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Omondi S, Kosgei J, Musula G, Muchoki M, Abong'o B, Agumba S, Ogwang C, McDermott DP, Donnelly MJ, Staedke SG, Schultz J, Gutman JR, Gimnig JE, Ochomo E. Late morning biting behaviour of Anopheles funestus is a risk factor for transmission in schools in Siaya, western Kenya. Malar J 2023; 22:366. [PMID: 38037026 PMCID: PMC10691009 DOI: 10.1186/s12936-023-04806-w] [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: 10/06/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Children in Kenya spend a substantial amount of time at school, including at dawn and dusk when mosquitoes are active. With changing vector behaviour towards early morning biting, it is important to determine whether there is an additional risk of transmission in schools. This study sought to understand whether late morning biting by Anopheles funestus, previously documented in households in western Kenya, was replicated in schools. METHODS From the 4th to the 6th of August 2023, human landing collections were conducted hourly in four schools in Alego Usonga sub-County, Siaya County. The collections were conducted in and outside five classrooms in each school and ran for 17 h, starting at 18:00 until 11:00 h the next morning. RESULTS Anopheles funestus was the predominant species collected, forming 93.2% (N = 727) of the entire collection, with peak landing between 06:00 and 07:00 h and continuing until 11:00 h. More than half of the collected An. funestus were either fed or gravid, potentially indicative of multiple bloodmeals within each gonotrophic cycle, and had a sporozoite rate of 2.05%. CONCLUSION School children spend up to 10 h of their daytime in schools, reporting between 06:00 and 07:00 h and staying in school until as late as 17:00 h, meaning that they receive potentially infectious mosquito bites during the morning hours in these settings. There is a need to consider vector control approaches targeting schools and other peridomestic spaces in the morning hours when An. funestus is active.
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Affiliation(s)
- Seline Omondi
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Jackline Kosgei
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - George Musula
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Margaret Muchoki
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Bernard Abong'o
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Silas Agumba
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Caroline Ogwang
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Daniel P McDermott
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Sarah G Staedke
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Jonathan Schultz
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Julie R Gutman
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - John E Gimnig
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Eric Ochomo
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya.
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Picón-Jaimes YA, Lozada-Martinez ID, Orozco-Chinome JE, Molina-Franky J, Acevedo-Lopez D, Acevedo-Lopez N, Bolaño-Romero MP, Visconti-Lopez FJ, Bonilla-Aldana DK, Rodriguez-Morales AJ. Relationship between Duffy Genotype/Phenotype and Prevalence of Plasmodium vivax Infection: A Systematic Review. Trop Med Infect Dis 2023; 8:463. [PMID: 37888591 PMCID: PMC10610806 DOI: 10.3390/tropicalmed8100463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/07/2023] [Accepted: 09/13/2023] [Indexed: 10/28/2023] Open
Abstract
The Duffy protein, a transmembrane molecule, functions as a receptor for various chemokines and facilitates attachment between the reticulocyte and the Plasmodium Duffy antigen-binding protein. Duffy expression correlates with the Duffy receptor gene for the chemokine, located on chromosome 1, and exhibits geographical variability worldwide. Traditionally, researchers have described the Duffy negative genotype as a protective factor against Plasmodium vivax infection. However, recent studies suggest that this microorganism's evolution could potentially diminish this protective effect. Nevertheless, there is currently insufficient global data to demonstrate this phenomenon. This study aimed to evaluate the relationship between the Duffy genotype/phenotype and the prevalence of P. vivax infection. The protocol for the systematic review was registered in PROSPERO as CRD42022353427 and involved reviewing published studies from 2012 to 2022. The Medline/PubMed, Web of Science, Scopus, and SciELO databases were consulted. Assessments of study quality were conducted using the STROBE and GRADE tools. A total of 34 studies were included, with Africa accounting for the majority of recorded studies. The results varied significantly regarding the relationship between the Duffy genotype/phenotype and P. vivax invasion. Some studies predominantly featured the negative Duffy genotype yet reported no malaria cases. Other studies identified minor percentages of infections. Conversely, certain studies observed a higher prevalence (99%) of Duffy-negative individuals infected with P. vivax. In conclusion, this systematic review found that the homozygous Duffy genotype positive for the A allele (FY*A/*A) is associated with a higher incidence of P. vivax infection. Furthermore, the negative Duffy genotype does not confer protection against vivax malaria.
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Affiliation(s)
| | - Ivan David Lozada-Martinez
- Epidemiology Program, Department of Graduate Studies in Health Sciences, Universidad Autónoma de Bucaramanga, Bucaramanga 44005, Colombia;
| | - Javier Esteban Orozco-Chinome
- Medical and Surgical Research Center, Future Surgeons Chapter, Colombian Surgery Association, Bogotá 10002, Colombia; (J.E.O.-C.); (N.A.-L.); (M.P.B.-R.)
| | - Jessica Molina-Franky
- Department of Inmunology and Theranostics, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope, Duarte, CA 91007, USA;
- Molecular Biology and Inmunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá 10001, Colombia
| | - Domenica Acevedo-Lopez
- School of Medicine, Fundación Universitaria Autónoma de las Américas-Institución Universitaria Visión de las Américas, Pereira 660003, Colombia;
| | - Nicole Acevedo-Lopez
- Medical and Surgical Research Center, Future Surgeons Chapter, Colombian Surgery Association, Bogotá 10002, Colombia; (J.E.O.-C.); (N.A.-L.); (M.P.B.-R.)
| | - Maria Paz Bolaño-Romero
- Medical and Surgical Research Center, Future Surgeons Chapter, Colombian Surgery Association, Bogotá 10002, Colombia; (J.E.O.-C.); (N.A.-L.); (M.P.B.-R.)
| | | | | | - Alfonso J. Rodriguez-Morales
- Clinical Epidemiology and Biostatistics Master Program, Universidad Cientifica del Sur, Lima 15067, Peru;
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut P.O. Box 36, Lebanon
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It Is Time to Strengthen the Malaria Control Policy of the Democratic Republic of Congo and Include Schools and School-Age Children in Malaria Control Measures. Pathogens 2022; 11:pathogens11070729. [PMID: 35889975 PMCID: PMC9315856 DOI: 10.3390/pathogens11070729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 02/04/2023] Open
Abstract
Despite a decade of sustained malaria control, malaria remains a serious public health problem in the Democratic Republic of Congo (DRC). Children under five years of age and school-age children aged 5–15 years remain at high risk of symptomatic and asymptomatic malaria infections. The World Health Organization’s malaria control, elimination, and eradication recommendations are still only partially implemented in DRC. For better malaria control and eventual elimination, the integration of all individuals into the national malaria control programme will strengthen malaria control and elimination strategies in the country. Thus, inclusion of schools and school-age children in DRC malaria control interventions is needed.
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Mitchell CL, Janko MM, Mwandagalirwa MK, Tshefu AK, Edwards JK, Pence BW, Juliano JJ, Emch M. Impact of extractive industries on malaria prevalence in the Democratic Republic of the Congo: a population-based cross-sectional study. Sci Rep 2022; 12:1737. [PMID: 35110617 PMCID: PMC8810856 DOI: 10.1038/s41598-022-05777-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/18/2022] [Indexed: 12/11/2022] Open
Abstract
Extraction of natural resources through mining and logging activities provides revenue and employment across sub-Saharan Africa, a region with the highest burden of malaria globally. The extent to which mining and logging influence malaria transmission in Africa remains poorly understood. Here, we evaluate associations between mining, logging, and malaria in the high transmission setting of the Democratic Republic of the Congo using population-representative malaria survey results and geographic data for environmental features and mining and logging concessions. We find elevated malaria prevalence among individuals in rural areas exposed to mining; however, we also detect significant spatial confounding among locations. Upon correction, effect estimates for mining and logging shifted toward the null and we did not find sufficient evidence to detect an association with malaria. Our findings reveal a complex interplay between mining, logging, space, and malaria prevalence. While mining concessions alone may not drive the high prevalence, unobserved features of mining-exposed areas, such as human migration, changing vector populations, or parasite genetics, may instead be responsible.
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Affiliation(s)
- Cedar L Mitchell
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599, USA.
| | - Mark M Janko
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Melchior K Mwandagalirwa
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599, USA.,Kinshasa School of Public Health, Hôpital General Provincial de Reference de Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Antoinette K Tshefu
- Kinshasa School of Public Health, Hôpital General Provincial de Reference de Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Jessie K Edwards
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599, USA
| | - Brian W Pence
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599, USA
| | - Jonathan J Juliano
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599, USA.,Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Michael Emch
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr., Chapel Hill, NC, 27599, USA.,Department of Geography, University of North Carolina, Chapel Hill, NC, USA
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Spatial cluster analysis of Plasmodium vivax and P. malariae exposure using serological data among Haitian school children sampled between 2014 and 2016. PLoS Negl Trop Dis 2022; 16:e0010049. [PMID: 34986142 PMCID: PMC8765618 DOI: 10.1371/journal.pntd.0010049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 01/18/2022] [Accepted: 12/03/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Estimation of malaria prevalence in very low transmission settings is difficult by even the most advanced diagnostic tests. Antibodies against malaria antigens provide an indicator of active or past exposure to these parasites. The prominent malaria species within Haiti is Plasmodium falciparum, but P. vivax and P. malariae infections are also known to be endemic. METHODOLOGY/PRINCIPAL FINDINGS From 2014-2016, 28,681 Haitian children were enrolled in school-based serosurveys and were asked to provide a blood sample for detection of antibodies against multiple infectious diseases. IgG against the P. falciparum, P. vivax, and P. malariae merozoite surface protein 19kD subunit (MSP119) antigens was detected by a multiplex bead assay (MBA). A subset of samples was also tested for Plasmodium DNA by PCR assays, and for Plasmodium antigens by a multiplex antigen detection assay. Geospatial clustering of high seroprevalence areas for P. vivax and P. malariae antigens was assessed by both Ripley's K-function and Kulldorff's spatial scan statistic. Of 21,719 children enrolled in 680 schools in Haiti who provided samples to assay for IgG against PmMSP119, 278 (1.27%) were seropositive. Of 24,559 children enrolled in 788 schools providing samples for PvMSP119 serology, 113 (0.46%) were seropositive. Two significant clusters of seropositivity were identified throughout the country for P. malariae exposure, and two identified for P. vivax. No samples were found to be positive for Plasmodium DNA or antigens. CONCLUSIONS/SIGNIFICANCE From school-based surveys conducted from 2014 to 2016, very few Haitian children had evidence of exposure to P. vivax or P. malariae, with no children testing positive for active infection. Spatial scan statistics identified non-overlapping areas of the country with higher seroprevalence for these two malarias. Serological data provides useful information of exposure to very low endemic malaria species in a population that is unlikely to present to clinics with symptomatic infections.
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Ngwej LM, Mashat EM, Mukeng CK, Mundongo HT, Malonga FK, Kashala JCK, Bangs MJ. Variable residual activity of K-Othrine® PolyZone and Actellic® 300 CS in semi-field and natural conditions in the Democratic Republic of the Congo. Malar J 2021; 20:358. [PMID: 34461898 PMCID: PMC8406736 DOI: 10.1186/s12936-021-03892-y] [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: 04/14/2021] [Accepted: 08/22/2021] [Indexed: 11/10/2022] Open
Abstract
Background Indoor Residual Spray (IRS) against vector mosquitoes is a primary means for combating malaria transmission. To combat increased patterns of resistance to chemicals against mosquito vectors, alternative candidate insecticide formulations should be screened. With mortality as the primary endpoint, the persistence of residual efficacy of a polymer-enhanced pyrethroid suspension concentrate containing deltamethrin (K-Othrine® PolyZone—KOPZ) applied at 25 mg active ingredient (ai)/m2 was compared with a microencapsulated organophosphate suspension formulation of pirimiphos-methyl (Actellic® 300CS—ACS) applied at 1 g ai/m2. Methods Following standard spray application, periodic contact bioassays were conducted for at least 38 weeks on four types of wall surfaces (unbaked clay, baked clay, cement, and painted cement) sprayed with either KOPZ or ACS in simulated semi-field conditions. Similarly, two types of existing walls in occupied houses (painted cement and baked clay) were sprayed and examined. A colonized strain of female Anopheles arabiensis mosquitoes were exposed to treated or untreated surfaces (controls) for 30 min. For each wall surface test period, 40 treatment mosquitoes (4 cones × 10) in semi-field and 90 (9 cones × 10) in ‘natural’ house conditions were used per wall. 30 mosquitoes (3 cones × 10) on a matching unsprayed surface served as the control. Insecticide, wall material, and sprayed location on wall (in houses) were compared by final mortality at 24 h. Results Insecticide, wall material, and sprayed location on wall surface produced significant difference for mean final mortality over time. In semi-field conditions, KOPZ produced a 72% mean mortality over a 38-week period, while ACS gave 65% (p < 0.001). Painted cement wall performed better than other wall surfaces throughout the study period (73% mean mortality). In the two occupied houses, KOPZ provided a mean mortality of 88%, significantly higher than ACS (p < 0.001). KOPZ provided an effective residual life (≥ 80% mortality) between 7.3 and 14 weeks on experimental walls and between 18.3 and 47.2 weeks in houses, while ACS persisted between 3 and 7.6 weeks under semi-field conditions and between 7.1 and 17.3 weeks in houses. Household painted cement walls provided a longer effective residual activity compared to baked clay for both formulations. Greater mortality was recorded at the top and middle sections of sprayed wall compared to the bottom portion near the floor. Conclusion KOPZ provided longer residual activity on all surfaces compared to ACS. Painted cement walls provided better residual longevity for both insecticides compared to other surfaces. Insecticides also performed better in an occupied house environment compared to semi-field constructed walls. This study illustrates the importance of collecting field-based observations to determine appropriate product active ingredient formulations and timing for recurring IRS cycles.
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Affiliation(s)
- Leonard M Ngwej
- China Molybdenum/International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of Congo. .,School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo.
| | - Emmanuel M Mashat
- China Molybdenum/International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of Congo
| | - Clarence K Mukeng
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Henri T Mundongo
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Françoise K Malonga
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Jean-Christophe K Kashala
- Faculty of Veterinary Medicine, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Michael J Bangs
- China Molybdenum/International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of Congo.,Public Health & Malaria Control Department, PT Freeport Indonesia, International SOS, Jl. Kertajasa, Kuala Kencana, Papua, 99920, Indonesia.,Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
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7
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Abdulraheem MA, Ernest M, Ugwuanyi I, Abkallo HM, Nishikawa S, Adeleke M, Orimadegun AE, Culleton R. High prevalence of Plasmodium malariae and Plasmodium ovale in co-infections with Plasmodium falciparum in asymptomatic malaria parasite carriers in southwestern Nigeria. Int J Parasitol 2021; 52:23-33. [PMID: 34390743 DOI: 10.1016/j.ijpara.2021.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/23/2021] [Accepted: 06/03/2021] [Indexed: 12/31/2022]
Abstract
Asymptomatic malaria parasite carriers do not seek anti-malarial treatment and may constitute a silent infectious reservoir. In order to assess the level of asymptomatic and symptomatic carriage amongst adolescents in a highly endemic area, and to identify the risk factors associated with such carriage, we conducted a cross-sectional survey of 1032 adolescents (ages 10-19 years) from eight schools located in Ibadan, southwestern Nigeria in 2016. Blood films and blood spot filter paper samples were prepared for microscopy and DNA analysis. The prevalence of asymptomatic malaria was determined using microscopy, rapid diagnostic tests and PCR for 658 randomly selected samples. Of these, we found that 80% of asymptomatic schoolchildren were positive for malaria parasites by PCR, compared with 47% and 9%, determined by rapid diagnostic tests and microscopy, respectively. Malaria parasite species typing was performed using PCR targeting the mitochondrial CoxIII gene, and revealed high rates of carriage of Plasmodium malariae (53%) and Plasmodium ovale (24%). Most asymptomatic infections were co-infections of two or more species (62%), with Plasmodium falciparum + P. malariae the most common (35%), followed by P. falciparum + P. malariae + P. ovale (21%) and P. falciparum + P. ovale (6%). Single infections of P. falciparum, P. malariae and P. ovale accounted for 24%, 10% and 4% of all asymptomatic infections, respectively. To compare the species composition of asymptomatic and symptomatic infections, further sample collection was carried out in 2017 at one of the previously sampled schools, and at a nearby hospital. Whilst the species composition of the asymptomatic infections was similar to that observed in 2016, the symptomatic infections were markedly different, with single infections of P. falciparum observed in 91% of patients, P. falciparum + P. malariae in 5% and P. falciparum + P. ovale in 4%.
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Affiliation(s)
- Muhydeen Abiodun Abdulraheem
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Diana Princess of Wales Hospital, Grimsby, Northeast Lincolnshire, United Kingdom
| | - Medard Ernest
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, United States
| | - Ifeoma Ugwuanyi
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; University of New South Wales (UNSW), Sydney, Australia
| | - Hussein M Abkallo
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100 Kenya
| | - Saori Nishikawa
- Graduate School of Social and Cultural Science, Kumamoto University, Japan
| | | | | | - Richard Culleton
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Protozoology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Division of Molecular Parasitology, Proteo-Science Centre, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.
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Prusty D, Gupta N, Upadhyay A, Dar A, Naik B, Kumar N, Prajapati VK. Asymptomatic malaria infection prevailing risks for human health and malaria elimination. INFECTION GENETICS AND EVOLUTION 2021; 93:104987. [PMID: 34216796 DOI: 10.1016/j.meegid.2021.104987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 01/09/2023]
Abstract
There has been a consistent rise in malaria cases in the last few years. The existing malaria control measures are challenged by insecticide resistance in the mosquito vector, drug résistance in parasite populations, and asymptomatic malaria (ASM) in healthy individuals. The absence of apparent malaria symptoms and the presence of low parasitemia makes ASM a hidden reservoir for malaria transmission and an impediment in malaria elimination efforts. This review focuses on ASM in malaria-endemic countries and the past and present research trends from those geographical locations. The harmful impacts of asymptomatic malaria on human health and its contribution to disease transmission are highlighted. We discuss certain crucial genetic changes in the parasite and host immune response necessary for maintaining low parasitemia leading to long-term parasite survival in the host. Since the chronic health effects and the potential roles for disease transmission of ASM remain mostly unknown to significant populations, we offer proposals for developing general awareness. We also suggest advanced technology-based diagnostic methods, and treatment strategies to eliminate ASM.
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Affiliation(s)
- Dhaneswar Prusty
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India.
| | - Nidhi Gupta
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
| | - Arun Upadhyay
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
| | - Ashraf Dar
- Department of Biochemistry, University of Kashmir, Hazaratbal, Srinagar 190006, Jammu and Kashmir, India
| | - Biswajit Naik
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
| | - Navin Kumar
- School of Biotechnology, Gautam Buddha University, Greater Noida, 201308, UP, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
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9
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Alwajeeh TS, Abdul-Ghani R, Allam AF, Farag HF, Khalil SSM, Shehab AY, El-Sayad MH, Alharbi RA, Almalki SSR, Azazy AA. Uncomplicated falciparum malaria among schoolchildren in Bajil district of Hodeidah governorate, west of Yemen: association with anaemia and underweight. Malar J 2020; 19:358. [PMID: 33028361 PMCID: PMC7542704 DOI: 10.1186/s12936-020-03431-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/01/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria, malnutrition and anaemia are major public health problems in Yemen, with Hodeidah being the most malaria-afflicted governorate. To address the lack of relevant studies, this study was conducted to determine the prevalence of Plasmodium falciparum and its relation to nutritional status and haematological indices among schoolchildren in Bajil district of Hodeidah governorate, west of Yemen. METHODS A cross-sectional study was conducted among 400 schoolchildren selected randomly from four schools in Bajil district. Data about demographic characteristics, risk factors and anthropometric measurements of age, height and weight were collected. Duplicate thick and thin blood films were prepared, stained with Giemsa and examined microscopically for malaria parasites. The density of P. falciparum asexual stages was estimated on thick films. EDTA-blood samples were examined for the haematological indices of haemoglobin (Hb) and blood cell counts. RESULTS Plasmodium falciparum was prevalent among 8.0% (32/400) of schoolchildren with a mean parasite density of 244.3 ± 299.3/µL of blood and most infections showing low-level parasitaemia, whereas Plasmodium vivax was detected in one child (0.25%). Residing near water collections was a significant independent predictor of falciparum malaria [adjusted odds ratio (AOR) = 2.6, 95.0% CI 1.20-5.72; p = 0.016] in schoolchildren. Mild anaemia was prevalent among more than half of P. falciparum-infected schoolchildren and significantly associated with falciparum malaria (AOR = 5.8, 95.0% CI 2.39-14.17; p < 0.001), with a mean Hb concentration of 10.7 ± 1.0 g/dL. Although the mean values of the total white blood cells, monocytes and platelets were significantly lower in infected than non-infected schoolchildren, they were within normal ranges. More than half of the children were malnourished, with stunting (39.3%) and underweight (36.0%) being the most prevalent forms of malnutrition; 6.3% of children were wasted. Underweight (AOR = 5.3, 95.0% CI 2.09-13.62; p < 0.001) but not stunting or wasting, was a significant predictor of falciparum malaria among schoolchildren. CONCLUSION Asymptomatic falciparum malaria is prevalent among schoolchildren in Bajil district of Hodeidah Governorate, with predominance of low parasitaemic infections and significant association with mild anaemia and underweight. Residence near water collection is a significant predictor of infection with falciparum malaria among schoolchildren. Further studies among children with severe malaria and those with high parasite densities are recommended.
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Affiliation(s)
- Talal S Alwajeeh
- Laboratory Department, Kuwait University Hospital, Sana'a University, Sana'a, Yemen
| | - Rashad Abdul-Ghani
- Department of Medical Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen. .,Tropical Disease Research Center, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana'a, Yemen.
| | - Amal F Allam
- Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Hoda F Farag
- Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Safia S M Khalil
- Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Amel Y Shehab
- Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Mona H El-Sayad
- Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Raed A Alharbi
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Al Baha University, Al Baha, Saudi Arabia
| | - Shaia S R Almalki
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Al Baha University, Al Baha, Saudi Arabia
| | - Ahmed A Azazy
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Al Baha University, Al Baha, Saudi Arabia
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10
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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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11
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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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12
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Chacky F, Runge M, Rumisha SF, Machafuko P, Chaki P, Massaga JJ, Mohamed A, Pothin E, Molteni F, Snow RW, Lengeler C, Mandike R. Nationwide school malaria parasitaemia survey in public primary schools, the United Republic of Tanzania. Malar J 2018; 17:452. [PMID: 30518365 PMCID: PMC6280377 DOI: 10.1186/s12936-018-2601-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/29/2018] [Indexed: 11/16/2022] Open
Abstract
Background A nationwide, school, malaria survey was implemented to assess the risk factors of malaria prevalence and bed net use among primary school children in mainland Tanzania. This allowed the mapping of malaria prevalence at council level and assessment of malaria risk factors among school children. Methods A cross-sectional, school, malaria parasitaemia survey was conducted in 25 regions, 166 councils and 357 schools in three phases: (1) August to September 2014; (2) May 2015; and, (3) October 2015. Children were tested for malaria parasites using rapid diagnostic tests and were interviewed about household information, parents’ education, bed net indicators as well as recent history of fever. Multilevel mixed effects logistic regression models were fitted to estimate odds ratios of risk factors for malaria infection and for bed net use while adjusting for school effect. Results In total, 49,113 children were interviewed and tested for malaria infection. The overall prevalence of malaria was 21.6%, ranging from < 0.1 to 53% among regions and from 0 to 76.4% among councils. The malaria prevalence was below 5% in 62 of the 166 councils and above 50% in 18 councils and between 5 and 50% in the other councils. The variation of malaria prevalence between schools was greatest in regions with a high mean prevalence, while the variation was marked by a few outlying schools in regions with a low mean prevalence. Overall, 70% of the children reported using mosquito nets, with the highest percentage observed among educated parents (80.7%), low land areas (82.7%) and those living in urban areas (82.2%). Conclusions The observed prevalence among school children showed marked variation at regional and sub-regional levels across the country. Findings of this survey are useful for updating the malaria epidemiological profile and for stratification of malaria transmission by region, council and age groups, which is essential for guiding resource allocation, evaluation and prioritization of malaria interventions. Electronic supplementary material The online version of this article (10.1186/s12936-018-2601-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Frank Chacky
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania. .,National Malaria Control Programme, Dar es Salaam, Tanzania.
| | - Manuela Runge
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Susan F Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Julius J Massaga
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ally Mohamed
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania.,National Malaria Control Programme, Dar es Salaam, Tanzania
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Fabrizio Molteni
- National Malaria Control Programme, Dar es Salaam, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Robert W Snow
- KEMRI-Welcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Renata Mandike
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania.,National Malaria Control Programme, Dar es Salaam, Tanzania
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