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Villena OC, Arab A, Lippi CA, Ryan SJ, Johnson LR. Influence of environmental, geographic, socio-demographic, and epidemiological factors on presence of malaria at the community level in two continents. Sci Rep 2024; 14:16734. [PMID: 39030306 PMCID: PMC11271557 DOI: 10.1038/s41598-024-67452-5] [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: 05/10/2024] [Accepted: 07/11/2024] [Indexed: 07/21/2024] Open
Abstract
The interactions of environmental, geographic, socio-demographic, and epidemiological factors in shaping mosquito-borne disease transmission dynamics are complex and changeable, influencing the abundance and distribution of vectors and the pathogens they transmit. In this study, 27 years of cross-sectional malaria survey data (1990-2017) were used to examine the effects of these factors on Plasmodium falciparum and Plasmodium vivax malaria presence at the community level in Africa and Asia. Monthly long-term, open-source data for each factor were compiled and analyzed using generalized linear models and classification and regression trees. Both temperature and precipitation exhibited unimodal relationships with malaria, with a positive effect up to a point after which a negative effect was observed as temperature and precipitation increased. Overall decline in malaria from 2000 to 2012 was well captured by the models, as was the resurgence after that. The models also indicated higher malaria in regions with lower economic and development indicators. Malaria is driven by a combination of environmental, geographic, socioeconomic, and epidemiological factors, and in this study, we demonstrated two approaches to capturing this complexity of drivers within models. Identifying these key drivers, and describing their associations with malaria, provides key information to inform planning and prevention strategies and interventions to reduce malaria burden.
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Affiliation(s)
- Oswaldo C Villena
- The Earth Commons Institute, Georgetown University, Washington, DC, 20057, USA.
| | - Ali Arab
- Department of Mathematics and Statistics, Georgetown University, Washington, DC, 20057, USA
| | - Catherine A Lippi
- Department of Geography, University of Florida, Gainesville, FL, 32611, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Sadie J Ryan
- Department of Geography, University of Florida, Gainesville, FL, 32611, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Leah R Johnson
- Department of Statistics, Virginia Tech, Blacksburg, VA, 24061, USA
- Computational Modeling and Data Analytics, Virginia Tech, Blacksburg, VA, 24061, USA
- Department of Biology, Virginia Tech, Blacksburg, VA, 24061, USA
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2
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Weng SC, Chen F, Li M, Lee S, Gerry C, Turksoy DC, Akbari OS. Establishing a Male-Positive Genetic Sexing Strain in the Asian Malaria Vector Anopheles stephensi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.17.603997. [PMID: 39071362 PMCID: PMC11275880 DOI: 10.1101/2024.07.17.603997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Genetic biocontrol interventions targeting mosquito-borne diseases require the release of male mosquitoes exclusively, as only females consume blood and transmit human pathogens. This reduces the risk of spreading pathogens while enabling effective population control. Robust sex sorting methods to enable early larval sorting in mosquitoes need to be developed to allow for scalable sex sorting for genetic biocontrol interventions. This study applies the SEPARATOR (Sexing Element Produced by Alternative RNA-splicing of A Transgenic Observable Reporter) system, previously developed for Aedes aegypti, to the Asian malaria vector Anopheles stephensi. We hypothesized that the intron from the doublesex gene in Anopheles gambiae would function in An. stephensi due to evolutionary conservation. Our results confirm that the splicing module from An. gambiae operates effectively in An. stephensi, demonstrating evolutionary conservation in sex-specific splicing events between these species. This system enables reliable positive male selection from first instar larval to pupal stages. RT-PCR analysis demonstrates that male-specific EGFP expression is dependent on doublesex sex-specific splicing events. The SEPARATOR system's independence from sex-chromosome linkage confers resistance to meiotic recombination and chromosomal rearrangements. This approach may facilitate the mass release of males, and the cross-species portability of SEPARATOR establishes it as a valuable tool for genetic biocontrol interventions across various pest species.
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Affiliation(s)
- Shih-Che Weng
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Fangying Chen
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ming Li
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sammy Lee
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Connor Gerry
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dylan Can Turksoy
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Omar S. Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
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3
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File T, Jemal F. Prevalence of Malaria and Associated Factors during the Minor Malaria Season among Febrile Under-Five Children Attending Mohammed Akile Memorial General Hospital. J Parasitol Res 2024; 2024:6365077. [PMID: 38774540 PMCID: PMC11108698 DOI: 10.1155/2024/6365077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 04/13/2024] [Accepted: 04/18/2024] [Indexed: 05/24/2024] Open
Abstract
Malaria is one of the major public health problems in sub-Saharan Africa, including Ethiopia. Children under the age of five are immunologically naive to plasmodium parasites, making them the most vulnerable group to clinical manifestations of malaria infection. Despite the severity of the disease in children under five years of age, most studies on malaria focus on the adult population. In the present study, a cross-sectional study design based on health facilities was used during the minor malaria season from February 18 to May 28, 2023, at Mohammed Akile Memorial General Hospital, in Afar Regional State, district of Amibara located in the town of Berta. The finding revealed that 19.8% prevalence among symptomatic children with 61.04% and 38.96% of P. falciparum and P. vivax, respectively. In the present study area, malaria infection in children under five years of age is significantly associated with the presence of stagnant water in the residential area, inappropriate or no use of insecticide-treated net, and indoor residual spraying (IRS). The prevalence of malaria among symptomatic children under five years of age is higher compared to the national prevalence of malaria among the general population. Therefore, community mobilization through health promotion, aiming to interrupt the transmission of malaria at the community level, is paramount.
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Affiliation(s)
- Temesgen File
- Department of Medical Laboratory Science, Rift Valley University, Adama, Ethiopia
| | - Feysal Jemal
- Department of Public Health, Rift Valley University, Adama, Ethiopia
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Nelder MP, Schats R, Poinar HN, Cooke A, Brickley MB. Pathogen prospecting of museums: Reconstructing malaria epidemiology. Proc Natl Acad Sci U S A 2024; 121:e2310859121. [PMID: 38527214 PMCID: PMC11009618 DOI: 10.1073/pnas.2310859121] [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] [Indexed: 03/27/2024] Open
Abstract
Malaria is a disease of global significance. Ongoing changes to the earth's climate, antimalarial resistance, insecticide resistance, and socioeconomic decline test the resilience of malaria prevention programs. Museum insect specimens present an untapped resource for studying vector-borne pathogens, spurring the question: Do historical mosquito collections contain Plasmodium DNA, and, if so, can museum specimens be used to reconstruct the historical epidemiology of malaria? In this Perspective, we explore molecular techniques practical to pathogen prospecting, which, more broadly, we define as the science of screening entomological museum specimens for human, animal, or plant pathogens. Historical DNA and pathogen prospecting provide a means of describing the coevolution of human, vector, and parasite, informing the development of insecticides, diagnostics, therapeutics, and vaccines.
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Affiliation(s)
- Mark P. Nelder
- Enteric, Zoonotic and Vector-Borne Diseases, Health Protection, Public Health Ontario, Toronto, ONM5G 1M1, Canada
| | - Rachel Schats
- Laboratory for Human Osteoarchaeology, Faculty of Archaeology, Leiden University, 2333 CCLeiden, The Netherlands
| | - Hendrik N. Poinar
- Department of Anthropology, McMaster University, Hamilton, ONL8S 4L9, Canada
- Department of Biochemistry, McMaster University, Hamilton, ONL8S 4L9, Canada
- McMaster Ancient DNA Centre, Department of Anthropology, McMaster University, Hamilton, ONL8S 4L9, Canada
| | - Amanda Cooke
- Department of Anthropology, McMaster University, Hamilton, ONL8S 4L9, Canada
| | - Megan B. Brickley
- Department of Anthropology, McMaster University, Hamilton, ONL8S 4L9, Canada
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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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Kua KP, Lee SWH, Chongmelaxme B. The impact of home-based management of malaria on clinical outcomes in sub-Saharan African populations: a systematic review and meta-analysis. Trop Med Health 2024; 52:7. [PMID: 38191459 PMCID: PMC10773121 DOI: 10.1186/s41182-023-00572-2] [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: 09/05/2023] [Accepted: 12/24/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUND Malaria remains a significant cause of morbidity and mortality globally and continues to disproportionately afflict the African population. We aimed to evaluate the effect of home management of malaria intervention on health outcomes. METHODS In our systematic review and meta-analysis, six databases (Pubmed, Cochrane CENTRAL, EMBASE, CAB Abstracts and Global Health, CINAHL Complete, and BIOSIS) were searched for studies of home management of malaria from inception until November 15, 2023. We included before-after studies, observational studies, and randomised controlled trials of home management intervention delivered in community settings. The primary outcomes were malaria mortality and all-cause mortality. The risk of bias in individual observational studies was assessed using the ROBINS-I tool, whilst randomised controlled trials were judged using a revised Cochrane risk of bias tool and cluster-randomised controlled trials were evaluated using an adapted Cochrane risk of bias tool for cluster-randomised trials. We computed risk ratios with accompanying 95% confidence intervals for health-related outcomes reported in the studies and subsequently pooled the results by using a random-effects model (DerSimonian-Laird method). RESULTS We identified 1203 citations through database and hand searches, from which 56 articles from 47 studies encompassing 234,002 participants were included in the systematic review. All studies were conducted in people living in sub-Saharan Africa and were rated to have a low or moderate risk of bias. Pooled analyses showed that mortality rates due to malaria (RR = 0.40, 95% CI = 0.29-0.54, P = 0.00001, I2 = 0%) and all-cause mortality rates (RR = 0.62, 95% CI = 0.53-0.72, P = 0.00001, I2 = 0%) were significantly lower among participants receiving home management intervention compared to the control group. However, in children under 5 years of age, there was no significant difference in mortality rates before and after implementation of home management of malaria. In terms of secondary outcomes, home management of malaria was associated with a reduction in the risk of febrile episodes (RR = 1.27, 95% CI = 1.09-1.47, P = 0.002, I2 = 97%) and higher effective rates of antimalarial treatments (RR = 2.72, 95% CI = 1.90-3.88, P < 0.00001, I2 = 96%) compared to standard care. Home malaria management combined with intermittent preventive treatment showed a significantly lower incidence risk of malaria than home management intervention that exclusively provided treatment to individuals with febrile illness suggestive of malaria. The risks for adverse events were found to be similar for home management intervention using different antimalarial drugs. Cost-effectiveness findings depicted that home malaria management merited special preferential scale-up. CONCLUSIONS Home management of malaria intervention was associated with significant reductions in malaria mortality and all-cause mortality. The intervention could help decrease health and economic burden attributable to malaria. Further clinical studies are warranted to enable more meaningful interpretations with regard to wide-scale implementation of the intervention, settings of differing transmission intensity, and new antimalarial drugs.
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Affiliation(s)
- Kok Pim Kua
- Department of Civil and Environmental Engineering, School of Engineering and Doerr School of Sustainability, Stanford University, Stanford, CA, 94305, USA
- MIT Alumni Association, Massachusetts Institute of Technology, Cambridge, MA, 02139-4822, USA
- Pharmacy Unit, Puchong Health Clinic, Petaling District Health Office, Ministry of Health Malaysia, 47100, Puchong, Selangor, Malaysia
- A.S. Watson Group, Watson's Personal Care Stores, 55188, Kuala Lumpur, Malaysia
| | - Shaun Wen Huey Lee
- School of Pharmacy, Monash University, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
- Asian Center for Evidence Synthesis in Population, Implementation, and Clinical Outcomes (PICO), Health and Well-Being Cluster, Global Asia in the 21st Century (GA21) Platform, Monash University, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
- Gerontechnology Laboratory, Global Asia in the 21st Century (GA21) Platform, Monash University, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
- Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, 47500, Lakeside CampusSelangor, Malaysia
- Center for Global Health, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Bunchai Chongmelaxme
- Department of Social and Administrative Pharmacy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok, 10330, Thailand.
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Santos-Vega M, Lowe R, Anselin L, Desai V, Vaishnav KG, Naik A, Pascual M. Quantifying climatic and socioeconomic drivers of urban malaria in Surat, India: a statistical spatiotemporal modelling study. Lancet Planet Health 2023; 7:e985-e998. [PMID: 38056969 DOI: 10.1016/s2542-5196(23)00249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 10/11/2023] [Accepted: 10/27/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Cities are becoming increasingly important habitats for mosquito vectors of disease. The pronounced heterogeneity of urban landscapes challenges our understanding of the effects of climate and socioeconomic factors on mosquito-borne disease dynamics at different spatiotemporal scales. Here, we quantify the impact of climatic and socioeconomic factors on urban malaria risk, using an extensive dataset in both space and time for reported Plasmodium falciparum cases in the city of Surat, northwest India. METHODS We analysed 10 years of monthly P falciparum cases resolved at three nested spatial resolutions (seven zones, 32 units, and 478 worker units) with a Bayesian hierarchical mixed model that incorporates the effects of population density, poverty, relative humidity, and temperature, in addition to random effects (structured and unstructured). To reduce dimensionality and avoid correlation of covariates, socioeconomic variables from survey data were summarised into main axes of variation using principal component analysis. With model selection, we identified the main drivers of spatiotemporal variation in malaria incidence rates at each of the three spatial resolutions. We also compared observations to model-fitted cases by quantifying the percentage of predictions within five discrete levels of malaria risk. FINDINGS The spatial variation of urban malaria cases was stationary over time, whereby locations with high and low yearly cases remained largely consistent across years. Local socioeconomic variation could be summarised with three principal components accounting for approximately 80% of the variance. The model that incorporated local temperature and relative humidity together with two of these principal components, largely representing population density and poverty, best explained monthly malaria patterns in models formulated at the three different spatial scales. As model resolution increased, the effect size of humidity decreased, whereas those of temperature and the principal component associated with population density increased. Model predictions accurately captured aggregated total monthly cases for the city; in space-time, they more closely matched observations at the intermediate scale, with around 57% of units estimated to fall in the observed category on average across years. The mean absolute error was lower at the intermediate level, showing that this is the best aggregation level to predict the space-time dynamics of malaria incidence rates across the city with the selected model. INTERPRETATION This statistical modelling framework provides a basis for development of a climate-driven early warning system for urban malaria for the units of Surat, including spatially explicit prediction of malaria risk several weeks to months in advance. Results indicate environmental and socioeconomic covariates for which further measurement at high resolution should lead to model improvement. Advanced warning combined with local surveillance and knowledge of disease hotspots within the city could inform targeted intervention as part of urban malaria elimination efforts. FUNDING US National Institutes of Health.
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Affiliation(s)
- Mauricio Santos-Vega
- Departamento de Ciencias Biológicas and Grupo de Investigación en Biología Matemática y Computacional BIOMAC, Universidad de los Andes, Bogotá, Colombia.
| | - Rachel Lowe
- Barcelona Supercomputing Center, Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain; Centre on Climate Change & Planetary Health and Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Luc Anselin
- Center for Spatial Data Science, University of Chicago, Chicago, IL, USA
| | - Vikas Desai
- Urban Health and Climate Resilience Center of Excellence (UHCRCE), Surat, India
| | - Keshav G Vaishnav
- Vector Borne Diseases Control Department, Surat Municipal Corporation, Surat, India
| | | | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA; Department of Biology and Department of Environmental Studies, New York University, NY, USA
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Emiru T, Getachew D, Murphy M, Sedda L, Ejigu LA, Bulto MG, Byrne I, Demisse M, Abdo M, Chali W, Elliott A, Vickers EN, Aranda-Díaz A, Alemayehu L, Behaksera SW, Jebessa G, Dinka H, Tsegaye T, Teka H, Chibsa S, Mumba P, Girma S, Hwang J, Yoshimizu M, Sutcliffe A, Taffese HS, Bayissa GA, Zohdy S, Tongren JE, Drakeley C, Greenhouse B, Bousema T, Tadesse FG. Evidence for a role of Anopheles stephensi in the spread of drug- and diagnosis-resistant malaria in Africa. Nat Med 2023; 29:3203-3211. [PMID: 37884028 PMCID: PMC10719088 DOI: 10.1038/s41591-023-02641-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Anopheles stephensi, an Asian malaria vector, continues to expand across Africa. The vector is now firmly established in urban settings in the Horn of Africa. Its presence in areas where malaria resurged suggested a possible role in causing malaria outbreaks. Here, using a prospective case-control design, we investigated the role of An. stephensi in transmission following a malaria outbreak in Dire Dawa, Ethiopia in April-July 2022. Screening contacts of patients with malaria and febrile controls revealed spatial clustering of Plasmodium falciparum infections around patients with malaria in strong association with the presence of An. stephensi in the household vicinity. Plasmodium sporozoites were detected in these mosquitoes. This outbreak involved clonal propagation of parasites with molecular signatures of artemisinin and diagnostic resistance. To our knowledge, this study provides the strongest evidence so far for a role of An. stephensi in driving an urban malaria outbreak in Africa, highlighting the major public health threat posed by this fast-spreading mosquito.
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Affiliation(s)
- Tadele Emiru
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Maxwell Murphy
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, Lancaster, UK
| | | | | | - Isabel Byrne
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Melat Abdo
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Wakweya Chali
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
- Radboudumc, Nijmegen, the Netherlands
| | - Aaron Elliott
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Eric Neubauer Vickers
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Andrés Aranda-Díaz
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Lina Alemayehu
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Gutema Jebessa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hunduma Dinka
- Adama Science and Technology University, Adama, Ethiopia
| | - Tizita Tsegaye
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hiwot Teka
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Sheleme Chibsa
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Peter Mumba
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Samuel Girma
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Jimee Hwang
- U.S. President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Alice Sutcliffe
- U.S. President's Malaria Initiative, Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Sarah Zohdy
- U.S. President's Malaria Initiative, Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jon Eric Tongren
- U.S. President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - Bryan Greenhouse
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | | | - Fitsum G Tadesse
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
- London School of Hygiene and Tropical Medicine, London, UK.
- Radboudumc, Nijmegen, the Netherlands.
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9
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Diop A, Ndiaye F, Sturm-Ramirez K, Konate L, Senghor M, Diouf EH, Dia AK, Diedhiou S, Samb B, Sene D, Zohdy S, Dotson E, Diouf MB, Koscelnik V, Gerberg L, Bangoura A, Faye O, Clark T, Niang EHA, Chabi J. Urban malaria vector bionomics and human sleeping behavior in three cities in Senegal. Parasit Vectors 2023; 16:331. [PMID: 37726787 PMCID: PMC10510207 DOI: 10.1186/s13071-023-05932-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 08/15/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND Malaria is endemic in Senegal, with seasonal transmission, and the entire population is at risk. In recent years, high malaria incidence has been reported in urban and peri-urban areas of Senegal. An urban landscape analysis was conducted in three cities to identify the malaria transmission indicators and human behavior that may be driving the increasing malaria incidence occurring in urban environments. Specifically, mosquito vector bionomics and human sleeping behaviors including outdoor sleeping habits were assessed to guide the optimal deployment of targeted vector control interventions. METHODS Longitudinal entomological monitoring using human landing catches and pyrethrum spray catches was conducted from May to December 2019 in Diourbel, Kaolack, and Touba, the most populous cities in Senegal after the capital Dakar. Additionally, a household survey was conducted in randomly selected houses and residential Koranic schools in the same cities to assess house structures, sleeping spaces, sleeping behavior, and population knowledge about malaria and vector control measures. RESULTS Of the 8240 Anopheles mosquitoes collected from all the surveyed sites, 99.4% (8,191) were An. gambiae s.l., and predominantly An. arabiensis (99%). A higher number of An. gambiae s.l. were collected in Kaolack (77.7%, n = 6496) than in Diourbel and Touba. The overall mean human biting rate was 14.2 bites per person per night (b/p/n) and was higher outdoors (15.9 b/p/n) than indoors (12.5 b/p/n). The overall mean entomological inoculation rates ranged from 3.7 infectious bites per person per year (ib/p/y) in Diourbel to 40.2 ib/p/y in Kaolack. Low anthropophilic rates were recorded at all sites (average 35.7%). Of the 1202 households surveyed, about 24.3% of household members slept outdoors, except during the short rainy season between July and October, despite understanding how malaria is transmitted and the vector control measures used to prevent it. CONCLUSION Anopheles arabiensis was the primary malaria vector in the three surveyed cities. The species showed an outdoor biting tendency, which represents a risk for the large proportion of the population sleeping outdoors. As all current vector control measures implemented in the country target endophilic vectors, these data highlight potential gaps in population protection and call for complementary tools and approaches targeting outdoor biting malaria vectors.
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Affiliation(s)
- Abdoulaye Diop
- U.S. President's Malaria Initiative (PMI) Abt Associates/VectorLink Project, Dakar, Senegal
| | - Fatou Ndiaye
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Katherine Sturm-Ramirez
- U.S. President's Malaria Initiative, Malaria Branch, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Lassana Konate
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Massila Senghor
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - El Hadji Diouf
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Abdoulaye Kane Dia
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Seynabou Diedhiou
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Badara Samb
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Doudou Sene
- National Malaria Control Programme, Dakar, Senegal
| | - Sarah Zohdy
- U.S. President's Malaria Initiative, Malaria Branch, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Ellen Dotson
- U.S. President's Malaria Initiative, Malaria Branch, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Mame Birame Diouf
- U.S. President's Malaria Initiative, United States Agency for International Development (USAID), Dakar, Senegal
| | - Valerie Koscelnik
- U.S. President's Malaria Initiative, United States Agency for International Development (USAID), Dakar, Senegal
| | - Lilia Gerberg
- U.S. President's Malaria Initiative, United States Agency for International Development (USAID), Washington, DC, USA
| | - Abdoulaye Bangoura
- U.S. President's Malaria Initiative, Abt Associates/VectorLink Project Rockville, Rockville, DC, USA
| | - Ousmane Faye
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Tiffany Clark
- U.S. President's Malaria Initiative, Abt Associates/VectorLink Project Rockville, Rockville, DC, USA
| | - El Hadji Amadou Niang
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Joseph Chabi
- U.S. President's Malaria Initiative, Abt Associates/VectorLink Project Rockville, Rockville, DC, USA.
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Hussein AK, Tarimo D, Reaves EJ, Chacky F, Abade AM, Mwalimu CD, Mohamed A, Nasser A, Kishimba RS. The quality of malaria case management in different transmission settings in Tanzania mainland, 2017-2018. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0002318. [PMID: 37603541 PMCID: PMC10441786 DOI: 10.1371/journal.pgph.0002318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 07/31/2023] [Indexed: 08/23/2023]
Abstract
Tanzania is undergoing an epidemiological transition for malaria transmission with some areas of the country having <10% (hypoendemic) and other areas 10% - 50% malaria prevalence (mesoendemic). It is not known whether there is a difference in the quality of malaria case management based on endemicity in Tanzania mainland. We examined the influence of endemicity on the quality of malaria case management at health facilities. We conducted a cross-sectional analysis of 1713 health facilities in Tanzania mainland, using data collected by the National Malaria Control Program through an assessment tool to evaluate quality of malaria case management. The data was gathered from September 2017 to December 2018. Using standard quality factors, mean scores from facilities in the different endemicity regions were compared by a Student's t-test. Simple and multiple linear regression analyses were performed to determine the association between facility performance (score) and endemicity (mesoendemic vs. hypoendemic). Facilities in mesoendemic regions scored higher than those in hypoendemic regions on the overall quality of services [difference in mean scores ([Formula: see text]) = 2.52; (95% Confidence Interval (CI) 1.12, 3.91)], site readiness [[Formula: see text] = 2.97; (95% CI 1.30, 4.61)], availability of malaria reference materials [[Formula: see text] = 4.91; (95% CI 2.05, 7.76)], availability of Health Management Information System tools [[Formula: see text] = 5.86; (95% CI 3.80, 7.92)] and patient satisfaction [[Formula: see text] = 6.61; (95% CI 3.75, 9.48)]. Predictors associated with lower facility scores included; being located in a hypoendemic region [β: -2.49; (95% CI -3.83, -1.15)] and urban area [β: -3.84; (95% CI -5.60, -2.08)]. These findings highlight the differences in quality of malaria case management based on endemicity, but there is still a need to target improvement efforts in underperforming facilities, regardless of endemicity.
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Affiliation(s)
- Ally Kassim Hussein
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, United Republic of Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, United Republic of Tanzania
| | - Donath Tarimo
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, United Republic of Tanzania
| | - Erik J. Reaves
- U.S. President’s Malaria Initiative, U.S. Centers for Disease Control and Prevention, Dar es Salaam, United Republic of Tanzania
| | - Frank Chacky
- National Malaria Control Program, Dodoma, United Republic of Tanzania
- Ministry of Health, Dodoma, United Republic of Tanzania
| | - Ahmed Mohamed Abade
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, United Republic of Tanzania
| | | | - Ally Mohamed
- National Malaria Control Program, Dodoma, United Republic of Tanzania
- Ministry of Health, Dodoma, United Republic of Tanzania
| | - Ahlam Nasser
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, United Republic of Tanzania
| | - Rogath Saika Kishimba
- Tanzania Field Epidemiology and Laboratory Training Program, Dar es Salaam, United Republic of Tanzania
- Ministry of Health, Dodoma, United Republic of Tanzania
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Teka H, Golassa L, Medhin G, Balkew M, Sisay C, Gadisa E, Nekorchuk DM, Wimberly MC, Tadesse FG. Trend analysis of malaria in urban settings in Ethiopia from 2014 to 2019. Malar J 2023; 22:235. [PMID: 37580690 PMCID: PMC10426206 DOI: 10.1186/s12936-023-04656-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 07/24/2023] [Indexed: 08/16/2023] Open
Abstract
BACKGROUND Urbanization generally improves health outcomes of residents and is one of the potential factors that might contribute to reducing malaria transmission. However, the expansion of Anopheles stephensi, an urban malaria vector, poses a threat for malaria control and elimination efforts in Africa. In this paper, malaria trends in urban settings in Ethiopia from 2014 to 2019 are reported with a focus on towns and cities where An. stephensi surveys were conducted. METHODS A retrospective study was conducted to determine malaria trends in urban districts using passive surveillance data collected at health facilities from 2014 to 2019. Data from 25 towns surveyed for An. stephensi were used in malaria trend analysis. Robust linear models were used to identify outliers and impute missing and anomalous data. The seasonal Mann-Kendal test was used to test for monotonic increasing or decreasing trends. RESULTS A total of 9,468,970 malaria cases were reported between 2014 and 2019 through the Public Health Emergency Management (PHEM) system. Of these, 1.45 million (15.3%) cases were reported from urban settings. The incidence of malaria declined by 62% between 2014 and 2018. In 2019, the incidence increased to 15 per 1000 population from 11 to 1000 in 2018. Both confirmed (microscopy or RDT) Plasmodium falciparum (67%) and Plasmodium vivax (28%) were reported with a higher proportion of P. vivax infections in urban areas. In 2019, An. stephensi was detected in 17 towns where more than 19,804 malaria cases were reported, with most of the cases (56%) being P. falciparum. Trend analysis revealed that malaria cases increased in five towns in Afar and Somali administrative regions, decreased in nine towns, and had no obvious trend in the remaining three towns. CONCLUSION The contribution of malaria in urban settings is not negligible in Ethiopia. With the rapid expansion of An. stephensi in the country, the receptivity is likely to be higher for malaria. Although the evidence presented in this study does not demonstrate a direct linkage between An. stephensi detection and an increase in urban malaria throughout the country, An. stephensi might contribute to an increase in malaria unless control measures are implemented as soon as possible. Targeted surveillance and effective response are needed to assess the contribution of this vector to malaria transmission and curb potential outbreaks.
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Affiliation(s)
- Hiwot Teka
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Girmay Medhin
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Meshesha Balkew
- Abt Associate PMI VectorLink Ethiopia Project, Addis Ababa, Ethiopia
| | | | | | - Dawn M Nekorchuk
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, USA
| | - Michael C Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, USA
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Chaparro Narváez PE, Jimenez-Serna MM, Gunturiz Albarracin ML, Carrasquilla Gutierrez G. Malaria prevalence in Commune 5 in Tumaco (Nariño, Colombia). F1000Res 2023; 11:448. [PMID: 38444515 PMCID: PMC10913070 DOI: 10.12688/f1000research.110361.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/11/2023] [Indexed: 03/07/2024] Open
Abstract
Background Urban malaria is a public health problem in Colombia and there is still lack of knowledge about its epidemiological characteristics, which are key to the implementation of control measures. The presence of urban malaria cases and disease diagnosis are some of the challenges faced by malaria elimination programs. The objective of this research was to estimate malaria prevalence, explore associated factors and detect pfhrp 2/3 genes, in the urban area of Tumaco between July and December 2019. Methods A prevalence study was conducted by using a stratified random probability sample. Structured surveys were administered and blood samples were taken and examined through optical microscopy, rapid diagnostic tests (RDT) and polymerase chain reaction (PCR). A logistic regression model was used to explore associated factors. Results 1,504 people living in 526 households were surveyed. The overall prevalence was 2.97% (95% CI: 2.1 - 4.3%). It was higher in males, in the 10-19 age group and in asymptomatic cases. The prevalence of pfhrp2 amplification was 2.16% (95% CI: 1.6 - 2.9%). Households with three or more people had a higher risk of malaria infection (adjusted odds ratio (ORa) 4.05; 95% confidence interval (CI) 1.57-10.43). All cases were due to P. falciparum. Conclusions The prevalence of urban malaria was low. Strategies to eliminate malaria in urban areas should be adjusted considering access to early diagnosis, asymptomatic infection, and the RDTs used to detect the presence of the pfhrp2 gene.
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Vanhuysse S, Diédhiou SM, Grippa T, Georganos S, Konaté L, Niang EHA, Wolff E. Fine-scale mapping of urban malaria exposure under data scarcity: an approach centred on vector ecology. Malar J 2023; 22:113. [PMID: 37009873 PMCID: PMC10069057 DOI: 10.1186/s12936-023-04527-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 03/08/2023] [Indexed: 04/04/2023] Open
Abstract
BACKGROUND Although malaria transmission has experienced an overall decline in sub-Saharan Africa, urban malaria is now considered an emerging health issue due to rapid and uncontrolled urbanization and the adaptation of vectors to urban environments. Fine-scale hazard and exposure maps are required to support evidence-based policies and targeted interventions, but data-driven predictive spatial modelling is hindered by gaps in epidemiological and entomological data. A knowledge-based geospatial framework is proposed for mapping the heterogeneity of urban malaria hazard and exposure under data scarcity. It builds on proven geospatial methods, implements open-source algorithms, and relies heavily on vector ecology knowledge and the involvement of local experts. METHODS A workflow for producing fine-scale maps was systematized, and most processing steps were automated. The method was evaluated through its application to the metropolitan area of Dakar, Senegal, where urban transmission has long been confirmed. Urban malaria exposure was defined as the contact risk between adult Anopheles vectors (the hazard) and urban population and accounted for socioeconomic vulnerability by including the dimension of urban deprivation that is reflected in the morphology of the built-up fabric. Larval habitat suitability was mapped through a deductive geospatial approach involving the participation of experts with a strong background in vector ecology and validated with existing geolocated entomological data. Adult vector habitat suitability was derived through a similar process, based on dispersal from suitable breeding site locations. The resulting hazard map was combined with a population density map to generate a gridded urban malaria exposure map at a spatial resolution of 100 m. RESULTS The identification of key criteria influencing vector habitat suitability, their translation into geospatial layers, and the assessment of their relative importance are major outcomes of the study that can serve as a basis for replication in other sub-Saharan African cities. Quantitative validation of the larval habitat suitability map demonstrates the reliable performance of the deductive approach, and the added value of including local vector ecology experts in the process. The patterns displayed in the hazard and exposure maps reflect the high degree of heterogeneity that exists throughout the city of Dakar and its suburbs, due not only to the influence of environmental factors, but also to urban deprivation. CONCLUSIONS This study is an effort to bring geospatial research output closer to effective support tools for local stakeholders and decision makers. Its major contributions are the identification of a broad set of criteria related to vector ecology and the systematization of the workflow for producing fine-scale maps. In a context of epidemiological and entomological data scarcity, vector ecology knowledge is key for mapping urban malaria exposure. An application of the framework to Dakar showed its potential in this regard. Fine-grained heterogeneity was revealed by the output maps, and besides the influence of environmental factors, the strong links between urban malaria and deprivation were also highlighted.
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Affiliation(s)
- Sabine Vanhuysse
- Department of Geosciences, Environment and Society, Université Libre de Bruxelles (ULB), 1050, Brussels, Belgium.
| | - Seynabou Mocote Diédhiou
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Université Cheikh-Anta-Diop de Dakar, Dakar, Sénégal
| | - Taïs Grippa
- Department of Geosciences, Environment and Society, Université Libre de Bruxelles (ULB), 1050, Brussels, Belgium
| | - Stefanos Georganos
- Geomatics, Department of Environmental and Life Sciences, Faculty of Health, Science and Technology, Karlstad University, Karlstad, Sweden
| | - Lassana Konaté
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Université Cheikh-Anta-Diop de Dakar, Dakar, Sénégal
| | - El Hadji Amadou Niang
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Université Cheikh-Anta-Diop de Dakar, Dakar, Sénégal
| | - Eléonore Wolff
- Department of Geosciences, Environment and Society, Université Libre de Bruxelles (ULB), 1050, Brussels, Belgium
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Guin P, Kumar EL, Mukhopadhyay I. Do climatic and socioeconomic factors explain population vulnerability to malaria? Evidence from a national survey, India. Indian J Public Health 2023; 67:226-234. [PMID: 37459017 DOI: 10.4103/ijph.ijph_964_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023] Open
Abstract
Background Malaria remains a public health challenge across several African and South-East Asia Region countries, including India, despite making gains in malaria-related morbidity and mortality. Poor climatic and socioeconomic factors are known to increase population vulnerability to malaria. However, there is scant literature from India exploring this link using large population-based data. Objectives This study aims to study the role of climatic and socioeconomic factors in determining population vulnerability to malaria in India. Materials and Methods We used logistic regression models on a nationally representative sample of 91,207 households, obtained from the National Sample Survey Organization (69th round), to study the determinants of household vulnerability. Results Households that resided in high (odds ratio [OR]: 1.876, P < 0.01) and moderately high (OR: 3.427, P < 0.01), compared to low climatically vulnerable states were at greater odds of suffering from malaria. Among households that faced the problem of mosquitoes/flies compared to the reference group, the urban households were at higher risk of suffering from malaria (OR: 8.318, P < 0.01) compared to rural households (OR: 2.951, P < 0.01). Households from the lower income quintiles, caste, poor physical condition of their houses, poor garbage management, and water stagnation around the source of drinking water, strongly predicted malaria vulnerability. Conclusion Household's vulnerability to malaria differed according to state climatic vulnerability level and socioeconomic factors. More efforts by integrating local endemicity, epidemiological, and entomological information about malaria transmission must be considered while designing malaria mitigation strategies for better prevention and treatment outcomes.
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Affiliation(s)
- Pradeep Guin
- Associate Professor, Jindal School of Government and Public Policy, O. P. Jindal Global University, Sonipat, Haryana, India
| | | | - Indranil Mukhopadhyay
- Professor, Jindal School of Government and Public Policy, O. P. Jindal Global University, Sonipat, Haryana, India
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Lalmalsawma P, Balasubramani K, James MM, Pautu L, Prasad KA, Sarma DK, Balabaskaran Nina P. Malaria hotspots and climate change trends in the hyper-endemic malaria settings of Mizoram along the India-Bangladesh borders. Sci Rep 2023; 13:4538. [PMID: 36941291 PMCID: PMC10025798 DOI: 10.1038/s41598-023-31632-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 03/15/2023] [Indexed: 03/23/2023] Open
Abstract
India has made tremendous progress in reducing malaria mortality and morbidity in the last decade. Mizoram State in North-East India is one of the few malaria-endemic regions where malaria transmission has continued to remain high. As Mizoram shares international borders with Bangladesh and Myanmar, malaria control in this region is critical for malaria elimination efforts in all the three countries. For identifying hotspots for targeted intervention, malaria data from 385 public health sub-centers across Mizoram were analyzed in the Geographic Information System. Almost all the sub-centers reporting high Annual Parasite Index (> 10) are located in Mizoram's districts that border Bangladesh. Getis-Ord Gi* statistic shows most of the sub-centers located along the Bangladesh border in the Lawngtlai and Lunglei districts to be the malaria hotspots. The hotspots also extended into the Mamit and Siaha districts, especially along the borders of Lawngtlai and Lunglei. Analysis of terrain, climatic, and land use/land cover datasets obtained from the Global Modelling and Assimilation Office and satellite images show Mizoram's western part (Lawngtlai, Lunglei, and Mamit districts) to experience similar topographic and climatic conditions as the bordering Rangamati district in the Chittagong division of Bangladesh. Climatic trends in this region from 1981 to 2021, estimated by the Mann-Kendall test and Sen's slope estimates, show an increasing trend in minimum temperature, relative humidity, rainfall, and the associated shift of climatic pattern (temperate to tropical monsoon) could facilitate malaria transmission. The quasi-Poisson regression model estimates a strong association (p < 0.001) between total malaria cases, temperature range, and elevation. The Kruskal-Wallis H test shows a statistically significant association between malaria cases and forest classes (p < 0.001). A regional coordination and strategic plan are required to eliminate malaria from this hyper-endemic malaria region of North-East India.
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Affiliation(s)
- Pachuau Lalmalsawma
- Integrated Disease Surveillance Programme, Health and Family Welfare Department, Aizawl, Mizoram, India
| | - K Balasubramani
- Department of Geography, School of Earth Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - Meenu Mariya James
- Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - Lalfakzuala Pautu
- Integrated Disease Surveillance Programme, Health and Family Welfare Department, Aizawl, Mizoram, India
- Department of Life Sciences, Pachhunga University College, Mizoram University, Aizawl, Mizoram, India
| | - Kumar Arun Prasad
- Department of Geography, School of Earth Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - Devojit Kumar Sarma
- ICMR- National Institute for Research in Environmental Health, Bhopal, Madhya Pradesh, India.
| | - Praveen Balabaskaran Nina
- Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India.
- Department of Public Health and Community Medicine, Central University of Kerala, Kasaragod, Kerala, India.
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Tian H. Modeling malaria elimination with changing landscapes, climate, and potentially invasive vectors. Proc Natl Acad Sci U S A 2023; 120:e2301653120. [PMID: 36877835 PMCID: PMC10242722 DOI: 10.1073/pnas.2301653120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Affiliation(s)
- Huaiyu Tian
- State Key Laboratory of Remote Sensing Science, Center for Global Change and Public Health, College of Global Change and Earth System Science, Beijing Normal University, 100875Beijing, China
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Tangena JAA, Mategula D, Sedda L, Atkinson PM. Unravelling the impact of insecticide-treated bed nets on childhood malaria in Malawi. Malar J 2023; 22:16. [PMID: 36635658 PMCID: PMC9837906 DOI: 10.1186/s12936-023-04448-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 01/06/2023] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND To achieve malaria elimination it is essential to understand the impact of insecticide-treated net (ITNs) programmes. Here, the impact of ITN access and use on malaria prevalence in children in Malawi was investigated using Malaria Indicator Survey (MIS) data. METHODS MIS data from 2012, 2014 and 2017 were used to investigate the relationship between malaria prevalence in children (6-59 months) and ITN use. Generalized linear modelling (GLM), geostatistical mixed regression modelling and non-stationary GLM were undertaken to evaluate trends, spatial patterns and local dynamics, respectively. RESULTS Malaria prevalence in Malawi was 27.1% (95% CI 23.1-31.2%) in 2012 and similar in both 2014 (32.1%, 95% CI 25.5-38.7) and 2017 (23.9%, 95% CI 20.3-27.4%). ITN coverage and use increased during the same time period, with household ITN access growing from 19.0% (95% CI 15.6-22.3%) of households with at least 1 ITN for every 2 people sleeping in the house the night before to 41.7% (95% CI 39.1-44.4%) and ITN use from 41.1% (95% CI 37.3-44.9%) of the population sleeping under an ITN the previous night to 57.4% (95% CI 55.0-59.9%). Both the geostatistical and non-stationary GLM regression models showed child malaria prevalence had a negative association with ITN population access and a positive association with ITN use although affected by large uncertainties. The non-stationary GLM highlighted the spatital heterogeneity in the relationship between childhood malaria and ITN dynamics across the country. CONCLUSION Malaria prevalence in children under five had a negative association with ITN population access and a positive association with ITN use, with spatial heterogeneity in these relationships across Malawi. This study presents an important modelling approach that allows malaria control programmes to spatially disentangle the impact of interventions on malaria cases.
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Affiliation(s)
- Julie-Anne A. Tangena
- grid.48004.380000 0004 1936 9764Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Donnie Mategula
- grid.48004.380000 0004 1936 9764Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK ,grid.419393.50000 0004 8340 2442Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Luigi Sedda
- grid.9835.70000 0000 8190 6402Lancaster Ecology and Epidemiology Group, Lancaster University, Lancaster, UK
| | - Peter M. Atkinson
- grid.9835.70000 0000 8190 6402Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YR UK ,grid.5491.90000 0004 1936 9297Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ UK ,grid.9227.e0000000119573309Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing, 100101 China
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Ahmed A, Irish SR, Zohdy S, Yoshimizu M, Tadesse FG. Strategies for conducting Anopheles stephensi surveys in non-endemic areas. Acta Trop 2022; 236:106671. [PMID: 36058292 PMCID: PMC11004664 DOI: 10.1016/j.actatropica.2022.106671] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/29/2022]
Abstract
Anopheles stephensi, a malaria vector species previously only known from Asia, was first detected in Africa in Djibouti in 2012, has been subsequently collected in Ethiopia, Sudan, and Somalia, and may be spreading further. Countries may wish to implement mosquito surveys to determine if An. stephensi is present, or to determine the extent of its distribution, if present. Furthermore, mosquito surveys can provide data on the bionomics of An. stephensi and its adaptation to the local environment that can help plan and implement control activities. The present strategies provide suggestions on surveillance approaches for monitoring An. stephensi. The first step is to determine the aim of the study, as this will determine the specific activities conducted in each location. Challenges related to identification and detection of resistance and sporozoites are also discussed. Results should be communicated to relevant stakeholders in a timely manner, both in country and internationally, to help understand the introduction, distribution, and bionomics of An. stephensi in a given country and work towards cross-border and coordinated international response.
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Affiliation(s)
- Ayman Ahmed
- Swiss Tropical and Public Health Institute (Swiss TPH), Kreuzstrasse 2, 4123 Allschwil, Switzerland; Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland; Institute of Endemic Diseases, University of Khartoum, P.O. Box 102, 11111 Khartoum, Sudan; Molecular Biology Unit, Sirius Training and Research Centre, 47 Al Steen Street, 11111 Khartoum, Sudan; Directorate of Environmental Health, Federal Ministry of Health, P.O. Box 303, 11111 Khartoum, Sudan
| | - Seth R Irish
- Swiss Tropical and Public Health Institute (Swiss TPH), Kreuzstrasse 2, 4123 Allschwil, Switzerland; Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland; U.S. President's Malaria Initiative, Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, United States.
| | - Sarah Zohdy
- U.S. President's Malaria Initiative, Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, United States
| | - Melissa Yoshimizu
- U.S. President's Malaria Initiative, U.S. Agency for International Development, 500 D Street SW, Washington, DC 20547, United States
| | - Fitsum G Tadesse
- Malaria and NTD directorate, Armauer Hansen Research Institute, P.O. Box 1005, ALERT Hospital Compound, Addis Ababa, Ethiopia
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Chakrabarti R, Chery-Karschney L, White J, Mascarenhas A, Skillman KM, Kanjee U, Babar PH, Patrapuvich R, Mohapatra PK, Patankar S, Smith JD, Anvikar A, Valecha N, Rahi M, Duraisingh MT, Rathod PK. Diverse Malaria Presentations across National Institutes of Health South Asia International Center for Excellence in Malaria Research Sites in India. Am J Trop Med Hyg 2022; 107:107-117. [PMID: 36228910 PMCID: PMC9662227 DOI: 10.4269/ajtmh.21-1344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 05/14/2022] [Indexed: 11/07/2022] Open
Abstract
The Malaria Evolution in South Asia (MESA) International Center for Excellence in Malaria Research (ICEMR) was established by the US National Institutes of Health (US NIH) as one of 10 malaria research centers in endemic countries. In 10 years of hospital-based and field-based work in India, the MESA-ICEMR has documented the changing epidemiology and transmission of malaria in four different parts of India. Malaria Evolution in South Asia-ICEMR activities, in collaboration with Indian partners, are carried out in the broad thematic areas of malaria case surveillance, vector biology and transmission, antimalarial resistance, pathogenesis, and host response. The program integrates insights from surveillance and field studies with novel basic science studies. This is a two-pronged approach determining the biology behind the disease patterns seen in the field, and generating new relevant biological questions about malaria to be tested in the field. Malaria Evolution in South Asia-ICEMR activities inform local and international stakeholders on the current status of malaria transmission in select parts of South Asia including updates on regional vectors of transmission of local parasites. The community surveys and new laboratory tools help monitor ongoing efforts to control and eliminate malaria in key regions of South Asia including the state of evolving antimalarial resistance in different parts of India, new host biomarkers of recent infection, and molecular markers of pathogenesis from uncomplicated and severe malaria.
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Affiliation(s)
- Rimi Chakrabarti
- Department of Chemistry, University of Washington, Seattle, Washington
- Department of Medicine, Goa Medical College and Hospital, Bambolim, Goa, India
| | | | - John White
- Department of Chemistry, University of Washington, Seattle, Washington
| | - Anjali Mascarenhas
- Department of Chemistry, University of Washington, Seattle, Washington
- Department of Medicine, Goa Medical College and Hospital, Bambolim, Goa, India
| | - Kristen M. Skillman
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Prasad H. Babar
- Department of Chemistry, University of Washington, Seattle, Washington
- Department of Medicine, Goa Medical College and Hospital, Bambolim, Goa, India
| | - Rapatbhorn Patrapuvich
- Drug Research Unit for Malaria (DRUM), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Swati Patankar
- Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai, India
| | | | - Anup Anvikar
- National Institute of Biologicals, Noida, UP, India
| | - Neena Valecha
- National Institute of Malaria Research, New Delhi, India
| | - Manju Rahi
- Division of Epidemiology and Communicable Disease, Indian Council of Medical Research, New Delhi, India
| | - Manoj T. Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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20
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Meireles ACA, da Silva LR, Simplício MF, de Lima AA, Rios FGF, de Menezes CA, Feitoza LHM, Julião GR. Anopheline diversity in urban and peri-urban malaria foci: comparison between alternative traps and seasonal effects in a city in the Western Brazilian Amazon. Malar J 2022; 21:258. [PMID: 36068530 PMCID: PMC9450372 DOI: 10.1186/s12936-022-04274-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 08/22/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Continuous vector surveillance and sustainable interventions are mandatory in order to prevent anopheline proliferation (or spread to new areas) and interrupt malaria transmission. Anopheline abundance and richness were evaluated in urban and peri-urban malaria foci at a medium-sized city in the Brazilian Amazon, comparing the protected human landing catch technique (PHLC) and alternative sampling methods over different seasonal periods. Additional information was assessed for female feeding behaviour and faunal composition. METHODS Anophelines were sampled bimonthly in four urban and peri-urban sites in the city of Porto Velho, state of Rondônia, Brazil. The average number of captured mosquitoes was compared between an PHLC (gold standard), a tent trap (Gazetrap), and a barrier screen by means of generalized linear mixed models (GLMM), which also included season and environment (peri-urban/urban) as predictors. RESULTS Overall, 2962 Anopheles individuals belonging to 12 species and one complex were caught; Anopheles darlingi represented 86% of the individuals. More mosquitoes were captured in the peri-urban setting, and the urban setting was more diverse. The model estimates that significantly more anophelines were collected by PHLC than by the Screen method, and Gazetrap captured fewer individuals. However, the Screen technique yielded more blood-engorged females. The peak hours of biting activity were from 6 to 7 p.m. in urban areas and from 7 to 8 p.m. in peri-urban areas. CONCLUSIONS Although peri-urban settings presented a greater abundance of anophelines, Shannon and Simpson diversities were higher in urban sites. Each technique proved to be useful, depending on the purpose: PHLC was more effective in capturing the highest anopheline densities, Gazetrap caught the greatest number of species, and the barrier screen technique captured more engorged individuals. There was no seasonal effect on Anopheles assemblage structure; however, a more diverse fauna was caught in the transitional season. Biting activity was more intense from 6 to 8 p.m., with a predominance of An. darlingi.
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Affiliation(s)
- Anne Caroline Alves Meireles
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil. .,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil.
| | - Lucas Rosendo da Silva
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil.,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil.,INCT-EpiAmO - National Institute of Epidemiology of Western Amazônia, Porto Velho, RO, Brazil
| | - Marlon Ferreira Simplício
- Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Alzemar Alves de Lima
- Centro de Pesquisa em Medicina Tropical de Rondônia, CEPEM-RO, Porto Velho, RO, 76812-329, Brazil.,Centro Universitário São Lucas, Porto Velho, RO, 76805-846, Brazil
| | - Flávia Geovana Fontineles Rios
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil.,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Carla Augusta de Menezes
- Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Luiz Henrique Maciel Feitoza
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil.,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Genimar Rebouças Julião
- Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil.,INCT-EpiAmO - National Institute of Epidemiology of Western Amazônia, Porto Velho, RO, Brazil
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Chala B, Tilaye T. Assessment of malaria prevalence in Boset District, East Shawa Zone, Oromia Regional State, Ethiopia: a retrospective study. J Int Med Res 2022. [PMCID: PMC9478720 DOI: 10.1177/03000605221121957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective In this study, we aimed to assess the epidemiological profile and associated
risk factors of malaria in Boset District using clinical records from the
Boset District Health Office Central Surveillance Unit, East Shawa Zone,
Oromia, Ethiopia. Methods This health facility-based retrospective cross-sectional study included
clinical malaria data for 5 years (2016–2020) recorded at all public and
private health facilities in the district. Results The present study revealed an overall malaria slide positivity rate of 12.4%
(21,059/169,986), ranging from 23.3% to 5.3% during 2016–2020 in Boset
District. Malaria cases were recorded in all age groups, but individuals
aged 15 years and above accounted for a higher (56.2%) average proportion of
malaria cases. Concerning the relative proportion of malaria parasite
species, Plasmodium falciparum was slightly predominant
(58%) over P. vivax (42%). Conclusion The present study revealed a declining trend in malaria cases over the 5-year
study period in Boset District. Scaling up the available malaria prevention
strategies and control measures is recommended to achieve malaria
pre-elimination.
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Affiliation(s)
- Bayissa Chala
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia
| | - Tigist Tilaye
- Olanchiti Hospital, Oromia Health Bureau, Oromia Regional State, Ethiopia
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22
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Hassen J, Dinka H. Magnitude of urban malaria and its associated risk factors: the case of Batu town, Oromia Regional State, Ethiopia. J Int Med Res 2022; 50:3000605221080686. [PMID: 35259963 PMCID: PMC8918979 DOI: 10.1177/03000605221080686] [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] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE This study aimed to assess the magnitude of malaria and its associated risk factors in urban, Batu town, Oromia Regional State, Ethiopia. METHODS This health-facility based prospective cross-sectional study enrolled 356 febrile malaria patients to assess risk factors associated with malaria infection. RESULTS An overall positivity rate of 17.13% (61/356) for malaria infection was observed. Among the malaria-positive patients, 50.8% (31/61) of them were positive for Plasmodium vivax, 45.90% (28/61) were positive for Plasmodium falciparum, and 3.3% (2/61) had mixed infections of P. falciparum and P. vivax. Logistic regression analysis revealed that individuals who possessed insecticide-treated net (Odds ratio [OR] = 0.38, 95% confidence interval [CI] [0.194, 0.743]) and whose houses were sprayed with insecticides (OR = 0.18, 95% CI [0.097, 0.34]) were significantly less likely to have a malaria infection. Individuals living closer to stagnant water had a significantly greater chance of malaria infection than those who lived a distance from stagnant water (OR = 0.34, 95% CI [0.19, 0.59]). CONCLUSION The present study revealed that malaria remains a public health problem in the urban area of Batu town, which suggests that the same might be true for other urban areas in the country.
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Affiliation(s)
- Jifar Hassen
- Department of Applied Biology, 125545Adama Science and Technology University, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Oromia, Ethiopia
| | - Hunduma Dinka
- Department of Applied Biology, 125545Adama Science and Technology University, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Oromia, Ethiopia
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Ravishankaran S, Asokan A, Justin NAJA, Thomas S, Joshua V, Mathai MT, Eapen A. Does the roof type of a house influence the presence of adult Anopheles stephensi, urban malaria vector? - evidence from a few slum settings in Chennai, India. Parasitol Res 2022; 121:105-114. [PMID: 34773504 PMCID: PMC8995298 DOI: 10.1007/s00436-021-07376-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/08/2021] [Indexed: 01/03/2023]
Abstract
In an urban setting, it is a difficult task to collect adult Anopheles stephensi, unlike the immature stages, due to various reasons. A longitudinal study was undertaken from January 2016 to April 2017, with CDC light traps to collect adult Anopheles stephensi and other mosquito species in houses located in a few slums of Chennai, India. A total of 203 trap collections were made indoors from human dwellings having different roof types, as well as outdoors. Three to four trap collections were made at night (18:00 to 06:00 h) once a week. Overall, Culex quinquefasciatus (64%) was the predominant mosquito species captured, followed by An. stephensi (24%). In 98 of the 203 trap collections (48.3%), at least one female An. stephensi was trapped. In all, 224 female An. stephensi were trapped, of which the majority were collected during monsoon and winter seasons. Compared to outdoors, 10% more An. stephensi, the majority of them unfed, were collected indoors, with relatively more contribution coming from asbestos-roofed houses (71.4%), followed by thatched-roof houses (47.3%). Overall, 2.2% positivity for Plasmodium vivax was detected in An. stephensi through Circumsporozoite-ELISA. Binary logistic regression model indicated that season (winter and monsoon), asbestos-roofed dwelling, lesser number of rooms in a house, and more members in a family were significant predictor variables for the odds of trapping an An. stephensi. The study brought out significant factors associated with the presence of An. stephensi in urban slums setting in Chennai, where malaria is declining. The findings would help in devising targeted, effective vector control interventions for malaria elimination in urban settings.
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Affiliation(s)
- Sangamithra Ravishankaran
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India,Department of Zoology, Madras Christian College, Tambaram, Chennai-600 059, Tamil Nadu, India
| | - Aswin Asokan
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India
| | - N A Johnson Amala Justin
- Regional Office for Health and Family Welfare, A-2A, Rajaji Bhavan, Besant Nagar, Chennai- 600 090, Tamil Nadu, India
| | - Shalu Thomas
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India,Department of Zoology, Madras Christian College, Tambaram, Chennai-600 059, Tamil Nadu, India
| | - Vasna Joshua
- ICMR-National Institute of Epidemiology, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India
| | - Manu Thomas Mathai
- Department of Zoology, Madras Christian College, Tambaram, Chennai-600 059, Tamil Nadu, India
| | - Alex Eapen
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India,Corresponding author:
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Nieto-Sanchez C, Dens S, Solomon K, Haile A, Yuan Y, Hawer T, Yewhalaw D, Addissie A, Grietens KP. Beyond eves and cracks: An interdisciplinary study of socio-spatial variation in urban malaria transmission in Ethiopia. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000173. [PMID: 36962186 PMCID: PMC10021683 DOI: 10.1371/journal.pgph.0000173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 02/23/2022] [Indexed: 11/18/2022]
Abstract
During the past century, the global trend of reduced malaria transmission has been concurrent with increasing urbanization. Although urbanization has traditionally been considered beneficial for vector control, the adaptation of malaria vectors to urban environments has created concerns among scientific communities and national vector control programs. Since urbanization rates in Ethiopia are among the highest in the world, the Ethiopian government developed an initiative focused on building multi-storied units organized in condominium housing. This study aimed to develop an interdisciplinary methodological approach that integrates architecture, landscape urbanism, medical anthropology, and entomology to characterize exposure to malaria vectors in this form of housing in three condominiums in Jimma Town. Mosquitoes were collected using light trap catches (LTCs) both indoor and outdoor during 2019's rainy season. Architectural drawings and ethnographic research were superposed to entomological data to detect critical interactions between uses of the space and settlement conditions potentially affecting malaria vector abundance and distribution. A total of 34 anopheline mosquitoes comprising three species (Anopheles gambiae s.l, An. pharoensis and An. coustani complex) were collected during the three months of mosquito collection. Anopheles gambiae s.l, the principal malaria vector in Ethiopia, was the predominant species of all the anophelines collected. Distribution of mosquito breeding sites across scales (household, settlement, urban landscape) is explained by environmental conditions, socio-cultural practices involving modification of existing spaces, and systemic misfits between built environment and territory. Variations in mosquito abundance and distribution in this study were mainly related to standard building practices that ignore the original logics of the territory, deficiency of water and waste disposal management systems, and adaptations of the space to fit heterogeneous lifestyles of residents. Our results indicate that contextualizing malaria control strategies in relation to vector ecology, social dynamics determining specific uses of the space, as well as building and territorial conditions could strengthen current elimination efforts. Although individual housing remains a critical unit of research for vector control interventions, this study demonstrates the importance of studying housing settlements at communal level to capture systemic interactions impacting transmission at the household level and in outdoor areas.
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Affiliation(s)
- Claudia Nieto-Sanchez
- Department of Public Health, Unit of Socio-Ecological Health Research, Institute of Tropical Medicine, Antwerp, Belgium
| | - Stefanie Dens
- Witteveen+Bos Belgium N.V., Antwerp, Belgium
- Research Group for Urban Development, Faculty of Design Sciences, University of Antwerp, Antwerp, Belgium
| | - Kalkidan Solomon
- Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Asgedom Haile
- Ethiopian Institute of Architecture, Building Construction, and City Development (EiABC), Addis Ababa University, Addis Ababa, Ethiopia
| | - Yue Yuan
- Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | | | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Adamu Addissie
- Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Koen Peeters Grietens
- Department of Public Health, Unit of Socio-Ecological Health Research, Institute of Tropical Medicine, Antwerp, Belgium
- Witteveen+Bos Belgium N.V., Antwerp, Belgium
- Research Group for Urban Development, Faculty of Design Sciences, University of Antwerp, Antwerp, Belgium
- Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
- Ethiopian Institute of Architecture, Building Construction, and City Development (EiABC), Addis Ababa University, Addis Ababa, Ethiopia
- Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
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Larson PS, Eisenberg JNS, Berrocal VJ, Mathanga DP, Wilson ML. An urban-to-rural continuum of malaria risk: new analytic approaches characterize patterns in Malawi. Malar J 2021; 20:418. [PMID: 34689786 PMCID: PMC8543962 DOI: 10.1186/s12936-021-03950-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 10/12/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The urban-rural designation has been an important risk factor in infectious disease epidemiology. Many studies rely on a politically determined dichotomization of rural versus urban spaces, which fails to capture the complex mosaic of infrastructural, social and environmental factors driving risk. Such evaluation is especially important for Plasmodium transmission and malaria disease. To improve targeting of anti-malarial interventions, a continuous composite measure of urbanicity using spatially-referenced data was developed to evaluate household-level malaria risk from a house-to-house survey of children in Malawi. METHODS Children from 7564 households from eight districts throughout Malawi were tested for presence of Plasmodium parasites through finger-prick blood sampling and slide microscopy. A survey questionnaire was administered and latitude and longitude coordinates were recorded for each household. Distances from households to features associated with high and low levels of development (health facilities, roads, rivers, lakes) and population density were used to produce a principal component analysis (PCA)-based composite measure for all centroid locations of a fine geo-spatial grid covering Malawi. Regression methods were used to test associations of the urbanicity measure against Plasmodium infection status and to predict parasitaemia risk for all locations in Malawi. RESULTS Infection probability declined with increasing urbanicity. The new urbanicity metric was more predictive than either a governmentally defined rural/urban dichotomous variable or a population density variable. One reason for this was that 23% of cells within politically defined rural areas exhibited lower risk, more like those normally associated with "urban" locations. CONCLUSIONS In addition to increasing predictive power, the new continuous urbanicity metric provided a clearer mechanistic understanding than the dichotomous urban/rural designations. Such designations often ignore urban-like, low-risk pockets within traditionally rural areas, as were found in Malawi, along with rural-like, potentially high-risk environments within urban areas. This method of characterizing urbanicity can be applied to other infectious disease processes in rapidly urbanizing contexts.
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Affiliation(s)
- Peter S Larson
- Department of Epidemiology, School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI, 48109, USA
| | - Joseph N S Eisenberg
- Department of Epidemiology, School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI, 48109, USA
| | - Veronica J Berrocal
- Department of Statistics, School of Information and Computer Sciences, University of California, Irvine, CA, 92697, USA
| | - Don P Mathanga
- Malaria Alert Centre, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Community Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI, 48109, USA.
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Reasons for seeking care and adherence to pretravel preparation in expatriate or long-term travelers' children in the tropics: A French prospective study. Travel Med Infect Dis 2021; 46:102184. [PMID: 34699957 DOI: 10.1016/j.tmaid.2021.102184] [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: 02/17/2021] [Revised: 09/16/2021] [Accepted: 10/18/2021] [Indexed: 11/21/2022]
Abstract
BACKGROUND Studies on pediatric travelers' health rarely address expat or long-term travelers' children. METHOD To investigate reasons for seeking care and adherence to pretravel preparation, we prospectively enrolled French children 0-15 years old, either expatriates or staying >6 months in tropical areas, who attended a French health center in Africa, Central America or Southern Pacific regions from October 01, 2011 to October 31, 2012. A standardized questionnaire was completed by a general practitioner at each visit, then anonymized and included in our database. RESULTS 464 questionnaires were collected from 367 children (sex ratio M/F: 1:1). Median age was 6.4 years (IQR: 3.6; 10.3). Reasons for seeking care were mostly infections (n = 378), of which 12 (3.2%) were tropical. There were no deaths, but one child with tuberculosis was repatriated. Coverage was high for routine immunization, but less for travel-related vaccines. Personal antivectorial protection was significantly lower in children aged >5 y or in non-malarial areas. Where indicated, malarial chemoprophylaxis was prescribed to only one third of the children, of whom 60% were poorly compliant. Advice regarding measures against diarrhea and sunburn was followed significantly more for stays >2 yrs. CONCLUSION Mild cosmopolitan illnesses predominated but protection against tropical threats should be optimized before and during the stay.
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Marques RD, Angelo JR, Lima AAD, Fuller T, Barcellos C. Production of Urban Space and the occurrence of malaria in the Brazilian Amazon: the Porto Velho case. CIENCIA & SAUDE COLETIVA 2021; 26:4263-4274. [PMID: 34586277 DOI: 10.1590/1413-81232021269.24242020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/23/2020] [Indexed: 11/22/2022] Open
Abstract
Due to intense ongoing urbanization in the Amazon, the urban pattern of malaria may be changing, both in its spatial distribution and epidemiological profile. The purpose of this paper is to analyze how the process of production of urban space in Porto Velho, the capital of the state of Rondonia, Brazil has contributed to the occurrence and maintenance of urban malaria. Using data collected from the Malaria Epidemiological Surveillance System (SIVEP-Malaria), we calculated malaria indices for the districts of Porto Velho from 2005 to 2018. We also developed two typologies for classifying urban space based on functional characteristics and features of the landscape. While the former considers characteristics of urban space in Porto Velho, the latter is based on suitability for malaria vectors. We found that the annual parasite index declined in Porto Velho during the study period. However, changes in the index were not uniform across the districts of the city. Periurban areas showed no decline in the index, which we attribute to these areas' high vegetation density and hydrological characteristics.
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Affiliation(s)
- Renata Duarte Marques
- Escola Nacional de Saúde Pública Sérgio Arouca, Fundação Oswaldo Cruz (Fiocruz). R. Leopoldo Bulhões 1480, Manguinhos. 21041-210 Rio de Janeiro RJ Brasil.
| | - Jussara Rafael Angelo
- Escola Nacional de Saúde Pública Sérgio Arouca, Fundação Oswaldo Cruz (Fiocruz). R. Leopoldo Bulhões 1480, Manguinhos. 21041-210 Rio de Janeiro RJ Brasil.
| | - Alzemar Alves de Lima
- Centro de Pesquisa em Medicina Tropical de Rondônia, Laboratório de Epidemiologia. Porto Velho RO Brasil
| | - Trevon Fuller
- Institute of the Environment and Sustainability, University of California. Los Angeles California USA
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Quaresima V, Agbenyega T, Oppong B, Awunyo JADA, Adu Adomah P, Enty E, Donato F, Castelli F. Are Malaria Risk Factors Based on Gender? A Mixed-Methods Survey in an Urban Setting in Ghana. Trop Med Infect Dis 2021; 6:161. [PMID: 34564545 PMCID: PMC8482108 DOI: 10.3390/tropicalmed6030161] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
Malaria still represents one of the most debilitating and deadly diseases in the world. It has been suggested that malaria has different impacts on women and men due to both social and biological factors. A gender perspective is therefore important to understand how to eliminate malaria. This study aimed to investigate malaria from a gender perspective in a non-for-profit private health facility, HopeXchange Medical Centre, based in Kumasi (Ghana). A sequential mixed-methods design, comprising quantitative and qualitative methods, was used. This study found low ownership (40%) and use (19%) of insecticide-treated nets (ITNs). Most malaria cases were women (62%), who were less educated and had more external risk factors associated with infection. Our study reported a trend of preferring malaria self-medication at home, which was practiced mostly by men (43%). Our data suggest that women are more likely to be exposed to malaria infections than men, especially due to their prolonged exposure to mosquito bites during the most dangerous hours. Our study highlighted the need for future malaria control policies to be more focused on social and behavioral aspects and from a gender perspective.
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Affiliation(s)
- Virginia Quaresima
- University Department of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili of Brescia, 25123 Brescia, Italy;
- Department of Civil, Environmental, Architectural Engineering and Mathematics (DICATAM), University of Brescia, 25123 Brescia, Italy
- Centro di Ricerca Emato-Oncologica AIL (CREA), Diagnostic Department, ASST Spedali Civili of Brescia, 25123 Brescia, Italy
| | - Tsiri Agbenyega
- Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana;
- HopeXchange Medical Centre, Kumasi, Ghana; (B.O.); (J.A.D.A.A.); (P.A.A.); (E.E.)
| | - Bismark Oppong
- HopeXchange Medical Centre, Kumasi, Ghana; (B.O.); (J.A.D.A.A.); (P.A.A.); (E.E.)
| | | | - Priscilla Adu Adomah
- HopeXchange Medical Centre, Kumasi, Ghana; (B.O.); (J.A.D.A.A.); (P.A.A.); (E.E.)
| | - Eunice Enty
- HopeXchange Medical Centre, Kumasi, Ghana; (B.O.); (J.A.D.A.A.); (P.A.A.); (E.E.)
| | - Francesco Donato
- University Department of Hygiene, Epidemiology and Public Health, University of Brescia, 25123 Brescia, Italy;
| | - Francesco Castelli
- University Department of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili of Brescia, 25123 Brescia, Italy;
- UNESCO Chair ‘Training and Empowering Human Resources for Health Development in Resource-Limited Countries’, University of Brescia, 25123 Brescia, Italy
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Deutsch-Feldman M, Brazeau NF, Parr JB, Thwai KL, Muwonga J, Kashamuka M, Tshefu Kitoto A, Aydemir O, Bailey JA, Edwards JK, Verity R, Emch M, Gower EW, Juliano JJ, Meshnick SR. Spatial and epidemiological drivers of Plasmodium falciparum malaria among adults in the Democratic Republic of the Congo. BMJ Glob Health 2021; 5:bmjgh-2020-002316. [PMID: 32601091 PMCID: PMC7326263 DOI: 10.1136/bmjgh-2020-002316] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/22/2020] [Accepted: 04/25/2020] [Indexed: 11/17/2022] Open
Abstract
Background Adults are frequently infected with malaria and may serve as a reservoir for further transmission, yet we know relatively little about risk factors for adult infections. In this study, we assessed malaria risk factors among adults using samples from the nationally representative, cross-sectional 2013–2014 Demographic and Health Survey (DHS) conducted in the Democratic Republic of the Congo (DRC). We further explored differences in risk factors by urbanicity. Methods Plasmodium falciparum infection was determined by PCR. Covariates were drawn from the DHS to model individual, community and environmental-level risk factors for infection. Additionally, we used deep sequencing data to estimate the community-level proportions of drug-resistant infections and included these estimates as potential risk factors. All identified factors were assessed for differences in associations by urbanicity. Results A total of 16 126 adults were included. Overall prevalence of malaria was 30.3% (SE=1.1) by PCR; province-level prevalence ranged from 6.7% to 58.3%. Only 17% of individuals lived in households with at least one bed-net for every two people, as recommended by the WHO. Protective factors included increasing within-household bed-net coverage (Prevalence Ratio=0.85, 95% CI=0.76–0.95) and modern housing (PR=0.58, 95% CI=0.49–0.69). Community-level protective factors included increased median wealth (PR=0.87, 95% CI=0.83–0.92). Education, wealth, and modern housing showed protective associations in cities but not in rural areas. Conclusions The DRC continues to suffer from a high burden of malaria; interventions that target high-risk groups and sustained investment in malaria control are sorely needed. Areas of high prevalence should be prioritised for interventions to target the largest reservoirs for further transmission.
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Affiliation(s)
- Molly Deutsch-Feldman
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nicholas F Brazeau
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jonathan B Parr
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Kyaw L Thwai
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jeremie Muwonga
- National AIDS Control Program, Kinshasa, Congo (the Democratic Republic)
| | - Melchior Kashamuka
- School of Public Health, University of Kinshasa Faculty of Medicine, Kinshasa, Congo (the Democratic Republic)
| | - Antoinette Tshefu Kitoto
- School of Public Health, University of Kinshasa Faculty of Medicine, Kinshasa, Congo (the Democratic Republic)
| | - Ozkan Aydemir
- Department of Pathology and Laboratory Medicine, Brown University Warren Alpert Medical School, Providence, Rhode Island, USA
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University Warren Alpert Medical School, Providence, Rhode Island, USA
| | - Jessie K Edwards
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Robert Verity
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Michael Emch
- Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Emily W Gower
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jonathan J Juliano
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Tadesse FG, Ashine T, Teka H, Esayas E, Messenger LA, Chali W, Meerstein-Kessel L, Walker T, Wolde Behaksra S, Lanke K, Heutink R, Jeffries CL, Mekonnen DA, Hailemeskel E, Tebeje SK, Tafesse T, Gashaw A, Tsegaye T, Emiru T, Simon K, Bogale EA, Yohannes G, Kedir S, Shumie G, Sabir SA, Mumba P, Dengela D, Kolaczinski JH, Wilson A, Churcher TS, Chibsa S, Murphy M, Balkew M, Irish S, Drakeley C, Gadisa E, Bousema T. Anopheles stephensi Mosquitoes as Vectors of Plasmodium vivax and falciparum, Horn of Africa, 2019. Emerg Infect Dis 2021; 27:603-607. [PMID: 33496217 PMCID: PMC7853561 DOI: 10.3201/eid2702.200019] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Anopheles stephensi mosquitoes, efficient vectors in parts of Asia and Africa, were found in 75.3% of water sources surveyed and contributed to 80.9% of wild-caught Anopheles mosquitoes in Awash Sebat Kilo, Ethiopia. High susceptibility of these mosquitoes to Plasmodium falciparum and vivax infection presents a challenge for malaria control in the Horn of Africa.
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McCoy KD, Weldon CT, Ansumana R, Lamin JM, Stenger DA, Ryan SJ, Bardosh K, Jacobsen KH, Dinglasan RR. Are malaria transmission-blocking vaccines acceptable to high burden communities? Results from a mixed methods study in Bo, Sierra Leone. Malar J 2021; 20:183. [PMID: 33849572 PMCID: PMC8045381 DOI: 10.1186/s12936-021-03723-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 04/04/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Malaria transmission-blocking vaccines (TBVs) could help break the cycle of malaria transmission by conferring community rather than individual protection. When introducing new intervention strategies, uptake is dependent on acceptability, not just efficacy. In this exploratory study on acceptability of TBVs in Sierra Leone, it was hypothesized that TBVs would be largely acceptable to adults and health workers in areas with relatively few ongoing malaria interventions, and that (i) knowledge of malaria and vaccines, (ii) health behaviours associated with malaria and vaccines, and (iii) attitudes towards different vaccines types could lead to greater TBV acceptability. METHODS This study used a mixed methods approach in Bo, Sierra Leone, to understand community knowledge, attitudes, and practices related to malaria and vaccination in general. This included: (i) a population-based cross-sectional survey (n=615 adults), (ii) 6 focus group discussions with parents, and (iii) 20 key informant interviews. The concept of a TBV was explained to participants before they were asked about their willingness to accept this vaccine modality as part of an integrated malaria elimination programme. RESULTS This study found that most adults would be willing to receive a TBV vaccine. Respondents noted mostly positive past experiences with adult and childhood vaccinations for other infectious diseases and high levels of engagement in other malaria prevention behaviors such as bed nets. Perceived barriers to TBV acceptance were largely focused on general community-level distribution of a vaccine, including personal fears of vaccination and possible costs. After an explanation of the TBV mechanism, nearly all focus group and interview participants believed that community members would accept the vaccine as part of an integrated malaria control approach. Both parents and health workers offered insight on how to successfully roll-out a future TBV vaccination programme. CONCLUSIONS The willingness of community members in Bo, Sierra Leone to accept a TBV as part of an integrated anti-malarial strategy suggests that the atypical mechanism of TBV action might not be an obstacle to future clinical trials. This study's findings suggests that perceived general barriers to vaccination implementation, such as perceived personal fears and vaccine cost, must be addressed in future clinical and implementation research studies.
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Affiliation(s)
- Kaci D McCoy
- CDC Southeastern Center of Excellence in Vector Borne Diseases, Gainesville, FL, USA
- Emerging Pathogens Institute, Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Caroline T Weldon
- CDC Southeastern Center of Excellence in Vector Borne Diseases, Gainesville, FL, USA
| | - Rashid Ansumana
- Mercy Hospital Research Laboratory, Bo, Sierra Leone
- School of Community Health Sciences, Njala University, Bo, Sierra Leone
| | | | - David A Stenger
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC, USA
| | - Sadie J Ryan
- CDC Southeastern Center of Excellence in Vector Borne Diseases, Gainesville, FL, USA
- Emerging Pathogens Institute, Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
- Department of Geography, College of Liberal Arts & Sciences, University of Florida, Gainesville, FL, USA
| | - Kevin Bardosh
- Center for One Health Research, School of Public Health, University of Washington, Seattle, WA, USA
| | - Kathryn H Jacobsen
- Department of Global and Community Health, College of Health and Human Services, George Mason University, Fairfax, VA, USA
| | - Rhoel R Dinglasan
- CDC Southeastern Center of Excellence in Vector Borne Diseases, Gainesville, FL, USA.
- Emerging Pathogens Institute, Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
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Fornace KM, Diaz AV, Lines J, Drakeley CJ. Achieving global malaria eradication in changing landscapes. Malar J 2021; 20:69. [PMID: 33530995 PMCID: PMC7856737 DOI: 10.1186/s12936-021-03599-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/20/2021] [Indexed: 11/10/2022] Open
Abstract
Land use and land cover changes, such as deforestation, agricultural expansion and urbanization, are one of the largest anthropogenic environmental changes globally. Recent initiatives to evaluate the feasibility of malaria eradication have highlighted impacts of landscape changes on malaria transmission and the potential of these changes to undermine malaria control and elimination efforts. Multisectoral approaches are needed to detect and minimize negative impacts of land use and land cover changes on malaria transmission while supporting development aiding malaria control, elimination and ultimately eradication. Pathways through which land use and land cover changes disrupt social and ecological systems to increase or decrease malaria risks are outlined, identifying priorities and opportunities for a global malaria eradication campaign. The impacts of land use and land cover changes on malaria transmission are complex and highly context-specific, with effects changing over time and space. Landscape changes are only one element of a complex development process with wider economic and social dimensions affecting human health and wellbeing. While deforestation and other landscape changes threaten to undermine malaria control efforts and have driven the emergence of zoonotic malaria, most of the malaria elimination successes have been underpinned by agricultural development and land management. Malaria eradication is not feasible without addressing these changing risks while, conversely, consideration of malaria impacts in land management decisions has the potential to significantly accelerate progress towards eradication. Multisectoral cooperation and approaches to linking malaria control and environmental science, such as conducting locally relevant ecological monitoring, integrating landscape data into malaria surveillance systems and designing environmental management strategies to reduce malaria burdens, are essential to achieve malaria eradication.
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Affiliation(s)
- Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. .,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK.
| | - Adriana V Diaz
- Pathology and Population Sciences, Royal Veterinary College, Hatfield, UK
| | - Jo Lines
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
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Johansen IC, Rodrigues PT, Ferreira MU. Human mobility and urban malaria risk in the main transmission hotspot of Amazonian Brazil. PLoS One 2020; 15:e0242357. [PMID: 33237945 PMCID: PMC7688137 DOI: 10.1371/journal.pone.0242357] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/30/2020] [Indexed: 11/22/2022] Open
Abstract
Malaria in the Amazon is often perceived as an exclusively rural disease, but transmission has been increasingly documented within and near urban centers. Here we explore patterns and causes of urban-to-rural mobility, which places travelers at risk of malaria in Mâncio Lima, the main malaria hotspot in northwestern Brazil. We also analyze rural-to-urban mobility caused by malaria treatment seeking, which poses an additional risk of infection to urban residents. We show that the rural localities most frequently visited by urban residents–typically farming settlements in the vicinity of the town–are those with the most intense malaria transmission and also the most frequent source localities of imported malaria cases diagnosed in the town. The most mobile urban residents are typically poor males 16 to 60-years old from multi-sited households who lack a formal job. Highly mobile residents represent a priority target for more intensive and effective malaria control interventions, that cannot be readily delivered to the entire community, in this and similar urbanized endemic settings across the Amazon.
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Affiliation(s)
- Igor C. Johansen
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo (SP), Brazil
- * E-mail: (ICJ); (MUF)
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo (SP), Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo (SP), Brazil
- * E-mail: (ICJ); (MUF)
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Rural-urban variation in insecticide-treated net utilization among pregnant women: evidence from 2018 Nigeria Demographic and Health Survey. Malar J 2020; 19:407. [PMID: 33176799 PMCID: PMC7659074 DOI: 10.1186/s12936-020-03481-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/04/2020] [Indexed: 11/25/2022] Open
Abstract
Background In 2018, Nigeria accounted for the highest prevalence of malaria worldwide. Pregnant women and children under five years bear the highest risk of malaria. Geographical factors affect utilization of insecticide-treated nets (ITN), yet existing literature have paid little attention to the rural–urban dimension of ITN utilization in Nigeria. This study aimed at investigating the rural–urban variation in ITN utilization among pregnant women in Nigeria using data from the 2018 Demographic and Health Survey. Methods A total of 2909 pregnant women were included in the study. The prevalence of ITN utilization for rural and urban pregnant women of Nigeria were presented with descriptive statistics. Chi-square test was employed to assess the association between residence, socio-demographic characteristics and ITN utilization at 95% level of significance. Subsequently, binary logistic regression was used to assess the influence of residence on ITN utilization. Results Eight out of ten of the rural residents utilized ITN (86.1%) compared with 74.1% among urban residents. Relative to urban pregnant women, those in rural Nigeria had higher odds of utilizing ITNs both in the crude [cOR = 2.17, CI = 1.66–2.84] and adjusted models [aOR = 1.18, CI = 1.05–1.24]. Pregnant women aged 40–44 had lower odds of ITN utilization compared to those aged 15–19 [aOR = 0.63, CI = 0.44–0.92]. Poorer pregnant women had higher odds of ITN utilization compared with poorest pregnant women [aOR = 1.09, CI = 1.04–1.32]. Across regions, those in the south [aOR = 0.26, CI = 0.14–0.49] and south-west [aOR = 0.29, CI = 0.16–0.54] had lower odds of ITN use compared to their counterparts in the north-west region. Conclusion The high use of ITNs among pregnant women in Nigeria may be due to the prioritization of rural communities by previous interventions. This is a dimension worth considering to enhance the attainment of the national anti-malarial initiatives. Since possession of ITN is not a guarantee for utilization, women in urban locations need constant reminder of ITN use through messages delivered at ANC and radio advertisements. Moreover, subsequent mass ITN campaigns ought to take cognizance of variations ITN use across regions and pragmatic steps be taken to increase the availability of ITN in households since there is a moderately high use in households with at least one ITN in Nigeria.
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Georganos S, Brousse O, Dujardin S, Linard C, Casey D, Milliones M, Parmentier B, van Lipzig NPM, Demuzere M, Grippa T, Vanhuysse S, Mboga N, Andreo V, Snow RW, Lennert M. Modelling and mapping the intra-urban spatial distribution of Plasmodium falciparum parasite rate using very-high-resolution satellite derived indicators. Int J Health Geogr 2020; 19:38. [PMID: 32958055 PMCID: PMC7504835 DOI: 10.1186/s12942-020-00232-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/08/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The rapid and often uncontrolled rural-urban migration in Sub-Saharan Africa is transforming urban landscapes expected to provide shelter for more than 50% of Africa's population by 2030. Consequently, the burden of malaria is increasingly affecting the urban population, while socio-economic inequalities within the urban settings are intensified. Few studies, relying mostly on moderate to high resolution datasets and standard predictive variables such as building and vegetation density, have tackled the topic of modeling intra-urban malaria at the city extent. In this research, we investigate the contribution of very-high-resolution satellite-derived land-use, land-cover and population information for modeling the spatial distribution of urban malaria prevalence across large spatial extents. As case studies, we apply our methods to two Sub-Saharan African cities, Kampala and Dar es Salaam. METHODS Openly accessible land-cover, land-use, population and OpenStreetMap data were employed to spatially model Plasmodium falciparum parasite rate standardized to the age group 2-10 years (PfPR2-10) in the two cities through the use of a Random Forest (RF) regressor. The RF models integrated physical and socio-economic information to predict PfPR2-10 across the urban landscape. Intra-urban population distribution maps were used to adjust the estimates according to the underlying population. RESULTS The results suggest that the spatial distribution of PfPR2-10 in both cities is diverse and highly variable across the urban fabric. Dense informal settlements exhibit a positive relationship with PfPR2-10 and hotspots of malaria prevalence were found near suitable vector breeding sites such as wetlands, marshes and riparian vegetation. In both cities, there is a clear separation of higher risk in informal settlements and lower risk in the more affluent neighborhoods. Additionally, areas associated with urban agriculture exhibit higher malaria prevalence values. CONCLUSIONS The outcome of this research highlights that populations living in informal settlements show higher malaria prevalence compared to those in planned residential neighborhoods. This is due to (i) increased human exposure to vectors, (ii) increased vector density and (iii) a reduced capacity to cope with malaria burden. Since informal settlements are rapidly expanding every year and often house large parts of the urban population, this emphasizes the need for systematic and consistent malaria surveys in such areas. Finally, this study demonstrates the importance of remote sensing as an epidemiological tool for mapping urban malaria variations at large spatial extents, and for promoting evidence-based policy making and control efforts.
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Affiliation(s)
- Stefanos Georganos
- Department of Geoscience, Environment & Society, Université Libre de Bruxelles, 1050, Brussels, Belgium.
| | - Oscar Brousse
- Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001, Louvain, Belgium
| | - Sébastien Dujardin
- Institute of Life, Earth and Environment, University of Namur, 5000, Namur, Belgium
- Department of Geography, University of Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
| | - Catherine Linard
- Institute of Life, Earth and Environment, University of Namur, 5000, Namur, Belgium
- Department of Geography, University of Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
| | - Daniel Casey
- Senator George J. Mitchell Center for Sustainability Solutions, University of Maine, 5710 Norman Smith Hall, Orono, ME, 04469-5710, USA
| | - Marco Milliones
- Department of Geography, University of Mary Washington, 1301 College Avenue, Fredericksburg, VA, 22401, USA
| | - Benoit Parmentier
- Senator George J. Mitchell Center for Sustainability Solutions, University of Maine, 5710 Norman Smith Hall, Orono, ME, 04469-5710, USA
- Department of Geography, University of Mary Washington, 1301 College Avenue, Fredericksburg, VA, 22401, USA
| | - Nicole P M van Lipzig
- Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001, Louvain, Belgium
| | | | - Tais Grippa
- Department of Geoscience, Environment & Society, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Sabine Vanhuysse
- Department of Geoscience, Environment & Society, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Nicholus Mboga
- Department of Geoscience, Environment & Society, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Verónica Andreo
- Instituto de Altos Estudios Espaciales "Mario Gulich". Comisión Nacional de Actividades Espaciales (CONAE), Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Robert W Snow
- Population and Health Unit, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Moritz Lennert
- Department of Geoscience, Environment & Society, Université Libre de Bruxelles, 1050, Brussels, Belgium
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Ipa M, Widawati M, Laksono AD, Kusrini I, Dhewantara PW. Variation of preventive practices and its association with malaria infection in eastern Indonesia: Findings from community-based survey. PLoS One 2020; 15:e0232909. [PMID: 32379812 PMCID: PMC7205284 DOI: 10.1371/journal.pone.0232909] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/23/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Geographical variation may likely influence the effectiveness of prevention efforts for malaria across Indonesia, in addition to factors at the individual level, household level, and contextual factors. This study aimed to describe preventive practices at individual and a household levels applied by rural communities in five provinces in eastern Indonesia and its association with the incidence of malaria among adult (≥15 years) populations. METHODS This study analyzed a subset of data of nationally representative community-based survey 2018 Riset Kesehatan Dasar (Riskesdas). Data for socio-demographic (age, gender, education and occupation) and preventive behaviors (use of mosquito bed nets while slept, insecticide-treated mosquito nets (ITNs), mosquito repellent, mosquito electric rackets, mosquito coil/electric anti-mosquito mats, and mosquito window screen) were collected. Data were analyzed using bivariate and multivariable logistic regression model. RESULTS Total of 56,159 respondents (n = 23,070 households) living in rural areas in Maluku (n = 8044), North Maluku (n = 7356), East Nusa Tenggara (n = 23,254), West Papua (n = 5759) and Papua (n = 11,746) were included in the study. In the multivariable models, using a bed net while slept likely reduced the odds of self-reported malaria among Maluku participants. Reduced odds ratios of self-reported malaria were identified in those participants who used ITNs (North Maluku, ENT, Papua), repellent (Maluku, West Papua, Papua), anti-mosquito racket (ENT), coil (Maluku, North Maluku, Papua) and window screen (West Papua, Papua). CONCLUSION Our study concluded that the protective effects of preventive practices were varied among localities, suggesting the need for specific intervention programs.
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Affiliation(s)
- Mara Ipa
- Pangandaran Unit for Health Research and Development, National Institute of Health Research and Development, National Ministry of Health of Indonesia, Pangandaran, West Java, Indonesia
| | - Mutiara Widawati
- Pangandaran Unit for Health Research and Development, National Institute of Health Research and Development, National Ministry of Health of Indonesia, Pangandaran, West Java, Indonesia
| | - Agung Dwi Laksono
- Center of Research and Development of Humanities and Health Management, National Institute of Health Research and Development, National Ministry of Health of Indonesia, Jakarta, Indonesia
| | - Ina Kusrini
- Magelang Unit for Health Research and Development, National Institute of Health Research and Development, National Ministry of Health of Indonesia, Magelang, Central Java, Indonesia
| | - Pandji Wibawa Dhewantara
- Pangandaran Unit for Health Research and Development, National Institute of Health Research and Development, National Ministry of Health of Indonesia, Pangandaran, West Java, Indonesia
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Hassen J, Dinka H. Retrospective analysis of urban malaria cases due to Plasmodium falciparum and Plasmodium vivax: the case of Batu town, Oromia, Ethiopia. Heliyon 2020; 6:e03616. [PMID: 32258471 PMCID: PMC7096753 DOI: 10.1016/j.heliyon.2020.e03616] [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: 10/29/2019] [Revised: 02/21/2020] [Accepted: 03/13/2020] [Indexed: 11/18/2022] Open
Abstract
Malaria is a major health problem in the world particularly in sub-Saharan Africa where 90% of malaria deaths occur. Likewise malaria is one of the leading causes of morbidity and mortality in Ethiopia. It has been reported that about 75% of the country is malarious where 60% of its population is at risk of this infection. Like many African countries, Ethiopian urban settings are characterized by poor housing, lack of sanitation and drainage of surface water which provide conducive environment for the breeding of vector mosquitoes for the transmission of malaria. There are few researches on urban malaria under the urban settings of Ethiopia. The purpose of this study was to assess the magnitude of malaria cases due to Plasmodium falciparum and Plasmodium vivax in Batu town, Oromia, Ethiopia. Retrospective laboratory confirmed malaria case record data of six years (2012–2017) were used to analyze the magnitude of malaria cases due to P. falciparum and P. vivax, in Batu town, Oromia, Ethiopia. The retrospective data analysis revealed an overall 21,797 malaria confirmed cases; of which 49.5% were due to P. falciparum and 50.5% were due to P. vivax, with a slight decline in malaria between 2012 and 2017. Malaria cases were recorded in both sexes and all age groups in the study area. From the result of the present analysis it can be concluded that both P. falciparum and P. vivax were the cause for malaria cases indicating malaria is still public health problem in Batu town. Therefore, appropriate strategic control measures must be designed to protect the public and eventually eliminate malaria from the area and the country as a whole.
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Affiliation(s)
- Jifar Hassen
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O.Box. 1888, Adama, Ethiopia
| | - Hunduma Dinka
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O.Box. 1888, Adama, Ethiopia
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Corder RM, Ferreira MU, Gomes MGM. Modelling the epidemiology of residual Plasmodium vivax malaria in a heterogeneous host population: A case study in the Amazon Basin. PLoS Comput Biol 2020; 16:e1007377. [PMID: 32168349 PMCID: PMC7108741 DOI: 10.1371/journal.pcbi.1007377] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 03/31/2020] [Accepted: 01/29/2020] [Indexed: 02/07/2023] Open
Abstract
The overall malaria burden in the Americas has decreased dramatically over the past two decades, but residual transmission pockets persist across the Amazon Basin, where Plasmodium vivax is the predominant infecting species. Current elimination efforts require a better quantitative understanding of malaria transmission dynamics for planning, monitoring, and evaluating interventions at the community level. This can be achieved with mathematical models that properly account for risk heterogeneity in communities approaching elimination, where few individuals disproportionately contribute to overall malaria prevalence, morbidity, and onwards transmission. Here we analyse demographic information combined with routinely collected malaria morbidity data from the town of Mâncio Lima, the main urban transmission hotspot of Brazil. We estimate the proportion of high-risk subjects in the host population by fitting compartmental susceptible-infected-susceptible (SIS) transmission models simultaneously to age-stratified vivax malaria incidence densities and the frequency distribution of P. vivax malaria attacks experienced by each individual over 12 months. Simulations with the best-fitting SIS model indicate that 20% of the hosts contribute 86% of the overall vivax malaria burden. Despite the low overall force of infection typically found in the Amazon, about one order of magnitude lower than that in rural Africa, high-risk individuals gradually develop clinical immunity following repeated infections and eventually constitute a substantial infectious reservoir comprised of asymptomatic parasite carriers that is overlooked by routine surveillance but likely fuels onwards malaria transmission. High-risk individuals therefore represent a priority target for more intensive and effective interventions that may not be readily delivered to the entire community.
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Affiliation(s)
- Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: (RMC); (MGMG)
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - M. Gabriela M. Gomes
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, and CMUP, Centro de Matemática da Universidade do Porto, Porto, Portugal
- * E-mail: (RMC); (MGMG)
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Abstract
The relative contribution of imported vs. locally acquired infections to urban malaria burden remains largely unexplored in Latin America, the most urbanised region in the developing world. Here we use a simple molecular epidemiology framework to examine the transmission dynamics of Plasmodium vivax in Mâncio Lima, the Amazonian municipality with the highest malaria incidence rate in Brazil. We prospectively genotyped 177 P. vivax infections diagnosed in urban residents between June 2014 and July 2015 and showed that local parasites are structured into several lineages of closely related microsatellite haplotypes, with the largest genetic cluster comprising 32% of all infections. These findings are very unlikely under the hypothesis of multiple independent imports of parasite strains from the rural surroundings. Instead, the presence of an endemic near-clonal parasite lineage circulating over 13 consecutive months is consistent with a local P. vivax transmission chain in the town, with major implications for malaria elimination efforts in this and similar urban environments across the Amazon.
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40
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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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Feachem RGA, Chen I, Akbari O, Bertozzi-Villa A, Bhatt S, Binka F, Boni MF, Buckee C, Dieleman J, Dondorp A, Eapen A, Sekhri Feachem N, Filler S, Gething P, Gosling R, Haakenstad A, Harvard K, Hatefi A, Jamison D, Jones KE, Karema C, Kamwi RN, Lal A, Larson E, Lees M, Lobo NF, Micah AE, Moonen B, Newby G, Ning X, Pate M, Quiñones M, Roh M, Rolfe B, Shanks D, Singh B, Staley K, Tulloch J, Wegbreit J, Woo HJ, Mpanju-Shumbusho W. Malaria eradication within a generation: ambitious, achievable, and necessary. Lancet 2019; 394:1056-1112. [PMID: 31511196 DOI: 10.1016/s0140-6736(19)31139-0] [Citation(s) in RCA: 187] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/26/2019] [Accepted: 05/07/2019] [Indexed: 01/04/2023]
Affiliation(s)
- Richard G A Feachem
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Ingrid Chen
- Global Health Group, University of California San Francisco, San Francisco, CA, USA.
| | - Omar Akbari
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Amelia Bertozzi-Villa
- Malaria Atlas Project, University of Oxford, Oxford, UK; Institute for Disease Modeling, Bellevue, WA, USA
| | - Samir Bhatt
- Malaria Atlas Project, University of Oxford, Oxford, UK
| | - Fred Binka
- School of Public Health, University of Health and Allied Sciences, Ho, Ghana
| | - Maciej F Boni
- Center for Infectious Disease Dynamics, Department of Biology, Penn State, University Park, PA, USA
| | - Caroline Buckee
- Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Joseph Dieleman
- Institute for Health Metrics, University of Washington, Seattle, WA, USA
| | - Arjen Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | - Alex Eapen
- National Institute of Malaria Research, Chennai, India
| | - Neelam Sekhri Feachem
- Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Scott Filler
- The Global Fund to Fight AIDS, Tuberculosis and Malaria, Geneva, Switzerland
| | - Peter Gething
- Malaria Atlas Project, University of Oxford, Oxford, UK
| | - Roly Gosling
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Annie Haakenstad
- Institute for Health Metrics, University of Washington, Seattle, WA, USA
| | - Kelly Harvard
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Arian Hatefi
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Dean Jamison
- Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Kate E Jones
- Department of Genetics, Evolution and Environment, University College London, London, UK
| | | | | | - Altaf Lal
- Sun Pharma Industries, Mumbai, India
| | - Erika Larson
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Margaret Lees
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Neil F Lobo
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Angela E Micah
- Institute for Health Metrics, University of Washington, Seattle, WA, USA
| | - Bruno Moonen
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Gretchen Newby
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Xiao Ning
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, China
| | - Muhammad Pate
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Martha Quiñones
- Department of Public Health, Universidad Nacional de Colombia, Bogota, Colombia
| | - Michelle Roh
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Ben Rolfe
- Asia Pacific Leaders Malaria Alliance, Singapore
| | | | - Balbir Singh
- Malaria Research Center, University Malaysia Sarawak, Sarawak, Malaysia
| | | | | | - Jennifer Wegbreit
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Hyun Ju Woo
- Global Health Group, University of California San Francisco, San Francisco, CA, USA
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Corder RM, Paula GA, Pincelli A, Ferreira MU. Statistical modeling of surveillance data to identify correlates of urban malaria risk: A population-based study in the Amazon Basin. PLoS One 2019; 14:e0220980. [PMID: 31398228 PMCID: PMC6688813 DOI: 10.1371/journal.pone.0220980] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/28/2019] [Indexed: 11/22/2022] Open
Abstract
Despite the recent malaria burden reduction in the Americas, focal transmission persists across the Amazon Basin. Timely analysis of surveillance data is crucial to characterize high-risk individuals and households for better targeting of regional elimination efforts. Here we analyzed 5,480 records of laboratory-confirmed clinical malaria episodes combined with demographic and socioeconomic information to identify risk factors for elevated malaria incidence in Mâncio Lima, the main urban transmission hotspot of Brazil. Overdispersed malaria count data clustered into households were fitted with random-effects zero-inflated negative binomial regression models. Random-effect predictors were used to characterize the spatial heterogeneity in malaria risk at the household level. Adult males were identified as the population stratum at greatest risk, likely due to increased occupational exposure away of the town. However, poor housing and residence in the less urbanized periphery of the town were also found to be key predictors of malaria risk, consistent with a substantial local transmission. Two thirds of the 8,878 urban residents remained uninfected after 23,975 person-years of follow-up. Importantly, we estimated that nearly 14% of them, mostly children and older adults living in the central urban hub, were free of malaria risk, being either unexposed, naturally unsusceptible, or immune to infection. We conclude that statistical modeling of routinely collected, but often neglected, malaria surveillance data can be explored to characterize drivers of transmission heterogeneity at the community level and provide evidence for the rational deployment of control interventions.
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Affiliation(s)
- Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: (RMC); (MUF)
| | - Gilberto A. Paula
- Department of Statistics, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil
| | - Anaclara Pincelli
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: (RMC); (MUF)
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File T, Dinka H, Golassa L. A retrospective analysis on the transmission of Plasmodium falciparum and Plasmodium vivax: the case of Adama City, East Shoa Zone, Oromia, Ethiopia. Malar J 2019; 18:193. [PMID: 31185977 PMCID: PMC6558791 DOI: 10.1186/s12936-019-2827-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 06/04/2019] [Indexed: 12/05/2022] Open
Abstract
Background Malaria is more often considered a problem of the rural poor and the disease has been overlooked in urban settings for centuries due to the assumption that economic development in urban areas results in better life conditions, such as improved housing, drainage system and environmental changes that makes urban areas not conducive for breeding of the malaria vector. But, for many African countries, including Ethiopia, in most urban areas, although there are rapid developments, they are characterized by poor housing, lack of sanitation and drainage of surface water that would provide favourable conditions for vector breeding. Limited studies have been conducted as far as urban malaria is concerned in Ethiopia. The purpose of this study was to assess the status of falciparum and vivax malaria transmission in Adama City, Eastern Shoa Zone, Oromia, Ethiopia. Understanding the local epidemiology of malaria will help policy makers and other stakeholders to design and implement tailored cost effective and efficient intervention strategies targeting urban malaria. Methods The study was designed to analyse 5-year trends of malaria burden by two co-endemic species in Ethiopia (Plasmodium falciparum and Plasmodium vivax) and its annual and seasonal transmission pattern in the city, by using retrospective data on malaria burden by species, malaria related inpatient department (IPD) and outpatient department (OPD) consultations from 2013/14 to 2017/18. Results OPD retrospective data analysis indicated that adolescents and adults (≥ 15 years of age) were most affected by P. vivax 43.5% (2986/6862) and P. falciparum 31.7% (2179/6862). Plasmodium vivax was found to be a predominant species in causing malaria burden in the city exhibiting less seasonal occurrence, and the relative burden of P. vivax is gradually increasing from year to year over P. falciparum. Conclusion Malaria is endemic to the city showing a public health problem. The productive group of the community, adolescents and adults, were most affected exacerbating poverty. Plasmodium vivax was found to be the highest malaria burden in the city and the observed epidemiological shift from P. falciparum to P. vivax calls for additional tailored intervention strategies to reduce the associated burden.
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Affiliation(s)
- Temesgen File
- Department of Applied Biology, Adama Science and Technology University, P.O.Box 1888, Adama, Ethiopia
| | - Hunduma Dinka
- Department of Applied Biology, Adama Science and Technology University, P.O.Box 1888, Adama, Ethiopia.
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O.Box 1176, Addis Ababa, Ethiopia
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Geostatistical analysis and mapping of malaria risk in children under 5 using point-referenced prevalence data in Ghana. Malar J 2019; 18:67. [PMID: 30871551 PMCID: PMC6419518 DOI: 10.1186/s12936-019-2709-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/06/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria remains a major challenge in sub-Saharan Africa and Ghana is not an exception. Effective malaria transmission control requires evidence-based targeting and utilization of resources. Disease risk mapping provides an effective and efficient tool for monitoring transmission and control efforts. The aim of this study is to analyse and map malaria risk in children under 5 years old, with the ultimate goal of identifying areas where control efforts can be targeted. METHODS Data collected from the 2016 Ghana demographic and health survey was analyzed. Binomial logistic regression was applied to examine the determinants of malaria risk among children. Model-based geostatistical methods were applied to analyze, predict and map malaria prevalence. RESULTS There is a significant association of malaria prevalence with area of residence (rural/urban), age, indoor residual spray use, social economic status and mother's education level. Overall, parasitaemia prevalence among children under 5 years old for the year 2016 is low albeit characterized by "hotspots" in specific areas. CONCLUSION The risk maps indicate the spatial heterogeneity of malaria prevalence. The high resolution maps can serve as an effective tool in the identification of locations that require targeted interventions by programme implementers; this is key and relevant for reducing malaria burden in Ghana.
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Seyfarth M, Khaireh BA, Abdi AA, Bouh SM, Faulde MK. Five years following first detection of Anopheles stephensi (Diptera: Culicidae) in Djibouti, Horn of Africa: populations established-malaria emerging. Parasitol Res 2019; 118:725-732. [PMID: 30671729 DOI: 10.1007/s00436-019-06213-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/10/2019] [Indexed: 12/24/2022]
Abstract
The Asian malaria mosquito, Anopheles stephensi, is a well-known and important vector of Plasmodium falciparum and P. vivax. Until 2013, its geographical distribution was confined to central and southern Asia including the Arabian Peninsula. In the Horn of Africa (HoA) Region, An. stephensi was first recorded from Djibouti in 2012, when it was linked geographically and temporally with an unusual outbreak of urban P. falciparum malaria. In 2016, An. stephensi was detected in the neighbouring Somali Region of Ethiopia. In order to determine whether An. stephensi populations have become established in Djibouti and contributed to the unusual rise in local malaria cases there, we carried out continuous vector surveillance from January 2013 to December 2017, investigated seasonal changes in An. stephensi population densities and bionomics, analysed available literature describing malaria in Djibouti since 2013, and investigated whether An. stephensi may have contributed to local malaria transmission by detecting circumsporozoite antigen of P. falciparum and P. vivax in female anophelines. From 2013 to 2016, seasonal activity of An. stephensi in urban Djibouti City primarily occurred during the colder, wetter season between September and May, with either no or rare trap catches from June to August. Unlike past years, this species was detected year-round, including the extremely hot summer months of June to August 2017. This change in seasonal occurrence may indicate that An. stephensi populations are adapting to their new environment in sub-Saharan Africa, facilitating their spread within Djibouti City. Among the 96 female An. stephensi investigated for malaria infectivity, three (3.1%) were positive for P. falciparum circumsporozoite antigen, including one P. falciparum/P. vivax VK 210 double infection. Subsequent to the unusual resurgence of local malaria in 2013, with 1684 confirmed cased reported for that year, malaria case numbers increased continuously, peaking at 14,810 in 2017. Prior to 2016, only P. falciparum malaria cases had been reported, but in 2016, autochthonously acquired P. vivax malaria cases occurred for the first time at a rate of 16.7% among all malaria cases recorded that year. This number increased to 36.7% in 2017. Our data indicate that the dynamics of malaria species in Djibouti is currently changing rapidly, and that An. stephensi can be involved in the transmission of both P. falciparum and P. vivax, simultaneously. Considering the extremely high potential impact of urban malaria on public health, the timely deployment of optimal multinational vector surveillance and control programs against An. stephensi is strongly recommended, not only for the HoA Region, but for the entire African continent.
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Affiliation(s)
- Marco Seyfarth
- Bundeswehr Medical Office, Office of the Surgeon General, Koblenz, Germany
| | - Bouh A Khaireh
- Solidaris Health, Public Health and Development Research Center, 10 Boulevard de la République, BP 1000, Djibouti, Republic of Djibouti.,Department of Microbiology, Faculty of Medicine, University of Djibouti, BP 1906, 12 Rue de l'École de Médecine, Djibouti, Republic of Djibouti
| | - Abdoulilah A Abdi
- President Health Advisor, Cabinet of the President, Republic of Djibouti and Directorate, Djiboutian Armed Forces Health Service, Djibouti City, Republic of Djibouti
| | - Samatar M Bouh
- Director Health Information System, Ministry of Health, Djibouti City, Republic of Djibouti
| | - Michael K Faulde
- Department XXI B, Section Medical Entomology/Zoology, Bundeswehr Central Hospital, PO Box 7460, D-56064, Koblenz, Germany. .,Institute of Medical Microbiology, Immunology and Parasitology, University Clinics Bonn, 53105, Bonn, Germany.
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Li B, Liu X, Wang WJ, Zhao F, An ZY, Zhao H. Metanetwork Transmission Model for Predicting a Malaria-Control Strategy. Front Genet 2018; 9:446. [PMID: 30386373 PMCID: PMC6199348 DOI: 10.3389/fgene.2018.00446] [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: 07/03/2018] [Accepted: 09/14/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Mosquitoes are the primary vectors responsible for malaria transmission to humans, with numerous experiments having been conducted to aid in the control of malaria transmission. One of the main approaches aims to develop malaria parasite resistance within the mosquito population by introducing a resistance (R) allele. However, when considering this approach, some critical factors, such as the life of the mosquito, female mosquito fertility capacity, and human and mosquito mobility, have not been considered. Thus, an understanding of how mosquitoes and humans affect disease dynamics is needed to better inform malaria control policymaking. Methods: In this study, a method was proposed to create a metanetwork on the basis of the geographic maps of Gambia, and a model was constructed to simulate evolution within a mixed population, with factors such as birth, death, reproduction, biting, infection, incubation, recovery, and transmission between populations considered in the network metrics. First, the same number of refractory mosquitoes (RR genotype) was introduced into each population, and the prevalence of the R allele (the ratio of resistant alleles to all alleles) and malaria were examined. In addition, a series of simulations were performed to evaluate two different deployment strategies for the reduction of the prevalence of malaria. The R allele and malaria prevalence were calculated for both the strategies, with 10,000 refractory mosquitoes deployed into randomly selected populations or selection based on nodes with top-betweenness values. The 10,000 mosquitoes were deployed among 1, 5, 10, 20, or 40 populations. Results: The simulations in this paper showed that a higher RR genotype (resistant-resistant genes) ratio leads to a higher R allele prevalence and lowers malaria prevalence. Considering the cost of deployment, the simulation was performed with 10,000 refractory mosquitoes deployed among 1 or 5 populations, but this approach did not reduce the original malaria prevalence. Thus, instead, the 10,000 refractory mosquitoes were distributed among 10, 20, or 40 populations and were shown to effectively reduce the original malaria prevalence. Thus, deployment among a relatively small fraction of central nodes can offer an effective strategy to reduce malaria. Conclusion: The standard network centrality measure is suitable for planning the deployment of refractory mosquitoes. Importance: Malaria is an infectious disease that is caused by a plasmodial parasite, and some control strategies have focused on genetically modifying the mosquitoes. This work aims to create a model that takes into account mosquito development and malaria transmission among the population and how these factors influence disease dynamics so as to better inform malaria-control policymaking.
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Affiliation(s)
- Bo Li
- Shandong Technology and Business University, School of Computer Science and Technology, Yantai, China
- Shandong Co-Innovation Center of Future Intelligent Computing, Yantai, China
| | - Xiao Liu
- Northeastern University, School of Computer Science and Engineering, Shenyang, China
| | - Wen-Juan Wang
- Yantai Yuhuangding Hospital of Qingdao University, Reproduction Medical Center, Yantai, China
| | - Feng Zhao
- Shandong Technology and Business University, School of Computer Science and Technology, Yantai, China
- Shandong Co-Innovation Center of Future Intelligent Computing, Yantai, China
| | - Zhi-Yong An
- Shandong Technology and Business University, School of Computer Science and Technology, Yantai, China
- Shandong Co-Innovation Center of Future Intelligent Computing, Yantai, China
| | - Hai Zhao
- Northeastern University, School of Computer Science and Engineering, Shenyang, China
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Eder M, Cortes F, Teixeira de Siqueira Filha N, Araújo de França GV, Degroote S, Braga C, Ridde V, Turchi Martelli CM. Scoping review on vector-borne diseases in urban areas: transmission dynamics, vectorial capacity and co-infection. Infect Dis Poverty 2018; 7:90. [PMID: 30173661 PMCID: PMC6120094 DOI: 10.1186/s40249-018-0475-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/02/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transmission dynamics, vectorial capacity, and co-infections have substantial impacts on vector-borne diseases (VBDs) affecting urban and suburban populations. Reviewing key factors can provide insight into priority research areas and offer suggestions for potential interventions. MAIN BODY Through a scoping review, we identify knowledge gaps on transmission dynamics, vectorial capacity, and co-infections regarding VBDs in urban areas. Peer-reviewed and grey literature published between 2000 and 2016 was searched. We screened abstracts and full texts to select studies. Using an extraction grid, we retrieved general data, results, lessons learned and recommendations, future research avenues, and practice implications. We classified studies by VBD and country/continent and identified relevant knowledge gaps. Of 773 articles selected for full-text screening, 50 were included in the review: 23 based on research in the Americas, 15 in Asia, 10 in Africa, and one each in Europe and Australia. The largest body of evidence concerning VBD epidemiology in urban areas concerned dengue and malaria. Other arboviruses covered included chikungunya and West Nile virus, other parasitic diseases such as leishmaniasis and trypanosomiasis, and bacterial rickettsiosis and plague. Most articles retrieved in our review combined transmission dynamics and vectorial capacity; only two combined transmission dynamics and co-infection. The review identified significant knowledge gaps on the role of asymptomatic individuals, the effects of co-infection and other host factors, and the impacts of climatic, environmental, and socioeconomic factors on VBD transmission in urban areas. Limitations included the trade-off from narrowing the search strategy (missing out on classical modelling studies), a lack of studies on co-infections, most studies being only descriptive, and few offering concrete public health recommendations. More research is needed on transmission risk in homes and workplaces, given increasingly dynamic and mobile populations. The lack of studies on co-infection hampers monitoring of infections transmitted by the same vector. CONCLUSIONS Strengthening VBD surveillance and control, particularly in asymptomatic cases and mobile populations, as well as using early warning tools to predict increasing transmission, were key strategies identified for public health policy and practice.
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Affiliation(s)
- Marcus Eder
- Public Health England Sierra Leone Country Office, Freetown, Sierra Leone
- Aggeu Magalhaes Institute (IAM) / Oswaldo Cruz Foundation (Fiocruz), Avenida Professor Moraes Rego, s/n. Cidade Universitaria. CEP 50, Recife, Pernambuco 740-465 Brazil
| | - Fanny Cortes
- Universidade de Pernambuco (UPE), Recife, Pernambuco Brazil
| | | | | | - Stéphanie Degroote
- University of Montreal School of Public Health (ESPUM), Montreal, Quebec Canada
| | - Cynthia Braga
- Aggeu Magalhaes Institute (IAM) / Oswaldo Cruz Foundation (Fiocruz), Avenida Professor Moraes Rego, s/n. Cidade Universitaria. CEP 50, Recife, Pernambuco 740-465 Brazil
| | - Valéry Ridde
- University of Montreal School of Public Health (ESPUM), Montreal, Quebec Canada
- IRD (French Institute For Research on Sustainable Development), CEPED (IRD-Université Paris Descartes), Universités Paris Sorbonne Cités, ERL INSERM SAGESUD, Paris, France
| | - Celina Maria Turchi Martelli
- Aggeu Magalhaes Institute (IAM) / Oswaldo Cruz Foundation (Fiocruz), Avenida Professor Moraes Rego, s/n. Cidade Universitaria. CEP 50, Recife, Pernambuco 740-465 Brazil
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Voumbo-Matoumona DF, Kouna LC, Madamet M, Maghendji-Nzondo S, Pradines B, Lekana-Douki JB. Prevalence of Plasmodium falciparum antimalarial drug resistance genes in Southeastern Gabon from 2011 to 2014. Infect Drug Resist 2018; 11:1329-1338. [PMID: 30214253 PMCID: PMC6118251 DOI: 10.2147/idr.s160164] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE The introduction of artemisinin-based combination therapies (ACTs) in treating uncomplicated malaria and sulfadoxine-pyrimethamine (SP) as intermittent preventive treatment during pregnancy drastically decreased the burden of malarial disease around the world. However, ACTs are known to select for drug resistance markers. In Gabon, artemether-lumefantrine induced an increase in the prevalence of N86-Pfmdr1, which is associated with treatment failure. However, little data are available regarding resistance markers in Southeastern Gabon. This study aimed to evaluate the evolution of resistance haplotypes in the Pfcrt, Pfdhps, Pfdhfr, and PfK13 genes from 2011 to 2014 in Southeastern Gabon. METHODS A total of 233 Plasmodium falciparum DNA samples were collected from febrile pediatric patients in South Gabon: Franceville, an urban area; Koulamoutou, a semi-urban area; and Lastourville, a rural area. Pfcrt, Pfdhps, Pfdhfr, and the propeller domain of PfK13 were sequenced for all isolates. RESULTS The overall prevalence (3.7%-11.5%) of the wild-type haplotype Pfcrt 72-76 CVMNK was not significantly different between 2011 and 2014 in Southeast Gabon. For Pfdhfr (codons 51, 59, 108, 164), the IRNI triple-mutant haplotype was the most prevalent (>89.0%). The ICNI and NCNI mutant haplotypes and the NCSI wild-type haplotype showed a minor prevalence. There were no differences in the distributions of these haplotypes across the 4 years and the three study sites. For Pfdhps, the AAKAA and SGKAA mutant haplotypes and the SAKAA wild-type haplotype were similarly present in the three areas during the study period. The AGKAA double mutant was first observed in 2013 in Franceville and in 2014 in Koulamoutou and Lastourville. Interestingly, only the A578S mutation (0.4%) and two new A494V (0.4%) and V504A (0.9%) mutations were found in PfK13. CONCLUSION Despite the withdrawal of chloroquine, the frequency of the resistant allele 76T remained high in the south of Gabon. Moreover, a high level of resistant haplotypes against IPTp-SP was found.
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Affiliation(s)
- Dominique Fatima Voumbo-Matoumona
- Unit of Evolution, Epidemiology and Parasitic Resistances (UNEEREP), International Medical Research Center of Franceville (CIRMF), Franceville, Gabon,
- Parasitology and Entomology Unit, Department of Infectious Diseases, Biomedical Research Institute of Army, Marseille, France
- Regional Doctoral School of Central Africa in Tropical Infectiology, Franceville, Gabon
| | - Lady Charlène Kouna
- Department of Parasitology, Mycology and Tropical Medicine, University of Health Sciences, Libreville, Gabon,
| | - Marylin Madamet
- Parasitology and Entomology Unit, Department of Infectious Diseases, Biomedical Research Institute of Army, Marseille, France
- Research Unit on Infectious and Tropical Emerging Diseases, Aix Marseille University, Marseille, France
- National Malaria Reference Center, Marseille, France
| | - Sydney Maghendji-Nzondo
- Department of Parasitology, Mycology and Tropical Medicine, University of Health Sciences, Libreville, Gabon,
| | - Bruno Pradines
- Parasitology and Entomology Unit, Department of Infectious Diseases, Biomedical Research Institute of Army, Marseille, France
- Research Unit on Infectious and Tropical Emerging Diseases, Aix Marseille University, Marseille, France
- National Malaria Reference Center, Marseille, France
| | - Jean Bernard Lekana-Douki
- Unit of Evolution, Epidemiology and Parasitic Resistances (UNEEREP), International Medical Research Center of Franceville (CIRMF), Franceville, Gabon,
- Department of Parasitology, Mycology and Tropical Medicine, University of Health Sciences, Libreville, Gabon,
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Local classifications of fever and treatment sought among populations at risk of zoonotic diseases in Ghana. PLoS One 2018; 13:e0201526. [PMID: 30138341 PMCID: PMC6107132 DOI: 10.1371/journal.pone.0201526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 07/17/2018] [Indexed: 11/19/2022] Open
Abstract
In the past four decades, there has been an increase in the occurrence of zoonotic diseases. Some outbreaks have been devastating because of the inability of individuals and health workers to identify the diseases early. Generally, most zoonotic diseases are heralded by a fever. While fevers are common, they are often the symptoms of different diseases. This paper explores how a population at potential risk of zoonotic diseases identify fevers, and what treatments they seek when they develop fevers. The data are from focus group discussions and a survey of three communities in the Brong Ahafo, Volta and Greater Accra regions in Ghana. The quantitative data were analysed using descriptive statistics while the qualitative data were analysed using thematic analysis. The findings indicate that the perceived causes of fever differ from the traditional biomedical view. While orthodox treatment was the preferred choice for most participants, rural dwellers utilised traditional medicine more than their urban counterparts. Though there is no record of bat-borne zoonotic disease in Ghana, our findings could be used as a proxy to indicate how populations at risk of exposure might respond in the event of a spillover event from a zoonosis. We recommend that educational campaigns on zoonotic diseases should target rural dwellers, especially farmers, who may be most at risk of zoonoses.
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Lee EH, Olsen CH, Koehlmoos T, Masuoka P, Stewart A, Bennett JW, Mancuso J. A cross-sectional study of malaria endemicity and health system readiness to deliver services in Kenya, Namibia and Senegal. Health Policy Plan 2018; 32:iii75-iii87. [PMID: 29149315 DOI: 10.1093/heapol/czx114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2017] [Indexed: 11/13/2022] Open
Abstract
Despite good progress towards elimination, malaria continues to contribute substantially to the sub-Saharan African disease burden. Sustaining previous gains requires continued readiness to deliver malaria services in response to actual disease burden, which in turn contributes to health systems strengthening. This study investigates a health system innovation. We examined whether malaria prevalence, or endemicity, is a driver of health facility readiness to deliver malaria services. To estimate this association, we geo-linked cross-sectional facility survey data to endemicity data for Kenya, Namibia and Senegal. We tested the validity and reliability of the primary study outcome, the malaria service readiness index and mapped service readiness components in a geographic information system. We conducted a weighted multivariable linear regression analysis of the relationship between endemicity and malaria service readiness, stratified for urban or rural facility location. As endemicity increased in rural areas, there was a concurrent, modest increase in service readiness at the facility level [β: 0.028; (95% CI 0.008, 0.047)], whereas no relationship existed in urban settings. Private-for-profit facilities were generally less prepared than public [β: -0.102; (95% CI - 0.154, -0.050)]. Most facilities had the necessary supplies to diagnose malaria, yet availability of malaria guidelines and adequately trained staff as well as medicines and commodities varied. Findings require cautious interpretation outside the study sample, which was a more limited subset of the original surveys' sampling schemes. Our approach and findings may be used by national malaria programs to identify low performing facilities in malarious areas for targeted service delivery interventions. This study demonstrates use of existing data sources to evaluate health system performance and to identify within- and cross-country variations for targeted interventions.
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Affiliation(s)
- Elizabeth H Lee
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720-A Rockledge Drive, Suite 100, Bethesda, MD 20817, USA.,Division of Tropical Public Health, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Cara H Olsen
- Division of Tropical Public Health, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Tracey Koehlmoos
- Division of Tropical Public Health, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Penny Masuoka
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720-A Rockledge Drive, Suite 100, Bethesda, MD 20817, USA.,Division of Tropical Public Health, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Ann Stewart
- Division of Tropical Public Health, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Jason W Bennett
- Division of Tropical Public Health, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.,Multidrug Resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD 20910, USA
| | - James Mancuso
- United States Army Medical Directorate - Kenya, Nyanza, Kenya
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