is a need to integrate other data layers on mortality related to malaria, malaria vector composition, insecticide resistance and bionomic, malaria care-seeking behaviour and current levels of unmet need of malaria interventions.
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Affiliation(s)
- Victor A. Alegana
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
- Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Peter M. Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Health Informatics, Computing, and Statistics, Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - Samuel Muchiri
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Eda Mumo
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Elvis Oyugi
- Division of National Malaria Programme, Ministry of Health, Nairobi, Kenya
| | - Alice Kamau
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Frank Chacky
- National Malaria Control Programme, Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania
| | - Sumaiyya Thawer
- National Malaria Control Programme, Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Fabrizio Molteni
- National Malaria Control Programme, Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Damian Rutazanna
- National Malaria Control Division, Ministry of Health, Kampala, Uganda
| | - Catherine Maiteki-Sebuguzi
- National Malaria Control Division, Ministry of Health, Kampala, Uganda
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Abdisalan M. Noor
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Robert W. Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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Geisen WR, Bartone C, Gerdes D, Lewis C. Rapid diagnostic testing as an indicator of malaria prevalence in Rorya District, Tanzania. MALARIAWORLD JOURNAL 2021; 12:4. [PMID: 34532227 PMCID: PMC8415055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Rapid Diagnostic Testing (RDT), a point-of-care, qualitative test for Plasmodium antigen, has been a catalyst in the diagnosis of patients in malaria-endemic regions. While blood-smear microscopy remains the gold standard, RDT allows for swift diagnosis in resource-poor settings. Our study sought to utilize RDT to quantify local malaria prevalence in the Rorya district of Tanzania. MATERIALS AND METHODS Two field clinics were established and 1,032 patients were screened. Those that described malaria symptoms were tested via RDT. The percentage of positive tests was compared to national data from the World Health Organization's 2019 World Malaria report and the President's Malaria Initiative Report for Tanzania. Intake data (sex, age, heart rate (HR), and temperature) were compared between the malaria-positive and malaria-negative groups. RESULTS 772 patients received RDT of whom 487 tested positive. There was a statistically significant difference in the percentage of positive patients between the two sites (52.0% vs 38.2%). Sixty percent of malaria-positives were female and the median age of this group was 10 yrs (range 5-15 yrs). Intake data showed a notable difference in median heart rates between malaria-positive and malaria-negative persons, 84.0 (72-100) and 72.0 (74-84) beats per minute (bpm), respectively. CONCLUSIONS The prevalence of malaria in Rorya was significantly higher than the reported Tanzanian average. Additionally, children were at a statistically higher risk of contracting malaria. Our data indicates that RDT offers enhanced insight into the local malarial burden that may be valuable to (governmental) health providers for the disbursement of resources in malaria-endemic regions.
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Affiliation(s)
- Will R. Geisen
- The Christ Hospital, Department of Internal Medicine, Cincinnati, OH, USA,
| | - Cheryl Bartone
- The Christ Hospital, Department of Heart Failure, Cincinnati, OH, USA
| | - Deborah Gerdes
- The Christ Hospital, Department of Internal Medicine, Cincinnati, OH, USA
| | - Christopher Lewis
- University of Cincinnati, Department of Family Medicine, Cincinnati, OH, USA
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An increasing role of pyrethroid-resistant Anopheles funestus in malaria transmission in the Lake Zone, Tanzania. Sci Rep 2021; 11:13457. [PMID: 34188090 PMCID: PMC8241841 DOI: 10.1038/s41598-021-92741-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
Anopheles funestus is playing an increasing role in malaria transmission in parts of sub-Saharan Africa, where An. gambiae s.s. has been effectively controlled by long-lasting insecticidal nets. We investigated vector population bionomics, insecticide resistance and malaria transmission dynamics in 86 study clusters in North-West Tanzania. An. funestus s.l. represented 94.5% (4740/5016) of all vectors and was responsible for the majority of malaria transmission (96.5%), with a sporozoite rate of 3.4% and average monthly entomological inoculation rate (EIR) of 4.57 per house. Micro-geographical heterogeneity in species composition, abundance and transmission was observed across the study district in relation to key ecological differences between northern and southern clusters, with significantly higher densities, proportions and EIR of An. funestus s.l. collected from the South. An. gambiae s.l. (5.5%) density, principally An. arabiensis (81.1%) and An. gambiae s.s. (18.9%), was much lower and closely correlated with seasonal rainfall. Both An. funestus s.l. and An. gambiae s.l. were similarly resistant to alpha-cypermethrin and permethrin. Overexpression of CYP9K1, CYP6P3, CYP6P4 and CYP6M2 and high L1014S-kdr mutation frequency were detected in An. gambiae s.s. populations. Study findings highlight the urgent need for novel vector control tools to tackle persistent malaria transmission in the Lake Region of Tanzania.
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Odhiambo JN, Kalinda C, Macharia PM, Snow RW, Sartorius B. Spatial and spatio-temporal methods for mapping malaria risk: a systematic review. BMJ Glob Health 2021; 5:bmjgh-2020-002919. [PMID: 33023880 PMCID: PMC7537142 DOI: 10.1136/bmjgh-2020-002919] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 12/21/2022] Open
Abstract
Background Approaches in malaria risk mapping continue to advance in scope with the advent of geostatistical techniques spanning both the spatial and temporal domains. A substantive review of the merits of the methods and covariates used to map malaria risk has not been undertaken. Therefore, this review aimed to systematically retrieve, summarise methods and examine covariates that have been used for mapping malaria risk in sub-Saharan Africa (SSA). Methods A systematic search of malaria risk mapping studies was conducted using PubMed, EBSCOhost, Web of Science and Scopus databases. The search was restricted to refereed studies published in English from January 1968 to April 2020. To ensure completeness, a manual search through the reference lists of selected studies was also undertaken. Two independent reviewers completed each of the review phases namely: identification of relevant studies based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, data extraction and methodological quality assessment using a validated scoring criterion. Results One hundred and seven studies met the inclusion criteria. The median quality score across studies was 12/16 (range: 7–16). Approximately half (44%) of the studies employed variable selection techniques prior to mapping with rainfall and temperature selected in over 50% of the studies. Malaria incidence (47%) and prevalence (35%) were the most commonly mapped outcomes, with Bayesian geostatistical models often (31%) the preferred approach to risk mapping. Additionally, 29% of the studies employed various spatial clustering methods to explore the geographical variation of malaria patterns, with Kulldorf scan statistic being the most common. Model validation was specified in 53 (50%) studies, with partitioning data into training and validation sets being the common approach. Conclusions Our review highlights the methodological diversity prominent in malaria risk mapping across SSA. To ensure reproducibility and quality science, best practices and transparent approaches should be adopted when selecting the statistical framework and covariates for malaria risk mapping. Findings underscore the need to periodically assess methods and covariates used in malaria risk mapping; to accommodate changes in data availability, data quality and innovation in statistical methodology.
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Affiliation(s)
| | - Chester Kalinda
- Discipline of Public Health Medicine, University of KwaZulu-Natal, Durban, South Africa.,Faculty of Agriculture and Natural Resources, University of Namibia, Windhoek, Namibia
| | - Peter M Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Robert W Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Benn Sartorius
- Discipline of Public Health Medicine, University of KwaZulu-Natal, Durban, South Africa.,Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Cleary E, Hetzel MW, Siba PM, Lau CL, Clements ACA. Spatial prediction of malaria prevalence in Papua New Guinea: a comparison of Bayesian decision network and multivariate regression modelling approaches for improved accuracy in prevalence prediction. Malar J 2021; 20:269. [PMID: 34120604 PMCID: PMC8201920 DOI: 10.1186/s12936-021-03804-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Considerable progress towards controlling malaria has been made in Papua New Guinea through the national malaria control programme’s free distribution of long-lasting insecticidal nets, improved diagnosis with rapid diagnostic tests and improved access to artemisinin combination therapy. Predictive prevalence maps can help to inform targeted interventions and monitor changes in malaria epidemiology over time as control efforts continue. This study aims to compare the predictive performance of prevalence maps generated using Bayesian decision network (BDN) models and multilevel logistic regression models (a type of generalized linear model, GLM) in terms of malaria spatial risk prediction accuracy. Methods Multilevel logistic regression models and BDN models were developed using 2010/2011 malaria prevalence survey data collected from 77 randomly selected villages to determine associations of Plasmodium falciparum and Plasmodium vivax prevalence with precipitation, temperature, elevation, slope (terrain aspect), enhanced vegetation index and distance to the coast. Predictive performance of multilevel logistic regression and BDN models were compared by cross-validation methods. Results Prevalence of P. falciparum, based on results obtained from GLMs was significantly associated with precipitation during the 3 driest months of the year, June to August (β = 0.015; 95% CI = 0.01–0.03), whereas P. vivax infection was associated with elevation (β = − 0.26; 95% CI = − 0.38 to − 3.04), precipitation during the 3 driest months of the year (β = 0.01; 95% CI = − 0.01–0.02) and slope (β = 0.12; 95% CI = 0.05–0.19). Compared with GLM model performance, BDNs showed improved accuracy in prediction of the prevalence of P. falciparum (AUC = 0.49 versus 0.75, respectively) and P. vivax (AUC = 0.56 versus 0.74, respectively) on cross-validation. Conclusions BDNs provide a more flexible modelling framework than GLMs and may have a better predictive performance when developing malaria prevalence maps due to the multiple interacting factors that drive malaria prevalence in different geographical areas. When developing malaria prevalence maps, BDNs may be particularly useful in predicting prevalence where spatial variation in climate and environmental drivers of malaria transmission exists, as is the case in Papua New Guinea.
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Affiliation(s)
- Eimear Cleary
- Research School of Population Health, Australian National University, Canberra, Australia.
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.,Centre for Health Research and Diagnostics, Divine Word University, Madang, Papua New Guinea
| | - Colleen L Lau
- Research School of Population Health, Australian National University, Canberra, Australia.,School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, Australia
| | - Archie C A Clements
- Faculty of Health Sciences, Curtin University, Bentley, Australia.,Telethon Kids Institute, Nedlands, Australia
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38
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Kitojo C, Chacky F, Kigadye ES, Mugasa JP, Lusasi A, Mohamed A, Reaves EJ, Gutman JR, Ishengoma DS. Acceptability of single screening and treatment policy for the control of malaria in pregnancy: perceptions of providers and pregnant women from selected health facilities in Lindi region, Tanzania. Malar J 2021; 20:256. [PMID: 34103047 PMCID: PMC8188655 DOI: 10.1186/s12936-021-03782-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 05/25/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tanzania started implementing single screening and treatment (SST) for all pregnant women attending their first antenatal care (ANC) visits in 2014, using malaria rapid diagnostic tests (RDTs) and treating those who test positive according to the national guidelines. However, there is a paucity of data to show the acceptability of SST to both pregnant women and health care workers (HCWs), taking into consideration the shortage of workers and the added burden of this policy to the health system. This study assessed the perceptions and opinions of health service users and providers to determine the acceptability of SST policy. METHODS Pregnant women and HCWs in eight health facilities in two districts of Lindi region (Kilwa and Lindi) were interviewed using semi-structured questionnaires with open and close-ended questions. Both qualitative and quantitative data were collected, including demographic characteristics, women's experience, their perception on SST and challenges they face when receiving services for malaria offered at ANC. Experience of HCWs regarding the implementation of SST as part of routine services and the challenges encountered when providing ANC services for malaria in pregnancy (MIP) were also assessed. RESULTS Of the 143 pregnant women interviewed, 97% viewed testing favourably and would wish to be tested for malaria again, while 95% were satisfied with services and reasons for testing during the first ANC visit. Nearly all (99%) would recommend their fellow pregnant women to be tested for malaria and all women recommended that the Ministry of Health should continue the SST strategy. This was despite the fact that 76% of the women experienced pain and 16% had anxiety as a result of finger prick. Sixteen HCWs (mostly nurses) were interviewed; they also viewed SST implementation favourably and reported feeling empowered to use RDTs for malaria screening. The main challenge identified by HCWs was that nurses are not allowed to prescribe anti-malarials to women who test positive and need to refer them to the outpatient department for treatment. CONCLUSION SST was considered an acceptable approach to control MIP by HCWs and pregnant women, and they recommended the continuation of the policy. In addition, consideration should be given to implementing a task-shifting policy to allow nurses to dispense anti-malarials to pregnant women.
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Affiliation(s)
- Chonge Kitojo
- US President's Malaria Initiative, United States Agency for International Development, Dar es Salaam, United Republic of Tanzania. .,The Open University of Tanzania, Dar es Salaam, United Republic of Tanzania.
| | - Frank Chacky
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Emmanuel S Kigadye
- The Open University of Tanzania, Dar es Salaam, United Republic of Tanzania
| | - Joseph P Mugasa
- PMI Impact Malaria Population Services International (PSI), Dar es Salaam, United Republic of Tanzania
| | - Abdallah Lusasi
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Ally Mohamed
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Erik J Reaves
- US President's Malaria Initiative, Centers for Disease Control and Prevention, Dar es Salaam, United Republic of Tanzania
| | - Julie R Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, United Republic of Tanzania.,Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia.,School of Public Health, Harvard University, Boston, MA, USA
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Giorgi E, Fronterrè C, Macharia PM, Alegana VA, Snow RW, Diggle PJ. Model building and assessment of the impact of covariates for disease prevalence mapping in low-resource settings: to explain and to predict. J R Soc Interface 2021; 18:20210104. [PMID: 34062104 PMCID: PMC8169216 DOI: 10.1098/rsif.2021.0104] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This paper provides statistical guidance on the development and application of model-based geostatistical methods for disease prevalence mapping. We illustrate the different stages of the analysis, from exploratory analysis to spatial prediction of prevalence, through a case study on malaria mapping in Tanzania. Throughout the paper, we distinguish between predictive modelling, whose main focus is on maximizing the predictive accuracy of the model, and explanatory modelling, where greater emphasis is placed on understanding the relationships between the health outcome and risk factors. We demonstrate that these two paradigms can result in different modelling choices. We also propose a simple approach for detecting over-fitting based on inspection of the correlation matrix of the estimators of the regression coefficients. To enhance the interpretability of geostatistical models, we introduce the concept of domain effects in order to assist variable selection and model validation. The statistical ideas and principles illustrated here in the specific context of disease prevalence mapping are more widely applicable to any regression model for the analysis of epidemiological outcomes but are particularly relevant to geostatistical models, for which the separation between fixed and random effects can be ambiguous.
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Affiliation(s)
- Emanuele Giorgi
- CHICAS, Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Claudio Fronterrè
- CHICAS, Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Peter M Macharia
- CHICAS, Lancaster Medical School, Lancaster University, Lancaster, UK.,Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Victor A Alegana
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Robert W Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Peter J Diggle
- CHICAS, Lancaster Medical School, Lancaster University, Lancaster, UK
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Okumu F, Finda M. Key Characteristics of Residual Malaria Transmission in Two Districts in South-Eastern Tanzania-Implications for Improved Control. J Infect Dis 2021; 223:S143-S154. [PMID: 33906218 PMCID: PMC8079133 DOI: 10.1093/infdis/jiaa653] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
After 2 decades of using insecticide-treated nets (ITNs) and improved case management, malaria burden in the historically-holoendemic Kilombero valley in Tanzania has significantly declined. We review key characteristics of the residual transmission and recommend options for improvement. Transmission has declined by >10-fold since 2000 but remains heterogeneous over small distances. Following the crash of Anopheles gambiae, which coincided with ITN scale-up around 2005-2012, Anopheles funestus now dominates malaria transmission. While most infections still occur indoors, substantial biting happens outdoors and before bed-time. There is widespread resistance to pyrethroids and carbamates; An. funestus being particularly strongly-resistant. In short and medium-term, these challenges could be addressed using high-quality indoor residual spraying with nonpyrethroids, or ITNs incorporating synergists. Supplementary tools, eg, spatial-repellents may expand protection outdoors. However, sustainable control requires resilience-building approaches, particularly improved housing and larval-source management to suppress mosquitoes, stronger health systems guaranteeing case-detection and treatment, greater community-engagement and expanded health education.
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Affiliation(s)
- Fredros Okumu
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- School of Public Health, University of the Witwatersrand, Johannesburg, Republic of South Africa
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Marceline Finda
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- School of Public Health, University of the Witwatersrand, Johannesburg, Republic of South Africa
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41
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Mmbando AS, Kaindoa EW, Ngowo HS, Swai JK, Matowo NS, Kilalangongono M, Lingamba GP, Mgando JP, Namango IH, Okumu FO, Nelli L. Fine-scale distribution of malaria mosquitoes biting or resting outside human dwellings in three low-altitude Tanzanian villages. PLoS One 2021; 16:e0245750. [PMID: 33507908 PMCID: PMC7842886 DOI: 10.1371/journal.pone.0245750] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/06/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND While malaria transmission in Africa still happens primarily inside houses, there is a substantial proportion of Anopheles mosquitoes that bite or rest outdoors. This situation may compromise the performance of indoor insecticidal interventions such as insecticide-treated nets (ITNs). This study investigated the distribution of malaria mosquitoes biting or resting outside dwellings in three low-altitude villages in south-eastern Tanzania. The likelihood of malaria infections outdoors was also assessed. METHODS Nightly trapping was done outdoors for 12 months to collect resting mosquitoes (using resting bucket traps) and host-seeking mosquitoes (using odour-baited Suna® traps). The mosquitoes were sorted by species and physiological states. Pooled samples of Anopheles were tested to estimate proportions infected with Plasmodium falciparum parasites, estimate proportions carrying human blood as opposed to other vertebrate blood and identify sibling species in the Anopheles gambiae complex and An. funestus group. Environmental and anthropogenic factors were observed and recorded within 100 meters from each trapping positions. Generalised additive models were used to investigate relationships between these variables and vector densities, produce predictive maps of expected abundance and compare outcomes within and between villages. RESULTS A high degree of fine-scale heterogeneity in Anopheles densities was observed between and within villages. Water bodies covered with vegetation were associated with 22% higher densities of An. arabiensis and 51% lower densities of An. funestus. Increasing densities of houses and people outdoors were both associated with reduced densities of An. arabiensis and An. funestus. Vector densities were highest around the end of the rainy season and beginning of the dry seasons. More than half (14) 58.3% of blood-fed An. arabiensis had bovine blood, (6) 25% had human blood. None of the Anopheles mosquitoes caught outdoors was found infected with malaria parasites. CONCLUSION Outdoor densities of both host-seeking and resting Anopheles mosquitoes had significant heterogeneities between and within villages, and were influenced by multiple environmental and anthropogenic factors. Despite the high Anopheles densities outside dwellings, the substantial proportion of non-human blood-meals and absence of malaria-infected mosquitoes after 12 months of nightly trapping suggests very low-levels of outdoor malaria transmission in these villages.
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Affiliation(s)
- Arnold S. Mmbando
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Emmanuel W. Kaindoa
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Parktown, Republic of South Africa
| | - Halfan S. Ngowo
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Johnson K. Swai
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Nancy S. Matowo
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Masoud Kilalangongono
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Godfrey P. Lingamba
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Joseph P. Mgando
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Isaac H. Namango
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Fredros O. Okumu
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Parktown, Republic of South Africa
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science & Technology, Arusha, Tanzania
| | - Luca Nelli
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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42
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Alegana VA, Suiyanka L, Macharia PM, Ikahu-Muchangi G, Snow RW. Malaria micro-stratification using routine surveillance data in Western Kenya. Malar J 2021; 20:22. [PMID: 33413385 PMCID: PMC7788718 DOI: 10.1186/s12936-020-03529-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/27/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is an increasing need for finer spatial resolution data on malaria risk to provide micro-stratification to guide sub-national strategic plans. Here, spatial-statistical techniques are used to exploit routine data to depict sub-national heterogeneities in test positivity rate (TPR) for malaria among patients attending health facilities in Kenya. METHODS Routine data from health facilities (n = 1804) representing all ages over 24 months (2018-2019) were assembled across 8 counties (62 sub-counties) in Western Kenya. Statistical model-based approaches were used to quantify heterogeneities in TPR and uncertainty at fine spatial resolution adjusting for missingness, population distribution, spatial data structure, month, and type of health facility. RESULTS The overall monthly reporting rate was 78.7% (IQR 75.0-100.0) and public-based health facilities were more likely than private facilities to report ≥ 12 months (OR 5.7, 95% CI 4.3-7.5). There was marked heterogeneity in population-weighted TPR with sub-counties in the north of the lake-endemic region exhibiting the highest rates (exceedance probability > 70% with 90% certainty) where approximately 2.7 million (28.5%) people reside. At micro-level the lowest rates were in 14 sub-counties (exceedance probability < 30% with 90% certainty) where approximately 2.2 million (23.1%) people lived and indoor residual spraying had been conducted since 2017. CONCLUSION The value of routine health data on TPR can be enhanced when adjusting for underlying population and spatial structures of the data, highlighting small-scale heterogeneities in malaria risk often masked in broad national stratifications. Future research should aim at relating these heterogeneities in TPR with traditional community-level prevalence to improve tailoring malaria control activities at sub-national levels.
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Affiliation(s)
- Victor A Alegana
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya. .,Geography and Environmental Science, University of Southampton, Southampton, SO17 1BJ, UK. .,Faculty of Science and Technology, Lancaster University, Lancaster, LAI 4YW, UK.
| | - Laurissa Suiyanka
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya
| | - Peter M Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya
| | - Grace Ikahu-Muchangi
- National Malaria Control Programme, Ministry of Health, P.O Box 30016-00100, Nairobi, Kenya
| | - Robert W Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7LJ, UK
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43
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Moser KA, Madebe RA, Aydemir O, Chiduo MG, Mandara CI, Rumisha SF, Chaky F, Denton M, Marsh PW, Verity R, Watson OJ, Ngasala B, Mkude S, Molteni F, Njau R, Warsame M, Mandike R, Kabanywanyi AM, Mahende MK, Kamugisha E, Ahmed M, Kavishe RA, Greer G, Kitojo CA, Reaves EJ, Mlunde L, Bishanga D, Mohamed A, Juliano JJ, Ishengoma DS, Bailey JA. Describing the current status of Plasmodium falciparum population structure and drug resistance within mainland Tanzania using molecular inversion probes. Mol Ecol 2020; 30:100-113. [PMID: 33107096 DOI: 10.1111/mec.15706] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/25/2020] [Accepted: 10/13/2020] [Indexed: 02/05/2023]
Abstract
High-throughput Plasmodium genomic data is increasingly useful in assessing prevalence of clinically important mutations and malaria transmission patterns. Understanding parasite diversity is important for identification of specific human or parasite populations that can be targeted by control programmes, and to monitor the spread of mutations associated with drug resistance. An up-to-date understanding of regional parasite population dynamics is also critical to monitor the impact of control efforts. However, this data is largely absent from high-burden nations in Africa, and to date, no such analysis has been conducted for malaria parasites in Tanzania countrywide. To this end, over 1,000 P. falciparum clinical isolates were collected in 2017 from 13 sites in seven administrative regions across Tanzania, and parasites were genotyped at 1,800 variable positions genome-wide using molecular inversion probes. Population structure was detectable among Tanzanian P. falciparum parasites, approximately separating parasites from the northern and southern districts and identifying genetically admixed populations in the north. Isolates from nearby districts were more likely to be genetically related compared to parasites sampled from more distant districts. Known drug resistance mutations were seen at increased frequency in northern districts (including two infections carrying pfk13-R561H), and additional variants with undetermined significance for antimalarial resistance also varied by geography. Malaria Indicator Survey (2017) data corresponded with genetic findings, including average region-level complexity-of-infection and malaria prevalence estimates. The parasite populations identified here provide important information on extant spatial patterns of genetic diversity of Tanzanian parasites, to which future surveys of genetic relatedness can be compared.
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Affiliation(s)
- Kara A Moser
- Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC, USA
| | | | - Ozkan Aydemir
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Mercy G Chiduo
- National Institute for Medical Research, Tanga, Tanzania
| | - Celine I Mandara
- National Institute for Medical Research, Tanga, Tanzania.,Kilimanjaro Christian Medical Centre/Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Susan F Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Frank Chaky
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | - Madeline Denton
- Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC, USA
| | - Patrick W Marsh
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Robert Verity
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Oliver J Watson
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA.,MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Billy Ngasala
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Sigsbert Mkude
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | | | - Ritha Njau
- World Health Organization Country Office, Dar es Salaam, Tanzania
| | - Marian Warsame
- Gothenburg University, Gothenburg, Sweden.,Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Renata Mandike
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | | | | | - Erasmus Kamugisha
- Catholic University of Health and Allied Sciences/Bugando Medical Centre, Mwanza, Tanzania
| | - Maimuna Ahmed
- Catholic University of Health and Allied Sciences/Bugando Medical Centre, Mwanza, Tanzania
| | - Reginald A Kavishe
- Kilimanjaro Christian Medical Centre/Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - George Greer
- U.S. President's Malaria Initiative, U.S. Agency for International Development, U.S. Embassy, Dar es Salaam, Tanzania
| | - Chonge A Kitojo
- U.S. President's Malaria Initiative, U.S. Agency for International Development, U.S. Embassy, Dar es Salaam, Tanzania
| | - Erik J Reaves
- U.S. President's Malaria Initiative, U.S. Agency for International Development, U.S. Embassy, Dar es Salaam, Tanzania
| | - Linda Mlunde
- Jhpiego/Boresha Afya Project, Dar es Salaam, Tanzania
| | | | - Ally Mohamed
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | - Jonathan J Juliano
- Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC, USA.,Curriculum in Genetics and Molecular Biology, University of North Carolina Chapel Hill, Chapel Hill, NC, USA.,Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, NC, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania.,Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Vic, Australia.,Harvard T.H. Chan School of Public health, Harvard University, Boston, MA, USA
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
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Gesicho MB, Were MC, Babic A. Data cleaning process for HIV-indicator data extracted from DHIS2 national reporting system: a case study of Kenya. BMC Med Inform Decis Mak 2020; 20:293. [PMID: 33187520 PMCID: PMC7664027 DOI: 10.1186/s12911-020-01315-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 11/04/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The District Health Information Software-2 (DHIS2) is widely used by countries for national-level aggregate reporting of health-data. To best leverage DHIS2 data for decision-making, countries need to ensure that data within their systems are of the highest quality. Comprehensive, systematic, and transparent data cleaning approaches form a core component of preparing DHIS2 data for analyses. Unfortunately, there is paucity of exhaustive and systematic descriptions of data cleaning processes employed on DHIS2-based data. The aim of this study was to report on methods and results of a systematic and replicable data cleaning approach applied on HIV-data gathered within DHIS2 from 2011 to 2018 in Kenya, for secondary analyses. METHODS Six programmatic area reports containing HIV-indicators were extracted from DHIS2 for all care facilities in all counties in Kenya from 2011 to 2018. Data variables extracted included reporting rate, reporting timeliness, and HIV-indicator data elements per facility per year. 93,179 facility-records from 11,446 health facilities were extracted from year 2011 to 2018. Van den Broeck et al.'s framework, involving repeated cycles of a three-phase process (data screening, data diagnosis and data treatment), was employed semi-automatically within a generic five-step data-cleaning sequence, which was developed and applied in cleaning the extracted data. Various quality issues were identified, and Friedman analysis of variance conducted to examine differences in distribution of records with selected issues across eight years. RESULTS Facility-records with no data accounted for 50.23% and were removed. Of the remaining, 0.03% had over 100% in reporting rates. Of facility-records with reporting data, 0.66% and 0.46% were retained for voluntary medical male circumcision and blood safety programmatic area reports respectively, given that few facilities submitted data or offered these services. Distribution of facility-records with selected quality issues varied significantly by programmatic area (p < 0.001). The final clean dataset obtained was suitable to be used for subsequent secondary analyses. CONCLUSIONS Comprehensive, systematic, and transparent reporting of cleaning-process is important for validity of the research studies as well as data utilization. The semi-automatic procedures used resulted in improved data quality for use in secondary analyses, which could not be secured by automated procedures solemnly.
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Affiliation(s)
- Milka Bochere Gesicho
- Department of Information Science and Media Studies, University of Bergen, Bergen, Norway. .,Institute of Biomedical Informatics, Moi University, Eldoret, Kenya.
| | - Martin Chieng Were
- Vanderbilt University Medical Center, Nashville, USA.,Institute of Biomedical Informatics, Moi University, Eldoret, Kenya
| | - Ankica Babic
- Department of Information Science and Media Studies, University of Bergen, Bergen, Norway.,Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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Kamau A, Mtanje G, Mataza C, Malla L, Bejon P, Snow RW. The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. PLoS One 2020; 15:e0240058. [PMID: 33027313 PMCID: PMC7540858 DOI: 10.1371/journal.pone.0240058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Malaria surveillance is a key pillar in the control of malaria in Africa. The value of using routinely collected data from health facilities to define malaria risk at community levels remains poorly defined. METHODS Four cross-sectional parasite prevalence surveys were undertaken among residents at 36 enumeration zones in Kilifi county on the Kenyan coast and temporally and spatially matched to fever surveillance at 6 health facilities serving the same communities over 12 months. The age-structured functional form of the relationship between test positivity rate (TPR) and community-based parasite prevalence (PR) was explored through the development of regression models fitted by alternating the linear, exponential and polynomial terms for PR. The predictive ranges of TPR were explored for PR endemicity risk groups of control programmatic value using cut-offs of low (PR <5%) and high (PR ≥ 30%) transmission intensity. RESULTS Among 28,134 febrile patients encountered for malaria diagnostic testing in the health facilities, 12,143 (43.2%: 95% CI: 42.6%, 43.7%) were positive. The overall community PR was 9.9% (95% CI: 9.2%, 10.7%) among 6,479 participants tested for malaria. The polynomial model was the best fitting model for the data that described the algebraic relationship between TPR and PR. In this setting, a TPR of ≥ 49% in all age groups corresponded to an age-standardized PR of ≥ 30%, while a TPR of < 40% corresponded to an age-standardized PR of < 5%. CONCLUSION A non-linear relationship was observed between the relative change in TPR and changes in the PR, which is likely to have important implications for malaria surveillance programs, especially at the extremes of transmission. However, larger, more spatially diverse data series using routinely collected TPR data matched to community-based infection prevalence data are required to explore the more practical implications of using TPR as a replacement for community PR.
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Affiliation(s)
- Alice Kamau
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Grace Mtanje
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Christine Mataza
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Ministry of Health, Kilifi County Government, Kilifi, Kenya
| | - Lucas Malla
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Robert W. Snow
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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Ghilardi L, Okello G, Nyondo-Mipando L, Chirambo CM, Malongo F, Hoyt J, Lee J, Sedekia Y, Parkhurst J, Lines J, Snow RW, Lynch CA, Webster J. How useful are malaria risk maps at the country level? Perceptions of decision-makers in Kenya, Malawi and the Democratic Republic of Congo. Malar J 2020; 19:353. [PMID: 33008465 PMCID: PMC7530951 DOI: 10.1186/s12936-020-03425-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/23/2020] [Indexed: 11/24/2022] Open
Abstract
Background Declining malaria prevalence and pressure on external funding have increased the need for efficiency in malaria control in sub-Saharan Africa (SSA). Modelled Plasmodium falciparum parasite rate (PfPR) maps are increasingly becoming available and provide information on the epidemiological situation of countries. However, how these maps are understood or used for national malaria planning is rarely explored. In this study, the practices and perceptions of national decision-makers on the utility of malaria risk maps, showing prevalence of parasitaemia or incidence of illness, was investigated. Methods A document review of recent National Malaria Strategic Plans was combined with 64 in-depth interviews with stakeholders in Kenya, Malawi and the Democratic Republic of Congo (DRC). The document review focused on the type of epidemiological maps included and their use in prioritising and targeting interventions. Interviews (14 Kenya, 17 Malawi, 27 DRC, 6 global level) explored drivers of stakeholder perceptions of the utility, value and limitations of malaria risk maps. Results Three different types of maps were used to show malaria epidemiological strata: malaria prevalence using a PfPR modelled map (Kenya); malaria incidence using routine health system data (Malawi); and malaria prevalence using data from the most recent Demographic and Health Survey (DRC). In Kenya the map was used to target preventative interventions, including long-lasting insecticide-treated nets (LLINs) and intermittent preventive treatment in pregnancy (IPTp), whilst in Malawi and DRC the maps were used to target in-door residual spraying (IRS) and LLINs distributions in schools. Maps were also used for operational planning, supply quantification, financial justification and advocacy. Findings from the interviews suggested that decision-makers lacked trust in the modelled PfPR maps when based on only a few empirical data points (Malawi and DRC). Conclusions Maps were generally used to identify areas with high prevalence in order to implement specific interventions. Despite the availability of national level modelled PfPR maps in all three countries, they were only used in one country. Perceived utility of malaria risk maps was associated with the epidemiological structure of the country and use was driven by perceived need, understanding (quality and relevance), ownership and trust in the data used to develop the maps.
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Affiliation(s)
- Ludovica Ghilardi
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
| | - George Okello
- Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya
| | - Linda Nyondo-Mipando
- Department of Health Systems and Policy, College of Medicine, University of Malawi, Blantyre, Malawi
| | | | - Fathy Malongo
- Kinshasa School of Public Health, University of Kinshasa, Mont Amba/Lemba, BP 11850 Kin I, Kinshasa, Democratic Republic of Congo
| | - Jenna Hoyt
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Jieun Lee
- World Vision UK, 1rb, 11 Belgrave Rd, Pimlico, London, SW1V 1RB, UK
| | - Yovitha Sedekia
- Mwanza Intervention Trials Unit (MITU)/ National Institute for Medical Research (NIMR)- Mwanza Research Centre, P.O BOX 11936, Isamilo road, Mwanza, Tanzania
| | - Justin Parkhurst
- London School of Economics and Political Science, Houghton Street, London, WC2A 2AE, UK
| | - Jo Lines
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Robert W Snow
- Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, OX3 7LJ, Oxford, UK
| | - Caroline A Lynch
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Jayne Webster
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
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