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Gupta H, Sharma S, Gilyazova I, Satyamoorthy K. Molecular tools are crucial for malaria elimination. Mol Biol Rep 2024; 51:555. [PMID: 38642192 DOI: 10.1007/s11033-024-09496-4] [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: 01/19/2024] [Accepted: 03/27/2024] [Indexed: 04/22/2024]
Abstract
The eradication of Plasmodium parasites, responsible for malaria, is a daunting global public health task. It requires a comprehensive approach that addresses symptomatic, asymptomatic, and submicroscopic cases. Overcoming this challenge relies on harnessing the power of molecular diagnostic tools, as traditional methods like microscopy and rapid diagnostic tests fall short in detecting low parasitaemia, contributing to the persistence of malaria transmission. By precisely identifying patients of all types and effectively characterizing malaria parasites, molecular tools may emerge as indispensable allies in the pursuit of malaria elimination. Furthermore, molecular tools can also provide valuable insights into parasite diversity, drug resistance patterns, and transmission dynamics, aiding in the implementation of targeted interventions and surveillance strategies. In this review, we explore the significance of molecular tools in the pursuit of malaria elimination, shedding light on their key contributions and potential impact on public health.
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Affiliation(s)
- Himanshu Gupta
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura, Uttar Pradesh, India.
| | - Sonal Sharma
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura, Uttar Pradesh, India
| | - Irina Gilyazova
- Subdivision of the Ufa Federal Research Centre of the Russian Academy of Sciences, Institute of Biochemistry and Genetics, Ufa, 450054, Russia
- Bashkir State Medical University, Ufa, 450008, Russia
| | - Kapaettu Satyamoorthy
- SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwara (SDM) University, Manjushree Nagar, Sattur, Dharwad, 580009, Karnataka, India
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Jaramillo-Underwood A, Herman C, Jean SE, Nace D, Elder ES, Robinson K, Knipes A, Worrell CM, Fox LM, Desir L, Fayette C, Javel A, Monestime F, Mace KE, Udhayakumar V, Won KY, Chang MA, Lemoine JF, Rogier E. Geospatial analysis of Plasmodium falciparum serological indicators: school versus community sampling in a low-transmission malaria setting. BMC Med 2024; 22:31. [PMID: 38254075 PMCID: PMC10804471 DOI: 10.1186/s12916-023-03145-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 10/31/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Due to low numbers of active infections and persons presenting to health facilities for malaria treatment, case-based surveillance is inefficient for understanding the remaining disease burden in low malaria transmission settings. Serological data through the detection of IgG antibodies from previous malaria parasite exposure can fill this gap by providing a nuanced picture of where sustained transmission remains. Study enrollment at sites of gathering provides a potential approach to spatially estimate malaria exposure and could preclude the need for more intensive community-based sampling. METHODS This study compared spatial estimates of malaria exposure from cross-sectional school- and community-based sampling in Haiti. A total of 52,405 blood samples were collected from 2012 to 2017. Multiplex bead assays (MBAs) tested IgG against P. falciparum liver stage antigen-1 (LSA-1), apical membrane antigen 1 (AMA1), and merozoite surface protein 1 (MSP1). Predictive geospatial models of seropositivity adjusted for environmental covariates, and results were compared using correlations by coordinate points and communes across Haiti. RESULTS Consistent directional associations were observed between seroprevalence and environmental covariates for elevation (negative), air temperature (negative), and travel time to urban centers (positive). Spearman's rank correlation for predicted seroprevalence at coordinate points was lowest for LSA-1 (ρ = 0.10, 95% CI: 0.09-0.11), but improved for AMA1 (ρ = 0.36, 95% CI: 0.35-0.37) and MSP1 (ρ = 0.48, 95% CI: 0.47-0.49). CONCLUSIONS In settings approaching P. falciparum elimination, case-based prevalence data does not provide a resolution of ongoing malaria transmission in the population. Immunogenic antigen targets (e.g., AMA1, MSP1) that give higher population rates of seropositivity provide moderate correlation to gold standard community sampling designs and are a feasible approach to discern foci of residual P. falciparum transmission in an area.
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Affiliation(s)
- Alicia Jaramillo-Underwood
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, 37830, USA
| | - Camelia Herman
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
- CDC Foundation, Atlanta, GA, 30308, USA
| | - Samuel E Jean
- Population Services International, Port-Au-Prince, Haiti
| | - Doug Nace
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - E Scott Elder
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Keri Robinson
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Alaine Knipes
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Caitlin M Worrell
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - LeAnne M Fox
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | | | - Carl Fayette
- IMA World Health, Port-Au-Prince, Haiti
- RTI International, Port-Au-Prince, Haiti
| | - Alain Javel
- IMA World Health, Port-Au-Prince, Haiti
- RTI International, Port-Au-Prince, Haiti
| | | | - Kimberly E Mace
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | | | - Kimberly Y Won
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Michelle A Chang
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Jean F Lemoine
- Ministère de La Santé Publique Et de La Population, Port Au Prince, Haiti
| | - Eric Rogier
- Division of Digestive Diseases and Nutrition, University of Kentucky, Lexington, United States.
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Ouattara SM, Ouattara D, Badoum ES, Diarra A, Hien D, Ouedraogo AZ, Nébié I, Ouedraogo A, Tiono AB, Sirima SB. Malariometric Indices in the Context of Seasonal Malaria Chemoprevention in Children Aged 1.5 to 12 Years during the Period of High Malaria Transmission in the Suburban Area of Banfora, Burkina Faso. Trop Med Infect Dis 2023; 8:442. [PMID: 37755903 PMCID: PMC10535583 DOI: 10.3390/tropicalmed8090442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023] Open
Abstract
Continuous monitoring of malaria epidemiology is needed in malaria-endemic settings to inform malaria control and elimination strategies. This study aimed to compare the malariometric indices between the under-fives and school-age children. We surveyed children aged 1.5 to 12 years for plasmodia carriage with the aim of including them in a longitudinal follow-up cohort. The survey took place from 7-11 September 2020 in a southwest area of Burkina Faso. Clinical and demographic data including malaria control measures were collected. A finger prick blood sample was taken for haemoglobin testing, and blood smears and dried blood spot preparation. The malariometric indices were calculated and compared between school-age children and those under the age of five. Multiple logistic regression was fitted to assess the association between malaria parasite carriage and age categories. Based on the PCR results, the parasite prevalence was 21.4% in the under-fives versus 44.2% in school-age children (p-value < 0.0001), with a pooled prevalence of 32.7% (CI = [28.8, 36.8]). The gametocyte prevalence was also significantly higher in school-age children (11.9%) compared to the under-fives (3.7%). Adjusted for covariates, school-age children were 2.9 times (IC = [2.0, 4.2]) more likely to carry the asexual parasite, compared to the under-fives. Malaria was moderate and stable endemic in this area and school-age children play a key role in the spread of the disease. The WHO conditional recommendation for intermittent preventive treatment of malaria in school-aged children living in malaria-endemic settings with moderate to high perennial or seasonal transmission should be implemented.
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Affiliation(s)
- San M Ouattara
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Daouda Ouattara
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Emilie S Badoum
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Amidou Diarra
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Denise Hien
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Amidou Z Ouedraogo
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Issa Nébié
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Alphonse Ouedraogo
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Alfred B Tiono
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
| | - Sodiomon B Sirima
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou 06 BP 10248, Burkina Faso
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Oyibo W, Latham V, Oladipo O, Ntadom G, Uhomoibhi P, Ogbulafor N, Okoronkwo C, Okoh F, Mahmoud A, Shekarau E, Oresanya O, Cherima YJ, Jalingo I, Abba B, Audu M, Conway DJ. Malaria parasite density and detailed qualitative microscopy enhances large-scale profiling of infection endemicity in Nigeria. Sci Rep 2023; 13:1599. [PMID: 36709336 PMCID: PMC9884197 DOI: 10.1038/s41598-023-27535-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/04/2023] [Indexed: 01/29/2023] Open
Abstract
With global progress towards malaria reduction stalling, further analysis of epidemiology is required, particularly in countries with the highest burden. National surveys have mostly analysed infection prevalence, while large-scale data on parasite density and different developmental forms rarely available. In Nigeria, the country with the largest burden globally, blood slide microscopy of children up to 5 years of age was conducted in the 2018 National Demographic and Health Survey, and parasite prevalence previously reported. In the current study, malaria parasite density measurements are reported and analysed for 7783 of the children sampled across the 36 states within the six geopolitical zones of the country. Asexual and sexual stages, and infections with different malaria parasite species are analysed. Across all states of Nigeria, there was a positive correlation between mean asexual parasite density within infected individuals and prevalence of infection in the community (Spearman's rho = 0.39, P = 0.02). Asexual parasite densities were highest in the northern geopolitical zones (geometric means > 2000 μL-1), extending the evidence of exceptionally high infection burden in many areas. Sexual parasite prevalence in each state was highly correlated with asexual parasite prevalence (Spearman's rho = 0.70, P < 0.001), although sexual parasite densities were low (geometric means < 100 μL-1 in all zones). Infants had lower parasite densities than children above 1 year of age, but there were no differences between male and female children. Most infections were of P. falciparum, which had higher asexual densities but lower sexual parasite densities than P. malariae or P. ovale mono-infections. However, mixed species infections had the highest asexual parasite densities. It is recommended that future large surveys in high burden countries measure parasite densities as well as developmental stages and species, to improve the quality of malaria epidemiology and tracking of future changes.
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Affiliation(s)
- Wellington Oyibo
- ANDI Centre of Excellence for Malaria Diagnosis, College of Medicine, University of Lagos, Lagos, Nigeria.
| | | | - Oladosu Oladipo
- ANDI Centre of Excellence for Malaria Diagnosis, College of Medicine, University of Lagos, Lagos, Nigeria
- Pure and Applied Biology Programme, Bowen University, Iwo, Osun State, Nigeria
| | - Godwin Ntadom
- Epidemiology Unit, Federal Ministry of Health, Abuja, Nigeria
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Perpetua Uhomoibhi
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Nnenna Ogbulafor
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Chukwu Okoronkwo
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Festus Okoh
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Aminu Mahmoud
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Emmanuel Shekarau
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | | | | | | | - Bintu Abba
- National Population Commission, Abuja, Nigeria
| | - Mohammed Audu
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - David J Conway
- London School of Hygiene and Tropical Medicine, London, UK.
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Stresman G, Stratil AS, Gomane S, Armando S, Rodrigues M, Candrinho B, Roca-Feltrer A. Optimizing Routine Malaria Surveillance Data in Urban Environments: A Case Study in Maputo City, Mozambique. Am J Trop Med Hyg 2023; 108:24-31. [PMID: 36191871 PMCID: PMC9904158 DOI: 10.4269/ajtmh.22-0166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/03/2022] [Indexed: 02/04/2023] Open
Abstract
In urban settings in malaria-endemic countries, malaria incidence is not well characterized and assumed to be typically very low and consisting largely of imported infections. In such contexts, surveillance systems should adapt to ensure that data are of sufficient spatial and temporal resolution to inform appropriate programmatic interventions. The aim of this research was to 1) assess spatial and temporal trends in reported malaria cases in Maputo City, Mozambique, using an expanded case notification form and 2) to determine how malaria surveillance can be optimized to characterize the local epidemiological context, which can then be used to inform targeted entomological investigations and guide implementation of localized malaria responses. This study took place in all six health facilities of KaMavota District in Maputo City, Mozambique. A questionnaire was administered to all confirmed cases from November 2019 to August 2021. Households of cases were retrospectively geolocated using local landmarks as reference. Overall, 2,380 malaria cases were reported, with the majority being uncomplicated (97.7%) and a median age of 21 years; 70.8% of cases had reported traveling outside the city in the past month with nine reporting traveling internationally. Maps of the 1,314 malaria cases that were geolocated showed distinct spatial patterns. The expanded case notification form enables a more granular overview of the malaria epidemiology in Maputo City; the geolocation data clearly show the areas where endemic transmission is likely, thus informing where resources should be prioritized. As urbanization is rapidly increasing in malaria endemic areas, identifying systems and key variables to collect ensures an operational way to characterize urban malaria through optimization of routine data to inform decision-making.
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Affiliation(s)
- Gillian Stresman
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London United Kingdom
| | | | | | | | | | | | - Arantxa Roca-Feltrer
- Malaria Consortium, London, United Kingdom;,Address correspondence to Arantxa Roca-Feltrer, Malaria Control and Elimination Partnership in Africa (MACEPA), 2201 Westlake Avenue, Suite 200, Seattle, WA 98121. E-mail:
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6
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Elmardi KA, Adam I, Malik EM, Kafy HT, Abdin MS, Kleinschmidt I, Kremers S, Gubbels JS. Impact of malaria control interventions on malaria infection and anaemia in low malaria transmission settings: a cross-sectional population-based study in Sudan. BMC Infect Dis 2022; 22:927. [PMID: 36496398 PMCID: PMC9737986 DOI: 10.1186/s12879-022-07926-x] [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: 02/07/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The past two decades were associated with innovation and strengthening of malaria control interventions, which have been increasingly adopted at large scale. Impact evaluations of these interventions were mostly performed in moderate or high malaria transmission areas. This study aimed to evaluate the use and performance of malaria interventions in low transmission areas on malaria infections and anaemia. METHODS Data from the 2016 Sudan malaria indicator survey was used. Multi-level logistic regression analysis was used to assess the strength of association between real-life community-level utilization of malaria interventions [diagnosis, artemisinin-based combination therapies (ACTs) and long-lasting insecticidal nets (LLINs)] and the study outcomes: malaria infections and anaemia (both overall and moderate-to-severe anaemia). RESULTS The study analysis involved 26,469 individuals over 242 clusters. Malaria infection rate was 7.6%, overall anaemia prevalence was 47.5% and moderate-to-severe anaemia prevalence was 4.5%. The average community-level utilization was 31.5% for malaria diagnosis, 29.9% for ACTs and 35.7% for LLINs. The odds of malaria infection was significantly reduced by 14% for each 10% increase in the utilization of malaria diagnosis (adjusted odds ratio (aOR) per 10% utilization 0.86, 95% CI 0.78-0.95, p = 0.004). However, the odds of infection was positively associated with the utilization of LLINs at community-level (aOR per 10% utilization 1.20, 95% CI 1.11-1.29, p < 0.001). No association between malaria infection and utilization of ACTs was identified (aOR per 10% utilization 0.97, 95% CI 0.91-1.04, p = 0.413). None of the interventions was associated with overall anaemia nor moderate-to-severe anaemia. CONCLUSION There was strong evidence that utilization of malaria diagnosis at the community level was highly protective against malaria infection. No protective effect was seen for community utilization of ACTs or LLINs. No association was established between any of the interventions and overall anaemia or moderate-to-severe anaemia. This lack of effectiveness could be due to the low utilization of interventions or the low level of malaria transmission in the study area. Identification and response to barriers of access and low utilization of malaria interventions are crucial. It is crucial to ensure that every suspected malaria case is tested in a timely way, notably in low transmission settings.
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Affiliation(s)
- Khalid Abdelmutalab Elmardi
- grid.414827.cHealth Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan ,grid.5012.60000 0001 0481 6099Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
| | - Ishag Adam
- grid.412602.30000 0000 9421 8094Department of Obstetrics and Gynecology, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | - Elfatih Mohamed Malik
- grid.9763.b0000 0001 0674 6207Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Hmooda Toto Kafy
- grid.414827.cDirectorate General of Primary Health Care, Federal Ministry of Health, Khartoum, Sudan
| | - Mogahid Sheikheldien Abdin
- grid.414827.cHealth Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan
| | - Immo Kleinschmidt
- grid.8991.90000 0004 0425 469XMRC International Statistics and Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK ,grid.11951.3d0000 0004 1937 1135Faculty of Health Sciences, School of Pathology, Wits Research Institute for Malaria, University of the Witwatersrand, Johannesburg, South Africa ,Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Stef Kremers
- grid.5012.60000 0001 0481 6099Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
| | - Jessica Sophia Gubbels
- grid.5012.60000 0001 0481 6099Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
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Byrne I, Cramer E, Nelli L, Rerolle F, Wu L, Patterson C, Rosado J, Dumont E, Tetteh KKA, Dantzer E, Hongvanthong B, Fornace KM, Stresman G, Lover A, Bennett A, Drakeley C. Characterizing the spatial distribution of multiple malaria diagnostic endpoints in a low-transmission setting in Lao PDR. Front Med (Lausanne) 2022; 9:929366. [PMID: 36059850 PMCID: PMC9433740 DOI: 10.3389/fmed.2022.929366] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/22/2022] [Indexed: 11/21/2022] Open
Abstract
The epidemiology of malaria changes as prevalence falls in low-transmission settings, with remaining infections becoming more difficult to detect and diagnose. At this stage active surveillance is critical to detect residual hotspots of transmission. However, diagnostic tools used in active surveillance generally only detect concurrent infections, and surveys may benefit from sensitive tools such as serological assays. Serology can be used to interrogate and characterize individuals' previous exposure to malaria over longer durations, providing information essential to the detection of remaining foci of infection. We ran blood samples collected from a 2016 population-based survey in the low-transmission setting of northern Lao PDR on a multiplexed bead assay to characterize historic and recent exposures to Plasmodium falciparum and vivax. Using geostatistical methods and remote-sensing data we assessed the environmental and spatial associations with exposure, and created predictive maps of exposure within the study sites. We additionally linked the active surveillance PCR and serology data with passively collected surveillance data from health facility records. We aimed to highlight the added information which can be gained from serology as a tool in active surveillance surveys in low-transmission settings, and to identify priority areas for national surveillance programmes where malaria risk is higher. We also discuss the issues faced when linking malaria data from multiple sources using multiple diagnostic endpoints.
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Affiliation(s)
- Isabel Byrne
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- *Correspondence: Isabel Byrne
| | - Estee Cramer
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Luca Nelli
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Francois Rerolle
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, CA, United States
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States
| | - Lindsey Wu
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Catriona Patterson
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jason Rosado
- Unit of Malaria: Parasites and Hosts, Institut Pasteur, Paris, France
- Infectious Diseases Epidemiology and Analytics G5 Unit, Institut Pasteur, Paris, France
| | - Elin Dumont
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kevin K. A. Tetteh
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Emily Dantzer
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, CA, United States
| | - Bouasy Hongvanthong
- Center for Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Laos
| | - Kimberley M. Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Gillian Stresman
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andrew Lover
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Adam Bennett
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, CA, United States
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Sudathip P, Naowarat S, Kitchakarn S, Gopinath D, Bisanzio D, Pinyajeerapat N, Sintasath D, Shah JA. Assessing Thailand's 1-3-7 surveillance strategy in accelerating malaria elimination. Malar J 2022; 21:222. [PMID: 35850687 PMCID: PMC9294779 DOI: 10.1186/s12936-022-04229-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 06/21/2022] [Indexed: 12/19/2022] Open
Abstract
Background Thailand’s strong malaria elimination programme relies on effective implementation of its 1-3-7 surveillance strategy, which was endorsed and implemented nationwide in 2016. For each confirmed malaria patient, the Ministry of Public Health’s Division of Vector Borne Diseases (DVBD) ensures completion of case notification within 1 day, case investigation within 3 days, and foci investigation within 7 days. To date, there has not been a comprehensive assessment of the performance and achievements of the 1-3-7 surveillance strategy although such results could help Thailand’s future malaria elimination strategic planning. Methods This study examined adherence to the 1-3-7 protocols, tracked progress against set targets, and examined geographic variations in implementation of the 1-3-7 strategy in the programme’s initial 5 years. An auto-regressive integrated moving average (ARIMA) time series analysis with seasonal decomposition assessed the plausible implementation effect of the 1-3-7 strategy on malaria incidence in the programme’s initial 5 years. The quantitative analysis included all confirmed malaria cases from public health and non-governmental community facilities from October 2014 to September 2021 (fiscal year [FY] 2015 to FY 2021) (n = 77,405). The spatial analysis included active foci with known geocoordinates that reported more than five cases from FY 2018 to FY 2021. Results From FY 2017 to FY 2021, on-time case notification improved from 24.4% to 89.3%, case investigations from 58.0% to 96.5%, and foci investigations from 37.9% to 87.2%. Adherence to timeliness protocols did not show statistically significant variation by area risk classification. However, adherence to 1-3-7 protocols showed a marked spatial heterogeneity among active foci, and the ARIMA model showed a statistically significant acceleration in the reduction of malaria incidence. The 1-3-7 strategy national indicators and targets in Thailand have shown progressive success, and most targets were achieved for FY 2021. Conclusion The results of Thailand’s 1-3-7 surveillance strategy are associated with a decreased incidence in the period following the adoption of the strategy although there is notable geographic variation. The DVBD will continue to implement and adapt the 1-3-7 strategy to accelerate progress toward malaria elimination. This assessment may be useful for domestic strategic planning and to other countries considering more intensive case and foci investigation and response strategies.
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Affiliation(s)
- Prayuth Sudathip
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Sathapana Naowarat
- Inform Asia: USAID's Health Research Program, RTI International, Bangkok, Thailand
| | - Suravadee Kitchakarn
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | | | - Donal Bisanzio
- Inform Asia: USAID's Health Research Program, RTI International, Bangkok, 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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Yukich JO, Lindblade K, Kolaczinski J. Receptivity to malaria: meaning and measurement. Malar J 2022; 21:145. [PMID: 35527264 PMCID: PMC9080212 DOI: 10.1186/s12936-022-04155-0] [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: 05/12/2021] [Accepted: 04/07/2022] [Indexed: 01/13/2023] Open
Abstract
"Receptivity" to malaria is a construct developed during the Global Malaria Eradication Programme (GMEP) era. It has been defined in varied ways and no consistent, quantitative definition has emerged over the intervening decades. Despite the lack of consistency in defining this construct, the idea that some areas are more likely to sustain malaria transmission than others has remained important in decision-making in malaria control, planning for malaria elimination and guiding activities during the prevention of re-establishment (POR) period. This manuscript examines current advances in methods of measurement. In the context of a decades long decline in global malaria transmission and an increasing number of countries seeking to eliminate malaria, understanding and measuring malaria receptivity has acquired new relevance.
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Affiliation(s)
- Joshua O. Yukich
- grid.265219.b0000 0001 2217 8588Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA USA
| | - Kim Lindblade
- grid.3575.40000000121633745Global Malaria Programme, World Health Organization, Geneva, CH USA
| | - Jan Kolaczinski
- grid.3575.40000000121633745Global Malaria Programme, World Health Organization, Geneva, CH USA
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10
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Distinct kinetics of antibodies to 111 Plasmodium falciparum proteins identifies markers of recent malaria exposure. Nat Commun 2022; 13:331. [PMID: 35039519 PMCID: PMC8764098 DOI: 10.1038/s41467-021-27863-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 12/15/2021] [Indexed: 11/09/2022] Open
Abstract
Strengthening malaria surveillance is a key intervention needed to reduce the global disease burden. Reliable serological markers of recent malaria exposure could improve current surveillance methods by allowing for accurate estimates of infection incidence from limited data. We studied the IgG antibody response to 111 Plasmodium falciparum proteins in 65 adult travellers followed longitudinally after a natural malaria infection in complete absence of re-exposure. We identified a combination of five serological markers that detect exposure within the previous three months with >80% sensitivity and specificity. Using mathematical modelling, we examined the antibody kinetics and determined that responses informative of recent exposure display several distinct characteristics: rapid initial boosting and decay, less inter-individual variation in response kinetics, and minimal persistence over time. Such serological exposure markers could be incorporated into routine malaria surveillance to guide efforts for malaria control and elimination. Serological markers of recent Plasmodium falciparum infection could be useful to estimate incidence. Here, the authors identify a combination of five serological markers to detect exposure to infection within the previous three months with >80% sensitivity and specificity.
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11
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Gore-Langton GR, Cano J, Simpson H, Tatem A, Tejedor-Garavito N, Wigley A, Carioli A, Gething P, Weiss DJ, Chandramohan D, Walker PGT, Cairns ME, Chico RM. Global estimates of pregnancies at risk of Plasmodium falciparum and Plasmodium vivax infection in 2020 and changes in risk patterns since 2000. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0001061. [PMID: 36962612 PMCID: PMC10022219 DOI: 10.1371/journal.pgph.0001061] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/03/2022] [Indexed: 11/11/2022]
Abstract
BACKGROUND Women are at risk of severe adverse pregnancy outcomes attributable to Plasmodium spp. infection in malaria-endemic areas. Malaria control efforts since 2000 have aimed to reduce this burden of disease. METHODS We used data from the Malaria Atlas Project and WorldPop to calculate global pregnancies at-risk of Plasmodium spp. infection. We categorised pregnancies as occurring in areas of stable and unstable P. falciparum and P. vivax transmission. We further stratified stable endemicity as hypo-endemic, meso-endemic, hyper-endemic, or holo-endemic, and estimated pregnancies at risk in 2000, 2005, 2010, 2015, 2017, and 2020. FINDINGS In 2020, globally 120.4M pregnancies were at risk of P. falciparum, two-thirds (81.0M, 67.3%) were in areas of stable transmission; 85 2M pregnancies were at risk of P. vivax, 93.9% (80.0M) were in areas of stable transmission. An estimated 64.6M pregnancies were in areas with both P. falciparum and P. vivax transmission. The number of pregnancies at risk of each of P. falciparum and P. vivax worldwide decreased between 2000 and 2020, with the exception of sub-Saharan Africa, where the total number of pregnancies at risk of P. falciparum increased from 37 3M in 2000 to 52 4M in 2020. INTERPRETATION Historic investments in malaria control have reduced the number of women at risk of malaria in pregnancy in all endemic regions except sub-Saharan Africa. Population growth in Africa has outpaced reductions in malaria prevalence. Interventions that reduce the risk of malaria in pregnancy are needed as much today as ever.
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Affiliation(s)
- Georgia R Gore-Langton
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jorge Cano
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Expanded Special Project for Elimination of Neglected Tropical Diseases, WHO Regional Office for Africa, Brazzaville, Democratic Republic of the Congo
| | - Hope Simpson
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Andrew Tatem
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Natalia Tejedor-Garavito
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Adelle Wigley
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Alessandra Carioli
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Peter Gething
- Malaria Atlas Project, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Daniel J Weiss
- Malaria Atlas Project, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Daniel Chandramohan
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Patrick G T Walker
- Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom
| | - Matthew E Cairns
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - R Matthew Chico
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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12
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Nalugwa A, Tukahebwa EM, Olsen A, Nuwaha F. Regression of Schistosoma mansoni associated morbidity among Ugandan preschool children following praziquantel treatment: A randomised trial. PLoS One 2021; 16:e0259338. [PMID: 34780499 PMCID: PMC8592404 DOI: 10.1371/journal.pone.0259338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/06/2021] [Indexed: 11/18/2022] Open
Abstract
Preschool children suffer from morbidity attributable to Schistosoma mansoni. We compared a single and double dose of praziquantel treatment on the regression of S. mansoni associated morbidity in children less than six years in Uganda. We measured the sizes of spleen and liver as well as liver fibrosis before treatment and 8 months after treatment among children who either received one dose (n = 201) or two doses (n = 184) of praziquantel (standard oral dose of 40 mg/kg body weight). Heamoglobin measurements were also taken. Overall, liver enlargement reduced from 52.2% (95% CI (Confidence interval) 45.1, 59.3) to 17.9% (95% CI 12.9, 23.9) with a single dose and from 48.4 (95% CI 40.9, 55.8) to 17.9% (95% CI 12.7, 24.3) with a double dose and there was no significant difference between the changes in proportion of children with enlarged liver between the two treatment groups. The proportion of children with enlarged spleen was not significantly reduced in the group treated with either one or two doses, 47.8% (95% CI 41.7, 54.9) to 45.3% (95% CI 38.3, 52.4) and 48.4% (95% CI 40.9,55.8) to 40.8% 95% CI 33.6, 48.2), respectively. Liver fibrosis detected among children getting single dose (n = 9) or double doses (n = 13) resolved after treatment with praziquantel. The number of children with low heamoglobin significantly reduced from 51.2% (95% CI 44.1, 58.3) to 0.5% (0.2, 0.8) and 61.4% (95% CI 53.9,68.5) to 1.1% (95% CI 0.1, 3.9) after single and double dose treatment, respectively. These results suggest that there is no evidence of a difference in effect between one dose of praziquantel and two doses in reversing morbidity attributable to S. mansoni among children less than six years of age.
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Affiliation(s)
- Allen Nalugwa
- Child Health and Development Centre, College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Annette Olsen
- Parasitology and Aquatic Diseases, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Fred Nuwaha
- Disease Control and Prevention, Makerere University, Kampala, Uganda
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13
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Fatunla OAT, Olatunya OS, Ogundare EO, Fatunla TO, Oluwayemi IO, Oluwadiya KS, Oyelami OA. Towards malaria control in Nigeria: implications of the malaria parasite rate and spleen rate among children living in a rural community in southwest Nigeria. Trans R Soc Trop Med Hyg 2021; 115:1330-1338. [PMID: 34460920 DOI: 10.1093/trstmh/trab131] [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: 04/20/2021] [Revised: 07/14/2021] [Accepted: 08/11/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The World Health Organization prioritizes malaria surveillance for accurate tracking of progress of intervention programmes. The malaria parasite rate (PR) and spleen rate (SR) are economical surveillance tools. There has been a global decline in the burden of malaria over the last decade, but most African countries, like Nigeria, have a slow rate of decline. There is a need for adequate malaria surveillance to guide malaria control strategies and policymaking. METHODS A community-based cross-sectional study was conducted among 363 children ages 1-15 y in rural southwest Nigeria. The participants' PR was determined by microscopy and the SR was determined by palpation and ultrasonography. The associations between PR and SR and other covariates were assessed. RESULTS The PR was 26.7% and the SR was 12.9%. There was no significant association between PR or SR across age groups, but low social class was significantly associated with PR (55 [33.5%], p=0.004) and SR (29 [17.3%], p=0.013). The odds of having splenomegaly doubled with malaria parasitaemia (odds ratio 2.03 [95% confidence interval 1.06 to 3.88). CONCLUSIONS The PR and SR suggest that the study area is meso-endemic. The PR in the study area was almost equal across age groups; our findings suggest there may be a need for policy review to plan malaria intervention programmes and include older children, not just children <5 y of age. Routine malaria surveillance using simple tools such as the PR and SR are necessary for reviewing malaria control programmes in the community.
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Affiliation(s)
- Odunayo A T Fatunla
- Department of Paediatrics, Ekiti State University Teaching Hospital, Ado-Ekiti, Ekiti State, Nigeria
| | - Oladele S Olatunya
- Department of Paediatrics, Ekiti State University Teaching Hospital, Ado-Ekiti, Ekiti State, Nigeria.,Department of Paediatrics, College of Medicine, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria
| | - Ezra O Ogundare
- Department of Paediatrics, Ekiti State University Teaching Hospital, Ado-Ekiti, Ekiti State, Nigeria.,Department of Paediatrics, College of Medicine, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria
| | - Tolulope O Fatunla
- Department of Family Medicine, Ekiti State University Teaching Hospital, Ado-Ekiti, Ekiti State, Nigeria
| | - Isaac O Oluwayemi
- Department of Paediatrics, Ekiti State University Teaching Hospital, Ado-Ekiti, Ekiti State, Nigeria.,Department of Paediatrics, College of Medicine, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria
| | - Kehinde S Oluwadiya
- Department of Surgery, College of Medicine, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria
| | - Oyeku A Oyelami
- Department of Paediatrics, Ekiti State University Teaching Hospital, Ado-Ekiti, Ekiti State, Nigeria.,Department of Paediatrics, College of Medicine, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria
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14
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Kaaya RD, Kajeguka DC, Matowo JJ, Ndaro AJ, Mosha FW, Chilongola JO, Kavishe RA. Predictive markers of transmission in areas with different malaria endemicity in north-eastern Tanzania based on seroprevalence of antibodies against Plasmodium falciparum. BMC Res Notes 2021; 14:404. [PMID: 34717734 PMCID: PMC8557592 DOI: 10.1186/s13104-021-05818-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/22/2021] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE A community-based cross-sectional study was done to assess Plasmodium falciparum exposure in areas with different malaria endemicity in north-eastern Tanzania using serological markers; PfAMA-1 and PfMSP-119. RESULTS Bondo had a higher seroprevalence 36.6% (188) for PfAMA-1 as compared to Hai 13.8% (33), χ2 = 34.66, p < 0.01. Likewise, Bondo had a higher seroprevalence 201(36.6%) for PfMSP-1 as compared to Hai 41 (17.2%), χ2 = 29.62, p < 0.01. Anti-PfAMA-1 titters were higher in malaria positive individuals (n = 47) than in malaria negative individuals (n = 741) (p = 0.07). Anti-PfMSP-1 antibody concentrations were significantly higher in malaria-positive individuals (n = 47) than in malaria-negative individuals (n = 741) (p = 0.003). Antibody response against PfAMA-1 was significantly different between the three age groups; < 5 years, 5 to 15 years and > 15 years in both sites of Bondo and Hai. Likewise, antibody response against PfMSP-119 was significantly different between the three age groups in the two sites (p < 0.001). We also found significant differences in the anti-PfAMA-1and anti-PfMSP-119 antibody concentrations among the three age groups in the two sites (p = 0.004 and 0.005) respectively. Immunological indicators of P. falciparum exposure have proven to be useful in explaining long-term changes in the transmission dynamics, especially in low transmission settings.
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Affiliation(s)
- Robert D Kaaya
- Departmentof Parasitology and Entomology, Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Tanzania. .,Pan-African Malaria Vector Research Consortium, Moshi, Tanzania.
| | - Debora C Kajeguka
- Department of Microbiology, Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Johnson J Matowo
- Departmentof Parasitology and Entomology, Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Tanzania.,Pan-African Malaria Vector Research Consortium, Moshi, Tanzania
| | - Arnold J Ndaro
- Kilimanjaro Christian Medical Centre (KCMC), Moshi, Tanzania
| | - Franklin W Mosha
- Departmentof Parasitology and Entomology, Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Tanzania.,Pan-African Malaria Vector Research Consortium, Moshi, Tanzania
| | - Jaffu O Chilongola
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Reginald A Kavishe
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Tanzania
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15
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Amoah B, McCann RS, Kabaghe AN, Mburu M, Chipeta MG, Moraga P, Gowelo S, Tizifa T, van den Berg H, Mzilahowa T, Takken W, van Vugt M, Phiri KS, Diggle PJ, Terlouw DJ, Giorgi E. Identifying Plasmodium falciparum transmission patterns through parasite prevalence and entomological inoculation rate. eLife 2021; 10:65682. [PMID: 34672946 PMCID: PMC8530514 DOI: 10.7554/elife.65682] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Background Monitoring malaria transmission is a critical component of efforts to achieve targets for elimination and eradication. Two commonly monitored metrics of transmission intensity are parasite prevalence (PR) and the entomological inoculation rate (EIR). Comparing the spatial and temporal variations in the PR and EIR of a given geographical region and modelling the relationship between the two metrics may provide a fuller picture of the malaria epidemiology of the region to inform control activities. Methods Using geostatistical methods, we compare the spatial and temporal patterns of Plasmodium falciparum EIR and PR using data collected over 38 months in a rural area of Malawi. We then quantify the relationship between EIR and PR by using empirical and mechanistic statistical models. Results Hotspots identified through the EIR and PR partly overlapped during high transmission seasons but not during low transmission seasons. The estimated relationship showed a 1-month delayed effect of EIR on PR such that at lower levels of EIR, increases in EIR are associated with rapid rise in PR, whereas at higher levels of EIR, changes in EIR do not translate into notable changes in PR. Conclusions Our study emphasises the need for integrated malaria control strategies that combine vector and human host managements monitored by both entomological and parasitaemia indices. Funding This work was supported by Stichting Dioraphte grant number 13050800.
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Affiliation(s)
- Benjamin Amoah
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - Robert S McCann
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.,Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, United States
| | - Alinune N Kabaghe
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Monicah Mburu
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.,Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Michael G Chipeta
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Malawi-Liverpool Wellcome Trust Research Programme, Blantyre, Malawi.,Big Data Institute, University of Oxford, Oxford, United Kingdom
| | - Paula Moraga
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom.,Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Steven Gowelo
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.,Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Tinashe Tizifa
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Henk van den Berg
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands
| | - Themba Mzilahowa
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands
| | - Michele van Vugt
- Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Kamija S Phiri
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Peter J Diggle
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - Dianne J Terlouw
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Malawi-Liverpool Wellcome Trust Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Emanuele Giorgi
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
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16
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Nyasa RB, Fotabe EL, Ndip RN. Trends in malaria prevalence and risk factors associated with the disease in Nkongho-mbeng; a typical rural setting in the equatorial rainforest of the South West Region of Cameroon. PLoS One 2021; 16:e0251380. [PMID: 34003847 PMCID: PMC8130964 DOI: 10.1371/journal.pone.0251380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 04/23/2021] [Indexed: 11/18/2022] Open
Abstract
Globally, malaria in recent years has witnessed a decline in the number of cases and death, though the most recent world malaria report shows a slight decrease in the number of cases in 2018 compared to 2017 and, increase in 2017 compared to 2016. Africa remains the region with the greatest burden of the disease. Cameroon is among the countries with a very high burden of malaria, with the coastal and forest regions carrying the highest burden of the disease. Nkongho-mbeng is a typical rural setting in the equatorial rain forest region of Cameroon, with no existing knowledge of the epidemiology of malaria in this locality. This study aimed at determining the current status of malaria epidemiology in Nkongho-mbeng. A cross-sectional survey was conducted, during which blood samples were collected from 500 participants and examined by microscopy. Risk factors such as, age, sex, duration of stay in the locality, housing type, environmental sanitation and intervention strategies including use of, LLINs and drugs were investigated. Trends in malaria morbidity were also determined. Of the 500 samples studied, 60 were positive, giving an overall prevalence of 12.0% with the prevalence of asymptomatic infection (10.8%), more than quadruple the prevalence of symptomatic infections (1.2%) and, fever burden not due to malaria was 1.4%. The GMPD was 6,869.17 parasites/μL of blood (95% C.I: 4,977.26/μL– 9,480.19/μL). A LLINs coverage of 84.4% and 77.88% usage was observed. Unexpectedly, the prevalence of malaria was higher among those sleeping under LLINs (12.56%) than those not sleeping under LLINs (8.97%), though the difference was not significant (p = 0.371). Being a male (p = 0.044), being unemployed (p = 0.025) and, living in Mbetta (p = 0.013) or Lekwe (p = 0.022) and the presence bushes around homes (p = 0.002) were significant risk factors associated with malaria infection. Trends in proportion demonstrated that, the prevalence of malaria amongst patients receiving treatment in the health center from 2015 to 2019 decreased significantly (p < 0.001) and linearly from 9.74% to 3.08% respectively. Data generated from this study can be exploited for development of a more effective control measures to curb the spread of malaria within Nkongho-mbeng.
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Affiliation(s)
- Raymond Babila Nyasa
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Faculty of Science, Biotechnology Unit, University of Buea, Buea, South West Region, Cameroon
| | | | - Roland N. Ndip
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Laboratory for Emerging Infectious Diseases, University of Buea, Buea, South West Region, Cameroon
- * E-mail: ,
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17
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Demarta-Gatsi C, Mécheri S. Vector saliva controlled inflammatory response of the host may represent the Achilles heel during pathogen transmission. J Venom Anim Toxins Incl Trop Dis 2021; 27:e20200155. [PMID: 34035796 PMCID: PMC8128132 DOI: 10.1590/1678-9199-jvatitd-2020-0155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Infection with vector-borne pathogens starts with the inoculation of these pathogens during blood feeding. In endemic regions, the population is regularly bitten by naive vectors, implicating a permanent stimulation of the immune system by the vector saliva itself (pre-immune context). Comparatively, the number of bites received by exposed individuals from non-infected vectors is much higher than the bites from infected ones. Therefore, vector saliva and the immunological response in the skin may play an important role, so far underestimated, in the establishment of anti-pathogen immunity in endemic areas. Hence, the parasite biology and the disease pathogenesis in “saliva-primed” and “saliva-unprimed” individuals must be different. This integrated view on how the pathogen evolves within the host together with vector salivary components, which are known to be endowed with a variety of pharmacological and immunological properties, must remain the focus of any investigational study dealing with vector-borne diseases. Considering this three-way partnership, the host skin (immune system), the pathogen, and the vector saliva, the approach that consists in the validation of vector saliva as a source of molecular entities with anti-disease vaccine potential has been recently a subject of active and fruitful investigation. As an example, the vaccination with maxadilan, a potent vasodilator peptide extracted from the saliva of the sand fly Lutzomyia longipalpis, was able to protect against infection with various leishmanial parasites. More interestingly, a universal mosquito saliva vaccine that may potentially protect against a range of mosquito-borne infections including malaria, dengue, Zika, chikungunya and yellow fever. In this review, we highlight the key role played by the immunobiology of vector saliva in shaping the outcome of vector-borne diseases and discuss the value of studying diseases in the light of intimate cross talk among the pathogen, the vector saliva, and the host immune mechanisms.
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Affiliation(s)
- Claudia Demarta-Gatsi
- Institut Pasteur, Unité de Biologie des Interactions Hôte Parasites, Paris, France.,CNRS ERL9195, Paris, France.,INSERM U1201, Paris, France.,Medicines for Malaria Venture (MMV), Geneva, Switzerland.,Institut Pasteur, Unité de Biologie des Interactions Hôte Parasites, Paris, France
| | - Salah Mécheri
- Institut Pasteur, Unité de Biologie des Interactions Hôte Parasites, Paris, France.,CNRS ERL9195, Paris, France.,INSERM U1201, Paris, France
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18
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Unwin HJT, Routledge I, Flaxman S, Rizoiu MA, Lai S, Cohen J, Weiss DJ, Mishra S, Bhatt S. Using Hawkes Processes to model imported and local malaria cases in near-elimination settings. PLoS Comput Biol 2021; 17:e1008830. [PMID: 33793564 PMCID: PMC8043404 DOI: 10.1371/journal.pcbi.1008830] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 04/13/2021] [Accepted: 02/23/2021] [Indexed: 01/29/2023] Open
Abstract
Developing new methods for modelling infectious diseases outbreaks is important for monitoring transmission and developing policy. In this paper we propose using semi-mechanistic Hawkes Processes for modelling malaria transmission in near-elimination settings. Hawkes Processes are well founded mathematical methods that enable us to combine the benefits of both statistical and mechanistic models to recreate and forecast disease transmission beyond just malaria outbreak scenarios. These methods have been successfully used in numerous applications such as social media and earthquake modelling, but are not yet widespread in epidemiology. By using domain-specific knowledge, we can both recreate transmission curves for malaria in China and Eswatini and disentangle the proportion of cases which are imported from those that are community based.
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Affiliation(s)
- H. Juliette T. Unwin
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute for Disease and Emergency Analytics, Imperial College, London, United Kingdom
| | - Isobel Routledge
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute for Disease and Emergency Analytics, Imperial College, London, United Kingdom
- Department of Medicine, University of California, San Francisco, California, United States of America
| | - Seth Flaxman
- Department of Mathematics, Imperial College, London, United Kingdom
| | | | - Shengjie Lai
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Justin Cohen
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Daniel J. Weiss
- Malaria Atlas Project, Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Telethon Kids Institute, Perth Children’s Hospital, Nedlands, Western Australia, Australia
- Curtin University, Bentley, Western Australia, Australia
| | - Swapnil Mishra
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute for Disease and Emergency Analytics, Imperial College, London, United Kingdom
| | - Samir Bhatt
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute for Disease and Emergency Analytics, Imperial College, London, United Kingdom
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19
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Eba K, Habtewold T, Yewhalaw D, Christophides GK, Duchateau L. Anopheles arabiensis hotspots along intermittent rivers drive malaria dynamics in semi-arid areas of Central Ethiopia. Malar J 2021; 20:154. [PMID: 33731115 PMCID: PMC7971958 DOI: 10.1186/s12936-021-03697-z] [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: 12/22/2020] [Accepted: 03/11/2021] [Indexed: 11/30/2022] Open
Abstract
Background Understanding malaria vector’s population dynamics and their spatial distribution is important to define when and where the largest infection risks occur and implement appropriate control strategies. In this study, the seasonal spatio-temporal dynamics of the malaria vector population and transmission intensity along intermittent rivers in a semi-arid area of central Ethiopia were investigated. Methods Mosquitoes were collected monthly from five clusters, 2 close to a river and 3 away from a river, using pyrethrum spray catches from November 2014 to July 2016. Mosquito abundance was analysed by the mixed Poisson regression model. The human blood index and sporozoite rate was compared between seasons by a logistic regression model. Results A total of 2784 adult female Anopheles gambiae sensu lato (s.l.) were collected during the data collection period. All tested mosquitoes (n = 696) were identified as Anopheles arabiensis by polymerase chain reaction. The average daily household count was significantly higher (P = 0.037) in the clusters close to the river at 5.35 (95% CI 2.41–11.85) compared to the clusters away from the river at 0.033 (95% CI 0.02–0.05). Comparing the effect of vicinity of the river by season, a significant effect of closeness to the river was found during the dry season (P = 0.027) and transition from dry to wet season (P = 0.032). Overall, An. arabiensis had higher bovine blood index (62.8%) as compared to human blood index (23.8%), ovine blood index (9.2%) and canine blood index (0.1%). The overall sporozoite rate was 3.9% and 0% for clusters close to and away from the river, respectively. The overall Plasmodium falciparum and Plasmodium vivax entomologic inoculation rates for An. arabiensis in clusters close to the river were 0.8 and 2.2 infective bites per person/year, respectively. Conclusion Mosquito abundance and malaria transmission intensity in clusters close to the river were higher which could be attributed to the riverine breeding sites. Thus, vector control interventions including targeted larval source management should be implemented to reduce the risk of malaria infection in the area. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03697-z.
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Affiliation(s)
- Kasahun Eba
- Biometrics Research Centre, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.,Department of Environmental Health Science and Technology, Jimma University, P.O. Box 378, Jimma, Ethiopia
| | - Tibebu Habtewold
- Department of Life Sciences, Imperial College London, London, UK
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Jimma University, P.O.Box 378, Jimma, Ethiopia.,Tropical and Infectious Diseases Research Center, Jimma University, P.O.Box 378, Jimma, Ethiopia
| | | | - Luc Duchateau
- Biometrics Research Centre, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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20
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Zheng J, Shi B, Xia S, Yang G, Zhou XN. Spatial patterns of <em>Plasmodium vivax</em> transmission explored by multivariate auto-regressive state-space modelling - A case study in Baoshan Prefecture in southern China. GEOSPATIAL HEALTH 2021; 16. [PMID: 33733649 DOI: 10.4081/gh.2021.879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/21/2020] [Indexed: 06/12/2023]
Abstract
The transition from the control phase to elimination of malaria in China through the national malaria elimination programme has focussed attention on the need for improvement of the surveillance- response systems. It is now understood that routine passive surveillance is inadequate in the parasite elimination phase that requires supplementation by active surveillance in foci where cluster cases have occurred. This study aims to explore the spatial clusters and temporal trends of malaria cases by the multivariate auto-regressive state-space model (MARSS) along the border to Myanmar in southern China. Data for indigenous cases spanning the period from 2007 to 2010 were extracted from the China's Infectious Diseases Information Reporting Management System (IDIRMS). The best MARSS model indicated that malaria transmission in the study area during 36 months could be grouped into three clusters. The estimation of malaria transmission patterns showed a downward trend across all clusters. The proposed methodology used in this study offers a simple and rapid, yet effective way to categorize patterns of foci which provide assistance for active monitoring of malaria in the elimination phase.
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Affiliation(s)
- Jinxin Zheng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
| | - Benyun Shi
- School of Computer Science and Technology, Nanjing Tech University, Nanjing, Jiangsu.
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
| | - Guojing Yang
- Hainan Medical University, Laboratory of Tropical Environment and Health, Haikou, Hainan, China; Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute; University of Basel, Basel.
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
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21
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Digitized smart surveillance and micromanagement using information technology for malaria elimination in Mangaluru, India: an analysis of five-year post-digitization data. Malar J 2021; 20:139. [PMID: 33685454 PMCID: PMC7938374 DOI: 10.1186/s12936-021-03656-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/17/2021] [Indexed: 12/02/2022] Open
Abstract
Background Malaria control system (MCS), an Information technology (IT)-driven surveillance and monitoring intervention is being adopted for elimination of malaria in Mangaluru city, Karnataka, India since October 2015. This has facilitated ‘smart surveillance’ followed by required field response within a timeline. The system facilitated data collection of individual case, data driven mapping and strategies for malaria elimination programme. This paper aims to present the analysis of post-digitization data of 5 years, discuss the current operational functionalities of MCS and its impact on the malaria incidence. Methods IT system developed for robust malaria surveillance and field response is being continued in the sixth year. Protocol for surveillance control was followed as per the national programme guidelines mentioned in an earlier publication. Secondary data from the malaria control system was collated and analysed. Incidence of malaria, active surveillance, malariogenic conditions and its management, malariometric indices, shrinking malaria maps were also analysed. Results Smart surveillance and subsequent response for control was sustained and performance improved in five years with participation of all stakeholders. Overall malaria incidence significantly reduced by 83% at the end of 5 years when compared with year of digitization (DY) (p < 0.001). Early reporting of new cases (within 48 h) was near total followed by complete treatment and vector control. Slide positivity rate (SPR) decreased from 10.36 (DY) to 6.5 (PDY 5). Annual parasite incidence (API) decreased from 16.17 (DY) to 2.64 (PDY 5). There was a negative correlation between contact smears and incidence of malaria. Five-year data analyses indicated declining trends in overall malaria incidence and correlation between closures by 14 days. The best impact on reduction in incidence of malaria was recorded in the pre-monsoon months (~ 85%) compared to lower impact in July–August months (~ 40%). Conclusion MCS helped to micromanage control activities, such as robust reporting, incidence-centric active surveillance, early and complete treatment, documentation of full treatment of each malaria patient, targeted mosquito control measures in houses surrounding reported cases. The learnings and analytical output from the data helped to modify strategies for control of both disease and the vector, heralding the city into the elimination stage.
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22
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Zhou G, Zhong D, Lee MC, Wang X, Atieli HE, Githure JI, Githeko AK, Kazura J, Yan G. Multi-Indicator and Multistep Assessment of Malaria Transmission Risks in Western Kenya. Am J Trop Med Hyg 2021; 104:1359-1370. [PMID: 33556042 DOI: 10.4269/ajtmh.20-1211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/24/2020] [Indexed: 11/07/2022] Open
Abstract
Malaria risk factor assessment is a critical step in determining cost-effective intervention strategies and operational plans in a regional setting. We develop a multi-indicator multistep approach to model the malaria risks at the population level in western Kenya. We used a combination of cross-sectional seasonal malaria infection prevalence, vector density, and cohort surveillance of malaria incidence at the village level to classify villages into malaria risk groups through unsupervised classification. Generalized boosted multinomial logistics regression analysis was performed to determine village-level risk factors using environmental, biological, socioeconomic, and climatic features. Thirty-six villages in western Kenya were first classified into two to five operational groups based on different combinations of malaria risk indicators. Risk assessment indicated that altitude accounted for 45-65% of all importance value relative to all other factors; all other variable importance values were < 6% in all models. After adjusting by altitude, villages were classified into three groups within distinct geographic areas regardless of the combination of risk indicators. Risk analysis based on altitude-adjusted classification indicated that factors related to larval habitat abundance accounted for 63% of all importance value, followed by geographic features related to the ponding effect (17%), vegetation cover or greenness (15%), and the number of bed nets combined with February temperature (5%). These results suggest that altitude is the intrinsic factor in determining malaria transmission risk in western Kenya. Malaria vector larval habitat management, such as habitat reduction and larviciding, may be an important supplement to the current first-line vector control tools in the study area.
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Affiliation(s)
- Guofa Zhou
- 1Program in Public Health, University of California, Irvine, California
| | - Daibin Zhong
- 1Program in Public Health, University of California, Irvine, California
| | - Ming-Chieh Lee
- 1Program in Public Health, University of California, Irvine, California
| | - Xiaoming Wang
- 1Program in Public Health, University of California, Irvine, California
| | - Harrysone E Atieli
- 2School of Public Health and Community Development, Maseno University, Kisumu, Kenya
| | - John I Githure
- 3International Center of Excellence in Malaria Research, Tom Mboya University College, Homabay, Kenya
| | - Andrew K Githeko
- 4Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - James Kazura
- 5Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Guiyun Yan
- 1Program in Public Health, University of California, Irvine, California
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23
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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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24
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Mathematical assessment of the impact of human-antibodies on sporogony during the within-mosquito dynamics of Plasmodium falciparum parasites. J Theor Biol 2020; 515:110562. [PMID: 33359209 DOI: 10.1016/j.jtbi.2020.110562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/25/2020] [Accepted: 12/14/2020] [Indexed: 11/23/2022]
Abstract
We develop and analyze a deterministic ordinary differential equation mathematical model for the within-mosquito dynamics of the Plasmodium falciparum malaria parasite. Our model takes into account the action and effect of blood resident human-antibodies, ingested by the mosquito during a blood meal from humans, in inhibiting gamete fertilization. The model also captures subsequent developmental processes that lead to the different forms of the parasite within the mosquito. Continuous functions are used to model the switching transition from oocyst to sporozoites as well as human antibody density variations within the mosquito gut are proposed and used. In sum, our model integrates the developmental stages of the parasite within the mosquito such as gametogenesis, fertilization and sporogenesis culminating in the formation of sporozoites. Quantitative and qualitative analyses including a sensitivity analysis for influential parameters are performed. We quantify the average sporozoite load produced at the end of the within-mosquito malaria parasite's developmental stages. Our analysis shows that an increase in the efficiency of the ingested human antibodies in inhibiting fertilization within the mosquito's gut results in lowering the density of oocysts and hence sporozoites that are eventually produced by each mosquito vector. So, it is possible to control and limit oocysts development and hence sporozoites development within a mosquito by boosting the efficiency of antibodies as a pathway to the development of transmission-blocking vaccines which could potentially reduce oocysts prevalence among mosquitoes and hence reduce the transmission potential from mosquitoes to human.
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25
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Elmardi KA, Adam I, Malik EM, Ibrahim AA, Elhassan AH, Kafy HT, Nawai LM, Abdin MS, Kremers S. Anaemia prevalence and determinants in under 5 years children: findings of a cross-sectional population-based study in Sudan. BMC Pediatr 2020; 20:538. [PMID: 33250057 PMCID: PMC7702668 DOI: 10.1186/s12887-020-02434-w] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/17/2020] [Indexed: 11/25/2022] Open
Abstract
Background Early childhood is an age at risk of anaemia and its deleterious consequences. In Sudan, there is limited evidence on the prevalence and determinant of anaemia in under-five children. This study was conducted in Sudan to assess the prevalence of anaemia in children and to identify its determinants. Methods We conducted a household survey involving children aged 6 months to 5 years in November 2016. A representative population was sampled across rural, urban and camps settlements across 18 states in Sudan. We used a pre-designed questionnaire data collection. Haemoglobin (Hb) level and malaria infection were checked. In this cross-sectional study, we dichotomized the outcome variable and performed logistic regression analyses. Results A total of 3094 children under 5 years enrolled in the study, 1566 (50.6%) of them were female and 690 (22.3%) of them were under 2 years old. Anaemia prevalence in the whole cohort (6 months - < 5 years) was 49.4% and the mean haemoglobin concentration was 108.1 (standard deviation (SD): 15.4) g/L. The prevalence in younger (6 months - < 2 years) children (61.9%) was higher than in older (2 - < 5 years) children (45.6%) (p < 0.001). Severe anaemia (Hb < 70 g/L) prevalence in the whole population was 1.6%. Age (Odds ratio (OR) 2.25, 95% confidence interval (95%CI) 1.75–2.90, p < 0.001), type of place of residence (OR 0.37, 95%CI 0.18–0.74, p = 0.005), maternal anaemia (OR 1.74, 95%CI 1.39–2.17, p < 0.001), and malaria infection (OR 2.82, 95%CI 1.56–5.11, p < 0.001) were the identified predictors of anaemia in the whole cohort. In younger children, only the economic class was an anaemia predictor, with a lower anaemia risk among the rich wealth class (OR 2.70, 95%CI 1.29–5.62, p = 0.008). However, in older children, three anaemia predictors were identified. These are maternal anaemia (OR 1.79, 95%CI 1.40–2.28, < 0.001), malaria infection (OR 2.77, 95%CI 1.48–5.21, p = 0.002), and type of residency (where camps’ residents were less likely affected with anaemia than rural children (OR 0.38, 95%CI 0.17–0.87, p = 0.022)). Conclusions About half of the under-5 children in Sudan are anaemic, with worse prevalence in younger children. Efforts targeted at improving socio-economic status, decreasing maternal anaemia and childhood malaria infection may mitigate this alarming trend. Supplementary Information The online version contains supplementary material available at 10.1186/s12887-020-02434-w.
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Affiliation(s)
- Khalid Abdelmutalab Elmardi
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan.
| | - Ishag Adam
- Department of Obstetrics and Gynecology, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | | | - Abdalla Ahmed Ibrahim
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | | | - Hmooda Toto Kafy
- Directorate General of Primary Health Care, Federal Ministry of Health, Khartoum, Sudan
| | - Lubna Mohammed Nawai
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | - Mujahid Sheikhedin Abdin
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan
| | - Stef Kremers
- Department of Health Promotion, NUTRIM School of Nutrition and Translational Research in Metabolism, Faculty of Health, Medicine and Life Sciences, Maastricht, The Netherlands
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26
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Bennett A, Porter TR, Mwenda MC, Yukich JO, Finn TP, Lungu C, Silumbe K, Mambwe B, Chishimba S, Mulube C, Bridges DJ, Hamainza B, Slutsker L, Steketee RW, Miller JM, Eisele TP. A Longitudinal Cohort to Monitor Malaria Infection Incidence during Mass Drug Administration in Southern Province, Zambia. Am J Trop Med Hyg 2020; 103:54-65. [PMID: 32618245 PMCID: PMC7416973 DOI: 10.4269/ajtmh.19-0657] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Rigorous evidence of effectiveness is needed to determine where and when to apply mass drug administration (MDA) or focal MDA (fMDA) as part of a malaria elimination strategy. The Zambia National Malaria Elimination Centre recently completed a community-randomized controlled trial in Southern Province to evaluate MDA and fMDA for transmission reduction. To assess the role of MDA and fMDA on infection incidence, we enrolled a longitudinal cohort for an 18-month period of data collection including monthly malaria parasite infection detection based on polymerase chain reaction and compared time to first infection and cumulative infection incidence outcomes across study arms using Cox proportional hazards and negative binomial models. A total of 2,026 individuals from 733 households were enrolled and completed sufficient follow-up for inclusion in analysis. Infection incidence declined dramatically across all study arms during the period of study, and MDA was associated with reduced risk of first infection (hazards ratio: 0.36; 95% CI: 0.16–0.80) and cumulative infection incidence during the first rainy season (first 5 months of follow-up) (incidence rate ratio: 0.34; 95% CI: 0.12–0.95). No significant effect was found for fMDA or for either arm over the full study period. Polymerase chain reaction infection status at baseline was strongly associated with follow-up infection. The short-term effects of MDA suggest it may be an impactful accelerator of transmission reduction in areas with high coverage of case management and vector control and should be considered as part of a malaria elimination strategy.
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Affiliation(s)
- Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California
| | - Travis R Porter
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Mulenga C Mwenda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Joshua O Yukich
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Timothy P Finn
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Chris Lungu
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Kafula Silumbe
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Brenda Mambwe
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Sandra Chishimba
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Conceptor Mulube
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Daniel J Bridges
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Busiku Hamainza
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | | | | | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Thomas P Eisele
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
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27
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Adeniji E, Asante KP, Boahen O, Compaoré G, Coulibaly B, Kaali S, Kabore Y, Lamy M, Lusingu J, Malabeja A, Mens P, Orsini M, Otieno L, Otieno W, Owusu-Agyei S, Oyieko J, Pirçon JY, Praet N, Roman F, Sie A, Sing’oei V, Sirima SB, Sylla K, Tine R, Tiono AB, Tivura M, Usuf E, Wéry S. Estimating Annual Fluctuations in Malaria Transmission Intensity and in the Use of Malaria Control Interventions in Five Sub-Saharan African Countries. Am J Trop Med Hyg 2020; 103:1883-1892. [PMID: 32959764 PMCID: PMC7646796 DOI: 10.4269/ajtmh.19-0795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 08/07/2020] [Indexed: 11/08/2022] Open
Abstract
RTS,S/AS01E malaria vaccine safety, effectiveness, and impact will be assessed in pre- and post-vaccine introduction studies, comparing the occurrence of malaria cases and adverse events in vaccinated versus unvaccinated children. Because those comparisons may be confounded by potential year-to-year fluctuations in malaria transmission intensity and malaria control intervention usage, the latter should be carefully monitored to adequately adjust the analyses. This observational cross-sectional study is assessing Plasmodium falciparum parasite prevalence (PfPR) and malaria control intervention usage over nine annual surveys performed at peak parasite transmission. Plasmodium falciparum parasite prevalence was measured by microscopy and nucleic acid amplification test (quantitative PCR) in parallel in all participants, and defined as the proportion of infected participants among participants tested. Results of surveys 1 (S1) and 2 (S2), conducted in five sub-Saharan African countries, including some participating in the Malaria Vaccine Implementation Programme (MVIP), are reported herein; 4,208 and 4,199 children were, respectively, included in the analyses. Plasmodium falciparum parasite prevalence estimated using microscopy varied between study sites in both surveys, with the lowest prevalence in Senegalese sites and the highest in Burkina Faso. In sites located in the MVIP areas (Kintampo and Kombewa), PfPR in children aged 6 months to 4 years ranged from 24.8% to 27.3%, depending on the study site and the survey. Overall, 89.5% and 86.4% of children used a bednet in S1 and S2, of whom 68.7% and 77.9% used impregnated bednets. No major difference was observed between the two surveys in terms of PfPR or use of malaria control interventions.
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Affiliation(s)
- RTS,S Epidemiology EPI-MAL-005 Study Group The RTS,S Epidemiology EPI-MAL-005 study group is composed of (per alphabetical order):
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
- Centre de Recherche en Santé de Nouna, Nouna, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
- Aixial c/o GSK, Wavre, Belgium
- National Institute for Medical Research (NIMR), Korogwe, Tanzania
- University of Copenhagen, Copenhagen, Denmark
- Parasitology Unit, Department of Medical Microbiology, Academic Medical Center, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- 4Clinics c/o GSK, Wavre, Belgium
- KEMRI - Walter Reed Project, US Army Medical Research Directorate-Kenya, Kombewa, Kenya
- GSK, Wavre, Belgium
- Département de Parasitologie, Centre de Recherche de Keur Socé, Faculté de Médecine, Université Cheikh Anta Diop, Dakar, Senegal
- Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Elisha Adeniji
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
| | - Kwaku Poku Asante
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
| | - Owusu Boahen
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
| | | | | | - Seyram Kaali
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
| | - Youssouf Kabore
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | | | - John Lusingu
- National Institute for Medical Research (NIMR), Korogwe, Tanzania
- University of Copenhagen, Copenhagen, Denmark
| | | | - Petra Mens
- Parasitology Unit, Department of Medical Microbiology, Academic Medical Center, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Lucas Otieno
- KEMRI - Walter Reed Project, US Army Medical Research Directorate-Kenya, Kombewa, Kenya
| | - Walter Otieno
- KEMRI - Walter Reed Project, US Army Medical Research Directorate-Kenya, Kombewa, Kenya
| | - Seth Owusu-Agyei
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
| | - Janet Oyieko
- KEMRI - Walter Reed Project, US Army Medical Research Directorate-Kenya, Kombewa, Kenya
| | | | | | | | - Ali Sie
- Centre de Recherche en Santé de Nouna, Nouna, Burkina Faso
| | - Valentine Sing’oei
- KEMRI - Walter Reed Project, US Army Medical Research Directorate-Kenya, Kombewa, Kenya
| | - Sodiomon B. Sirima
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Khadime Sylla
- Département de Parasitologie, Centre de Recherche de Keur Socé, Faculté de Médecine, Université Cheikh Anta Diop, Dakar, Senegal
| | - Roger Tine
- Département de Parasitologie, Centre de Recherche de Keur Socé, Faculté de Médecine, Université Cheikh Anta Diop, Dakar, Senegal
| | - Alfred B. Tiono
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Mathilda Tivura
- Kintampo Health Research Centre, Ghana Health Service, Kintampo, Ghana
| | - Effua Usuf
- Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
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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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29
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Konan KV, Le TC, Mateescu MA. Antiplasmodial Combined Formulation of Artemisinin with Peschiera fuchsiaefolia Bis-Indole Alkaloids. J Pharm Sci 2020; 110:135-145. [PMID: 32987093 DOI: 10.1016/j.xphs.2020.09.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/19/2020] [Accepted: 09/22/2020] [Indexed: 11/28/2022]
Abstract
Antimalarial agents used as monotherapy are increasingly ineffective due to the emergence of Plasmodium resistant strains. Artemisinin (Arte), extracted from Artemisia annua, presents a good efficiency against the Plasmodium strains and is currently used to treat malaria. To avoid the appearance of new resistant strains to artemisinin, the use of Artemisinin-based Combination Therapy (ACT) with another antimalaria agent was recommended by WHO to provide an effective cure and delayed resistance. Although combined formulations of various drugs with Artemisinin have been developed, their release is immediate, and they require multiple doses with side detrimental effects and effectiveness still desired. To improve its efficiency, controlled release formulations were developed to ensure long-term antiplasmodial activity by associating Artemisinin with a natural antimalarial agent extracted from Peschiera fuchsiaefolia (Pf). The Pf extract (containing mostly low soluble alkaloids) was complexed with carboxymethylcellulose to improve its solubility and stability. Two formulation types are reported. As bilayer tablet dosage form, the kinetic release pattern was an immediate release of Artemisinin, followed by a slow sustained release of Pf for 12 h. As monolithic tablet, the release profile shows a simultaneous sustained release of the two active agents, about of 10 h for Arte and 12 h for Pf.
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Affiliation(s)
- Kouadio Victorien Konan
- Department of Chemistry, Research Chair on Enteric Dysfunctions "Allerdys" and CERMO-FC Center, Université du Québec à Montréal, C.P. 8888, Branch A, Montréal, Québec H3C 3P8, Canada
| | - Tien Canh Le
- Department of Chemistry, Research Chair on Enteric Dysfunctions "Allerdys" and CERMO-FC Center, Université du Québec à Montréal, C.P. 8888, Branch A, Montréal, Québec H3C 3P8, Canada
| | - Mircea Alexandru Mateescu
- Department of Chemistry, Research Chair on Enteric Dysfunctions "Allerdys" and CERMO-FC Center, Université du Québec à Montréal, C.P. 8888, Branch A, Montréal, Québec H3C 3P8, Canada.
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30
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Stresman G, Sepúlveda N, Fornace K, Grignard L, Mwesigwa J, Achan J, Miller J, Bridges DJ, Eisele TP, Mosha J, Lorenzo PJ, Macalinao ML, Espino FE, Tadesse F, Stevenson JC, Quispe AM, Siqueira A, Lacerda M, Yeung S, Sovannaroth S, Pothin E, Gallay J, Hamre KE, Young A, Lemoine JF, Chang MA, Phommasone K, Mayxay M, Landier J, Parker DM, Von Seidlein L, Nosten F, Delmas G, Dondorp A, Cameron E, Battle K, Bousema T, Gething P, D'Alessandro U, Drakeley C. Association between the proportion of Plasmodium falciparum and Plasmodium vivax infections detected by passive surveillance and the magnitude of the asymptomatic reservoir in the community: a pooled analysis of paired health facility and community data. THE LANCET. INFECTIOUS DISEASES 2020; 20:953-963. [PMID: 32277908 PMCID: PMC7391005 DOI: 10.1016/s1473-3099(20)30059-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/23/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Passively collected malaria case data are the foundation for public health decision making. However, because of population-level immunity, infections might not always be sufficiently symptomatic to prompt individuals to seek care. Understanding the proportion of all Plasmodium spp infections expected to be detected by the health system becomes particularly paramount in elimination settings. The aim of this study was to determine the association between the proportion of infections detected and transmission intensity for Plasmodium falciparum and Plasmodium vivax in several global endemic settings. METHODS The proportion of infections detected in routine malaria data, P(Detect), was derived from paired household cross-sectional survey and routinely collected malaria data within health facilities. P(Detect) was estimated using a Bayesian model in 431 clusters spanning the Americas, Africa, and Asia. The association between P(Detect) and malaria prevalence was assessed using log-linear regression models. Changes in P(Detect) over time were evaluated using data from 13 timepoints over 2 years from The Gambia. FINDINGS The median estimated P(Detect) across all clusters was 12·5% (IQR 5·3-25·0) for P falciparum and 10·1% (5·0-18·3) for P vivax and decreased as the estimated log-PCR community prevalence increased (adjusted odds ratio [OR] for P falciparum 0·63, 95% CI 0·57-0·69; adjusted OR for P vivax 0·52, 0·47-0·57). Factors associated with increasing P(Detect) included smaller catchment population size, high transmission season, improved care-seeking behaviour by infected individuals, and recent increases (within the previous year) in transmission intensity. INTERPRETATION The proportion of all infections detected within health systems increases once transmission intensity is sufficiently low. The likely explanation for P falciparum is that reduced exposure to infection leads to lower levels of protective immunity in the population, increasing the likelihood that infected individuals will become symptomatic and seek care. These factors might also be true for P vivax but a better understanding of the transmission biology is needed to attribute likely reasons for the observed trend. In low transmission and pre-elimination settings, enhancing access to care and improvements in care-seeking behaviour of infected individuals will lead to an increased proportion of infections detected in the community and might contribute to accelerating the interruption of transmission. FUNDING Wellcome Trust.
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Affiliation(s)
- Gillian Stresman
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK.
| | - Nuno Sepúlveda
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK; Centre of Statistics and Its Applications, University of Lisbon, Lisbon, Portugal
| | - Kimberly Fornace
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Lynn Grignard
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Julia Mwesigwa
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia; Department of Global Health, University of Antwerp, Antwerp, Belgium
| | - Jane Achan
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - John Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds Lusaka, Zambia
| | - Daniel J Bridges
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds Lusaka, Zambia
| | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Jacklin Mosha
- National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Pauline Joy Lorenzo
- Department of Parasitology, Research Institute for Tropical Medicine, Research Drive, Alabang, Muntinlupa, Metro Manila, Philippines
| | - Maria Lourdes Macalinao
- Department of Parasitology, Research Institute for Tropical Medicine, Research Drive, Alabang, Muntinlupa, Metro Manila, Philippines
| | - Fe Esperanza Espino
- Department of Parasitology, Research Institute for Tropical Medicine, Research Drive, Alabang, Muntinlupa, Metro Manila, Philippines
| | - Fitsum Tadesse
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Jennifer C Stevenson
- Macha Research Trust, Choma District, Zambia; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - André Siqueira
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil; Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil; Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Marcus Lacerda
- Fundacao de Medicine Tropical Dr. Heitor Viera Dourado, Manaus, Brazil; Institutos Nacionais de Ciencia e Technologia (INCT), Instituto Elimina, Manaus, Brazil
| | - Shunmay Yeung
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Emilie Pothin
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland; Clinton Health Access Initiative, Boston, MA, USA
| | - Joanna Gallay
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Karen E Hamre
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, USA; CDC Foundation, Atlanta, GA, USA
| | - Alyssa Young
- Clinton Health Access Initiative, Port-au-Prince, Haiti
| | - Jean Frantz Lemoine
- Programme National de Contrôle de la Malaria, Ministère de la Santé Publique et de la Population (MSPP), Port-au-Prince, Haiti
| | - Michelle A Chang
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, USA
| | - Koukeo Phommasone
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Institute of Research and Education Development, University of Health Sciences, Vientiane, Laos
| | - Jordi Landier
- Aix Marseille Univ, IRD, INSERM, SESSTIM, Marseille, France
| | - Daniel M Parker
- Department of Population Health and Disease Prevention and Department of Epidemiology, University of California, Irvine, CA, USA
| | - Lorenz Von Seidlein
- Oxford Tropical Medicine Research Unit, Mahidol University Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Francois Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Gilles Delmas
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Arjen Dondorp
- Oxford Tropical Medicine Research Unit, Mahidol University Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ewan Cameron
- Telethon Kids Institute, Perth Children's Hospital, Nedlands, WA, Australia; Curtin University, Bentley, WA, Australia
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Peter Gething
- Telethon Kids Institute, Perth Children's Hospital, Nedlands, WA, Australia; Curtin University, Bentley, WA, Australia
| | - Umberto D'Alessandro
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK; Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
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Elmardi KA, Adam I, Malik EM, Abdelrahim TA, Elhag MS, Ibrahim AA, Babiker MA, Elhassan AH, Kafy HT, Elshafie AT, Nawai LM, Abdin MS, Kremers S. Prevalence and determinants of anaemia in women of reproductive age in Sudan: analysis of a cross-sectional household survey. BMC Public Health 2020; 20:1125. [PMID: 32680488 PMCID: PMC7367227 DOI: 10.1186/s12889-020-09252-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Anaemia is a global health problem and women in reproductive age (WRA) are amongst the most affected population. Its consequences include low birth weight and maternal mortality. This study aimed to assess the prevalence of anaemia and to identify its determinants in Sudanese women in reproductive age. METHODS A population-based cross-sectional study was conducted in Sudan in 2016. A multi-stage stratified cluster sampling design was executed with consideration of rural population, urban population, and internally displaced persons/refugees camps residents. All women in reproductive age (15-49 years), classified by pregnancy status, in the targeted households were surveyed and personal characteristic data were collected. Their haemoglobin level and malaria infection (using rapid diagnostic test, RDT) were assessed. The World Health Organization (WHO) haemoglobin level cut-off for defining anaemia and severe anaemia in pregnant and non-pregnant women was used. Logistic regression analyses were performed. RESULTS A total of 4271 women (WRA) of which 421 (9.9%) pregnant women (PW) were included in the study. The overall anaemia prevalence in WRA was 35.6%. It was 36.0 and 35.5% in PW and non-pregnant women (NPW), respectively. The average haemoglobin level was found to be 113.9 g/L (SD 16.3) and 123.2 g/L (SD 15.7) for PW and NPW respectively. Severe anaemia prevalence was 1.2% in each group. In the logistic regression model, anaemia was associated with malaria infection in PW (aOR 4.100, 95%CI 1.523-11.039, p = 0.003), NPW (aOR 2.776, 95%CI 1.889-4.080, p < 0.001), and WRA (aOR 2.885, 95%CI 2.021-4.119, p < 0.001). Other identified determinants of anaemia in NPW was living in camps (aOR 1.499, 95%CI 1.115-2.017, p = 0.007) and in WRA was being in the poorest economic class (aOR 1.436, 95%CI 1.065-1.936, p = 0.018). CONCLUSIONS Anaemia is a public health problem in Sudan. The study supported the association between malaria infection and anaemia, but not with low and moderate malaria transmission areas. Resources need to be allocated for all anaemic populations with special attention for the populations in most need and interventions need to be implemented based on local variations. Malaria control interventions, specifically case management, may have a major impact in reducing anaemia prevalence in low to moderate malaria transmission areas.
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Affiliation(s)
- Khalid Abdelmutalab Elmardi
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan.
| | - Ishag Adam
- Department of Obstetrics and Gynecology, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | | | - Tarig Abdalla Abdelrahim
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | - Mousab Siddig Elhag
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | - Abdalla Ahmed Ibrahim
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | - Mariam Adam Babiker
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | | | - Hmooda Toto Kafy
- Directorate General of Primary Health Care, Federal Ministry of Health, Khartoum, Sudan
| | - Azza Tageldin Elshafie
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | - Lubna Mohammed Nawai
- Communicable and Non-Communicable Diseases Control Directorate, Federal Ministry of Health, Khartoum, Sudan
| | - Mujahid Sheikhedin Abdin
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan
| | - Stef Kremers
- Department of Health Promotion, NUTRIM School of Nutrition and Translational Research in Metabolism, Faculty of Health, Medicine and Life Sciences, Maastricht, The Netherlands
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Beavogui AH, Delamou A, Camara BS, Camara D, Kourouma K, Camara R, Sagara I, Lama EK, Djimde A. Prevalence of malaria and factors associated with infection in children aged 6 months to 9 years in Guinea: Results from a national cross-sectional study. Parasite Epidemiol Control 2020; 11:e00162. [PMID: 32715113 PMCID: PMC7378695 DOI: 10.1016/j.parepi.2020.e00162] [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: 01/03/2020] [Revised: 04/23/2020] [Accepted: 06/18/2020] [Indexed: 01/03/2023] Open
Abstract
Worldwide, a child dies every two minutes due to malaria with Africa bearing about 90% of all malaria deaths particularly among children. This study aimed to describe malaria prevalence and its associated factors among children aged 6 months to 9 years in Guinea. We conducted a cross-sectional household survey between 02 and 29 August 2014 in children aged 6 months to 9 years in the four natural regions of the country. A five-level cluster sampling using the national database from the national institute of statistics was used to select study participants. A total of 1984 children aged 6 months to 9 years were enrolled. The mean age was 50 months (SD, 27). The rapid diagnostic test showed a high malaria prevalence (44%) countrywide along with regional variation ranging from 38% to 61%. A multivariate analysis showed that living in Forest Guinea (AOR: 2.48; 95% CI: 1.78–3.46), in rural areas (AOR: 1.91; 95% IC: 1.45–2.5) and having a splenomegaly (AOR: 2.66; 95% CI: 1.75–4.04) were highly associated with malaria. This study shows that malaria is still prevalent in Guinea among children aged 6 months to 9 years of age.
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Affiliation(s)
- Abdoul Habib Beavogui
- Centre National de formation et de recherche en santé rurale (CNFRSR) de Maferinyah, Forécariah, Guinea
- Department of Bioclinical and Fundamental Sciences, Gamal Abdel Nasser University, Conakry, Guinea
- Centre d'Excellence Africain pour la Prevention des Maladies Transmissibles (CEA-PCMT), Gamal Abdel Nasser University, Conakry, Guinea
- Corresponding author at: Centre National de formation et de recherche en santé rurale (CNFRSR) de Maferinyah, Forécariah, PoBox: 2649, Conakry, Guinea.
| | - Alexandre Delamou
- Centre National de formation et de recherche en santé rurale (CNFRSR) de Maferinyah, Forécariah, Guinea
- Centre d'Excellence Africain pour la Prevention des Maladies Transmissibles (CEA-PCMT), Gamal Abdel Nasser University, Conakry, Guinea
- Department of Public Health, Gamal Abdel Nasser University, Conakry, Guinea
| | - Bienvenu Salim Camara
- Centre National de formation et de recherche en santé rurale (CNFRSR) de Maferinyah, Forécariah, Guinea
| | - Daouda Camara
- Centre National de formation et de recherche en santé rurale (CNFRSR) de Maferinyah, Forécariah, Guinea
| | - Karifa Kourouma
- Centre National de formation et de recherche en santé rurale (CNFRSR) de Maferinyah, Forécariah, Guinea
| | - Robert Camara
- National Institute of Public Health, Conakry, Guinea
| | - Issaka Sagara
- Malaria Research and Training Center, Faculty of Pharmacy, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Abdoulaye Djimde
- Malaria Research and Training Center, Faculty of Pharmacy, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
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Druetz T, Stresman G, Ashton RA, van den Hoogen LL, Joseph V, Fayette C, Monestime F, Hamre KE, Chang MA, Lemoine JF, Drakeley C, Eisele TP. Programmatic options for monitoring malaria in elimination settings: easy access group surveys to investigate Plasmodium falciparum epidemiology in two regions with differing endemicity in Haiti. BMC Med 2020; 18:141. [PMID: 32571323 PMCID: PMC7310408 DOI: 10.1186/s12916-020-01611-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/29/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND As in most eliminating countries, malaria transmission is highly focal in Haiti. More granular information, including identifying asymptomatic infections, is needed to inform programmatic efforts, monitor intervention effectiveness, and identify remaining foci. Easy access group (EAG) surveys can supplement routine surveillance with more granular information on malaria in a programmatically tractable way. This study assessed how and which type of venue for EAG surveys can improve understanding malaria epidemiology in two regions with different transmission profiles. METHODS EAG surveys were conducted within the departments of Artibonite and Grand'Anse (Haiti), in regions with different levels of transmission intensity. Surveys were conducted in three venue types: primary schools, health facilities, and churches. The sampling approach varied accordingly. Individuals present at the venues at the time of the survey were eligible whether they presented malaria symptoms or not. The participants completed a questionnaire and were tested for Plasmodium falciparum by a highly sensitive rapid diagnostic test (hsRDT). Factors associated with hsRDT positivity were assessed by negative binomial random-effects regression models. RESULTS Overall, 11,029 individuals were sampled across 39 venues in Artibonite and 41 in Grand'Anse. The targeted sample size per venue type (2100 in Artibonite and 2500 in Grand'Anse) was reached except for the churches in Artibonite, where some attendees left the venue before they could be approached or enrolled. Refusal rate and drop-out rate were < 1%. In total, 50/6003 (0.8%) and 355/5026 (7.1%) sampled individuals were hsRDT positive in Artibonite and Grand'Anse, respectively. Over half of all infections in both regions were identified at health facilities. Being male and having a current or reported fever in the previous 2 weeks were consistently identified with increased odds of being hsRDT positive. CONCLUSIONS Surveys in churches were problematic because of logistical and recruitment issues. However, EAG surveys in health facilities and primary schools provided granular information about malaria burden within two departments in Haiti. The EAG surveys were able to identify residual foci of transmission that were missed by recent national surveys. Non-care seeking and/or asymptomatic malaria infections can be identified in this alternative surveillance tool, facilitating data-driven decision-making for improved targeting of interventions.
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Affiliation(s)
- Thomas Druetz
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA. .,Department of Social and Preventive Medicine, School of Public Health, University of Montreal, Montreal, QC, Canada.
| | - Gillian Stresman
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Ruth A Ashton
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Lotus L van den Hoogen
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA.,Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Vena Joseph
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA.,Malaria Zero Alliance, CDC Foundation, Port-Au-Prince, Haiti
| | | | | | - Karen E Hamre
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.,CDC Foundation, Atlanta, GA, USA
| | - Michelle A Chang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jean F Lemoine
- Programme National de Contrôle de la Malaria, Ministère de la Santé Publique et de la Population (MSPP), Port-au-Prince, Haiti
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
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Thawer SG, Chacky F, Runge M, Reaves E, Mandike R, Lazaro S, Mkude S, Rumisha SF, Kumalija C, Lengeler C, Mohamed A, Pothin E, Snow RW, Molteni F. Sub-national stratification of malaria risk in mainland Tanzania: a simplified assembly of survey and routine data. Malar J 2020; 19:177. [PMID: 32384923 PMCID: PMC7206674 DOI: 10.1186/s12936-020-03250-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/29/2020] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Recent malaria control efforts in mainland Tanzania have led to progressive changes in the prevalence of malaria infection in children, from 18.1% (2008) to 7.3% (2017). As the landscape of malaria transmission changes, a sub-national stratification becomes crucial for optimized cost-effective implementation of interventions. This paper describes the processes, data and outputs of the approach used to produce a simplified, pragmatic malaria risk stratification of 184 councils in mainland Tanzania. METHODS Assemblies of annual parasite incidence and fever test positivity rate for the period 2016-2017 as well as confirmed malaria incidence and malaria positivity in pregnant women for the period 2015-2017 were obtained from routine district health information software. In addition, parasite prevalence in school children (PfPR5to16) were obtained from the two latest biennial council representative school malaria parasitaemia surveys, 2014-2015 and 2017. The PfPR5to16 served as a guide to set appropriate cut-offs for the other indicators. For each indicator, the maximum value from the past 3 years was used to allocate councils to one of four risk groups: very low (< 1%PfPR5to16), low (1- < 5%PfPR5to16), moderate (5- < 30%PfPR5to16) and high (≥ 30%PfPR5to16). Scores were assigned to each risk group per indicator per council and the total score was used to determine the overall risk strata of all councils. RESULTS Out of 184 councils, 28 were in the very low stratum (12% of the population), 34 in the low stratum (28% of population), 49 in the moderate stratum (23% of population) and 73 in the high stratum (37% of population). Geographically, most of the councils in the low and very low strata were situated in the central corridor running from the north-east to south-west parts of the country, whilst the areas in the moderate to high strata were situated in the north-west and south-east regions. CONCLUSION A stratification approach based on multiple routine and survey malaria information was developed. This pragmatic approach can be rapidly reproduced without the use of sophisticated statistical methods, hence, lies within the scope of national malaria programmes across Africa.
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Affiliation(s)
- Sumaiyya G Thawer
- Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Frank Chacky
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Manuela Runge
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Erik Reaves
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, and US President's Malaria Initiative, Dar es Salaam, United Republic of Tanzania
| | - Renata Mandike
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Samwel Lazaro
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Sigsbert Mkude
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Susan F Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Claud Kumalija
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ally Mohamed
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania
- National Malaria Control Programme, Dodoma, Tanzania
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Clinton Health Access Initiative, New York, USA
| | - 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
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Basel, Switzerland.
- National Malaria Control Programme, Dodoma, Tanzania.
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Kamau A, Mogeni P, Okiro EA, Snow RW, Bejon P. A systematic review of changing malaria disease burden in sub-Saharan Africa since 2000: comparing model predictions and empirical observations. BMC Med 2020; 18:94. [PMID: 32345315 PMCID: PMC7189714 DOI: 10.1186/s12916-020-01559-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/16/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The most widely used measures of declining burden of malaria across sub-Saharan Africa are predictions from geospatial models. These models apply spatiotemporal autocorrelations and covariates to parasite prevalence data and then use a function of parasite prevalence to predict clinical malaria incidence. We attempted to assess whether trends in malaria cases, based on local surveillance, were similar to those captured by Malaria Atlas Project (MAP) incidence surfaces. METHODS We undertook a systematic review (PROSPERO International Prospective Register of Systematic Reviews; ID = CRD42019116834) to identify empirical data on clinical malaria in Africa since 2000, where reports covered at least 5 continuous years. The trends in empirical data were then compared with the trends of time-space matched clinical malaria incidence from MAP using the Spearman rank correlation. The correlations (rho) between changes in empirically observed and modelled estimates of clinical malaria were displayed by forest plots and examined by meta-regression. RESULTS Sixty-seven articles met our inclusion criteria representing 124 sites from 24 African countries. The single most important factor explaining the correlation between empirical observations and modelled predictions was the slope of empirically observed data over time (rho = - 0.989; 95% CI - 0.998, - 0.939; p < 0.001), i.e. steeper declines were associated with a stronger correlation between empirical observations and modelled predictions. Factors such as quality of study, reported measure of malaria and endemicity were only slightly predictive of such correlations. CONCLUSIONS In many locations, both local surveillance data and modelled estimates showed declines in malaria burden and hence similar trends. However, there was a weak association between individual surveillance datasets and the modelled predictions where stalling in progress or resurgence of malaria burden was empirically observed. Surveillance data were patchy, indicating a need for improved surveillance to strengthen both empiric reporting and modelled predictions.
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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, UK.
| | | | | | - 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, UK
| | - 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, UK
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Nakakana UN, Mohammed IA, Onankpa BO, Jega RM, Jiya NM. A validation of the Malaria Atlas Project maps and development of a new map of malaria transmission in Sokoto, Nigeria: a cross-sectional study using geographic information systems. Malar J 2020; 19:149. [PMID: 32268904 PMCID: PMC7140379 DOI: 10.1186/s12936-020-03214-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 03/30/2020] [Indexed: 11/29/2022] Open
Abstract
Background Malaria remains a major cause of morbidity and mortality among children in Africa. There is inadequate information regarding malaria transmission-intensity in some of the worst-affected parts of sub-Saharan Africa (SSA). The Malaria Atlas Project (MAP) was developed in 2006, to project estimates of malaria transmission intensity where this data is not available, based on the vector behaviour for malaria. Data from malariometric studies globally were obtained and modelled to provide prevalence estimates. The sensitivity of these maps, however, reduces with unavailability of data. This necessitates a validation of these maps locally, and investigation into alternative methods of predicting prevalence to guide malaria control interventions and improve their efficiency and effectiveness. This study was conducted to compare the true estimates in Sokoto, Nigeria, with the MAP projections for north-western Nigeria, and it proposes an alternative way of mapping malaria intensity in Nigeria and beyond. Methods A malariometric survey was conducted including children aged 2–10 years in communities in Wamakko Local Government Area (LGA) of Sokoto State, Nigeria. Children had blood examinations for the presence of malaria parasitaemia and a physical examination for the signs of clinical malaria. All the sites from which children were included in the study were geo-located using a hand-held Global Positioning System (GPS) device and compared this to MAP maps of the same area. A mapping software was also used to generate a malaria prevalence map of the study area, considering the average flight distances of the vector. Results The prevalence among children 2 to 10 years was found to be 34.8% which was within the 30–40% projected prevalence for the study area by MAPs. However, it was much lower than the projection during the dry season (20.2%) and higher than the projected estimate during the rainy season (49.3%). There was monoparasitaemia of Plasmodium falciparum throughout the study area, although the study was not specifically designed to identify other species. The prevalence of parasitaemia and splenomegaly were similar when overall and when considered by age of the participants. The study also generated a map of malaria transmission, which mapped out areas where the prevalence was confirmed or likely to be to be within the range of 30–40%, based on the sites which constituted the study area for this study. Conclusion The study concludes that the prevalence of malaria and its transmission intensity in Sokoto are similar to Malaria Atlas Project predictions for the area and that, for malaria control planning purposes, the projections may be utilized, with more efforts at validation of the MAPs in other locations and terrains. Also, the vector behaviour may be used to map transmission of malaria and other vector-transmitted diseases, where this information is lacking.
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Affiliation(s)
- Usman Nasir Nakakana
- Department of Paediatrics, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria. .,Medical Research Council, The Gambia at London School of Tropical Medicine and Hygiene, Fajara, The Gambia.
| | - Ismaila Ahmed Mohammed
- Department of Community Medicine, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
| | - B O Onankpa
- Department of Paediatrics, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
| | - Ridwan M Jega
- Department of Paediatrics, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
| | - Nma Muhammad Jiya
- Department of Paediatrics, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
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Modeling an association between malaria cases and climate variables for Keonjhar district of Odisha, India: a Bayesian approach. J Parasit Dis 2020; 44:319-331. [PMID: 32508406 DOI: 10.1007/s12639-020-01210-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/03/2020] [Indexed: 01/05/2023] Open
Abstract
Malaria, a vector-borne disease, is a significant public health problem in Keonjhar district of Odisha (the malaria capital of India). Prediction of malaria, in advance, is an urgent need for reporting rolling cases of disease throughout the year. The climate condition do play an essential role in the transmission of malaria. Hence, the current study aims to develop and assess a simple and straightforward statistical model of an association between malaria cases and climate variates. It may help in accurate predictions of malaria cases given future climate conditions. For this purpose, a Bayesian Gaussian time series regression model is adopted to fit a relationship of the square root of malaria cases with climate variables with practical lag effects. The model fitting is assessed using a Bayesian version of R2 (RsqB). Whereas, the predictive ability of the model is measured using a cross-validation technique. As a result, it is found that the square root of malaria cases with lag 1, maximum temperature, and relative humidity with lag 3 and 0 (respectively), are significantly positively associated with the square root of the cases. However, the minimum and average temperatures with lag 2, respectively, are observed as negatively (significantly) related. The considered model accounts for moderate amount of variation in the square root of malaria cases as received through the results for RsqB. We also present Absolute Percentage Errors (APE) for each of the 12 months (January-December) for a better understanding of the seasonal pattern of the predicted (square root of) malaria cases. Most of the APEs obtained corresponding to test data points is reasonably low. Further, the analysis shows that the considered model closely predicted the actual (square root of) malaria cases, except for some peak cases during the particular months. The output of the current research might help the district to develop and strengthen early warning prediction of malaria cases for proper mitigation, eradication, and prevention in similar settings.
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Ratti V, Wallace DI. A Malaria Transmission Model Predicts Holoendemic, Hyperendemic, and Hypoendemic Transmission Patterns Under Varied Seasonal Vector Dynamics. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:568-584. [PMID: 31770428 DOI: 10.1093/jme/tjz186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Indexed: 06/10/2023]
Abstract
A model is developed of malaria (Plasmodium falciparum) transmission in vector (Anopheles gambiae) and human populations that include the capacity for both clinical and parasite suppressing immunity. This model is coupled with a population model for Anopheles gambiae that varies seasonal with temperature and larval habitat availability. At steady state, the model clearly distinguishes uns hypoendemic transmission patterns from stable hyperendemic and holoendemic patterns of transmission. The model further distinguishes hyperendemic from holoendemic disease based on seasonality of infection. For hyperendemic and holoendemic transmission, the model produces the relationship between entomological inoculation rate and disease prevalence observed in the field. It further produces expected rates of immunity and prevalence across all three endemic patterns. The model does not produce mesoendemic transmission patterns at steady state for any parameter choices, leading to the conclusion that mesoendemic patterns occur during transient states or as a result of factors not included in this study. The model shows that coupling the effect of varying larval habitat availability with the effects of clinical and parasite-suppressing immunity is enough to produce known patterns of malaria transmission.
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Runge M, Snow RW, Molteni F, Thawer S, Mohamed A, Mandike R, Giorgi E, Macharia PM, Smith TA, Lengeler C, Pothin E. Simulating the council-specific impact of anti-malaria interventions: A tool to support malaria strategic planning in Tanzania. PLoS One 2020; 15:e0228469. [PMID: 32074112 PMCID: PMC7029840 DOI: 10.1371/journal.pone.0228469] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/16/2020] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION The decision-making process for malaria control and elimination strategies has become more challenging. Interventions need to be targeted at council level to allow for changing malaria epidemiology and an increase in the number of possible interventions. Models of malaria dynamics can support this process by simulating potential impacts of multiple interventions in different settings and determining appropriate packages of interventions for meeting specific expected targets. METHODS The OpenMalaria model of malaria dynamics was calibrated for all 184 councils in mainland Tanzania using data from malaria indicator surveys, school parasitaemia surveys, entomological surveillance, and vector control deployment data. The simulations were run for different transmission intensities per region and five interventions, currently or potentially included in the National Malaria Strategic Plan, individually and in combination. The simulated prevalences were fitted to council specific prevalences derived from geostatistical models to obtain council specific predictions of the prevalence and number of cases between 2017 and 2020. The predictions were used to evaluate in silico the feasibility of the national target of reaching a prevalence of below 1% by 2020, and to suggest alternative intervention stratifications for the country. RESULTS The historical prevalence trend was fitted for each council with an agreement of 87% in 2016 (95%CI: 0.84-0.90) and an agreement of 90% for the historical trend (2003-2016) (95%CI: 0.87-0.93) The current national malaria strategy was expected to reduce the malaria prevalence between 2016 and 2020 on average by 23.8% (95% CI: 19.7%-27.9%) if current case management levels were maintained, and by 52.1% (95% CI: 48.8%-55.3%) if the case management were improved. Insecticide treated nets and case management were the most cost-effective interventions, expected to reduce the prevalence by 25.0% (95% CI: 19.7%-30.2) and to avert 37 million cases between 2017 and 2020. Mass drug administration was included in most councils in the stratification selected for meeting the national target at minimal costs, expected to reduce the prevalence by 77.5% (95%CI: 70.5%-84.5%) and to avert 102 million cases, with almost twice higher costs than those of the current national strategy. In summary, the model suggested that current interventions are not sufficient to reach the national aim of a prevalence of less than 1% by 2020 and a revised strategic plan needs to consider additional, more effective interventions, especially in high transmission areas and that the targets need to be revisited. CONCLUSION The methodology reported here is based on intensive interactions with the NMCP and provides a helpful tool for assessing the feasibility of country specific targets and for determining which intervention stratifications at sub-national level will have most impact. This country-led application could support strategic planning of malaria control in many other malaria endemic countries.
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Affiliation(s)
- Manuela Runge
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Robert W. Snow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, England, United Kingodm
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Sumaiyya Thawer
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Ally Mohamed
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Renata Mandike
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Emanuele Giorgi
- CHICAS, Lancaster Medical School, Lancaster University, Lancaster, England, United Kingodm
| | - Peter M. Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Thomas A. Smith
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
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Rosas-Aguirre A, Patra KP, Calderón M, Torres K, Gamboa D, Arocutipa E, Málaga E, Garro K, Fernández C, Trompeter G, Alnasser Y, Llanos-Cuentas A, Gilman RH, Vinetz JM. Anti-MSP-10 IgG indicates recent exposure to Plasmodium vivax infection in the Peruvian Amazon. JCI Insight 2020; 5:130769. [PMID: 31770108 DOI: 10.1172/jci.insight.130769] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 11/25/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUNDSerological tools for the accurate detection of recent malaria exposure are needed to guide and monitor malaria control efforts. IgG responses against Plasmodium vivax and P. falciparum merozoite surface protein-10 (MSP10) were measured as a potential way to identify recent malaria exposure in the Peruvian Amazon.METHODSA field-based study included 470 participants in a longitudinal cohort who completed a comprehensive evaluation: light microscopy and PCR on enrollment, at least 1 monthly follow-up by light microscopy, a second PCR, and serum and dried blood spots for serological analysis at the end of the follow-up. IgG titers against novel mammalian cell-produced recombinant PvMSP10 and PfMSP10 were determined by ELISA.RESULTSDuring the follow-up period, 205 participants were infected, including 171 with P. vivax, 26 with P. falciparum, 6 with infections by both species but at different times, and 2 with mixed infections. Exposure to P. vivax was more accurately identified when serological responses to PvMSP10 were obtained from serum (sensitivity, 58.1%; specificity, 81.8%; AUC: 0.76) than from dried blood spots (sensitivity, 35.2; specificity, 83.5%; AUC: 0.64) (PAUC < 0.001). Sensitivity was highest (serum, 82.9%; dried blood spot, 45.7%) with confirmed P. vivax infections occurring 7-30 days before sample collection; sensitivity decreased significantly in relation to time since last documented infection. PvMSP10 serological data did not show evidence of interspecies cross-reactivity. Anti-PfMSP10 responses poorly discriminated between P. falciparum-exposed and nonexposed individuals (AUC = 0.59; P > 0.05).CONCLUSIONAnti-PvMSP10 IgG indicates recent exposure to P. vivax at the population level in the Amazon region. Serum, not dried blood spots, should be used for such serological tests.FUNDINGCooperative agreement U19AI089681 from the United States Public Health Service, NIH/National Institute of Allergy and Infectious Diseases, as the Amazonian International Center of Excellence in Malaria Research.
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Affiliation(s)
- Angel Rosas-Aguirre
- Fund for Scientific Research FNRS, Brussels, Belgium.,Research Institute of Health and Society, Université catholique de Louvain, Brussels, Belgium.,Instituto de Medicina, Tropical "Alexander von Humboldt," Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Kailash P Patra
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, La Jolla, California, USA
| | - Maritza Calderón
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, and
| | - Katherine Torres
- Instituto de Medicina, Tropical "Alexander von Humboldt," Universidad Peruana Cayetano Heredia, Lima, Peru.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Dionicia Gamboa
- Instituto de Medicina, Tropical "Alexander von Humboldt," Universidad Peruana Cayetano Heredia, Lima, Peru.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, and.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Edith Arocutipa
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, and.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Edith Málaga
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, and.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Katherine Garro
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Carlos Fernández
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Grace Trompeter
- Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yossef Alnasser
- Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina, Tropical "Alexander von Humboldt," Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Robert H Gilman
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, and.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru.,Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, La Jolla, California, USA.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, and.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
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Bridges DJ, Chishimba S, Mwenda M, Winters AM, Slawsky E, Mambwe B, Mulube C, Searle KM, Hakalima A, Mwenechanya R, Larsen DA. The use of spatial and genetic tools to assess Plasmodium falciparum transmission in Lusaka, Zambia between 2011 and 2015. Malar J 2020; 19:20. [PMID: 31941493 PMCID: PMC6964105 DOI: 10.1186/s12936-020-3101-7] [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: 08/07/2019] [Accepted: 01/07/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Zambia has set itself the ambitious target of eliminating malaria by 2021. To continue tracking transmission to zero, new interventions, tools and approaches are required. METHODS Urban reactive case detection (RCD) was performed in Lusaka city from 2011 to 2015 to better understand the location and drivers of malaria transmission. Briefly, index cases were followed to their home and all consenting individuals living in the index house and nine proximal houses were tested with a malaria rapid diagnostic test and treated if positive. A brief survey was performed and for certain responses, a dried blood spot sample collected for genetic analysis. Aggregate health facility data, individual RCD response data and genetic results were analysed spatially and against environmental correlates. RESULTS Total number of malaria cases remained relatively constant, while the average age of incident cases and the proportion of incident cases reporting recent travel both increased. The estimated R0 in Lusaka was < 1 throughout the study period. RCD responses performed within 250 m of uninhabited/vacant land were associated with a higher probability of identifying additional infections. CONCLUSIONS Evidence suggests that the majority of malaria infections are imported from outside Lusaka. However there remains some level of local transmission occurring on the periphery of urban settlements, namely in the wet season. Unfortunately, due to the higher-than-expected complexity of infections and the small number of samples tested, genetic analysis was unable to identify any meaningful trends in the data.
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Affiliation(s)
- Daniel J Bridges
- PATH MACEPA, National Malaria Elimination Centre, Gt East Rd, Lusaka, Zambia. .,Akros, 45A Roan Road, Lusaka, Zambia.
| | - Sandra Chishimba
- PATH MACEPA, National Malaria Elimination Centre, Gt East Rd, Lusaka, Zambia.,Akros, 45A Roan Road, Lusaka, Zambia
| | - Mulenga Mwenda
- PATH MACEPA, National Malaria Elimination Centre, Gt East Rd, Lusaka, Zambia.,Akros, 45A Roan Road, Lusaka, Zambia
| | - Anna M Winters
- Akros, 45A Roan Road, Lusaka, Zambia.,School of Public and Community Health Sciences, University of Montana, Missoula, MT, USA
| | - Erik Slawsky
- Department of Public Health, Syracuse University, Syracuse, NY, USA
| | - Brenda Mambwe
- PATH MACEPA, National Malaria Elimination Centre, Gt East Rd, Lusaka, Zambia
| | - Conceptor Mulube
- PATH MACEPA, National Malaria Elimination Centre, Gt East Rd, Lusaka, Zambia
| | - Kelly M Searle
- School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Aves Hakalima
- Lusaka District Health Management Team, Ministry of Health, Lusaka, Zambia
| | - Roy Mwenechanya
- Akros, 45A Roan Road, Lusaka, Zambia.,Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - David A Larsen
- Akros, 45A Roan Road, Lusaka, Zambia.,Department of Public Health, Syracuse University, Syracuse, NY, USA
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Meredith HR, Furuya-Kanamori L, Yakob L. Optimising systemic insecticide use to improve malaria control. BMJ Glob Health 2019; 4:e001776. [PMID: 31798988 PMCID: PMC6861066 DOI: 10.1136/bmjgh-2019-001776] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 09/26/2019] [Accepted: 10/12/2019] [Indexed: 01/08/2023] Open
Abstract
Background Long-lasting insecticidal nets and indoor residual sprays have significantly reduced the burden of malaria. However, several hurdles remain before elimination can be achieved: mosquito vectors have developed resistance to public health insecticides, including pyrethroids, and have altered their biting behaviour to avoid these indoor control tools. Systemic insecticides, drugs applied directly to blood hosts to kill mosquitoes that take a blood meal, offer a promising vector control option. To date, most studies focus on repurposing ivermectin, a drug used extensively to treat river blindness. There is concern that overdependence on a single drug will inevitably repeat past experiences with the rapid spread of pyrethroid resistance in malaria vectors. Diversifying the arsenal of systemic insecticides used for mass drug administration would improve this strategy’s sustainability. Methods Here, a review was conducted to identify systemic insecticide candidates and consolidate their pharmacokinetic/pharmacodynamic properties. The impact of alternative integrated vector control options and different dosing regimens on malaria transmission reduction are illustrated through mathematical model simulation. Results The review identified drugs from four classes commonly used in livestock and companion animals: avermectins, milbemycins, isoxazolines and spinosyns. Simulations predicted that isoxazolines and spinosyns are promising candidates for mass drug administration, as they were predicted to need less frequent application than avermectins and milbemycins to maintain mosquitocidal blood concentrations. Conclusions These findings will provide a guide for investigating and applying different systemic insecticides to achieve more effective and sustainable control of malaria transmission.
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Affiliation(s)
- Hannah R Meredith
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Luis Furuya-Kanamori
- Research School of Population Health, College of Health and Medicine, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Laith Yakob
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Hare DJ, Braat S, Cardoso BR, Morgan C, Szymlek-Gay EA, Biggs BA. Health outcomes of iron supplementation and/or food fortification in iron-replete children aged 4-24 months: protocol for a systematic review and meta-analysis. Syst Rev 2019; 8:253. [PMID: 31676010 PMCID: PMC6824107 DOI: 10.1186/s13643-019-1185-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 10/05/2019] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Direct supplementation or food fortification with iron are two public health initiatives intended to reduce the prevalence of iron deficiency (ID) and iron deficiency anaemia (IDA) in 4-24-month-old infants. In most high-income countries where IDA prevalence is < 15%, the recommended daily intake levels of iron from supplements and/or consumption of fortified food products are at odds with World Health Organisation (WHO) guidelines that recommend shorter-term (3 months/year) supplementation only in populations with IDA prevalence > 40%. Emerging concerns about delayed neurological effects of early-life iron overexposure have raised questions as to whether recommended guidelines in high-income countries are unnecessarily excessive. This systematic review will gather evidence from supplementation/fortification trials, comparing health outcomes in studies where iron-replete children did or did not receive additional dietary iron; and determine if replete children at study outset were not receiving additional iron show changes in haematological indices of ID/IDA over the trial duration. METHODS We will perform a systematic review of the literature, including all studies of iron supplementation and/or fortification, including study arms with confirmed iron-replete infants at the commencement of the trial. This includes both dietary iron intervention or placebo/average dietary intakes. One reviewer will conduct searches in electronic databases of published and ongoing trials (Medline, Web of Science, Scopus, CENTRAL, EBSCO [e.g. CINAHL Complete, Food Science and Technology Abstracts], Embase, ClinicalTrials.gov, ClinicalTrialsRegister.eu and who.it/trialsearch), digital theses and dissertations (WorldCat, Networked Digital Library of Theses and Dissertations, DART-Europe E-theses Portal, Australasian Digital Theses Program, Theses Canada Portal and ProQuest). For eligible studies, one reviewer will use a data extraction form, and a second reviewing entered data for accuracy. Both reviewers will independently perform quality assessments before qualitative and, if appropriate, quantitative synthesis as a meta-analysis. We will resolve any discrepancies through discussion or consult a third author to resolve discrepancies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement will be used as the basis for reporting. DISCUSSION Recommended iron supplementation and food fortification practices in high-income countries have been criticised for being both excessive and based on outdated or underpowered studies. This systematic review will build a case for revisiting iron intake guidelines for infants through the design of new trials where health effects of additional iron intake in iron-replete infants are the primary outcome. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42018093744.
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Affiliation(s)
- Dominic J. Hare
- The Peter Doherty Institute for Infection and Immunity at The University of Melbourne, 792 Elizabeth Street, Melbourne, VIC 3000 Australia
- Department of Medicine at the Royal Melbourne Hospital and The University of Melbourne, 300 Grattan Street, Parkville, VIC 3052 Australia
- Melbourne Dementia Research Centre at The Florey Institute of Neuroscience and Mental Health and The University of Melbourne, 30 Royal Parade, Parkville, VIC 3052 Australia
| | - Sabine Braat
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Bárbara R. Cardoso
- Melbourne Dementia Research Centre at The Florey Institute of Neuroscience and Mental Health and The University of Melbourne, 30 Royal Parade, Parkville, VIC 3052 Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Locked Bag 20000, Geelong, VIC 3220 Australia
| | - Christopher Morgan
- Burnet Institute, 85 Commercial Road, Melbourne, VIC 3004 Australia
- Melbourne School of Population and Global Health, The University of Melbourne, 235 Bouverie Street, Carlton, VIC 3053 Australia
- School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road, Melbourne, VIC 3004 Australia
| | - Ewa A. Szymlek-Gay
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Locked Bag 20000, Geelong, VIC 3220 Australia
| | - Beverley-Ann Biggs
- The Peter Doherty Institute for Infection and Immunity at The University of Melbourne, 792 Elizabeth Street, Melbourne, VIC 3000 Australia
- Department of Medicine at the Royal Melbourne Hospital and The University of Melbourne, 300 Grattan Street, Parkville, VIC 3052 Australia
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, 300 Grattan Street, Parkville, VIC 3052 Australia
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44
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Sutanto I, Kosasih A, Elyazar IRF, Simanjuntak DR, Larasati TA, Dahlan MS, Wahid I, Mueller I, Koepfli C, Kusriastuti R, Surya A, Laihad FJ, Hawley WA, Collins FH, Baird JK, Lobo NF. Negligible Impact of Mass Screening and Treatment on Mesoendemic Malaria Transmission at West Timor in Eastern Indonesia: A Cluster-Randomized Trial. Clin Infect Dis 2019; 67:1364-1372. [PMID: 29579195 PMCID: PMC6186863 DOI: 10.1093/cid/ciy231] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 03/21/2018] [Indexed: 01/09/2023] Open
Abstract
Background Mass screening and treatment (MST) aims to reduce malaria risk in communities by identifying and treating infected persons without regard to illness. Methods A cluster-randomized trial evaluated malaria incidence with and without MST. Clusters were randomized to 3, 2, or no MST interventions: MST3, 6 clusters (156 households/670 individuals); MST2, 5 clusters (89 households/423 individuals); and MST0, 5 clusters (174 households/777 individuals). All clusters completed the study with 14 residents withdrawing. In a cohort of 324 schoolchildren (MST3, n = 124; MST2, n = 57; MST0, n = 143) negative by microscopy at enrollment, we evaluated the incidence density of malaria during 3 months of MST and 3 months following. The MST intervention involved community-wide expert malaria microscopic screening and standard therapy with dihydroartemisinin-piperaquine and primaquine for glucose-6 phosphate dehydrogenase–normal subjects. All blood examinations included polymerase chain reaction assays, which did not guide on-site treatment. Results The risk ratios for incidence density of microscopically patent malaria in MST3 or MST2 relative to that in MST0 clusters were 1.00 (95% confidence interval [CI], .53–1.91) and 1.22 (95% CI, .42–3.55), respectively. Similar results were obtained with molecular analysis and species-specific (P. falciparum and P. vivax) infections. Microscopically subpatent, untreated infections accounted for 72% of those infected. Conclusions Two or 3 rounds of MST within 3 months did not impact the force of anopheline mosquito-borne infection in these communities. The high rate of untreated microscopically subpatent infections likely explains the observed poor impact. Clinical Trials Registration NCT01878357.
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Affiliation(s)
- Inge Sutanto
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | - Ayleen Kosasih
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | | | - Deddy R Simanjuntak
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | - Tri A Larasati
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | | | - Isra Wahid
- Department of Parasitology, Faculty of Medicine, University of Hasanudin, Makasar, Indonesia
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Rita Kusriastuti
- Communicable Disease Control, Ministry of Health, Jakarta, Indonesia
| | - Asik Surya
- Communicable Disease Control, Ministry of Health, Jakarta, Indonesia
| | | | | | - Frank H Collins
- Eck Institute for Global Health, University of Notre Dame, Indiana
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Indonesia.,Center for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Indiana
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Benedetti G, White RA, Pasquale HA, Stassijns J, van den Boogaard W, Owiti P, Van den Bergh R. Identifying exceptional malaria occurrences in the absence of historical data in South Sudan: a method validation. Public Health Action 2019; 9:90-95. [PMID: 31803579 DOI: 10.5588/pha.19.0002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/10/2019] [Indexed: 11/10/2022] Open
Abstract
Background Detecting unusual malaria events that may require an operational intervention is challenging, especially in endemic contexts with continuous transmission such as South Sudan. Médecins Sans Frontières (MSF) utilises the classic average plus standard deviation (AV+SD) method for malaria surveillance. This and other available approaches, however, rely on antecedent data, which are often missing. Objective To investigate whether a method using linear regression (LR) over only 8 weeks of retrospective data could be an alternative to AV+SD. Design In the absence of complete historical malaria data from South Sudan, data from weekly influenza reports from 19 Norwegian counties (2006-2015) were used as a testing data set to compare the performance of the LR and the AV+SD methods. The moving epidemic method was used as the gold standard. Subsequently, the LR method was applied in a case study on malaria occurrence in MSF facilities in South Sudan (2010-2016) to identify malaria events that required a MSF response. Results For the Norwegian influenza data, LR and AV+SD methods did not perform differently (P > 0.05). For the South Sudanese malaria data, the LR method identified historical periods when an operational response was mounted. Conclusion The LR method seems a plausible alternative to the AV+SD method in situations where retrospective data are missing.
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Affiliation(s)
- G Benedetti
- Operational Research Unit, Medical Department, Médecins Sans Frontières Operational Centre Brussels, Brussels, Belgium
| | - R A White
- Department of Infectious Disease Epidemiology and Modelling, Norwegian Institute of Public Health, Oslo, Norway
| | - H Akello Pasquale
- National Malaria Control Programme, National Ministry of Health, Juba, Republic of South Sudan
| | - J Stassijns
- Medical Department, Médecins Sans Frontières Operational Centre Brussels, Brussels, Belgium
| | - W van den Boogaard
- Operational Research Unit, Medical Department, Médecins Sans Frontières Operational Centre Brussels, Brussels, Belgium
| | - P Owiti
- Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
| | - R Van den Bergh
- Operational Research Unit, Medical Department, Médecins Sans Frontières Operational Centre Brussels, Brussels, Belgium
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46
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Greenhouse B, Smith DL, Rodríguez-Barraquer I, Mueller I, Drakeley CJ. Taking Sharper Pictures of Malaria with CAMERAs: Combined Antibodies to Measure Exposure Recency Assays. Am J Trop Med Hyg 2019; 99:1120-1127. [PMID: 30298804 PMCID: PMC6221205 DOI: 10.4269/ajtmh.18-0303] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antibodies directed against malaria parasites are easy and inexpensive to measure but remain an underused surveillance tool because of a lack of consensus on what to measure and how to interpret results. High-throughput screening of antibodies from well-characterized cohorts offers a means to substantially improve existing assays by rationally choosing the most informative sets of responses and analytical methods. Recent data suggest that high-resolution information on malaria exposure can be obtained from a small number of samples by measuring a handful of properly chosen antibody responses. In this review, we discuss how standardized multi-antibody assays can be developed and efficiently integrated into existing surveillance activities, with potential to greatly augment the breadth and quality of information available to direct and monitor malaria control and elimination efforts.
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Affiliation(s)
- Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, San Francisco, California.,Chan Zuckerberg Biohub, San Francisco, California
| | - David L Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | | | - Ivo Mueller
- Institute Pasteur, Paris, France.,Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Chris J Drakeley
- London School of Hygiene & Tropical Medicine, London, United Kingdom
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Mayor A, Menéndez C, Walker PGT. Targeting Pregnant Women for Malaria Surveillance. Trends Parasitol 2019; 35:677-686. [PMID: 31395496 PMCID: PMC6708786 DOI: 10.1016/j.pt.2019.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022]
Abstract
Women attending antenatal care (ANC) are a generally healthy, easy-access population, contributing valuable data for infectious disease surveillance at the community level. ANC-based malaria surveillance would provide a routine measure of the malaria burden in pregnancy, which countries lack, whilst potentially improving pregnancy outcomes. It could also offer contemporary information on temporal trends and the geographic distribution of malaria burden as well as intervention coverage in the population to guide resource allocation and to assess progress towards elimination. Here, we review the factors underlying the relationship between Plasmodium falciparum in pregnancy and in the community, and outline strengths and limitations of an ANC-based surveillance in sub-Saharan Africa, its potential role within wider malaria surveillance systems, and subsequent programmatic applications.
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Affiliation(s)
- Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique.
| | - Clara Menéndez
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique
| | - Patrick G T Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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48
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Stresman G, Bousema T, Cook J. Malaria Hotspots: Is There Epidemiological Evidence for Fine-Scale Spatial Targeting of Interventions? Trends Parasitol 2019; 35:822-834. [PMID: 31474558 DOI: 10.1016/j.pt.2019.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/29/2019] [Accepted: 07/29/2019] [Indexed: 12/20/2022]
Abstract
As data at progressively granular spatial scales become available, the temptation is to target interventions to areas with higher malaria transmission - so-called hotspots - with the aim of reducing transmission in the wider community. This paper reviews literature to determine if hotspots are an intrinsic feature of malaria epidemiology and whether current evidence supports hotspot-targeted interventions. Hotspots are a consistent feature of malaria transmission at all endemicities. The smallest spatial unit capable of supporting transmission is the household, where peri-domestic transmission occurs. Whilst the value of focusing interventions to high-burden areas is evident, there is currently limited evidence that local-scale hotspots fuel transmission. As boundaries are often uncertain, there is no conclusive evidence that hotspot-targeted interventions accelerate malaria elimination.
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Affiliation(s)
- Gillian Stresman
- Infection Biology Department, London School of Hygiene and Tropical Medicine, London, UK.
| | - Teun Bousema
- Radboud University Medical Centre, Department of Microbiology, HB Nijmegen, The Netherlands.
| | - Jackie Cook
- Medical Research Council (MRC) Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
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49
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Odero NA, Samuels AM, Odongo W, Abong'o B, Gimnig J, Otieno K, Odero C, Obor D, Ombok M, Were V, Sang T, Hamel MJ, Kachur SP, Slutsker L, Lindblade KA, Kariuki S, Desai M. Community-based intermittent mass testing and treatment for malaria in an area of high transmission intensity, western Kenya: development of study site infrastructure and lessons learned. Malar J 2019; 18:255. [PMID: 31357997 PMCID: PMC6664589 DOI: 10.1186/s12936-019-2896-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 07/23/2019] [Indexed: 01/06/2023] Open
Abstract
Background Malaria transmission is high in western Kenya and the asymptomatic infected population plays a significant role in driving the transmission. Mathematical modelling and simulation programs suggest that interventions targeting asymptomatic infections through mass testing and treatment (MTaT) or mass drug administration (MDA) have the potential to reduce malaria transmission when combined with existing interventions. Objective This paper describes the study site, capacity development efforts required, and lessons learned for implementing a multi-year community-based cluster-randomized controlled trial to evaluate the impact of MTaT for malaria transmission reduction in an area of high transmission in western Kenya. Methods The study partnered with Kenya’s Ministry of Health (MOH) and other organizations on community sensitization and engagement to mobilize, train and deploy community health volunteers (CHVs) to deliver MTaT in the community. Within the health facilities, the study availed staff, medical and laboratory supplies and strengthened health information management system to monitor progress and evaluate impact of intervention. Results More than 80 Kenya MOH CHVs, 13 clinical officers, field workers, data and logistical staff were trained to carry out MTaT three times a year for 2 years in a population of approximately 90,000 individuals. A supply chain management was adapted to meet daily demands for large volumes of commodities despite the limitation of few MOH facilities having ideal storage conditions. Modern technology was adapted more to meet the needs of the high daily volume of collected data. Conclusions In resource-constrained settings, large interventions require capacity building and logistical planning. This study found that investing in relationships with the communities, local governments, and other partners, and identifying and equipping the appropriate staff with the skills and technology to perform tasks are important factors for success in delivering an intervention like MTaT.
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Affiliation(s)
- Norbert Awino Odero
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya.
| | - Aaron M Samuels
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Wycliffe Odongo
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Bernard Abong'o
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - John Gimnig
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Kephas Otieno
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Christopher Odero
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - David Obor
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Maurice Ombok
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Vincent Were
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Tony Sang
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Mary J Hamel
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - S Patrick Kachur
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | | | - Kim A Lindblade
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Simon Kariuki
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Meghna Desai
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
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50
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Abstract
For the control and elimination of malaria, information on the local vector dynamics is essential. This information provides guidance on appropriate and timely deployment of vector control tools and their subsequent success. The data on the dynamics of local mosquito populations can be collected using many different Anopheles sampling methods. Dependent on the objectives, resources, time, and local environment, different traps and methods can be chosen. This chapter describes the sampling of adult populations, focusing on the important preparatory stages and some of the widely used sampling methods. The trapping methods discussed in this chapter are the human landing catch, human-baited net trap, animal landing catch, animal-baited net trap, CDC miniature light trap, Biogents Suna trap, peripheral net collection, pyrethrum collection, exit/entry trap, and resting shelter. For optimal deployment in the field, a step-by-step description of the sampling methods is given.
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