High prevalence of asymptomatic malaria in Forest Guinea: Results from a rapid community survey

Summary Malaria is endemic in Guinea, however, the extent and role in transmission of asymptomatic malaria are not well understood. In May 2023, we conducted a rapid community survey to determine Plasmodium falciparum prevalence among asymptomatic individuals in Middle Guinea (Dalaba) and Forest Guinea (Guéckédou). We used a cluster sampling approach with purposive selection of two prefectures and four communities and full enrolment of all individuals in the selected communities. Prevalence was calculated with a 95% confidence interval (CI). In Dalaba, 6/239 (2.1%, CI 0.9-4.8%) individuals tested positive for P. falciparum by rapid diagnostic test, while in Guéckédou, 147/235 (60.9%, CI 54.5-66.9%) of participants tested positive. Asymptomatic malaria needs to be considered more strongly as a driver for transmission when designing control strategies, especially in Forest Guinea and potentially other hyper-endemic settings. Key results and their importance Prevalence of asymptomatic malaria was very high (60.9%, CI 54.5-66.9%) in the selected communities in Forest Guinea. Prevalence was expectedly low (2.1%, CI 0.9-4.8%) in the selected communities in Middle Guinea. Current control strategies in Forest Guinea seem insufficient to reduce malaria prevalence, and likely also transmission. Both policies and control strategies need to more proactively consider asymptomatic malaria in hyper-endemic settings.