Asymptomatic infection among primary schoolchildren and -mediated malaria transmission: A cross-sectional study in Ouidah; south-western Benin.

Understanding the contribution of asymptomatic carriers in malaria transmission might be helpful to design and implement new control measures. The present study explored the prevalence of asymptomatic and symptomatic infections (asexual and sexual stages) and the contribution of asymptomatic carriers to -mediated malaria transmission in Ouidah (Benin). Thick and thin blood smears were examined from finger-prick blood specimens using light microscopy, and the density of both asexual and sexual stages of species was calculated. Infectivity of gametocyte-infected blood samples to was assessed through direct membrane feeding assays. The prevalence of asymptomatic infections was 28.73% (289/1006). All the asymptomatic gametocyte-carriers (19/19), with gametocytaemia ranging from 10 - 1200 gametocytes/μL of blood, were infectious to mosquitoes. The mean oocyst prevalences varied significantly (  = 16.42,  = 7,  = 0.02) among laboratory mosquito strains (6.9 - 39.4%) and near-field mosquitoes (4.9 - 27.2%). Likewise, significant variation (  = 56.85,  = 7,  = 6.39 × 10) was observed in oocyst intensity. Our findings indicate that asymptomatic carriers could significantly contribute to malaria transmission. Overall, this study highlights the importance of diagnosing and treating asymptomatic and symptomatic infection carriers during malaria control programmes.