This paper describes a geographic sampling strategy for ecologic studies and describes the relationship between human activities and anopheline larval ecology in urban areas. Kisumu and Malindi, Kenya were mapped using global positioning systems, and a geographic information system was used to overlay a measured grid, which served as a sampling frame. Grid cells were stratified and randomly selected according to levels of planning and drainage. A cross-sectional survey was conducted in April and May 2001 to collect entomologic and human ecologic data. Multivariate regression analysis was used to test the relationship between the abundance of potential larval habitats, and house density, socioeconomic status, and planning and drainage. In Kisumu, 98 aquatic habitats were identified, 65% of which were human made and 39% were positive for anopheline larvae. In Malindi, 91 aquatic habitats were identified, of which, 93% were human made and 65% were harboring anopheline larvae. The regression model explains 82% of the variance associated with the abundance of potential larval habitats in Kisumu. In Malindi, 59% of the variance was explained. As the number of households increased, the number of larval habitats increased correspondingly to a point. Beyond a critical threshold, the density of households appeared to suppress the development of aquatic habitats. The proportion of high-income households and the planning and drainage variables tested insignificant in both locations. The integration of social and biologic sciences will allow local mosquito and malaria control groups an opportunity to assess the risk of encountering potentially infectious mosquitoes in a given area, and concentrate resources accordingly.

BackgroundThe World Health Organization (WHO) recommends integrated vector management (IVM) as a strategy to improve and sustain malaria vector control. However, this approach has not been widely adopted.ObjectivesWe comprehensively assessed experiences and findings on IVM in Kenya with a view to sharing lessons that might promote its wider application.MethodsThe assessment used information from a qualitative external evaluation of two malaria IVM projects implemented between 2006 and 2011 and an analysis of their accumulated entomological and malaria case data. The project sites were Malindi and Nyabondo, located in coastal and western Kenya, respectively. The assessment focused on implementation of five key elements of IVM: integration of vector control methods, evidence-based decision making, intersectoral collaboration, advocacy and social mobilization, and capacity building.ResultsIVM was more successfully implemented in Malindi than in Nyabondo owing to greater community participation and multistakeholder engagement. There was a significant decline in the proportion of malaria cases among children admitted to Malindi Hospital, from 23.7% in 2006 to 10.47% in 2011 (p < 0.001). However, the projects’ operational research methodology did not allow statistical attribution of the decline in malaria and malaria vectors to specific IVM interventions or other factors.ConclusionsSustaining IVM is likely to require strong participation and support from multiple actors, including community-based groups, non-governmental organizations, international and national research institutes, and various government ministries. A cluster-randomized controlled trial would be essential to quantify the effectiveness and impact of specific IVM interventions, alone or in combination.CitationMutero CM, Mbogo C, Mwangangi J, Imbahale S, Kibe L, Orindi B, Girma M, Njui A, Lwande W, Affognon H, Gichuki C, Mukabana WR. 2015. An assessment of participatory integrated vector management for malaria control in Kenya. Environ Health Perspect 123:1145–1151; http://dx.doi.org/10.1289/ehp.1408748

Larval control is a major component in mosquito control programs. This study evaluated the wide-scale application of Bti/Bs biolarvicide (Bacillus thuringiensis var. israelensis [Bti] and Bacillus sphaericus [Bs]) in different aquatic habitats in urban and peri-urban Malindi, Kenya. This study was done from June 2006 to December 2007. The urban and peri-urban area of Malindi town was mapped and categorized in grid cells of 1 km(2). A total of 16 1-km(2) cells were selected based on presence Community Based Organization dealing with malaria control within the cells. Each of the 16 1-km(2) cells was thoroughly searched for the presence of potential larval habitats. All habitats, whether positive or negative for larvae, were treated and rechecked 24 h (1 day), 6 days, and 10 days later for the efficacy of Bti/Bs. Weekly larval sampling was done to determine the mosquito larval dynamics in the aquatic habitats during the study period. Morphological identification of the mosquito larvae showed that Anopheles gambiae s.l. Giles was the most predominant species of the Anopheles and while in the culicines, Cx. quinquefasciatus Say was the predominant species. Anopheles larvae were all eliminated in habitats within a day post-application. For culicine larvae, 38.1% (n=8) of the habitat types responded within day 1 post-treatment and all the larvae were killed, they turned negative during the days of follow-up. Another 38.1% (n=8) of the habitat types had culicine larvae but turned negative by day 6, while three habitats (14.3%) had larvae by 6th day but turned negative by 10th day. However during this Bti/Bs application studies, two habitat types, house drainage and cesspits (9.5%), remained positive during the follow-up although the mosquito larvae were significantly reduced. Both early and late instars of Anopheles larvae immediately responded to Bti/Bs application and reached 100% mortality. The early and late instars of culicine responded to the Bti/Bs application but not as fast as the Anopheles larval instars. The early instars Culex, responded with 90.8% mortality at day 1 post-treatment, and the mortality was 99.9% at day 10. Similarly, the late instars Culex followed the same trend and exhibited same mortalities. The weekly sampling in the aquatic habitats showed that there was a 36.3% mosquito larval reduction in the aquatic habitats over the 18-months study period. In conclusion, Bti/Bs biolarvicide are useful in reducing the mosquito larval densities in a wide range of habitats which have a direct impact of adult mosquito populations.

Understanding mosquito breeding behavior as well as human perspectives and practices are crucial for designing interventions to control Aedes aegypti mosquito-borne diseases as these mosquitoes primarily breed in water-holding containers around people's homes. The objectives of this study were to identify productive mosquito breeding habitats in coastal Kenya and to understand household mosquito management behaviors and their behavioral determinants. The field team conducted entomological surveys in 444 households and semi-structured interviews with 35 female caregivers and 37 children in Kwale County, coastal Kenya, between May and December 2016. All potential mosquito habitats with or without water were located, abundances of mosquito immatures measured and their characteristics recorded. Interviews explored household mosquito management behaviors and their behavioral determinants. 2,452 container mosquito habitats were counted containing 1,077 larvae and 390 pupae, predominantly Aedes species. More than one-third of the positive containers were found outside houses in 1 of the 10 villages. Containers holding water with no intended purpose contained 55.2% of all immature mosquitoes. Containers filled with rainwater held 95.8% of all immature mosquitoes. Interviews indicated that households prioritize sleeping under bednets as a primary protection against mosquito-borne disease because of concern about night-time biting, malaria-transmitting Anopheles mosquitoes. Respondents had limited knowledge about the mosquito life cycle, especially with respect to daytime biting, container-breeding Aedes mosquitoes. Therefore, respondents did not prioritize source reduction. Most mosquitoes breed in containers that have no direct or immediate purpose ("no-purpose containers"). These containers may be left unattended for several days allowing rainwater to collect, and creating ideal conditions for mosquito breeding. An

Mosquito control programs at seven urban sites in Kenya, Egypt, Israel, Costa Rica, and Trinidad are described and compared. Site-specific urban and disease characteristics, organizational diagrams, and strengths, weaknesses, obstacles and threats (SWOT) analysis tools are used to provide a descriptive assessment of each mosquito control program, and provide a comparison of the factors affecting mosquito abatement. The information for SWOT analysis is collected from surveys, focus group discussions, and personal communication. SWOT analysis identified various issues affecting the efficiency and sustainability of mosquito control operations. The main outcome of our work was the description and comparison of mosquito control operations within the context of each study site's biological, social, political, management, and economic conditions. The issues identified in this study ranged from lack of inter-sector collaboration to operational issues of mosquito control efforts. A lack of sustainable funding for mosquito control was a common problem for most sites. Many unique problems were also identified, which included lack of mosquito surveillance, lack of law enforcement, and negative consequences of human behavior. Identifying common virtues and shortcomings of mosquito control operations is useful in identifying "best practices" for mosquito control operations, thus leading to better control of mosquito biting and mosquito-borne disease transmission.

Background Malaria prevention in Africa is mainly through the use of long-lasting insecticide treated nets (LLINs). The objective of the study was to assess the effect of supplementing LLINs with either larviciding with Bacillus thuringiensis israelensis (Bti) or community education and mobilization (CEM), or with both interventions in the context of integrated vector management (IVM). Methods The study involved a factorial, cluster-randomized, controlled trial conducted in Malindi and Nyabondo sites in Kenya and Tolay site in Ethiopia, to assess the impact of the following four intervention options on mosquitoes and malaria prevalence: LLINs only (arm 1); LLINs and Bti (arm 2); LLINs and CEM (arm 3); and, LLINs combined with Bti and CEM (arm 4). Between January 2013 and December 2015, CDC light traps were used to sample adult mosquitoes during the second, third and fourth quarter of each year in 10 houses in each of 16 villages at each of the three study sites. Larvae were sampled once a fortnight from potential mosquito-breeding habitats using standard plastic dippers. Cross-sectional malaria parasite prevalence surveys were conducted involving a total of 11,846 primary school children during the 3-year period, including 4800 children in Tolay, 3000 in Malindi and 4046 in Nyabondo study sites. Results Baseline relative indoor anopheline density was 0.11, 0.05 and 0.02 mosquitoes per house per night in Malindi, Tolay and Nyabondo sites, respectively. Nyabondo had the highest recorded overall average malaria prevalence among school children at 32.4%, followed by Malindi with 5.7% and Tolay 1.7%. There was no significant reduction in adult anopheline density at each of the three sites, which could be attributed to adding of the supplementary interventions to the usage of LLINs. Malaria prevalence was significantly reduced by 50% in Tolay when using LLINs coupled with application of Bti, community education and mobilization. The two other sites did not reveal significant reduction of prevalence as a result of combining LLINs with any of the other supplementary interventions. Conclusion Combining LLINs with larviciding with Bti and CEM further reduced malaria infection in a low prevalence setting in Ethiopia, but not at sites with relatively higher prevalence in Kenya. More research is necessary at the selected sites in Kenya to periodically determine the suite of vector control interventions and broader disease management strategies, which when integrated would further reduce adult anopheline populations and malaria prevalence beyond what is achieved with LLINs.

This study explored perceptions of HIV following local introduction of antiretroviral therapy (ART), among 30 HIV-positive and -negative female sex workers (FSWs) and 10 male bar patrons in Mombasa, Kenya. Semi-structured interviews were analyzed qualitatively to identify determinants of sexual risk behaviors. ART was not perceived as a barrier to safer sex and in some cases led to decreased high-risk behaviors. Barriers to safer sex included economic pressure and sexual partnership types. Many women reported that negotiating condom use is more difficult in long-term partnerships. These women favored short-term partnerships to minimize risk through consistent condom use. For women living with HIV, concern about maintaining health and avoiding HIV superinfection was a strong motivator of protective behaviors. For HIV-negative women, a negative HIV test was a powerful motivator. Incorporation of context- and serostatus-specific factors (e.g., self-protection for HIV-positive women) into tailored prevention counseling may support high-risk women to reduce risk behaviors.

Background: This study assesses the behavioural and socio-economic factors associated with avoiding mosquitoes and preventing malaria in urban environments in Kenya.