Study protocol for a cluster randomised controlled factorial design trial to assess the effectiveness and feasibility of reactive focal mass drug administration and vector control to reduce malaria transmission in the low endemic setting of Namibia

Abstract

IntroductionTo interrupt malaria transmission, strategies must target the parasite reservoir in both humans and mosquitos. Testing of community members linked to an index case, termed reactive case detection (RACD), is commonly implemented in low transmission areas, though its impact may be limited by the sensitivity of current diagnostics. Indoor residual spraying (IRS) before malaria season is a cornerstone of vector control efforts. Despite their implementation in Namibia, a country approaching elimination, these methods have been met with recent plateaus in transmission reduction. This study evaluates the effectiveness and feasibility of two new targeted strategies, reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) in Namibia.Methods and analysisThis is an open-label cluster randomised controlled trial with 2×2 factorial design. The interventions include: rfMDA (presumptive treatment with artemether-lumefantrine (AL)) versus RACD (rapid diagnostic testing and treatment using AL) and RAVC (IRS with Acellic 300CS) versus no RAVC. Factorial design also enables comparison of the combined rfMDA+RAVC intervention to RACD. Participants living in 56 enumeration areas will be randomised to one of four arms: rfMDA, rfMDA+RAVC, RACD or RACD+RAVC. These interventions, triggered by index cases detected at health facilities, will be targeted to individuals residing within 500 m of an index. The primary outcome is cumulative incidence of locally acquired malaria detected at health facilities over 1 year. Secondary outcomes include seroprevalence, infection prevalence, intervention coverage, safety, acceptability, adherence, cost and cost-effectiveness.Ethics and disseminationFindings will be reported on clinicaltrials.gov, in peer-reviewed publications and through stakeholder meetings with MoHSS and community leaders in Namibia.Trial registration numberNCT02610400; Pre-results.

“We were afraid of the lion that has roared next to us”; community response to reactive focal mass drug administration for malaria in Eswatini (formerly Swaziland)

“…Whether bed nets should be used in addition to IRS is beyond the scope of this study, but it is important to note that community members were interested in a strategy that addresses both humans and the mosquito. An rfMDA trial in Namibia is currently evaluating the effectiveness of rfMDA and reactive focal IRS, which could be considered if proven effective and acceptable to the community [13].…”

“…Such low density infections may not be of major clinical relevance, but are sufficient to maintain the transmission of malaria in regions with very low malaria endemicity, such as in Eswatini [5, 8, 9]. Reactive focal mass drug administration (rfMDA), or presumptive treatment of household members and neighbors of a passively identified case without malaria testing, overcomes the limitations of the diagnostics used in RACD and may be effective for interrupting malaria transmission in low endemic settings [10–13]. Treatment with an anti-malarial agent that has a long half-life (e.g., dihydroartemisinin/piperaquine (DP) can also provide a prophylactic effect to those members of the community who are at highest risk of infection, even if they were not infected at the time of treatment [13].…”

Subpatent malaria in a low transmission African setting: a cross-sectional study using rapid diagnostic testing (RDT) and loop-mediated isothermal amplification (LAMP) from Zambezi region, Namibia

“…However, if these infections were subpatent at time of presentation, there may be indication for more sensitive diagnostics in the clinical setting. Even with improved malaria care-seeking and improved point-of-care diagnostics in the clinical setting, there remains the challenge of subclinical infections, which may require a community-based screening and treatment approach using more sensitive diagnostics, or presumptive treatment [33].…”

Use of MALDI-TOF MS for the Identification of Chad Mosquitoes and the Origin of Their Blood Meal

“…6 Long-lasting insecticide-treated bed net, indoor residual spraying, larviciding, and community education to promote vector avoidance are commonly used approaches. 7 The implementation of vector control and surveillance strategies against mosquitoes requires entomological surveys including correct identification not only of the vectors but also of their blood meal for a better understanding of their biting behavior (endophilic or exophilic and anthropophilic or zoophilic). 8,9 Mosquito identification is most often performed using morphological criteria using identification keys and/or molecular methods.…”