Prevalence of Asymptomatic Malaria Infection in Malaria-Endemic Areas of Southeast Asia: A Scoping Review

Asymptomatic malaria remains a hidden barrier to elimination efforts in Southeast Asia. Individuals without symptoms often serve as undetected reservoirs of infection, making them difficult to capture through symptom-based surveillance. Understanding prevalence, species distribution, at-risk populations, and diagnostic approaches is essential to inform evidence-based interventions. The reported prevalence of asymptomatic malaria ranged from 1.03% to 88.6%, with the highest found in Southern Papua. Molecular methods such as PCR, qPCR, nested PCR and HVUSqPCR known for higher sensitivity, detected submicroscopic infections and reported prevalence up to 80% compared with RDTs and Microscopy. Among species, P. vivax showed the highest prevalence at 81%, followed by P. knowlesi, P. falciparum, P. ovale, P. cynomolgi, and P. malariae. High-risk groups is in border areas, forests, or highly mobile communities. The findings emphasize the need for active surveillance, sensitive diagnostics, and targeted interventions to address asymptomatic reservoirs and support evidence-informed elimination strategies in Southeast Asia.