Mosquito control by abatement programmes in the United States: perspectives and lessons for countries in sub-Saharan Africa.

Africa and the United States are both large, heterogeneous geographies with a diverse range of ecologies, climates and mosquito species diversity which contribute to disease transmission and nuisance biting. In the United States, mosquito control is nationally, and regionally coordinated and in so much as the Centers for Disease Control (CDC) provides guidance, the Environmental Protection Agency (EPA) provides pesticide registration, and the states provide legal authority and oversight, the implementation is usually decentralized to the state, county, or city level. Mosquito control operations are organized, in most instances, into fully independent mosquito abatement districts, public works departments, local health departments. In some cases, municipalities engage independent private contractors to undertake mosquito control within their jurisdictions. In sub-Saharan Africa (SSA), where most vector-borne disease endemic countries lie, mosquito control is organized centrally at the national level. In this model, the disease control programmes (national malaria control programmes or national malaria elimination programmes (NMCP/NMEP)) are embedded within the central governments' ministries of health (MoHs) and drive vector control policy development and implementation. Because of the high disease burden and limited resources, the primary endpoint of mosquito control in these settings is reduction of mosquito borne diseases, primarily, malaria. In the United States, however, the endpoint is mosquito control, therefore, significant (or even greater) emphasis is laid on nuisance mosquitoes as much as disease vectors. The authors detail experiences and learnings gathered by the delegation of African vector control professionals that participated in a formal exchange programme initiated by the Pan-African Mosquito Control Association (PAMCA), the University of Notre Dame, and members of the American Mosquito Control Association (AMCA), in the United States between the year 2021 and 2022. The authors highlight the key components of mosquito control operations in the United States and compare them to mosquito control programmes in SSA countries endemic for vector-borne diseases, deriving important lessons that could be useful for vector control in SSA.

Breast cancer molecular diagnostics in Rwanda: a cost-minimization study of immunohistochemistry versus a novel GeneXpert® mRNA expression assay.

Objective: To compare the financial and time cost of breast cancer biomarker analysis by immunohistochemistry with that by the Xpert® STRAT4 assay. Methods: We estimated costs (personnel, location, consumables and indirect) and time involved in breast cancer diagnosis at the Butaro Cancer Centre of Excellence, Rwanda, using time-driven activity-based costing. We performed a cost-minimization analysis to compare the cost of biomarker analysis for estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 status with immunohistochemistry versus STRAT4. We performed sensitivity analyses by altering laboratory-specific parameters for the two methods. Findings: We estimated that breast cancer diagnosis in Rwanda costs 138.29 United States dollars (US$) per patient when conducting biomarker analysis by immunohistochemistry. At a realistic immunohistochemistry antibody utilization efficiency of 70%, biomarker analysis comprises 48.7% (US$ 67.33) of diagnostic costs and takes 33 min. We determined that biomarker analysis with STRAT4 yields a reduction in diagnosis cost of US$ 7.33 (10.9%; 7.33/67.33), and in pathologist and technician time of 20 min (60.6%; 20/33), per patient. Our sensitivity analysis revealed that no cost savings would be made in laboratories with antibody utilization efficiencies over 90%, or where only estrogen and/or progesterone receptor status are assessed; however, such operational efficiencies are unlikely, and more laboratories are pursuing human epidermal growth factor receptor-2 analysis as targeted therapies become increasingly available. Conclusion: Breast cancer biomarker analysis with STRAT4 has the potential to reduce the required human and capital resources in sub-Saharan African laboratories, leading to improved treatment selection and better clinical outcomes.

The impact of Covid-19 on malaria services in three high endemic districts in Rwanda: a mixed-method study.

BACKGROUND: Rwanda has achieved impressive reductions in malaria morbidity and mortality over the past two decades. However, the disruption of essential services due to the current Covid-19 pandemic can lead to a reversal of these gains in malaria control unless targeted, evidence-based interventions are implemented to mitigate the impact of the pandemic. The extent to which malaria services have been disrupted has not been fully characterized. This study was conducted to assess the impact of Covid-19 on malaria services in Rwanda. METHODS: A mixed-methods study was conducted in three purposively selected districts in Rwanda. The quantitative data included malaria aggregated data reported at the health facility level and the community level. The data included the number of malaria tests, uncomplicated malaria cases, severe malaria cases, and malaria deaths. The qualitative data were collected using focus group discussions with community members and community health workers, as well as in-depth interviews with health care providers and staff working in the malaria programme. Interrupted time series analysis was conducted to compare changes in malaria presentations between the pre-Covid-19 period (January 2019 to February 2020) and Covid-19 period (from March 2020 to November 2020). The constant comparative method was used in qualitative thematic analysis. RESULTS: Compared to the pre-Covid-19 period, there was a monthly reduction in patients tested in health facilities of 4.32 per 1000 population and a monthly increase in patients tested in the community of 2.38 per 1000 population during the Covid-19 period. There was no change in the overall presentation rate for uncomplicated malaria. The was a monthly reduction in the proportion of severe malaria of 5.47 per 100,000 malaria cases. Additionally, although healthcare providers continued to provide malaria services, they were fearful that this would expose them and their families to Covid-19. Covid-19 mitigation measures limited the availability of transportation options for the community to seek care in health facilities and delayed the implementation of some key malaria interventions. The focus on Covid-19-related communication also reduced the amount of health information for other diseases provided to community members. CONCLUSION: The Covid-19 pandemic resulted in patients increasingly seeking care in the community and poses challenges to maintaining delivery of malaria services in Rwanda. Interventions to mitigate these challenges should focus on strengthening programming for the community and home-based care models and integrating malaria messages into Covid-19-related communication. Additionally, implementation of the interrupted interventions should be timed and overlap with the malaria transmission season to mitigate Covid-19 consequences on malaria.

Design and methods for a quasi-experimental pilot study to evaluate the impact of dual active ingredient insecticide-treated nets on malaria burden in five regions in sub-Saharan Africa.

BACKGROUND: Vector control tools have contributed significantly to a reduction in malaria burden since 2000, primarily through insecticidal-treated bed nets (ITNs) and indoor residual spraying. In the face of increasing insecticide resistance in key malaria vector species, global progress in malaria control has stalled. Innovative tools, such as dual active ingredient (dual-AI) ITNs that are effective at killing insecticide-resistant mosquitoes have recently been introduced. However, large-scale uptake has been slow for several reasons, including higher costs and limited evidence on their incremental effectiveness and cost-effectiveness. The present report describes the design of several observational studies aimed to determine the effectiveness and cost-effectiveness of dual-AI ITNs, compared to standard pyrethroid-only ITNs, at reducing malaria transmission across a variety of transmission settings. METHODS: Observational pilot studies are ongoing in Burkina Faso, Mozambique, Nigeria, and Rwanda, leveraging dual-AI ITN rollouts nested within the 2019 and 2020 mass distribution campaigns in each country. Enhanced surveillance occurring in select study districts include annual cross-sectional surveys during peak transmission seasons, monthly entomological surveillance, passive case detection using routine health facility surveillance systems, and studies on human behaviour and ITN use patterns. Data will compare changes in malaria transmission and disease burden in districts receiving dual-AI ITNs to similar districts receiving standard pyrethroid-only ITNs over three years. The costs of net distribution will be calculated using the provider perspective including financial and economic costs, and a cost-effectiveness analysis will assess incremental cost-effectiveness ratios for Interceptor® G2, Royal Guard®, and piperonyl butoxide ITNs in comparison to standard pyrethroid-only ITNs, based on incidence rate ratios calculated from routine data. CONCLUSIONS: Evidence of the effectiveness and cost-effectiveness of the dual-AI ITNs from these pilot studies will complement evidence from two contemporary cluster randomized control trials, one in Benin and one in Tanzania, to provide key information to malaria control programmes, policymakers, and donors to help guide decision-making and planning for local malaria control and elimination strategies. Understanding the breadth of contexts where these dual-AI ITNs are most effective and collecting robust information on factors influencing comparative effectiveness could improve uptake and availability and help maximize their impact.

Monitoring mosquito nuisance for the development of a citizen science approach for malaria vector surveillance in Rwanda.

BACKGROUND: Many countries, including Rwanda, have mosquito monitoring programmes in place to support decision making in the fight against malaria. However, these programmes can be costly, and require technical (entomological) expertise. Involving citizens in data collection can greatly support such activities, but this has not yet been thoroughly investigated in a rural African context. METHODS: Prior to the implementation of such a citizen-science approach, a household entomological survey was conducted in October-November 2017 and repeated one year later in Busoro and Ruhuha sectors, in southern and eastern province of Rwanda, respectively. The goal was to evaluate the perception of mosquito nuisance reported by citizens as a potential indicator for malaria vector hotspots. Firstly, mosquito abundance and species composition were determined using Centers for Disease Control and Prevention (CDC) light traps inside the houses. Secondly, household members were interviewed about malaria risk factors and their perceived level of mosquito nuisance. RESULTS: Tiled roofs, walls made of mud and wood, as well as the number of occupants in the house were predictors for the number of mosquitoes (Culicidae) in the houses, while the presence of eaves plus walls made of mud and wood were predictors for malaria vector abundance. Perception of mosquito nuisance reported indoors tended to be significantly correlated with the number of Anopheles gambiae sensu lato (s.l.) and Culicidae collected indoors, but this varied across years and sectors. At the village level, nuisance also significantly correlated with An. gambiae s.l. and total mosquito density, but only in 2018 while not in 2017. CONCLUSIONS: Perception of mosquito nuisance denoted in a questionnaire survey could be used as a global indicator of malaria vector hotspots. Hence, involving citizens in such activities can complement malaria vector surveillance and control.

Citizen science for monitoring the spatial and temporal dynamics of malaria vectors in relation to environmental risk factors in Ruhuha, Rwanda.

BACKGROUND: As part of malaria prevention and control efforts, the distribution and density of malaria mosquitoes requires continuous monitoring. Resources for long-term surveillance of malaria vectors, however, are often limited. The aim of the research was to evaluate the value of citizen science in providing insight into potential malaria vector hotspots and other malaria relevant information, and to determine predictors of malaria vector abundance in a region where routine mosquito monitoring has not been established to support vector surveillance. METHODS: A 1-year citizen science programme for malaria mosquito surveillance was implemented in five villages of the Ruhuha sector in Bugesera district, Rwanda. In total, 112 volunteer citizens were enrolled and reported monthly data on mosquitoes collected in their peridomestic environment using handmade carbon-dioxide baited traps. Additionally, they reported mosquito nuisance experienced as well as the number of confirmed malaria cases in their household. RESULTS: In total, 3793 female mosquitoes were collected, of which 10.8% were anophelines. For the entire period, 16% of the volunteers reported having at least one confirmed malaria case per month, but this varied by village and month. During the study year 66% of the households reported at least one malaria case. From a sector perspective, a higher mosquito and malaria vector abundance was observed in the two villages in the south of the study area. The findings revealed significant positive correlations among nuisance reported and confirmed malaria cases, and also between total number of Culicidae and confirmed malaria cases, but not between the numbers of the malaria vector Anopheles gambiae and malaria cases. At the sector level, of thirteen geographical risk factors considered for inclusion in multiple regression, distance to the river network and elevation played a role in explaining mosquito and malaria mosquito abundance. CONCLUSIONS: The study demonstrates that a citizen science approach can contribute to mosquito monitoring, and can help to identify areas that, in view of limited resources for control, are at higher risk of malaria.

History of malaria control in Rwanda: implications for future elimination in Rwanda and other malaria-endemic countries.

BACKGROUND: Malaria was first reported in Rwanda in the early 1900s with significant heterogeneity and volatility in transmission over subsequent decades. Here, a comprehensive literature review of malaria transmission patterns and control strategies in Rwanda between 1900 and 2018 is presented to provide insight into successes and challenges in the country and to inform the future of malaria control in Rwanda. METHODS: A systematic literature search of peer-reviewed publications (Web of Knowledge, PubMed, Google Scholar, and the World Health Organization Library (WHOLIS) and grey literature on malaria control in Rwanda between 1900 and 2019 was conducted with the following search terms: "malaria"", "Rwanda", "epidemiology", "control", "treatment", and/or "prevention." Reports and other relevant documents were also obtained from the Rwanda National Malaria Control Programme (NMCP). To inform this literature review and evidence synthesis, epidemiologic and intervention data were collated from NMCP and partner reports, the national routine surveillance system, and population surveys. RESULTS: Two hundred sixty-eight peer-reviewed publications and 56 grey literature items were reviewed, and information was extracted. The history of malaria control in Rwanda is thematically described here according to five phases: 1900 to 1954 before the launch of the Global Malaria Eradication Programme (GMEP); (2) Implementation of the GMEP from 1955 to 1969; (3) Post- GMEP to 1994 Genocide; (4) the re-establishment of malaria control from 1995 to 2005, and (5) current malaria control efforts from 2006 to 2018. The review shows that Rwanda was an early adopter of tools and approaches in the early 2000s, putting the country ahead of the curve and health systems reforms created an enabling environment for an effective malaria control programme. The last two decades have seen unprecedented investments in malaria in Rwanda, resulting in significant declines in disease burden from 2000 to 2011. However, in recent years, these gains appear to have reversed with increasing cases since 2012 although the country is starting to make progress again. CONCLUSION: The review shows the impact and fragility of gains against malaria, even in the context of sustained health system development. Also, as shown in Rwanda, country malaria control programmes should be dynamic and adaptive to respond and address changing settings.

Community-based biological control of malaria mosquitoes using Bacillus thuringiensis var. israelensis (Bti) in Rwanda: community awareness, acceptance and participation.

BACKGROUND: Targeting the aquatic stages of malaria vectors via larval source management (LSM) in collaboration with local communities could accelerate progress towards malaria elimination when deployed in addition to existing vector control strategies. However, the precise role that communities can assume in implementing such an intervention has not been fully investigated. This study investigated community awareness, acceptance and participation in a study that incorporated the socio-economic and entomological impact of LSM using Bacillus thuringiensis var. israelensis (Bti) in eastern Rwanda, and identified challenges and recommendations for future scale-up. METHODS: The implementation of the community-based LSM intervention took place in Ruhuha, Rwanda, from February to July 2015. The intervention included three arms: control, community-based (CB) and project-supervised (PS). Mixed methods were used to collect baseline and endline socio-economic data in January and October 2015. RESULTS: A high perceived safety and effectiveness of Bti was reported at the start of the intervention. Being aware of malaria symptoms and perceiving Bti as safe on other living organisms increased the likelihood of community participation through investment of labour time for Bti application. On the other hand, the likelihood for community participation was lower if respondents: (1) perceived rice farming as very profitable; (2) provided more money to the cooperative as a capital; and, (3) were already involved in rice farming for more than 6 years. After 6 months of implementation, an increase in knowledge and skills regarding Bti application was reported. The community perceived a reduction in mosquito density and nuisance biting on treated arms. Main operational, seasonal and geographical challenges included manual application of Bti, long working hours, and need for transportation for reaching the fields. Recommendations were made for future scale-up, including addressing above-mentioned concerns and government adoption of LSM as part of its vector control strategies. CONCLUSIONS: Community awareness and support for LSM increased following Bti application. A high effectiveness of Bti in terms of reduction of mosquito abundance and nuisance biting was perceived. The study confirmed the feasibility of community-based LSM interventions and served as evidence for future scale-up of Bti application and adoption into Rwandan malaria vector control strategies.

Malaria case clinical profiles and Plasmodium falciparum parasite genetic diversity: a cross sectional survey at two sites of different malaria transmission intensities in Rwanda.

BACKGROUND: Malaria remains a public health challenge in sub-Saharan Africa with Plasmodium falciparum being the principal cause of malaria disease morbidity and mortality. Plasmodium falciparum virulence is attributed, in part, to its population-level genetic diversity-a characteristic that has yet to be studied in Rwanda. Characterizing P. falciparum molecular epidemiology in an area is needed for a better understand of malaria transmission and to inform choice of malaria control strategies. METHODS: In this health-facility based survey, malaria case clinical profiles and parasite densities as well as parasite genetic diversity were compared among P. falciparum-infected patients identified at two sites of different malaria transmission intensities in Rwanda. Data on demographics and clinical features and finger-prick blood samples for microscopy and parasite genotyping were collected(.) Nested PCR was used to genotype msp-2 alleles of FC27 and 3D7. RESULTS: Patients' variables of age group, sex, fever (both by patient report and by measured tympanic temperatures), parasite density, and bed net use were found differentially distributed between the higher endemic (Ruhuha) and lower endemic (Mubuga) sites. Overall multiplicity of P. falciparum infection (MOI) was 1.73 but with mean MOI found to vary significantly between 2.13 at Ruhuha and 1.29 at Mubuga (p < 0.0001). At Ruhuha, expected heterozygosity (EH) for FC27 and 3D7 alleles were 0.62 and 0.49, respectively, whilst at Mubuga, EH for FC27 and 3D7 were 0.26 and 0.28, respectively. CONCLUSIONS: In this study, a higher geometrical mean parasite counts, more polyclonal infections, higher MOI, and higher allelic frequency were observed at the higher malaria-endemic (Ruhuha) compared to the lower malaria-endemic (Mubuga) area. These differences in malaria risk and MOI should be considered when choosing setting-specific malaria control strategies, assessing p. falciparum associated parameters such as drug resistance, immunity and impact of used interventions, and in proper interpretation of malaria vaccine studies.

Susceptibility of Anopheles gambiae to insecticides used for malaria vector control in Rwanda.

BACKGROUND: The widespread emergence of resistance to pyrethroids is a major threat to the gains made in malaria control. To monitor the presence and possible emergence of resistance against a variety of insecticides used for malaria control in Rwanda, nationwide insecticide resistance surveys were conducted in 2011 and 2013. METHODS: Larvae of Anopheles gambiae sensu lato mosquitoes were collected in 12 sentinel sites throughout Rwanda. These were reared to adults and analysed for knock-down and mortality using WHO insecticide test papers with standard diagnostic doses of the recommended insecticides. A sub-sample of tested specimens was analysed for the presence of knockdown resistance (kdr) mutations. RESULTS: A total of 14,311 mosquitoes were tested and from a sample of 1406 specimens, 1165 (82.9%) were identified as Anopheles arabiensis and 241 (17.1%) as Anopheles gambiae sensu stricto. Mortality results indicated a significant increase in resistance to lambda-cyhalothrin from 2011 to 2013 in 83% of the sites, permethrin in 25% of the sites, deltamethrin in 25% of the sites and DDT in 50% of the sites. Mosquitoes from 83% of the sites showed full susceptibility to bendiocarb and 17% of sites were suspected to harbour resistance that requires further confirmation. No resistance was observed to fenitrothion in all study sites during the entire survey. The kdr genotype results in An. gambiae s.s. showed that 67 (50%) possessed susceptibility (SS) alleles, while 35 (26.1%) and 32 (23.9%) mosquitoes had heterozygous (RS) and homozygous (RR) alleles, respectively. Of the 591 An. arabiensis genotyped, 425 (71.9%) possessed homozygous (SS) alleles while 158 (26.7%) and 8 (1.4%) had heterozygous (RS) and homozygous (RR) alleles, respectively. Metabolic resistance involving oxidase enzymes was also detected using the synergist PBO. CONCLUSION: This is the first nationwide study of insecticide resistance in malaria vectors in Rwanda. It shows the gradual increase of insecticide resistance to pyrethroids (lambda-cyhalothrin, deltamethrin, permethrin) and organochlorines (DDT) and the large presence of target site insensitivity. The results demonstrate the need for Rwanda to expand monitoring for insecticide resistance including further metabolic resistance testing and implement an insecticide resistance management strategy to sustain the gains made in malaria control.

Using an intervention mapping approach for planning, implementing and assessing a community-led project towards malaria elimination in the Eastern Province of Rwanda.

BACKGROUND: Active community participation in malaria control is key to achieving malaria pre-elimination in Rwanda. This paper describes development, implementation and evaluation of a community-based malaria elimination project in Ruhuha sector, Bugesera district, Eastern province of Rwanda. METHODS: Guided by an intervention mapping approach, a needs assessment was conducted using household and entomological surveys and focus group interviews. Data related to behavioural, epidemiological, entomological and economical aspects were collected. Desired behavioural and environmental outcomes were identified concurrently with behavioural and environmental determinants. Theoretical methods and their practical applications were enumerated to guide programme development and implementation. An operational plan including the scope and sequence as well as programme materials was developed. Two project components were subsequently implemented following community trainings: (1) community malaria action teams (CMATs) were initiated in mid-2014 as platforms to deliver malaria preventive messages at village level, and (2) a mosquito larval source control programme using biological substances was deployed for a duration of 6 months, implemented from January to July 2015. Process and outcome evaluation has been conducted for both programme components to inform future scale up. RESULTS: The project highlighted malaria patterns in the area and underpinned behavioural and environmental factors contributing to malaria transmission. Active involvement of the community in collaboration with CMATs contributed to health literacy, particularly increasing ability to make knowledgeable decisions in regards to malaria prevention and control. A follow up survey conducted six months following the establishment of CMATs reported a reduction of presumed malaria cases at the end of 2014. The changes were related to an increase in the acceptance and use of available preventive measures, such as indoor residual spraying and increase in community-based health insurance membership, also considered as a predictor of prompt and adequate care. The innovative larval source control intervention contributed to reduction in mosquito density and nuisance bites, increased knowledge and skills for malaria control as well as programme ownership. CONCLUSION: This community-based programme demonstrated the feasibility and effectiveness of active community participation in malaria control activities, which largely contributed to community empowerment and reduction of presumed malaria in the area. Further studies should explore how gains may be sustained to achieve the goal of malaria pre-elimination.

Determinants of prompt and adequate care among presumed malaria cases in a community in eastern Rwanda: a cross sectional study.

BACKGROUND: In order to understand factors influencing fever/malaria management practices among community-based individuals, the study evaluated psychosocial, socio-demographic and environmental determinants of prompt and adequate healthcare-seeking behaviours. METHODS: A quantitative household (HH) survey was conducted from December 2014 to February 2015 in Ruhuha sector, Bugesera district in the Eastern province of Rwanda. HHs that reported having had at least one member who experienced a fever and/or malaria episode in the previous 3 months prior to the study were included in the analysis. Healthcare-seeking behaviours associated with the last episode of illness were analysed. Socio-demographic, health facility access, long-lasting insecticidal-treated nets (LLINs), data on malaria knowledge, data and theory of planned behaviour (TPB) related variables (attitudes, subjective norms, perceived behavioural control) with regard to fever/malaria healthcare seeking, were collected. The primary outcome was prompt and adequate care defined as: (1) seeking advice or treatment at a health facility (health centre or hospital) or from a community health worker (CHW); (2) advice or treatment seeking within same/next day of symptoms onset; (3) received a laboratory diagnosis; (4) received advice or treatment; and, (5) reported completing the prescribed dose of medication. Determinants of prompt and adequate care among presumed malaria cases were evaluated using a logistic regression analysis. RESULTS: Overall, 302 (21 %) of the 1410 interviewed HHs reported at least one member as having experienced a fever or malaria within the 3 months prior to the survey. The number of HHs (where at least one member reported fever/malaria) that reported seeking advice or treatment at a health facility (health centre or hospital) or from a CHW was 249 (82.4 %). Of those who sought advice or treatment, 87.3 % had done so on same/next day of symptoms developing, 82.8 % received a laboratory diagnosis, and more than 90 % who received treatment reported completing the prescribed dosage. Prompt and adequate care was reported from 162 of the 302 HHs (53.6 %) that experienced fever or malaria for one or more HH members. Bivariate analyses showed that head of household (HoH)-related characteristics including reported knowledge of three or more malaria symptoms, having health insurance, being able to pay for medical services, use of LLINs the night before the survey, having a positive attitude, perceiving social support, as well as a high-perceived behavioural control with regard to healthcare seeking, were all significantly associated with prompt and adequate care. In the final logistic regression model, a high-perceived behavioural control (odds ratio (OR) 5.068, p = 0.042), having a health insurance (OR 2.410, p = 0.044) and having knowledge of malaria symptoms (OR 1.654, p = 0.049) significantly predicted prompt and adequate care. CONCLUSIONS: To promote prompt and adequate care seeking for malaria in the area, particular emphasis should be placed on community-focused strategies that promote early malaria symptom recognition, increased health insurance coverage and enhanced perceived behavioural control with regard to healthcare-seeking.

Malaria, anaemia and under-nutrition: three frequently co-existing conditions among preschool children in rural Rwanda.

BACKGROUND: Malaria, anaemia and under-nutrition are three highly prevalent and frequently co-existing diseases that cause significant morbidity and mortality particularly among children aged less than 5 years. Currently, there is paucity of conclusive studies on the burden of and associations between malaria, anaemia and under-nutrition in Rwanda and comparable sub-Saharan and thus, this study measured the prevalence of malaria parasitaemia, anaemia and under-nutrition among preschool age children in a rural Rwandan setting and evaluated for interactions between and risk determinants for these three conditions. METHODS: A cross-sectional household (HH) survey involving children aged 6-59 months was conducted. Data on malaria parasitaemia, haemoglobin densities, anthropometry, demographics, socioeconomic status (SES) and malaria prevention knowledge and practices were collected. RESULTS: The prevalences of malaria parasitaemia and anaemia were 5.9 and 7.0 %, respectively, whilst the prevalence of stunting was 41.3 %. Malaria parasitaemia risk differed by age groups with odds ratio (OR) = 2.53; P = 0.04 for age group 24-35 months, OR = 3.5; P = 0.037 for age group 36-47 months, and OR = 3.03; P = 0.014 for age group 48-60 months, whilst a reduced risk was found among children living in high SES HHs (OR = 0.37; P = 0.029). Risk of anaemia was high among children aged ≥12 months, those with malaria parasitaemia (OR = 3.86; P ≤ 0.0001) and children living in HHs of lower SES. Overall, under-nutrition was not associated with malaria parasitaemia. Underweight was higher among males (OR = 1.444; P = 0.019) and children with anaemia (OR = 1.98; P = 0.004). CONCLUSIONS: In this study group, four in 10 and one in 10 children were found stunted and underweight, respectively, in an area of low malaria transmission. Under-nutrition was not associated with malaria risk. While the high prevalence of stunting requires urgent response, reductions in malaria parasitaemia and anaemia rates may require, in addition to scaled-up use of insecticide-treated bed nets and indoor residual insecticide spraying, improvements in HH SES and better housing to reduce risk of malaria.

Long-lasting insecticidal net source, ownership and use in the context of universal coverage: a household survey in eastern Rwanda.

BACKGROUND: Universal long-lasting insecticidal net (LLIN) coverage (ULC) has reduced malaria morbidity and mortality across Africa. Although information is available on bed net use in specific groups, such as pregnant women and children under 5 years, there is paucity of data on their use among the general population. Bed net source, ownership and determinants of use among individuals from households in an eastern Rwanda community 8 months after a ULC were characterized. METHODS: Using household-based, interviewer-administered questionnaires and interviewer-direct observations, data on bed net source, ownership and key determinants of net use, including demographics, socio-economic status indicators, house structure characteristics, as well as of bed net quantity, type and integrity, were collected from 1400 randomly selected households. Univariate and mixed effects logistic regression modelling was done to assess for determinants of bed net use. RESULTS: A total of 1410 households and 6598 individuals were included in the study. Overall, the proportion of households with at least one net was 92 % while bed net usage was reported among 72 % of household members. Of the households surveyed, a total ownership of 2768 nets was reported, of which about 96 % were reportedly LLINs received from the ULC. By interviewer-physical observation, 88 % of the nets owned were of the LLIN type with the remaining 12 % did not carry any mark to enable type recognition. The odds of bed net use were significantly lower among males and individuals: from households of low socio-economic status, from households with

Malaria parasite carriage and risk determinants in a rural population: a malariometric survey in Rwanda.

BACKGROUND: Based on routine health facility case data, Rwanda has achieved a significant malaria burden reduction in the past ten years. However, community-based malaria parasitaemia burden and reasons for continued residual infections, despite a high coverage of control interventions, have yet to be characterized. Measurement of malaria parasitaemia rates and evaluation of associated risk factors among asymptomatic household members in a rural community in Rwanda were conducted. METHODS: A malariometric household survey was conducted between June and November 2013, involving 12,965 persons living in 3,989 households located in 35 villages in a sector in eastern Rwanda. Screening for malaria parasite carriage and collection of demographic, socio-economic, house structural features, and prior fever management data, were performed. Logistic regression models with adjustment for within- and between-households clustering were used to assess malaria parasitaemia risk determinants. RESULTS: Overall, malaria parasitaemia was found in 652 (5%) individuals, with 518 (13%) of households having at least one parasitaemic member. High malaria parasite carriage risk was associated with being male, child or adolescent (age group 4-15), reported history of fever and living in a household with multiple occupants. A malaria parasite carriage risk-protective effect was associated with living in households of, higher socio-economic status, where the head of household was educated and where the house floor or walls were made of cement/bricks rather than mud/earth/wood materials. Parasitaemia cases were found to significantly cluster in the Gikundamvura area that neighbours marshlands. CONCLUSION: Overall, Ruhuha Sector can be classified as hypo-endemic, albeit with a particular 'cell of villages' posing a higher risk for malaria parasitaemia than others. Efforts to further reduce transmission and eventually eliminate malaria locally should focus on investments in programmes that improve house structure features (that limit indoor malaria transmission), making insecticide-treated bed nets and indoor residual spraying implementation more effective.

Monitoring long-lasting insecticidal net (LLIN) durability to validate net serviceable life assumptions, in Rwanda.

BACKGROUND: To validate assumptions about the length of the distribution-replacement cycle for long-lasting insecticidal nets (LLINs) in Rwanda, the Malaria and other Parasitic Diseases Division, Rwanda Ministry of Health, used World Health Organization methods to independently confirm the three-year LLIN serviceable life span recommendation of WHO. METHODS: Approximately 3,000 coded LLINs, distributed as part of a national campaign, were monitored in six sites, by means of six-monthly visits to selected houses. Two indicators, survivorship/attrition, a measure of the number of nets remaining, and fabric integrity, the proportion of remaining nets in either 'good', 'serviceable' or 'needs replacement' condition, based on holes in the net material, were tracked. To validate the assumption that the intervention would remain effective for three years, LLIN coverage, calculated using either survivorship, or integrity, by removing nets in the 'needs replacement' category from the survivorship total, was compared with the predicted proportion of nets remaining, derived from a net loss model, that assumes an LLIN serviceable life of three years. RESULTS: After two years, there was close agreement between estimated LLIN survivorship at all sites, 75% (range 64-84%), and the predicted proportion of nets remaining, 75%. However, when integrity was considered, observed survivorship at all sites, declined to 42% (range 10-54%). CONCLUSIONS: More than half, 58%, of the LLINs fell into the 'needs replacement' category after two years. While these nets were counted for survivorship, they were judged to be of little-to-no benefit to a user. Therefore, when integrity was taken into account, survivorship was significantly lower than predicted, suggesting that net serviceable life was actually closer to two, rather than three years, and, by extension, that the impact of the intervention during year three of the LLIN distribution-replacement cycle could be well below that seen in years one and two.

Community mobilization for malaria elimination: application of an open space methodology in Ruhuha sector, Rwanda.

BACKGROUND: Despite the significant reduction of malaria transmission in Rwanda, Ruhuha sector is still a highly endemic area for malaria. The objective of this activity was to explore and brainstorm the potential roles of various community stakeholders in malaria elimination. METHODS: Horizontal participatory approaches such as 'open space' have been deployed to explore local priorities, stimulate community contribution to project planning, and to promote local capacity to manage programmes. Two open space meetings were conducted with 62 and 82 participants in years 1 and 2, respectively. Participants included purposively selected community and local organizations' representatives. RESULTS: Malaria was perceived as a health concern by the respondents despite the reported reduction in prevalence from 60 to 20% for cases at the local health centre. Some misconceptions of the cause of malaria and misuse of preventive strategies were noted. Poverty was deemed to be a contributing factor to malaria transmission, with suggestions that improvement of living conditions for poor families might help malaria reduction. Participants expressed willingness to contribute to malaria elimination and underscored the need for constant education, sensitization and mobilization towards malaria control in general. Active diagnosis, preventative strategies and prompt treatment of malaria cases were all mentioned by participants as ways to reduce malaria. Participants suggested that partnership of stakeholders at various levels could speed up programme activities. A community rewards system was deemed important to motivate engaged participants, i.e., community health workers and households. Establishment of malaria clubs in schools settings was also suggested as crucial to speed up community awareness and increase skills towards further malaria reduction. CONCLUSIONS: This bottom-up approach was found useful in engaging the local community, enabling them to explore issues related to malaria in the area and suggest solutions for sustainable malaria elimination gains.

Local resource mobilization for malaria vector control among Rwandan rice farmers: a pilot study into the role of community ownership.

BACKGROUND: Evidence suggests a vicious cycle between rice cultivation and malaria control in Rwanda. Rice fields offer an attractive breeding ground for malaria vectors, which increases the disease burden in rice farming communities, and, consequently, reduces productivity in the rice sector. Community-based larval source management in rice fields is propagated as a sustainable solution to break this cycle. A sense of agency and ownership of malaria control interventions, as well as the mobilization of resources at the local level, are often considered preconditions for success. However, an evidence gap exists regarding the interaction between the agentive and financial dimension of local sustainability. METHODS: We conduct a larviciding pilot involving three groups; one group where rice farmers sprayed their fields under expert supervision, one group where rice farmers organised the larviciding campaign themselves, and a (non-sprayed) control group. We test whether the difference in agency between the intervention groups affects farmers' willingness-to-pay for a larviciding campaign. Willingness-to-pay is elicited in a contingent valuation exercise, more specifically a bidding game, and is assessed both before and after the pilot (n = 288). Difference-in-difference estimates are computed, using a propensity score matching technique. Supplementary data were collected in a survey and two focus group discussions for triangulation. RESULTS: The high-agency (self-organised) group significantly outperforms the low-agency (expert-supervised) group in terms of maintaining its willingness to contribute financially. However, higher willingness-to-pay in the high-agency group does not appear to be driven by a stronger sense of ownership per se. The supplementary data indicate high levels of ownership in both treatment groups compared to the control group. A tentative explanation lies in diverging perceptions concerning the effectiveness of the pilot. CONCLUSIONS: The study supports the idea that community-led organization of larval source management can prove instrumental in mobilizing finance for malaria control in low-income settings where rice production interferes with the fight against malaria. However, the causality is complex. Feelings of ownership do not appear the main driver of willingness-to-pay, at least not directly, which opens up the possibility of initiating community-driven malaria control interventions that promote the agentive and financial dimension of local sustainability simultaneously.

Expanding the Role of Women in Vector Control: Case Studies From Madagascar, Rwanda, and Zambia.

BACKGROUND: Historically, vector control, including entomological monitoring, has been a field dominated by men. Each year, the U.S. President's Malaria Initiative (PMI) VectorLink project hires 50,000 to 70,000 seasonal workers across the countries in which it works to implement vector control activities, creating an economic opportunity for both men and women. Remaining barriers to women's employment in vector control include social and cultural norms regarding acceptability of formal employment for women, perceptions that women are not fit to serve as spray operators, and a historical context of male-dominated fields such as entomology. METHODS: We use PMI VectorLink project data from Madagascar, Rwanda, and Zambia for 2019-2021 and key informant interviews with project staff in these countries to examine levels of female employment, effectiveness and efficiency of female versus male malaria spray operators, and strategies to expand the role of women in vector control. RESULTS: The percentage of female seasonal employees ranges from 25% in Madagascar to 32% in Rwanda and 45% in Zambia. The percentage of women in leadership positions ranges from 32% in Madagascar and Rwanda to 38% in Zambia. Men and women are equally effective and efficient as spray operators. Best practices for recruiting and retaining women in vector control include engaging community leaders in recruitment, implementing affirmative action hiring policies, mentoring women to progress to leadership positions, and ensuring equitable, safe, and attractive workplaces. DISCUSSION: As vector control programs transition away from donor funding and are increasingly government led, sustaining gains in female empowerment is critical. Country programs should work closely with national, regional, district, and local leaders to demonstrate the importance of hiring women in vector control-including leadership positions-and the impact on female economic empowerment, community well-being, and success of vector control programs.

Impact of Pyrethroid Plus Piperonyl Butoxide Synergist-Treated Nets on Malaria Incidence 24 Months after a National Distribution Campaign in Rwanda.

Malaria remains a public health priority in Rwanda. The use of insecticide-treated nets (ITNs) is a key malaria prevention tool. However, expanding pyrethroid resistance threatens the gains made in malaria control. In 2018, the Rwandan malaria program strategic approach included the use of newer types of ITNs such as pyrethroid plus piperonyl butoxide (PBO) synergist-treated nets to counter pyrethroid resistance. In February 2020, 5,892,280 ITNs were distributed countrywide; 1,085,517 of these were PBO nets distributed in five districts. This study was a pragmatic observational study that leveraged the 2020 net distribution and routinely collected confirmed malaria cases to determine the impact of PBO nets 1 and 2 years after ITN distribution. No differences were observed in the average net coverage between the PBO and standard net districts. A significant reduction in malaria incidence was reported in both the PBO (P = 0.019) and two control districts that received standard nets (P = 0.008) 1 year after ITN distribution. However, 2 years after, this reduction was sustained only in the PBO (P = 0.013) and not in the standard net districts (P = 0.685). One year after net distribution, all districts had a significant reduction in malaria incidence rate (incidence rate ratio < 1). In the second year, incidence in districts with PBO nets continued to decrease, whereas in districts with standard nets, incidences were similar to predistribution levels. The results indicate that PBO nets are a promising tool to combat pyrethroid resistance in Rwanda, with protective effects of up to 2 years post distribution.