This study is the second phase of work in Zambezi and Ohangwena Regions, Namibia, building off a formative phase of work that characterized the risk behaviors migratory patterns, health-seeking behaviors, intervention strategies and social networks of agricultural workers and cattle herders, who are previously identified malaria high-risk populations (HRPs). This phase of the study now aims to determine the effectiveness, cost-effectiveness, acceptability, and feasibility of targeted delivery of a package of malaria interventions for improving effective coverage and reducing Plasmodium falciparum malaria transmission in these regions among these populations.~The study will specifically assess the coverage and impact of interventions delivered at worksites to HRPs, including presumptive treatment administered alongside vector control interventions (indoor residual spraying [IRS], long-lasting insecticidal nets [LLINs], and topical repellents). The effectiveness of these interventions will be compared against areas with no study interventions (standard of care) over the course of implementation (November 2019 - May 2020). Primary outcomes will include the coverage of each intervention at worksites over the study period and PCR-based P. falciparum prevalence measured at endline. Following a baseline cross-sectional survey in November/December 2019, the interventions will consist of 2 rounds of presumptive treatment spaced at least one month apart between January and March, and delivery of vector control interventions at worksites and key access points with support from employers, with the primary evaluation to be conducted through an endline cross-sectional survey in April/May 2020. Secondary outcomes around effectiveness will be assessed through incident case data providing measures of incidence in HRP and non-HRP populations, odds of infection associated with each intervention in cases compared to controls and entomological data collection. In addition, operational and feasibility outcomes will be assessed through qualitative data collection, population size estimation of HRP groups and a global positioning system (GPS) logger study.
This study aims to determine the effectiveness, cost-effectiveness, acceptability, and feasibility of targeted delivery of a package of malaria interventions for improving effective coverage and reducing Plasmodium falciparum malaria transmission among malaria high-risk populations in Northern Namibia. Previous research identified cattle herders and agricultural workers as populations at higher risk of infection. The investigators hypothesize that targeted delivery of interventions will lead improve coverage in these groups and lead to a reduction in P. falciparum transmission.