Effect of weekly fever-screening and treatment and monthly RDT testing and treatment on the infectious reservoir of malaria parasites in Burkina Faso: a cluster-randomised trial

Abstract

The majority of Plasmodium spp infections in endemic countries are asymptomatic and a source of onward transmission to mosquitoes. We aimed to examine whether Plasmodium falciparum transmission and malaria burden could be reduced by improving early detection and treatment of infections with active screening approaches. In this 18-month cluster randomised study in Sapone, Burkina Faso, households were enrolled and randomly assigned (1:1:1) to one of three groups: group 1 (control) received standard of care only, group 2 received active weekly, at home, fever screening by a community health worker regardless of symptoms, participants with a fever received a rapid diagnostic test (RDT) and treatment if RDT positive, and group 3 received active weekly fever screening (as in group 2) plus a monthly RDT regardless of symptoms, and treatment if RDT positive. Eligible households had a minimum of threeeligible residents, one in each age group (<5years, 5-15years, and >15years). The primary outcome was parasite prevalence by quantitative PCR (qPCR) in the end-of-study cross-sectional survey. Secondary outcomes included parasite and gametocyte prevalence and density in all three end-of-season cross-sectional surveys, incidence of infection, and the transmissibility of infections to mosquitoes. This trial was registered at ClinicalTrials.gov (NCT03705624) and is completed. A total of 906individuals from 181households were enrolled during two phases, and participated in the study. 412individuals were enrolled between Aug 9and 17, 2018, and participated in phase 1and 494individuals were enrolled between Jan 10and 31, 2019, in phase 2. In the end-of-study cross-sectional survey (conducted between Jan13and21,2020), Pfalciparum prevalence by qPCR was significantly lower in group 3 (29·26%; 79of 270), but not in group 2 (45·66%; 121of 265), when compared with group 1 (48·72%; 133of 273; risk ratio 0·65 [95% CI 0·52-0·81]; p=0·0001). Total parasite and gametocyte prevalence and density were also significantly lower in group3in all surveys. The largest differences were seen at the end of the dry season, with gametocyte prevalence 78·4% and predicted transmission potential 98·2% lower in group 3than in group1. Active monthly RDT testing and treatment can reduce parasite carriage and the infectious reservoir of Pfalciparum to less than 2% when used during the dry season. This insight might inform approaches for malaria control and elimination. Bill & Melinda Gates Foundation, European Research Council, and The Netherlands Organization for ScientificResearch.