Malaria Control Programmes In Africa Research Articles

Diversity of Anopheles Larvae in Toro Local Government Area, Bauchi State, North-East Nigeria

Vector control is a critical element of malaria control programs in Africa. To reduce human exposure to infective Anopheles mosquitoes, most programs rely on methods that kill adult mosquitoes. Therefore, the study on the distribution and abundance of Anopheles larvae in Toro Local Government Area (LGA.), Bauchi State, North-East Nigeria was carried out in July 2013. Five villages were randomly selected for the collection of Anopheles larvae. A total of 988 Anopheles larvae were collected from five habitat types. The paddy habitat recorded the highest abundance of 494(50%) while the canal habitat had the least abundance 53(5.36 %). The mean abundance of Anopheles larvae in relation to gradients of larval habitat to houses showed no significant difference (F9 = 0.434, Adjusted R2 = -0.39, P = 0.885). However, there was a significant difference (F14 = 9.18, Adjusted R2 = 0.65, P = 0.001) in the mean abundance of Anopheles larvae in relation to habitat types. The larval abundance in relation to water depths varied significantly (F13 = 29.61, Adjusted R2 = 0.888, P = 0.001). There was no significant difference (P > 0.05) in larval abundance between still and moving waters; light versus shaded water bodies; and clear versus turbid waters, respectively. In conclusion, the inhabitants of Toro LGA should always clear stagnant water bodies so as to hinder mosquitoes breeding success. Also, larval source management should focus more on paddy habitat in peri-urban agricultural sites when designing intervention programmes in order to control mosquitoes’ larvae.

Larval density and physicochemical properties of three different breeding habitats of Anopheles mosquitoes in Sudan Savannah Region of Jigawa State, Nigeria

Mosquitoes are tiny insects that can serve as vectors for numerous infectious diseases like malaria. Malaria is considered as one of the major causes of mortality, loss of productivity and a major contributor of poverty in the African continent. In 2020, most global malaria cases (94%) were recorded in the Africa Region. In Nigeria, about 97% of the estimated populations are at risk of malaria, with up to 27% and 24% of Africa and global malaria deaths respectively in 2018. Malaria control programmes in Africa have challenge of rising insecticide resistance in the main anopheline vectors, this affects primary malaria vector control interventions. In Africa, the dominant mosquito species that transmit malaria parasites are mainly Anopheles gambiae s.s. A key control strategy against major mosquito- borne diseases involves targeting mosquito vectors to disrupt the transmission of diseases. Environmental changes can alter the genetic structure, protein profiles and enzymes of mosquitoes leading to increase in insecticide resistance. Knowing the ecology, spatial distribution of mosquito larvae, and some environmental features like physicochemical factors are important in tackling insecticide resistance. Water and larval samples were collected from three Anopheles mosquito breeding sites in August, September and October, 2019. Physicochemical parameters, larval densities and morphological specie identifications were determined. Results from this study reveal variation in levels of each studied parameter according to the site of the study. These variations can be attributed to differences in activities that occur in each site of the study.. Correlation studies indicated a significantly higher larval density in agricultural site relative to industrial and residential sites, this was by a magnitude of 10.65 and 41.30 respectively. Anopheles gambiae s.s. complex was found to be predominant in all the three study sites. These physicochemical parameters can either have negative or positive effect on mosquito biology depending on their levels, hence can affect vector control measures making it significant in terms of vector control programmes.

Understanding evidence use from a programmatic perspective: conceptual development and empirical insights from national malaria control programmes

Background: Conceptualisations of what it means to use evidence in policymaking often appear divided between two extremes. On the one side are works presenting it as the implementation of research findings – particularly evaluations of intervention effect. In contrast stand theoretically informed works exploring the multiple meanings of evidence use, political complexities, and the constructed nature of research evidence itself. The first perspective has been criticised as over-simplistic, while the latter can make it difficult to answer questions of what might be good, or improved, uses of evidence in policymaking. Methods: To further debate, this paper develops a ‘programmatic approach’ to evidence use, drawing on theories of institutional decision making and empirical work on evidence use within 11 National Malaria Control Programmes in Africa. We apply the programmatic approach by investigating the key goals and tasks of programme officials, recognising that these will shape the routines and logics followed affecting evidence utilisation. We then map out the forms, sources, features, and applications of evidence that serve programme officials in their goals. Findings: In the case of malaria programmes, evidence use was understood in relation to tasks including: advocacy for funding, budget allocation, regulation development, national planning, and identification of information gaps – all of which might require different evidence sources, forms, and applications. Discussion and conclusions: Ultimately the programmatic approach aims to facilitate clearer understanding of what uses of evidence are appropriate to policymakers, while also allowing critical reflection on whether such uses are ‘good’ from both programme and broader social perspectives.

Genetic variation at the Cyp6m2 putative insecticide resistance locus in Anopheles gambiae and Anopheles coluzzii

BackgroundThe emergence of insecticide resistance is a major threat to malaria control programmes in Africa, with many different factors contributing to insecticide resistance in its vectors, Anopheles mosquitoes. CYP6M2 has previously been recognized as an important candidate in cytochrome P450-mediated detoxification in Anopheles. As it has been implicated in resistance against pyrethroids, organochlorines and carbamates, its broad metabolic activity makes it a potential agent in insecticide cross-resistance. Currently, allelic variation within the Cyp6m2 gene remains unknown.MethodsHere, Illumina whole-genome sequence data from Phase 2 of the Anopheles gambiae 1000 Genomes Project (Ag1000G) was used to examine genetic variation in the Cyp6m2 gene across 16 populations in 13 countries comprising Anopheles gambiae and Anopheles coluzzii mosquitoes. To identify whether these alleles show evidence of selection either through potentially modified enzymatic function or by being linked to variants that change the transcriptional profile of the gene, hierarchical clustering of haplotypes, linkage disequilibrium, median joining networks and extended haplotype homozygosity analyses were performed.ResultsFifteen missense biallelic substitutions at high frequency (defined as > 5% frequency in one or more populations) are found, which fall into five distinct haplotype groups that carry the main high frequency variants: A13T, D65A, E328Q, Y347F, I359V and A468S. Despite consistent reports of Cyp6m2 upregulation and metabolic activity in insecticide resistant Anophelines, no evidence of directional selection is found occurring on these variants or on the haplotype clusters in which they are found.ConclusionThese results imply that emerging resistance associated with Cyp6m2 is potentially driven by distant regulatory loci such as transcriptional factors rather than by its missense variants, or that other genes are playing a more significant role in conferring metabolic resistance.

Using Rainfall and Temperature Data in the Evaluation of National Malaria Control Programs in Africa.

.Since 2010, the Roll Back Malaria (RBM) Partnership, including National Malaria Control Programs, donor agencies (e.g., President's Malaria Initiative and Global Fund), and other stakeholders have been evaluating the impact of scaling up malaria control interventions on all-cause under-five mortality in several countries in sub-Saharan Africa. The evaluation framework assesses whether the deployed interventions have had an impact on malaria morbidity and mortality and requires consideration of potential nonintervention influencers of transmission, such as drought/floods or higher temperatures. Herein, we assess the likely effect of climate on the assessment of the impact malaria interventions in 10 priority countries/regions in eastern, western, and southern Africa for the President's Malaria Initiative. We used newly available quality controlled Enhanced National Climate Services rainfall and temperature products as well as global climate products to investigate likely impacts of climate on malaria evaluations and test the assumption that changing the baseline period can significantly impact on the influence of climate in the assessment of interventions. Based on current baseline periods used in national malaria impact assessments, we identify three countries/regions where current evaluations may overestimate the impact of interventions (Tanzania, Zanzibar, Uganda) and three countries where current malaria evaluations may underestimate the impact of interventions (Mali, Senegal and Ethiopia). In four countries (Rwanda, Malawi, Mozambique, and Angola) there was no strong difference in climate suitability for malaria in the pre- and post-intervention period. In part, this may be due to data quality and analysis issues.

Current status of insecticide resistance among malaria vectors in Kenya

BackgroundInsecticide resistance has emerged as one of the major challenges facing National Malaria Control Programmes in Africa. A well-coordinated national database on insecticide resistance (IRBase) can facilitate the development of effective strategies for managing insecticide resistance and sustaining the effectiveness of chemical-based vector control measures. The aim of this study was to assemble a database on the current status of insecticide resistance among malaria vectors in Kenya.MethodsData was obtained from published literature through PubMed, HINARI and Google Scholar searches and unpublished literature from government reports, research institutions reports and malaria control programme reports. Each data source was assigned a unique identification code and entered into Microsoft Excel 2010 datasheets. Base maps on the distribution of insecticide resistance and resistance mechanisms among malaria vectors in Kenya were generated using ArcGIS Desktop 10.1 (ESRI, Redlands, CA, USA).ResultsInsecticide resistance status among the major malaria vectors in Kenya was reported in all the four classes of insecticides including pyrethroids, carbamates, organochlorines and organophosphates. Resistance to pyrethroids has been detected in Anopheles gambiae (s.s.), An. arabiensis and An. funestus (s.s.) while resistance to carbamates was limited to An. gambiae (s.s.) and An. arabiensis. Resistance to the organochlorine was reported in An. gambiae (s.s.) and An. funestus (s.s.) while resistance to organophosphates was reported in An. gambiae (s.l.) only. The mechanisms of insecticide resistance among malaria vectors reported include the kdr mutations (L 1014S and L 1014F) and elevated activity in carboxylesterase, glutathione S-transferases (GST) and monooxygenases. The kdr mutations L 1014S and L 1014F were detected in An. gambiae (s.s.) and An. arabiensis populations. Elevated activity of monooxygenases has been detected in both An. arabiensis and An. gambiae (s.s.) populations while the elevated activity of carboxylesterase and GST has been detected only in An. arabiensis populations.ConclusionsThe geographical maps show the distribution of insecticide resistance and resistance mechanisms among malaria vectors in Kenya. The database generated will provide a guide to intervention policies and programmes in the fight against malaria.

Major Improvements in the Quality of Malaria Case-Management under the “Test and Treat” Policy in Kenya

BackgroundMonitoring implementation of the “test and treat” case-management policy for malaria is an important component of all malaria control programmes in Africa. Unfortunately, routine information systems are commonly deficient to provide necessary information. Using health facility surveys we monitored health systems readiness and malaria case-management practices prior to and following implementation of the 2010 “test and treat” policy in Kenya.Methods/FindingsBetween 2010 and 2013 six national, cross-sectional, health facility surveys were undertaken. The number of facilities assessed ranged between 172 and 176, health workers interviewed between 216 and 237 and outpatient consultations for febrile patients evaluated between 1,208 and 2,408 across six surveys. Comparing baseline and the last survey results, all readiness indicators showed significant (p<0.005) improvements: availability of parasitological diagnosis (55.2% to 90.7%); RDT availability (7.5% to 69.8%); total artemether-lumefantrine (AL) stock-out (27.2% to 7.0%); stock-out of one or more AL packs (59.5% to 21.6%); training coverage (0 to 50.2%); guidelines access (0 to 58.1%) and supervision (17.9% to 30.8%). Testing increased by 34.0% (23.9% to 57.9%; p<0.001) while testing and treatment according to test result increased by 34.2% (15.7% to 49.9%; p<0.001). Treatment adherence for test positive patients improved from 83.3% to 90.3% (p = 0.138) and for test negative patients from 47.9% to 83.4% (p<0.001). Significant testing and treatment improvements were observed in children and adults. There was no difference in practices with respect to the type and result of malaria test (RDT vs microscopy). Of eight dosing, dispensing and counseling tasks, improvements were observed for four tasks. Overall AL use for febrile patients decreased from 63.5% to 35.6% (p<0.001).ConclusionsMajor improvements in the implementation of “test and treat” policy were observed in Kenya. Some gaps towards universal targets still remained. Other countries facing similar needs and challenges may consider health facility surveys to monitor malaria case-management.

Pyrethroid-Resistant Mosquitoes Challenge Malaria Control

Insecticide-treated bednets are an essential component of malaria-control programs in Africa. However, with the widespread use of such nets, resistance has emerged in mosquitoes. To assess whether nets still protect once mosquitoes become resistant to pyrethroids, investigators conducted household trials in 2008 in Benin, where mosquitoes are mostly resistant in the south but remain mostly susceptible in the north. Sixteen households were selected …

Soft targets or partners in health? Retail pharmacies and their role in Tanzania’s malaria control program

The retail sector has been at the center of recent policy debates concerning its role in malaria control programs in Africa. This article closely examines the perspectives of owners and managers of retail pharmacies and drug shops in Dar es Salaam, toward the dominant public health discourse and practices surrounding the deployment of artemisinin-based combination therapy (ACT) as a way forward in malaria control. Drawing on fieldwork conducted between May-August 2007, and July-August 2009, involving in-depth interviews and participant observation in pharmacies and drug shops in Dar es Salaam, the article describes the social realities facing people who manage retail pharmacies, the nature of their interactions with customers, the kinds of antimalarials they sell, and their perspective on how the new malaria treatment guidelines have affected their business. Findings suggest that for most pharmacy owners and managers, it is 'business as usual' concerning the sale of conventional antimalarials, with a majority reporting that the introduction of ACT in public health facilities had not negatively affected their business. Implications of the research findings are examined in the context of proposed interventions to make pharmacy owners and managers more socially responsible and adhere to government health regulations. The article makes a case for actively involving pharmacy owners and managers in decision making processes surrounding the implementation of new treatment guidelines, and training programs that have an impact on their business, social responsibility, and community health. In considering regulatory interventions, health planners must explicitly address the concern that retail pharmacies fill an important role in the country's health care system, and that the complex nexus that drives the global pharmaceutical market often governs their operations at the local level.

A Temporal-Spatial Analysis of Malaria Transmission in Adama, Ethiopia

Urban malaria is a growing problem in Africa. Small-scale spatial studies are useful in identifying foci of malaria transmission in urban communities. A population-based cohort study comprising 8,088 individuals was conducted in Adama, Ethiopia. During a single malaria season, the Kulldorff scan statistic identified one temporally stable spatial malaria cluster within 350 m of a major Anopheles breeding site. Factors associated with malaria incidence were residential proximity to vector breeding site, poor house condition (incidence rate ratio [IRR] = 2.0, 95% confidence interval [CI] = 1.4, 2.9), and a high level of vegetation (IRR = 1.8, 95% CI = 1.0, 3.3). Maximum (IRR = 1.4, 95% CI = 1.1, 1.9) and minimum daily temperatures (degrees C; IRR = 1.3, 95% CI = 1.2, 1.5) were positively associated with malaria incidence after a 1-month delay. Rainfall was positively associated with malaria incidence after a 10-day delay. Findings support the use of small scale mapping and targeted vector control in urban malaria control programs in Africa.

Malaria prevention in north-eastern Tanzania: patterns of expenditure and determinants of demand at the household level

ObjectiveThis study aims to provide a better understanding of the amounts spent on different malaria prevention products and the determinants of these expenditures.Methods1,601 households were interviewed about their expenditure on malaria mosquito nets in the past five years, net re-treatments in the past six months and other expenditures prevention in the past two weeks. Simple random sampling was used to select villages and streets while convenience sampling was used to select households. Expenditure was compared across bed nets, aerosols, coils, indoor spraying, using smoke, drinking herbs and cleaning outside environment.Findings68% of households owned at least one bed net and 27% had treated their nets in the past six months. 29% were unable to afford a net. Every fortnight, households spent an average of US $0.18 on nets and their treatment, constituting about 47% of total prevention expenditure. Sprays, repellents and coils made up 50% of total fortnightly expenditure (US$0.21). Factors positively related to expenditure were household wealth, years of education of household head, household head being married and rainy season. Poor quality roads and living in a rural area had a negative impact on expenditure.ConclusionExpenditure on bed nets and on alternative malaria prevention products was comparable. Poor households living in rural areas spend significantly less on all forms of malaria prevention compared to their richer counterparts. Breaking the cycle between malaria and poverty is one of the biggest challenges facing malaria control programmes in Africa.

Integrated vector management for malaria control

Integrated vector management (IVM) is defined as "a rational decision-making process for the optimal use of resources for vector control" and includes five key elements: 1) evidence-based decision-making, 2) integrated approaches 3), collaboration within the health sector and with other sectors, 4) advocacy, social mobilization, and legislation, and 5) capacity-building. In 2004, the WHO adopted IVM globally for the control of all vector-borne diseases. Important recent progress has been made in developing and promoting IVM for national malaria control programmes in Africa at a time when successful malaria control programmes are scaling-up with insecticide-treated nets (ITN) and/or indoor residual spraying (IRS) coverage. While interventions using only ITNs and/or IRS successfully reduce transmission intensity and the burden of malaria in many situations, it is not clear if these interventions alone will achieve those critical low levels that result in malaria elimination. Despite the successful employment of comprehensive integrated malaria control programmes, further strengthening of vector control components through IVM is relevant, especially during the "end-game" where control is successful and further efforts are required to go from low transmission situations to sustained local and country-wide malaria elimination. To meet this need and to ensure sustainability of control efforts, malaria control programmes should strengthen their capacity to use data for decision-making with respect to evaluation of current vector control programmes, employment of additional vector control tools in conjunction with ITN/IRS tactics, case-detection and treatment strategies, and determine how much and what types of vector control and interdisciplinary input are required to achieve malaria elimination. Similarly, on a global scale, there is a need for continued research to identify and evaluate new tools for vector control that can be integrated with existing biomedical strategies within national malaria control programmes. This review provides an overview of how IVM programmes are being implemented, and provides recommendations for further development of IVM to meet the goals of national malaria control programmes in Africa.

Reduced bio-efficacy of permethrin EC impregnated bednets against an Anopheles gambiae strain with oxidase-based pyrethroid tolerance

BackgroundInsecticide-treated nets (ITNs) are an integral component of malaria control programmes in Africa. How much pyrethroid resistance in malaria vectors will impact on the efficacy of ITNs is controversial. The purpose of this study was to evaluate knockdown and killing effects of ITNs on a metabolic-based resistant or tolerant malaria vector strain.MethodsBio-efficacy of 500 mg/m2 permethrin EC treated bednets was assessed on the OCEAC laboratory (OC-Lab) strain of Anopheles gambiae s.s.. This strain is resistant to DDT and tolerant to pyrethroids, with elevated mixed function oxidases. The Kisumu reference susceptible strain of A. gambiae s.s. was used as control. Nets were impregnated in February 1998 and used by households of the Ebogo village. Then they were collected monthly over six months for Bio-assays (WHO cone test). Knockdown and mortality rates were compared between the OC-Lab and the Kisumu strains, by means of the Mantel-Haenszel chi-square test.ResultsDuring the whole trial, permethrin EC knockdown rates were impressive (mostly higher than 97%). No significant difference was observed between the two strains. However, the mortality rates were significantly decreased in the OC-Lab strain (40–80%) compared with that of the Kisumu strain (75–100%). The decrease of killing effect on the OC-Lab strain was attributed to permethrin EC tolerance, due to the high oxidase metabolic activity.ConclusionThese data suggested an impact of pyrethroid tolerance on the residual activity of ITNs. More attention should be given to early detection of resistance using biochemical or molecular assays for better resistance management.