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Endriyas M, Kassa M, Chisha Y, Mekonnen E, Misganaw T, Loha E, Astatkie A. Low long-lasting insecticidal net use in malaria elimination areas in Southern Ethiopia: results from community based cross-sectional study. Malar J 2024; 23:94. [PMID: 38575937 PMCID: PMC10996104 DOI: 10.1186/s12936-024-04909-y] [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: 10/20/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Despite remarkable progress in malaria burden reduction, malaria continues to be a major public health problem globally. Ethiopia has been distributing long-lasting insecticidal nets (LLINs) for free and nationwide distribution was completed in 2016. However, evidence suggests that the utilization of LLINs varies from setting to setting and from time to time due to different factors, and up-to-date evidence is required for LLIN related decision-making. Hence, this study was designed to assess LLIN utilization and its determinants in the Southern Nations, Nationalities, and People's Region (SNNPR) of Ethiopia. METHODS A community-based cross-sectional study was conducted in Southern Ethiopia in 2019. Using multi-stage sampling, a total of 2466 households were included. The region was stratified based on the annual malaria index as high, moderate, low, and free strata. Cluster sampling was then applied to select households from high, moderate, and low strata. Data on LLIN ownership, utilization and different determinant factors were collected using household questionnaire. SurveyCTO was used to collect data and data was managed using Stata 15. Descriptive statistics and multilevel mixed-effects logistic regression were performed to identify the determinants of utilization of LLINs. Effect measures were reported using adjusted odds ratio (AOR) with 95% CI. RESULTS From a total of 2466 households, 48.7% of households had at least one LLIN. LLIN adequacy based on family size was 23% while it was15.7% based on universal access and 29.2% based on sleeping space. From 1202 households that possessed LLIN(s), 66.0% of households reported that they slept under LLIN the night preceding the survey. However, when the total population in all surveyed households were considered, only 22.9% of household members slept under LLIN the night preceding the survey. Malaria endemicity, educational status, wealth status, and knowledge about malaria were associated with LLINs utilization. In addition, reasons for non-use included perceived absence of malaria, side effects of LLIN, conditions of LLINs, inconvenient space and low awareness. CONCLUSION Low LLIN coverage and low utilization were noted. A low level of utilization was associated with malaria endemicity, wealth status and level of awareness. Distribution of LLIN and continuous follow-up with community awareness creation activities are vital to improve coverage and utilization of LLINs, and to ensure the country's malaria elimination goal.
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Affiliation(s)
| | - Mekidim Kassa
- College of Medicine and Health Sciences, Arbaminch University, Arbaminch, Ethiopia
| | - Yilma Chisha
- College of Medicine and Health Sciences, Arbaminch University, Arbaminch, Ethiopia
| | | | | | - Eskindir Loha
- Centre for International Health, University of Bergen, Bergen, Norway
- Chr. Michelsen Institute, Bergen, Norway
| | - Ayalew Astatkie
- School of Public Health, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia
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Koenker H, Kumoji EK, Erskine M, Opoku R, Sternberg E, Taylor C. Reported reasons for non-use of insecticide-treated nets in large national household surveys, 2009-2021. Malar J 2023; 22:61. [PMID: 36810015 PMCID: PMC9942310 DOI: 10.1186/s12936-023-04490-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 02/13/2023] [Indexed: 02/23/2023] Open
Abstract
BACKGROUND Insecticide-treated nets (ITN) are the cornerstone of modern malaria vector control, with nearly 3 billion ITNs delivered to households in endemic areas since 2000. ITN access, i.e. availability within the household, based on the number of ITNs and number of household members, is a pre-requisite for ITN use. Factors determining ITN use are frequently examined in published literature, but to date, large household survey data on reasons given for non-use of nets have not been explored. METHODS A total of 156 DHS, MIS, and MICS surveys conducted between 2003 and 2021 were reviewed for questions on reasons why nets were not used the previous night, identifying twenty-seven surveys. The percent of nets that were reported used the previous night was calculated for the 156 surveys, and frequencies and proportions of reasons for non-use were calculated within the twenty-seven surveys. Results were stratified by household supply of ITNs in three categories (not enough", "enough", and "more than enough") and by residence (urban/rural). RESULTS The proportion of nets used the previous night averaged over 70% between 2003 and 2021, with no discernible change over this period. Reported reasons for why a net goes unused fell largely into three categories-nets that are extra/being saved for future use; the perception that there is little risk of malaria (particularly in dry season); and "other" responses. Net attributes such as colour, size, shape, and texture, and concerns related to chemicals were the least frequent reasons given. Reasons for non-use of nets varied by household net supply, and in some surveys by residence. In Senegal's continuous DHS, the proportion of nets used peaked during high transmission season, and the proportion of nets that went unused due to "no/few mosquitoes" peaked during the dry season. CONCLUSIONS Unused nets were primarily those being saved for later use, or were not used due to perceived low risk of malaria. Classifying reasons for non-use into broader categories facilitates the design of appropriate social and behaviour change interventions to address the major underlying reasons for non-use, where this is feasible.
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Affiliation(s)
| | - E. Kuor Kumoji
- grid.449467.c0000000122274844Johns Hopkins Center for Communication Programs, Baltimore, USA
| | - Marcy Erskine
- grid.475581.a0000 0004 0411 9738International Federation of Red Cross and Red Crescent Societies, Geneva, Switzerland
| | - Robert Opoku
- grid.475581.a0000 0004 0411 9738International Federation of Red Cross and Red Crescent Societies, Geneva, Switzerland
| | | | - Cameron Taylor
- grid.431760.70000 0001 0940 5336The DHS Program, ICF, Rockville, USA ,grid.5284.b0000 0001 0790 3681University of Antwerp, Medicine and Health Sciences, Antwerp, Belgium
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Unwin HJT, Sherrard-Smith E, Churcher TS, Ghani AC. Quantifying the direct and indirect protection provided by insecticide treated bed nets against malaria. Nat Commun 2023; 14:676. [PMID: 36750566 PMCID: PMC9905482 DOI: 10.1038/s41467-023-36356-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 01/27/2023] [Indexed: 02/09/2023] Open
Abstract
Long lasting insecticidal nets (LLINs) provide both direct and indirect protection against malaria. As pyrethroid resistance evolves in mosquito vectors, it will be useful to understand how the specific benefits LLINs afford individuals and communities may be affected. Here we use modelling to show that there is no minimum LLIN usage needed for users and non-users to benefit from community protection. Modelling results also indicate that pyrethroid resistance in local mosquitoes will likely diminish the direct and indirect benefits from insecticides, leaving the barrier effects intact, but LLINs are still expected to provide enhanced benefit over untreated nets even at high levels of pyrethroid resistance.
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Affiliation(s)
- H Juliette T Unwin
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK.
| | - Ellie Sherrard-Smith
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
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4
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Paaijmans KP, Lobo NF. Gaps in protection: the actual challenge in malaria elimination. Malar J 2023; 22:46. [PMID: 36747225 PMCID: PMC9902240 DOI: 10.1186/s12936-023-04473-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/29/2023] [Indexed: 02/08/2023] Open
Abstract
Progress in reducing both malaria cases and deaths has stalled with regression seen in many geographies. While significant attention is given to the contributing challenges of drug and insecticide resistance, 'residual' malaria is often diminished to transmission resulting from outdoor-biting or zoophagic/opportunistic mosquito vectors. These specific vector bionomic traits are only part of the problem, as residual transmission may be driven by (a combination of) (1) sub-optimal intervention coverage, quality, acceptance, and/or usage, (2) drug resistance, (3) insecticide resistance, (4) refractory, resistant and adaptive vector and human behaviours that lower intervention effectiveness, (5) lack of, limited access to, and/or willingness to use healthcare systems, (6) diagnostic sensitivity along with the parallel issue of hrp2/3 mutations, (7) (inter)national policy, (8) the research and development pipeline, and (9) external factors such as natural disasters and conflict zones. Towards combating the minimization of this extensive and multipronged issue among the scientific community, funding agencies, and public health officials responsible for guiding or developing malaria programmes, an alternative way of describing this transmission is proposed by focusing in on the causative 'gaps in protection'. Defining and wording it as such zeros in on the drivers that result in the observed remaining (or increasing) transmission, allowing the malaria community to focus on solutions by identifying the actual causes. Outlining, defining and quantifying the gaps in protection for a given system is of utmost importance to understand what needs to be done, differentiating what can be done versus what cannot be tackled at that moment, along with delineating the technical and financial capacity required.
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Affiliation(s)
- Krijn P Paaijmans
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA.
- The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA.
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, USA.
- Centro de Investigação Em Saúde de Manhiça, Fundação Manhiça, Maputo, Mozambique.
- ISGlobal, Barcelona, Spain.
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
- Malaria Elimination Initiative, University of California San Francisco, San Francisco, CA, USA
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Mbuba E, Odufuwa OG, Moore J, Mmbaga S, Tchicaya E, Edi C, Chalageri V, Uragayala S, Sharma A, Rahi M, Raghavendra K, Eapen A, Koenker H, Ross A, Moore SJ. Multi-country evaluation of the durability of pyrethroid plus piperonyl-butoxide insecticide-treated nets: study protocol. Malar J 2023; 22:30. [PMID: 36707886 PMCID: PMC9881340 DOI: 10.1186/s12936-023-04465-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 01/20/2023] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Mass distributions of long-lasting insecticidal nets (LLINs) have contributed to large reductions in the malaria burden. However, this success is in jeopardy due in part to the increasing pyrethroid-resistant mosquito population as well as low LLINs coverage in various areas because the lifespan of LLINs is often shorter than the interval between replenishment campaigns. New insecticide-treated nets (ITNs) containing pyrethroid and piperonyl-butoxide (PBO) have shown a greater reduction in the incidence of malaria than pyrethroid LLINs in areas with pyrethroid-resistant mosquitoes. However, the durability (attrition, bio-efficacy, physical integrity and chemical retainment) of pyrethroid-PBO ITNs under operational settings has not been fully characterized. This study will measure the durability of pyrethroid-PBO ITNs to assess whether they meet the World Health Organization (WHO) three years of operational performance criteria required to be categorized as "long-lasting". METHODS A prospective household randomized controlled trial will be conducted simultaneously in Tanzania, India and Côte d'Ivoire to estimate the field durability of three pyrethroid-PBO ITNs (Veeralin®, Tsara® Boost, and Olyset® Plus) compared to a pyrethroid LLIN: MAGNet®. Durability monitoring will be conducted up to 36 months post-distribution and median survival in months will be calculated. The proportion of ITNs: (1) lost (attrition), (2) physical integrity, (3) resistance to damage score, (4) meeting WHO bio-efficacy (≥ 95% knockdown after 1 h or ≥ 80% mortality after 24 h for WHO cone bioassay, or ≥ 90% blood-feeding inhibition or ≥ 80% mortality after 24 h for WHO Tunnel tests) criteria against laboratory-reared resistant and susceptible mosquitoes, and insecticidal persistence over time will be estimated. The non-inferiority of Veeralin® and Tsara® Boost to the first-in-class, Olyset® Plus will additionally be assessed for mortality, and the equivalence of 20 times washed ITNs compared to field aged ITNs will be assessed for mortality and blood-feeding inhibition endpoints in the Ifakara Ambient Chamber Test, Tanzania. CONCLUSION This will be the first large-scale prospective household randomized controlled trial of pyrethroid-PBO ITNs in three different countries in East Africa, West Africa and South Asia, simultaneously. The study will generate information on the replenishment intervals for PBO nets.
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Affiliation(s)
- Emmanuel Mbuba
- Vector Control Product Testing Unit, Environmental Health and Ecological Science, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania.
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland.
- University of Basel, St. Petersplatz 1, 4002, Basel, Switzerland.
| | - Olukayode G Odufuwa
- Vector Control Product Testing Unit, Environmental Health and Ecological Science, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, St. Petersplatz 1, 4002, Basel, Switzerland
- Epidemiology and Population Health Department, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Jason Moore
- Vector Control Product Testing Unit, Environmental Health and Ecological Science, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
| | - Selemani Mmbaga
- Vector Control Product Testing Unit, Environmental Health and Ecological Science, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania
| | - Emile Tchicaya
- Swiss Centre for Scientific Research in Côte d'Ivoire, 1303, Abidjan, Côte d'Ivoire
- Vegro Aps, Copenhagen, Denmark, Refshalevej 213A
| | - Constant Edi
- Swiss Centre for Scientific Research in Côte d'Ivoire, 1303, Abidjan, Côte d'Ivoire
| | - Vani Chalageri
- Field Unit, ICMR-National Institute of Malaria Research, Bangalore, Karnataka, India
| | - Sreehari Uragayala
- Field Unit, ICMR-National Institute of Malaria Research, Bangalore, Karnataka, India
| | - Amit Sharma
- ICMR-National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India
| | - Manju Rahi
- ICMR-Indian Council of Medical Research, Ansari Nagar, New Delhi, India
| | - Kamaraju Raghavendra
- ICMR-National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, 110077, India
| | - Alex Eapen
- Field Unit, ICMR-Indian Council of Medical Research, Chennai, India
| | | | - Amanda Ross
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, St. Petersplatz 1, 4002, Basel, Switzerland
| | - Sarah J Moore
- Vector Control Product Testing Unit, Environmental Health and Ecological Science, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, St. Petersplatz 1, 4002, Basel, Switzerland
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6
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Diallo OO, Ozodiegwu ID, Camara A, Galatas B, Gerardin J. Factors associated with the ownership and use of insecticide-treated nets in Guinea: an analysis of the 2018 Demographic and Health Survey. Malar J 2023; 22:29. [PMID: 36703147 PMCID: PMC9878948 DOI: 10.1186/s12936-023-04463-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Malaria is a leading cause of outpatient visits and deaths among children in Guinea. Despite several mass distribution campaigns of insecticide-treated nets (ITNs) in Guinea, ITN ownership and use remain low. Identifying the underlying factors affecting household ITN ownership and ITN usage among those with access will allow the Guinea National Malaria Control Programme to develop targeted initiatives to improve bed net ownership and usage. METHODS To understand national and regional drivers of ITN ownership and use, multivariable binary logistic regression models were applied to data from the 2018 Demographic and Health Survey to identify risk factors of household ITN ownership and risk factors of ITN use among individuals with access. Akaike Information Criterion (AIC) was used for model parameter selection. Odds ratios were estimated with corresponding 95% confidence intervals. RESULTS The proportion of households in Guinea with at least one ITN was 44%, ranging from a low of 25% in Conakry to a high of 54% in Labé. Use of ITNs among those with access was 66.1% nationally, ranging from 35.2% in Labé to 89.7% in N'zérékoré. Risk factors for household ITN ownership were household size, marital status of the household head, education level of the household head, and region. For ITN use among those with access, risk factors were age, wealth quintile, marital status, and region. In the seven regions of Guinea and capital of Conakry, risk factors for household ITN ownership were household size in Boké, Faranah, and Kankan; education level of the household head in Boké, Faranah, and N'zérékoré; age of the household head in Conakry and Labé; children under five in the household in Kankan; and wealth quintile in Mamou. For ITN use among those with access, risk factors were marital status in Conakry, Faranah, Kindia, Labé, Mamou, and N'zérékoré; place of residence in Labé; children under five in the household in Labé; wealth quintile in Mamou; and age in Faranah and N'zérékoré. CONCLUSIONS This analysis identified national and region-specific factors that affect ownership and use among those with access in Guinea. Future ITN and social-behavioural change campaigns in Guinea may particularly want to target larger households, households without children, and areas with lower perceived risk of malaria if universal coverage and usage are to be achieved for optimal malaria prevention.
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Affiliation(s)
- Ousmane Oumou Diallo
- Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, USA.
| | - Ifeoma D. Ozodiegwu
- grid.16753.360000 0001 2299 3507Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, USA
| | | | - Beatriz Galatas
- grid.3575.40000000121633745Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Jaline Gerardin
- grid.16753.360000 0001 2299 3507Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, USA
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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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Fernández Montoya L, Alafo C, Martí-Soler H, Máquina M, Malheia A, Sacoor C, Abílio AP, Marrenjo D, Cuamba N, Galatas B, Aide P, Saúte F, Paaijmans KP. An evaluation of LLIN ownership, access, and use during the Magude project in southern Mozambique. PLoS One 2023; 18:e0282209. [PMID: 36972236 PMCID: PMC10042371 DOI: 10.1371/journal.pone.0282209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 02/07/2023] [Indexed: 03/29/2023] Open
Abstract
The Magude Project assessed the feasibly of eliminating malaria in a low transmission setting in southern Mozambique using a package of interventions. This study measured the ownership, access and use of long-lasting insecticide treated nets (LLINs) and inequalities in these indicators across household wealth, size and population subgroups, to understand the protection that LLINs provided during the project. Data were obtained from various household surveys. At least 31% of the nets distributed during the 2014 and 2017 campaigns were lost during the first year post-distribution. Most nets (77.1%) present in the district were Olyset Nets. LLIN access never exceeded 76.3% and use varied seasonally between 40% and 76.4%. LLIN access limited LLIN use during the project, especially during the high transmission season. LLIN ownership, access and use were lower in harder-to-reach localities, in poorer and larger households. Children and women below 30 had poorer access to LLINs than the overall population. Net use was lowest among school-aged children and young adults, especially among young males, and highest in children under 5, pregnant women, in older adults and in households that received indoor residual spraying (IRS). This study revealed that LLIN mass-distribution campaigns alone are not sufficient to achieve the high level of net protection needed during elimination programs and that reviewing the LLIN allocation scheme, top-up distributions and/or community engagement campaigns is needed, also to reduce inequalities in populations' access to LLINs.
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Affiliation(s)
- Lucia Fernández Montoya
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
- ISGlobal, Barcelona, Spain
| | - Celso Alafo
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
| | | | - Mara Máquina
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
| | - Arlindo Malheia
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
| | - Charfudin Sacoor
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
| | - Ana Paula Abílio
- Instituto Nacional da Saúde, Ministério da Saúde, Maputo, Mozambique
| | - Dulcisaria Marrenjo
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
| | - Nelson Cuamba
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
- PMI VectorLink Project, Abt Associates Inc., Maputo, Mozambique
| | - Beatriz Galatas
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
- ISGlobal, Barcelona, Spain
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
- Instituto Nacional da Saúde, Ministério da Saúde, Maputo, Mozambique
| | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
| | - Krijn P Paaijmans
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhiça Maputo, Mozambique
- ISGlobal, Barcelona, Spain
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, United States of America
- The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, United States of America
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, United States of America
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Ngonghala CN, Bhattacharyya S. An evolutionary game model of individual choices and bed net use: elucidating key aspect in malaria elimination strategies. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220685. [PMID: 36405633 PMCID: PMC9667140 DOI: 10.1098/rsos.220685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Insecticide-treated net (ITN) is the most applicable and cost-effective malaria intervention measure in sub-Saharan Africa and elsewhere. Although ITNs have been widely distributed to malaria-endemic regions in the past, their success has been threatened by misuses (in fishing, agriculture etc.) and decay in ITN efficacy. Decision-making in using the ITNs depends on multiple coevolving factors: malaria prevalence, mosquito density, ITN availability and its efficacy, and other socio-economic determinants. While ITN misuse increases as the efficacy of ITNs declines, high efficacy also impedes proper use due to free-riding. This irrational usage leads to increased malaria prevalence, thereby worsening malaria control efforts. It also remains unclear if the optimum ITN use for malaria elimination can be achieved under such an adaptive social learning process. Here, we incorporate evolutionary game theory into a disease transmission model to demonstrate these behavioural interactions and their impact on malaria prevalence. We show that social optimum usage is a function of transmission potential, ITN efficacy and mosquito demography. Under specific parameter regimes, our model exhibits patterns of ITN usage similar to observed data from parts of Africa. Our study suggests that the provision of financial incentives as prompt feedback to improper ITN use can reduce misuse and contribute positively towards malaria elimination efforts in Africa and elsewhere.
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Affiliation(s)
- Calistus N. Ngonghala
- Department of Mathematics and Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
| | - Samit Bhattacharyya
- Disease Modelling Lab, Department of Mathematics, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
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10
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Mwangu LM, Mapuroma R, Ibisomi L. Factors associated with non-use of insecticide-treated bed nets among pregnant women in Zambia. Malar J 2022; 21:290. [PMID: 36221068 PMCID: PMC9555102 DOI: 10.1186/s12936-022-04313-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/23/2022] [Indexed: 12/04/2022] Open
Abstract
Background Despite the Zambian government’s efforts to ensure 80% use of insecticide-treated nets (ITNs) among pregnant women, ITN use remains critically low. Only 49% of pregnant women reported sleeping under an ITN in 2018 in the country. This study aims to determine the prevalence of, and the factors associated with the non-use of ITNs among pregnant women in Zambia. Methods This study was a secondary analysis of the data collected during the 2018 Zambian Demographic and Health Survey. One thousand one hundred and thirty-eight (1 138) pregnant women were included in the study. The prevalence of the non-use of ITNs was computed and univariable and multivariable logistic regression models were fitted to determine the factors associated with the non-use of ITNs in the study population. Results The study found that 578 (50.8%) pregnant women reported not using an ITN the night before the survey. The results of the multivariable logistic regression indicated that, primary level education (OR = 2.13, 95% CI 1.23–3.68), ITN per household member (OR = 0.01, 95% CI 0.00–0.02), parity (OR = 0.83, 95% CI 0.70–0.99), moderate malaria prevalence provinces (OR = 0.34, 95% CI 0.23–0.50), high malaria prevalence provinces (OR = 0.26, 95% CI 0.18–0.39) and currently in a union (OR = 0.52, 95% CI 0.30–0.88) were significantly associated with the non-use of ITNs. Conclusion This study showed a high prevalence of the non-use of ITNs among pregnant women in Zambia. Factors found to be associated with the non-use of ITNs in the study population are: ITN per household member, parity, education, marital status and malaria prevalence provinces. Addressing the identified factors will require intensification of ITN programming and other malaria preventive measures.
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Affiliation(s)
- Luwi Mercy Mwangu
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Relebogile Mapuroma
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Latifat Ibisomi
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Nigerian Institute of Medical Research, Lagos, Nigeria
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11
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Fernandez Montoya L, Alafo C, Martí-Soler H, Máquina M, Comiche K, Cuamba I, Munguambe K, Cator L, Aide P, Galatas B, Cuamba N, Marrenjo D, Saúte F, Paaijmans KP. Overlaying human and mosquito behavioral data to estimate residual exposure to host-seeking mosquitoes and the protection of bednets in a malaria elimination setting where indoor residual spraying and nets were deployed together. PLoS One 2022; 17:e0270882. [PMID: 36107865 PMCID: PMC9477321 DOI: 10.1371/journal.pone.0270882] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 06/21/2022] [Indexed: 11/18/2022] Open
Abstract
Characterizing persistent malaria transmission that occurs after the combined deployment of indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) is critical to guide malaria control and elimination efforts. This requires a detailed understanding of both human and vector behaviors at the same temporal and spatial scale. Cross-sectional human behavior evaluations and mosquito collections were performed in parallel in Magude district, Mozambique. Net use and the exact time when participant moved into each of five environments (outdoor, indoor before bed, indoor in bed, indoor after getting up, and outdoor after getting up) were recorded for individuals from three different age groups and both sexes during a dry and a rainy season. Malaria mosquitoes were collected with CDC light traps in combination with collection bottle rotators. The percentage of residual exposure to host-seeking vectors that occurred in each environment was calculated for five local malaria vectors with different biting behaviors, and the actual (at observed levels of LLIN use) and potential (i.e. if all residents had used an LLIN) personal protection conferred by LLINs was estimated. Anopheles arabiensis was responsible for more than 74% of residents' residual exposure to host-seeking vectors during the Magude project. The other four vector species (An. funestus s.s., An. parensis, An. squamosus and An. merus) were responsible for less than 10% each. The personal protection conferred by LLINs prevented only 39.2% of the exposure to host-seeking vectors that survived the implementation of both IRS and LLINs, and it differed significantly across seasons, vector species and age groups. At the observed levels of bednet use, 12.5% of all residual exposure to host-seeking vectors occurred outdoor during the evening, 21.9% indoor before going to bed, almost two thirds (64%) while people were in bed, 1.4% indoors after getting up and 0.2% outdoor after leaving the house. Almost a third of the residual exposure to host-seeking vectors (32.4%) occurred during the low transmission season. The residual bites of An. funestus s.s. and An. parensis outdoors and indoor before bedtime, of An. arabiensis indoors when people are in bed, and of An. squamosus both indoors and outdoors, are likely to have sustained malaria transmission throughout the Magude project. By increasing LLIN use, an additional 24.1% of exposure to the remaining hosts-seeking vectors could have been prevented. Since An. arabiensis, the most abundant vector, feeds primarily while people are in bed, increasing net use and net feeding inhibition (through e.g. community awareness activities and the selection of more effective LLINs) could significantly reduce the exposure to remaining host-seeking mosquitoes. Nonetheless, supplementary interventions aiming to reduce human-vector contact outdoors and/or indoors before people go to bed (e.g. through larval source management, window and eave screening, eave tubes, and spatial repellents) will be needed to reduce residual exposure to the outdoor and early biting An. funestus s.s. and An. parensis.
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Affiliation(s)
- Lucia Fernandez Montoya
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | - Celso Alafo
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
- Goodbye Malaria, Tchau Tchau Malaria Foundation, Chibungo, Mozambique
| | | | - Mara Máquina
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | - Kiba Comiche
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | - Inocencia Cuamba
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | - Khatia Munguambe
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | | | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
- Instituto Nacional da Saúde, Ministério da Saúde, Maputo, Mozambique
| | - Beatriz Galatas
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | - Nelson Cuamba
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
- PMI VectorLink Project, Abt Associates Inc., Maputo, Mozambique
| | - Dulcisaria Marrenjo
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
| | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
| | - Krijn P. Paaijmans
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Mozambique
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, United States of America
- The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, United States of America
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, United States of America
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12
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Koenker H, Worges M, Kamala B, Gitanya P, Chacky F, Lazaro S, Mwalimu CD, Aaron S, Mwingizi D, Dadi D, Selby A, Serbantez N, Msangi L, Loll D, Yukich J. Annual distributions of insecticide-treated nets to schoolchildren and other key populations to maintain higher ITN access than with mass campaigns: a modelling study for mainland Tanzania. Malar J 2022; 21:246. [PMID: 36028866 PMCID: PMC9417077 DOI: 10.1186/s12936-022-04272-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 08/16/2022] [Indexed: 11/12/2022] Open
Abstract
Background Since 2013, the National Malaria Control Programme in mainland Tanzania has deployed annual distributions of insecticide-treated nets (ITNs) through primary schools to maintain ITN access and use. This School Net Programme (SNP) is slated to be used throughout mainland Tanzania by 2023. This modelling study projects ITN access under different ITN distribution strategies and quantification approaches. Methods A stock and flow model with a Tanzania-specific ITN decay rate was used to calculate annual net crops for four different ITN distribution strategies, varying quantification approaches within each strategy. Annual nets-per-capita (NPC) was derived from net crop and a standardized population projection. Nonparametric conditional quartile functions for the proportion of the population with access to an ITN (ITN access) as a function of NPC were used to predict ITN access and its variability. The number of ITNs required under the varying quantification approaches for the period 2022–2030 was calculated. Results Annual SNP quantified using a “population times 15%” approach maintained ITN access between 80 and 90%, when combined with reproductive and child health (RCH) ITN distribution, requiring 133.2 million ITNs. The same strategy quantified with “population times 22%” maintained ITN access at or above 90%, requiring 175.5 million ITNs. Under 5-year mass campaigns with RCH distribution for pregnant women and infants, ITN access reached 90% post-campaign and fell to 27–35% in the 4th year post-campaign, requiring 120.5 million ITNs over 8 years. 3-yearly mass campaigns with RCH reached 100% ITN access post-campaign and fell to 70% in the 3rd year post-campaign, requiring 154.4 million ITNs. Conclusion Given an ITN retention time in Tanzania of 2.15 years, the model predicts that mass campaigns conducted every 3 years in mainland Tanzania will not maintain ITN access at target levels of 80%, even with strong RCH channels. Mainland Tanzania can however expect to maintain ITN access at 80% or above by quantifying SNP using “population × 15%”, in addition to RCH ITN delivery. This strategy requires 14% fewer ITNs than a 3-year campaign strategy while providing more consistent ITN coverage. Meeting the targets of 80% ITN use would require maintaining 90% ITN access, achievable using a “population times 22%” quantification approach for SNP. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04272-w.
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Affiliation(s)
- Hannah Koenker
- USAID Tanzania Vector Control Activity, Tropical Health, Baltimore, MD, USA.
| | - Matt Worges
- USAID Tanzania Vector Control Activity, Tropical Health, New Orleans, LA, USA
| | - Benjamin Kamala
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programmes, Dar es Salaam, Tanzania
| | - Peter Gitanya
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | - Frank Chacky
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | - Samwel Lazaro
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | | | - Sijenunu Aaron
- National Malaria Control Programme, Ministry of Health, Dodoma, Tanzania
| | - Deodatus Mwingizi
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programmes, Dar es Salaam, Tanzania
| | - David Dadi
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programmes, Dar es Salaam, Tanzania
| | - Ato Selby
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programmes, Dar es Salaam, Tanzania
| | | | - Lulu Msangi
- US President's Malaria Initiative, Dar es Salaam, Tanzania
| | - Dana Loll
- USAID Tanzania Vector Control Activity, Johns Hopkins University School of Public Health Center for Communication Programs, Baltimore, MD, USA
| | - Joshua Yukich
- USAID Tanzania Vector Control Activity, Tropical Health, New Orleans, LA, USA
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13
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Sadoine ML, Smargiassi A, Liu Y, Gachon P, Dueymes G, Dorsey G, Fournier M, Nankabirwa JI, Rek J, Zinszer K. The influence of the environment and indoor residual spraying on malaria risk in a cohort of children in Uganda. Sci Rep 2022; 12:11537. [PMID: 35798826 PMCID: PMC9262898 DOI: 10.1038/s41598-022-15654-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 06/27/2022] [Indexed: 12/24/2022] Open
Abstract
Studies have estimated the impact of the environment on malaria incidence although few have explored the differential impact due to malaria control interventions. Therefore, the objective of the study was to evaluate the effect of indoor residual spraying (IRS) on the relationship between malaria and environment (i.e. rainfall, temperatures, humidity, and vegetation) using data from a dynamic cohort of children from three sub-counties in Uganda. Environmental variables were extracted from remote sensing sources and averaged over different time periods. General linear mixed models were constructed for each sub-counties based on a log-binomial distribution. The influence of IRS was analysed by comparing marginal effects of environment in models adjusted and unadjusted for IRS. Great regional variability in the shape (linear and non-linear), direction, and magnitude of environmental associations with malaria risk were observed between sub-counties. IRS was significantly associated with malaria risk reduction (risk ratios vary from RR = 0.03, CI 95% [0.03-0.08] to RR = 0.35, CI95% [0.28-0.42]). Model adjustment for this intervention changed the magnitude and/or direction of environment-malaria associations, suggesting an interaction effect. This study evaluated the potential influence of IRS in the malaria-environment association and highlighted the necessity to control for interventions when they are performed to properly estimate the environmental influence on malaria. Local models are more informative to guide intervention program compared to national models.
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Affiliation(s)
- Margaux L. Sadoine
- grid.14848.310000 0001 2292 3357School of Public Health, Université de Montréal, Montréal, Québec Canada ,grid.14848.310000 0001 2292 3357Public Health Research Center, Université de Montréal, Montréal, Québec Canada
| | - Audrey Smargiassi
- grid.14848.310000 0001 2292 3357School of Public Health, Université de Montréal, Montréal, Québec Canada ,grid.14848.310000 0001 2292 3357Public Health Research Center, Université de Montréal, Montréal, Québec Canada
| | - Ying Liu
- grid.14848.310000 0001 2292 3357School of Public Health, Université de Montréal, Montréal, Québec Canada ,grid.14848.310000 0001 2292 3357Public Health Research Center, Université de Montréal, Montréal, Québec Canada
| | - Philippe Gachon
- grid.38678.320000 0001 2181 0211ESCER (Étude et Simulation du Climat à l’Échelle Régionale) Centre, Université du Québec à Montréal, Montréal, Québec Canada
| | - Guillaume Dueymes
- grid.38678.320000 0001 2181 0211ESCER (Étude et Simulation du Climat à l’Échelle Régionale) Centre, Université du Québec à Montréal, Montréal, Québec Canada
| | - Grant Dorsey
- grid.266102.10000 0001 2297 6811University of California San Francisco, San Francisco, USA
| | - Michel Fournier
- Montreal Regional Department of Public Health, Montréal, Québec Canada
| | - Joaniter I. Nankabirwa
- grid.463352.50000 0004 8340 3103Infectious Disease Research Collaboration, Kampala, Uganda ,grid.11194.3c0000 0004 0620 0548Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - John Rek
- grid.463352.50000 0004 8340 3103Infectious Disease Research Collaboration, Kampala, Uganda
| | - Kate Zinszer
- grid.14848.310000 0001 2292 3357School of Public Health, Université de Montréal, Montréal, Québec Canada ,grid.14848.310000 0001 2292 3357Public Health Research Center, Université de Montréal, Montréal, Québec Canada
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14
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Sherrard-Smith E, Ngufor C, Sanou A, Guelbeogo MW, N'Guessan R, Elobolobo E, Saute F, Varela K, Chaccour CJ, Zulliger R, Wagman J, Robertson ML, Rowland M, Donnelly MJ, Gonahasa S, Staedke SG, Kolaczinski J, Churcher TS. Inferring the epidemiological benefit of indoor vector control interventions against malaria from mosquito data. Nat Commun 2022; 13:3862. [PMID: 35790746 PMCID: PMC9256631 DOI: 10.1038/s41467-022-30700-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/11/2022] [Indexed: 12/03/2022] Open
Abstract
The cause of malaria transmission has been known for over a century but it is still unclear whether entomological measures are sufficiently reliable to inform policy decisions in human health. Decision-making on the effectiveness of new insecticide-treated nets (ITNs) and the indoor residual spraying of insecticide (IRS) have been based on epidemiological data, typically collected in cluster-randomised control trials. The number of these trials that can be conducted is limited. Here we use a systematic review to highlight that efficacy estimates of the same intervention may vary substantially between trials. Analyses indicate that mosquito data collected in experimental hut trials can be used to parameterize mechanistic models for Plasmodium falciparum malaria and reliably predict the epidemiological efficacy of quick-acting, neuro-acting ITNs and IRS. Results suggest that for certain types of ITNs and IRS using this framework instead of clinical endpoints could support policy and expedite the widespread use of novel technologies.
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Affiliation(s)
| | - Corine Ngufor
- Centre de Recherches Entomologiques de Cotonou, Cotonou, Benin
- London School of Hygiene and Tropical Medicine, London, UK
| | - Antoine Sanou
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Moussa W Guelbeogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Raphael N'Guessan
- London School of Hygiene and Tropical Medicine, London, UK
- Institut Pierre Richet, Bouake, Côte d'Ivoire
| | - Eldo Elobolobo
- Centro de Investigação em Saúde de Manhiça, Manhiça, Mozambique
| | - Francisco Saute
- Centro de Investigação em Saúde de Manhiça, Manhiça, Mozambique
| | | | | | - Rose Zulliger
- US President's Malaria Initiative, USAID, Washington, DC, USA
| | | | | | - Mark Rowland
- London School of Hygiene and Tropical Medicine, London, UK
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15
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Orish VN, Maalman RSE, Donkor OY, Ceruantes BYH, Osei E, Amu H, Appiah PK, Konlan KD, Mumuni H, Kim E, Kim S, Jung H, Ofori-Amoah J, Kofie P, Adjuik M, Alhassan RK, Donkor ES, Zottor FB, Kweku M, Amuna P, Kim SY, Gyapong JO. Assessing health-seeking behaviour and malaria prevention practices among communities in four districts of the Volta Region of Ghana. Malar J 2021; 20:450. [PMID: 34838027 PMCID: PMC8626995 DOI: 10.1186/s12936-021-03986-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 11/16/2021] [Indexed: 11/22/2022] Open
Abstract
Background Malaria is a preventable disease that causes huge morbidity and mortality in malaria-endemic areas, especially among children and pregnant women. The malaria control programme focuses on the prevention of mosquito bites using insecticide-treated nets (ITNs) and mosquito aerosol sprays and coils, as well as prevention of severe disease among those infected through prompt and adequate treatment. The success of the malaria control programme in Ghana is dependent on the malaria prevention practices of people in the community. Therefore, this study evaluated the malaria prevention practices of participants in four districts of the Volta Region of Ghana. Methods This was a cross-sectional study conducted in Ketu South, Nkwanta South, Hohoe Municipality and Ho West districts of the Volta Region of Ghana. Questionnaire were administered to adults who consented to each household visited. Questions were asked on the socio-demographics and malaria prevention practices of the households. Data analysis was done using SPSS version 23 with frequency distribution done for all the variables. Pearson chi-square was used to determine the significant association between socio-demographics and malaria prevention practices, and Multivariate nominal logistic regression analysis was used to model the relationship between dichotomous dependent variables (ITN ownership and usage) and independent variables. Results Out of the 2493 participants; 2234 (89.6%) owned ITN and 1528 (68.4%) used ITN a night before this study, 768 (30.8%) used mosquito aerosol spray and 368 (15%) used mosquito coil. More females significantly owned ITN than males (1293, 92.4%, p ≤ 0.001). Participants from Ketu South had 1.5 times higher odds of owning an ITN compared to Ho West whose odds are not different from Nkwanta South or Hohoe (AOR, 1.56 [95% 1.09–2.22]; p = 0.01). In terms of ITN usage, participants in Nkwanta South were less likely to use ITN compared to the other districts; AOR, 0.434 [95% CI 0.31–0.62, p < 0.001]. Also, of the 668 participants that had a fever within the past 3 days, 268 (40.1%) visited a patent medicine store and 156 (23.4%) visited health facilities. Conclusion There is high ownership of ITNs, but relatively low utilization among the community members. Education on malaria prevention practices should be intensified and continuous among the population of the Volta Region to ensure the success of malaria control in the region.
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Affiliation(s)
- Verner N Orish
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | | | - Otchere Y Donkor
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | | | - Eric Osei
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana.,Department of Public Health Graduate School, Yonsei University, Seoul, Republic of Korea
| | - Hubert Amu
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Prince Kubi Appiah
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana.,Department of Public Health Graduate School, Yonsei University, Seoul, Republic of Korea
| | - Kennedy Diema Konlan
- Department of Public Health Graduate School, Yonsei University, Seoul, Republic of Korea.,School of Nursing and Midwifery, University of Health and Allied Sciences, Ho, Ghana
| | - Hadiru Mumuni
- School of Nursing and Midwifery, University of Health and Allied Sciences, Ho, Ghana
| | - Eunji Kim
- Korea Foundation for International Healthcare Ghana Office, Accra, Ghana
| | - Siwoo Kim
- Asian Institute for Bioethics and Health Law, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - Hajun Jung
- Asian Institute for Bioethics and Health Law, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - Jones Ofori-Amoah
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Philip Kofie
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Martin Adjuik
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Robert Kaba Alhassan
- Directorate of International Affairs, University of Health and Allied Sciences, Ho, Ghana
| | | | | | - Margaret Kweku
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Paul Amuna
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - So Yoo Kim
- Asian Institute for Bioethics and Health Law, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - John Owusu Gyapong
- Office of the Vice-Chancellor, University of Health and Allied Sciences, Ho, Ghana
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16
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Gatua JG. Information and cooperation in preventive health behavior: The case of bed net use in rural Kenya. HEALTH ECONOMICS 2021; 30:2124-2143. [PMID: 34096642 DOI: 10.1002/hec.4365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/07/2021] [Accepted: 05/17/2021] [Indexed: 06/12/2023]
Abstract
This paper assesses whether providing people with information on the public benefits of bed net use, and on other people's bed net use, changes their bed net use behavior. I use a survey experiment from rural Kenya, where randomly selected households are provided with information on the public benefits generated by bed net use, and on the consequences of an individual's own bed net use on the health of the immediate neighbor. The results show that information increased willingness to use bed nets, and that people are more willing to use bed nets when they know other people are using them as well. Results are robust to the inclusion of a broad set of controls, including risk aversion; number of household members to have suffered from malaria in the past 12 months; and number of children in the household who are below five years age. Overall, these results suggest that in addition to free distribution of bed nets, informing people on the private and public benefits of bed net use could potentially save many more lives.
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Affiliation(s)
- Josephine G Gatua
- Overseas Development Institute, London, United Kingdom
- Nigeria Centre for Disease Control, Abuja, Nigeria
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17
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Maps and metrics of insecticide-treated net access, use, and nets-per-capita in Africa from 2000-2020. Nat Commun 2021; 12:3589. [PMID: 34117240 PMCID: PMC8196080 DOI: 10.1038/s41467-021-23707-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/12/2021] [Indexed: 02/05/2023] Open
Abstract
Insecticide-treated nets (ITNs) are one of the most widespread and impactful malaria interventions in Africa, yet a spatially-resolved time series of ITN coverage has never been published. Using data from multiple sources, we generate high-resolution maps of ITN access, use, and nets-per-capita annually from 2000 to 2020 across the 40 highest-burden African countries. Our findings support several existing hypotheses: that use is high among those with access, that nets are discarded more quickly than official policy presumes, and that effectively distributing nets grows more difficult as coverage increases. The primary driving factors behind these findings are most likely strong cultural and social messaging around the importance of net use, low physical net durability, and a mixture of inherent commodity distribution challenges and less-than-optimal net allocation policies, respectively. These results can inform both policy decisions and downstream malaria analyses.
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18
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Tassembedo M, Coulibaly S, Ouedraogo B. Factors associated with the use of insecticide-treated nets: analysis of the 2018 Burkina Faso Malaria Indicator Survey. Malar J 2021; 20:220. [PMID: 34001104 PMCID: PMC8130301 DOI: 10.1186/s12936-021-03756-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 05/08/2021] [Indexed: 11/12/2022] Open
Abstract
Background Sleeping under an ITN reduces contact with mosquitoes through the combination of a physical barrier and an insecticidal effect, which reduces the incidence of malaria. The 2016–2020 Burkina Faso National Malaria Strategic Plan aims to have at least 90% of the population, 100% of children under age 5, and 100% of pregnant women sleep under an ITN. Methods The analysis examines individual, household, and community-level factors associated with ITN usage. According to the 2017–18 Burkina Faso MIS, 58% of individuals in households that own at least one ITN reported that they slept under an ITN on the night before the survey. Results The use of ITNs was significantly associated with individual, household, and community-level variables that included age, gender, age of household head, number of sleeping rooms, wealth, malaria prevalence, residence, and region. Conclusions The results highlight areas of intervention at the individual, household, and community levels that can increase ITN use.
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Affiliation(s)
- Mahamadi Tassembedo
- Institut de Formation et de Recherche Interdisciplinaires en Sciences de la Santé et de l'Education (IFRISSE), Ouagadougou, Burkina Faso. .,Direction du Suivi, de l'évaluation et de la Capitalisation, Ministère de la santé, Ouagadougou, Burkina Faso.
| | - Soumaila Coulibaly
- Institut de Formation et de Recherche Interdisciplinaires en Sciences de la Santé et de l'Education (IFRISSE), Ouagadougou, Burkina Faso.,Centre National de Recherche et de Formation sur le Paludisme (CNRFP)/Institut National de Santé Publique (INSP), Ministère de la santé, Ouagadougou, Burkina Faso
| | - Boukary Ouedraogo
- Institut de Formation et de Recherche Interdisciplinaires en Sciences de la Santé et de l'Education (IFRISSE), Ouagadougou, Burkina Faso.,Direction des systèmes d'information en santé, Ministère de la santé, Ouagadougou, Burkina Faso
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19
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Scott J, Kanyangarara M, Nhama A, Macete E, Moss WJ, Saute F. Factors associated with use of insecticide-treated net for malaria prevention in Manica District, Mozambique: a community-based cross-sectional survey. Malar J 2021; 20:200. [PMID: 33906642 PMCID: PMC8077836 DOI: 10.1186/s12936-021-03738-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 04/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insecticide-treated net (ITN) use is crucial for preventing malaria infection. Despite significant improvements in ITN access and use over the past two decades, many malaria-endemic countries in sub-Saharan Africa have not yet reached global targets for universal coverage of ITNs. To reduce the gaps in ITN use, it is important to understand the factors associated with ITN use. The goal of this analysis was to determine the factors associated with ITN use in Manica District, Mozambique. METHODS A cross-sectional community-based survey was conducted from October to November 2019. Households were randomly selected, and all members of selected households were eligible to participate. Data on socio-demographic characteristics, housing construction and the ownership, use and characteristics of ITNs were collected using structured questionnaires. Factors independently associated with ITN use were identified using generalized estimating equations multivariate logistic regression. RESULTS Of the 302 households surveyed, 209 (69.2%) owned at least one ITN and 176 (58.3%) had one ITN for every two household members. The multivariate analysis indicated that the odds of ITN use was significantly lower among individuals in households with 3 or more members. However, the odds of ITN use was significantly higher among older age groups, poorer households, and as the number of ITNs in a household increased. CONCLUSIONS The findings of this analysis highlight the need for behaviour change communication strategies targeting young people and ITN distribution campaigns targeting larger households to increase ITN ownership, thereby improving ITN use in Manica District.
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Affiliation(s)
- Julia Scott
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, 915 Greene Street, Columbia, SC, 29201, USA
| | - Mufaro Kanyangarara
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, 915 Greene Street, Columbia, SC, 29201, USA.
| | - Abel Nhama
- Centro de Investigação Em Saúde de Manhiça (CISM), Maputo, Mozambique.,Instituto Nacional de Saúde (INS), Maputo, Mozambique
| | - Eusebio Macete
- Centro de Investigação Em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - William John Moss
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Francisco Saute
- Centro de Investigação Em Saúde de Manhiça (CISM), Maputo, Mozambique
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20
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Ozodiegwu ID, Ambrose M, Battle KE, Bever C, Diallo O, Galatas B, Runge M, Gerardin J. Beyond national indicators: adapting the Demographic and Health Surveys' sampling strategies and questions to better inform subnational malaria intervention policy. Malar J 2021; 20:122. [PMID: 33648499 PMCID: PMC7919087 DOI: 10.1186/s12936-021-03646-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/11/2021] [Indexed: 11/17/2022] Open
Abstract
In malaria-endemic countries, prioritizing intervention deployment to areas that need the most attention is crucial to ensure continued progress. Global and national policy makers increasingly rely on epidemiological data and mathematical modelling to help optimize health decisions at the sub-national level. The Demographic and Health Surveys (DHS) Program is a critical data source for understanding subnational malaria prevalence and intervention coverage, which are used for parameterizing country-specific models of malaria transmission. However, data to estimate indicators at finer resolutions are limited, and surveys questions have a narrow scope. Examples from the Nigeria DHS are used to highlight gaps in the current survey design. Proposals are then made for additional questions and expansions to the DHS and Malaria Indicator Survey sampling strategy that would advance the data analyses and modelled estimates that inform national policy recommendations. Collaboration between the DHS Program, national malaria control programmes, the malaria modelling community, and funders is needed to address the highlighted data challenges.
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Affiliation(s)
- Ifeoma D Ozodiegwu
- Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, IL, USA.
| | | | | | | | - Ousmane Diallo
- Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, IL, USA
| | - Beatriz Galatas
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Manuela Runge
- Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, IL, USA
| | - Jaline Gerardin
- Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, IL, USA
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21
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Briet O, Koenker H, Norris L, Wiegand R, Vanden Eng J, Thackeray A, Williamson J, Gimnig JE, Fortes F, Akogbeto M, Yadouleton AW, Ombok M, Bayoh MN, Mzilahowa T, Abílio AP, Mabunda S, Cuamba N, Diouf E, Konaté L, Hamainza B, Katebe-Sakala C, Ponce de León G, Asamoa K, Wolkon A, Smith SC, Swamidoss I, Green M, Gueye S, Mihigo J, Morgan J, Dotson E, Craig AS, Tan KR, Wirtz RA, Smith T. Attrition, physical integrity and insecticidal activity of long-lasting insecticidal nets in sub-Saharan Africa and modelling of their impact on vectorial capacity. Malar J 2020; 19:310. [PMID: 32859210 PMCID: PMC7456088 DOI: 10.1186/s12936-020-03383-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 08/19/2020] [Indexed: 11/25/2022] Open
Abstract
Background Long-lasting insecticidal nets (LLINs) are the primary malaria prevention and control intervention in many parts of sub-Saharan Africa. While LLINs are expected to last at least 3 years under normal use conditions, they can lose effectiveness because they fall out of use, are discarded, repurposed, physically damaged, or lose insecticidal activity. The contributions of these different interrelated factors to durability of nets and their protection against malaria have been unclear. Methods Starting in 2009, LLIN durability studies were conducted in seven countries in Africa over 5 years. WHO-recommended measures of attrition, LLIN use, insecticidal activity, and physical integrity were recorded for eight different net brands. These data were combined with analyses of experimental hut data on feeding inhibition and killing effects of LLINs on both susceptible and pyrethroid resistant malaria vectors to estimate the protection against malaria transmission—in terms of vectorial capacity (VC)—provided by each net cohort over time. Impact on VC was then compared in hypothetical scenarios where one durability outcome measure was set at the best possible level while keeping the others at the observed levels. Results There was more variability in decay of protection over time by country than by net brand for three measures of durability (ratios of variance components 4.6, 4.4, and 1.8 times for LLIN survival, use, and integrity, respectively). In some countries, LLIN attrition was slow, but use declined rapidly. Non-use of LLINs generally had more effect on LLIN impact on VC than did attrition, hole formation, or insecticide loss. Conclusions There is much more variation in LLIN durability among countries than among net brands. Low levels of use may have a larger impact on effectiveness than does variation in attrition or LLIN degradation. The estimated entomological effects of chemical decay are relatively small, with physical decay probably more important as a driver of attrition and non-use than as a direct cause of loss of effect. Efforts to maximize LLIN impact in operational settings should focus on increasing LLIN usage, including through improvements in LLIN physical integrity. Further research is needed to understand household decisions related to LLIN use, including the influence of net durability and the presence of other nets in the household.
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Affiliation(s)
- Olivier Briet
- Swiss Tropical and Public Health Institute, 4051, Basel, Switzerland.,University of Basel, 4001, Basel, Switzerland
| | - Hannah Koenker
- PMI VectorWorks, JHU Center for Communication Programs, Baltimore, MD, USA.,Tropical Health LLP, Baltimore, MD, USA
| | - Laura Norris
- U.S. President's Malaria Initiative, U.S. Agency for International Development, Washington, DC, USA.,Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Ryan Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Jodi Vanden Eng
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | | | - John Williamson
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - John E Gimnig
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Filomeno Fortes
- National Malaria Control Program (NMCP), Ministry of Health, Luanda, Angola.,Institute of Hygiene and Tropical Medicine, NOVA University Lisbon, Lisbon, Portugal
| | - Martin Akogbeto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Anges W Yadouleton
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin.,Programme National de Lutte contre le Paludisme (PNLP), Ministry of Health, Cotonou, Bénin
| | - Maurice Ombok
- Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - M Nabie Bayoh
- Kenya Medical Research Institute (KEMRI), Kisumu, Kenya.,PMI VectorLink Project, Abt Associates, Lusaka, Zambia
| | - Themba Mzilahowa
- College of Medicine, Malaria Alert Centre, P/Bag 360, Blantyre 3, Malawi
| | - Ana Paula Abílio
- Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique
| | - Samuel Mabunda
- Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique.,National Malaria Control Programme (NMCP), Ministry of Health, Maputo, Mozambique
| | - Nelson Cuamba
- Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique.,National Malaria Control Programme (NMCP), Ministry of Health, Maputo, Mozambique
| | - Elhadji Diouf
- Faculté des Sciences et Techniques (FST), Université Cheikh Anta Diop (UCAD), Dakar, Senegal
| | - Lassana Konaté
- Faculté des Sciences et Techniques (FST), Université Cheikh Anta Diop (UCAD), Dakar, Senegal
| | | | | | - Gabriel Ponce de León
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Kwame Asamoa
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Adam Wolkon
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Stephen C Smith
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Isabel Swamidoss
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Mike Green
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Salam Gueye
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Jules Mihigo
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Juliette Morgan
- U.S. President's Malaria Initiative, Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Ellen Dotson
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Allen S Craig
- U.S. President's Malaria Initiative, Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Kathrine R Tan
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Robert A Wirtz
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA
| | - Tom Smith
- Swiss Tropical and Public Health Institute, 4051, Basel, Switzerland. .,University of Basel, 4001, Basel, Switzerland.
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22
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Monroe A, Moore S, Okumu F, Kiware S, Lobo NF, Koenker H, Sherrard-Smith E, Gimnig J, Killeen GF. Methods and indicators for measuring patterns of human exposure to malaria vectors. Malar J 2020; 19:207. [PMID: 32546166 PMCID: PMC7296719 DOI: 10.1186/s12936-020-03271-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 05/29/2020] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Effective targeting and evaluation of interventions that protect against adult malaria vectors requires an understanding of how gaps in personal protection arise. An improved understanding of human and mosquito behaviour, and how they overlap in time and space, is critical to estimating the impact of insecticide-treated nets (ITNs) and determining when and where supplemental personal protection tools are needed. Methods for weighting estimates of human exposure to biting Anopheles mosquitoes according to where people spend their time were first developed over half a century ago. However, crude indoor and outdoor biting rates are still commonly interpreted as indicative of human-vector contact patterns without any adjustment for human behaviour or the personal protection effects of ITNs. MAIN TEXT A small number of human behavioural variables capturing the distribution of human populations indoors and outdoors, whether they are awake or asleep, and if and when they use an ITN over the course of the night, can enable a more accurate representation of human biting exposure patterns. However, to date no clear guidance is available on what data should be collected, what indicators should be reported, or how they should be calculated. This article presents an integrated perspective on relevant indicators of human-vector interactions, the critical entomological and human behavioural data elements required to quantify human-vector interactions, and recommendations for collecting and analysing such data. CONCLUSIONS If collected and used consistently, this information can contribute to an improved understanding of how malaria transmission persists in the context of current intervention tools, how exposure patterns may change as new vector control tools are introduced, and the potential impact and limitations of these tools. This article is intended to consolidate understanding around work on this topic to date and provide a consistent framework for building upon it. Additional work is needed to address remaining questions, including further development and validation of methods for entomological and human behavioural data collection and analysis.
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Affiliation(s)
- April Monroe
- Johns Hopkins Center for Communication Programs, PMI VectorWorks Project, Baltimore, MD, USA.
- University of Basel, Basel, Switzerland.
- Swiss Tropical and Public Health Institute, Basel, Switzerland.
| | - Sarah Moore
- University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Fredros Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Republic of South Africa
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Samson Kiware
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Hannah Koenker
- Johns Hopkins Center for Communication Programs, PMI VectorWorks Project, Baltimore, MD, USA
| | - Ellie Sherrard-Smith
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - John Gimnig
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Gerry F Killeen
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
- School of Biological, Earth & Environmental Sciences and Environmental Research Institute, University College Cork, Cork, Republic of Ireland
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23
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Obi E, Okoh F, Blaufuss S, Olapeju B, Akilah J, Okoko OO, Okechukwu A, Maire M, Popoola K, Yahaya MA, Uneke CJ, Awolola S, Pigeon O, Babalola S, Koenker H, Kilian A. Monitoring the physical and insecticidal durability of the long-lasting insecticidal net DawaPlus ® 2.0 in three States in Nigeria. Malar J 2020; 19:124. [PMID: 32228592 PMCID: PMC7106771 DOI: 10.1186/s12936-020-03194-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 03/20/2020] [Indexed: 11/23/2022] Open
Abstract
Background Following guidance from the US President’s Malaria Initiative, durability monitoring of DawaPlus® 2.0 brand of long-lasting insecticidal net (LLIN) distributed during the 2015/16 mass campaign was set up in three ecologically different states: Zamfara, Ebonyi and Oyo. Methods This was a prospective cohort study of representative samples of households from each location, recruited at baseline, 1 to 6 months after the mass campaign. All campaign nets in the households were labelled and followed up over a period of 36 months in Zamfara and Ebonyi and 24 months in Oyo. Primary outcome was the “proportion of nets surviving in serviceable condition” based on attrition and integrity measures and the median survival in years. The outcome for insecticidal durability was determined by bio-assay from sub-samples of campaign nets. Results A total of 439 households (98% of target) and 1096 campaign nets (106%) were included in the study. Definite outcomes could be determined for 92% of the cohort nets in Zamfara, 88% in Ebonyi and 75% in Oyo. All-cause attrition was highest in Oyo with 47% no longer present after 24 months, 53% in Ebonyi and 28% in Zamfara after 36 months. Overall only 1% of all campaign nets were used for other purposes. Estimated survival in serviceable condition of the campaign nets was 80% in Zamfara, 55% in Ebonyi (36 months follow-up) and 75% in Oyo (24 months follow-up) corresponding to median survival of 5.3, 3.3, 3.2 years, respectively. Factors associated with better survival were exposure to social messaging combined with a positive net-care attitude and only adult users. Failing to fold the net when hanging and having children under 5 years of age in the household negatively impacted net survival. Insecticidal effectiveness testing at final survey showed knock-down rates of 50–69%, but 24-h mortality above 95% resulting in 100% optimal performance in Ebonyi and Oyo and 97% in Zamfara. Conclusions Results confirm the strong influence of net-use environment and behavioural factors in the physical survival of the same LLIN brand, which can increase the time until 50% of nets are no longer serviceable by up to 2 years.
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Affiliation(s)
- Emmanuel Obi
- PMI VectorWorks Project, Tropical Health LLP, Abuja, Nigeria
| | - Festus Okoh
- National Malaria Elimination Programme, Abuja, Nigeria
| | - Sean Blaufuss
- PMI VectorWorks Project, JHU Center for Communication Programs, Baltimore, MD, USA
| | - Bolanle Olapeju
- PMI VectorWorks Project, JHU Center for Communication Programs, Baltimore, MD, USA
| | - Joel Akilah
- National Malaria Elimination Programme, Abuja, Nigeria
| | | | - Abidemi Okechukwu
- U.S. President's Malaria Initiative, U.S. Agency for International Development, Abuja, Nigeria
| | - Mark Maire
- U.S. President's Malaria Initiative, Centers for Disease Control and Prevention, Abuja, Nigeria
| | | | | | - Chigozie Jesse Uneke
- Dept. of Medical Microbiology/Parasitology, Ebonyi State University, Abakaliki, Nigeria
| | | | | | - Stella Babalola
- PMI VectorWorks Project, JHU Center for Communication Programs, Baltimore, MD, USA
| | - Hannah Koenker
- PMI VectorWorks Project, JHU Center for Communication Programs, Baltimore, MD, USA
| | - Albert Kilian
- PMI VectorWorks Project, Tropical Health LLP, Montagut, Spain.
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