Morbidity and mortality burden of COVID-19 in rural Madagascar: results from a longitudinal cohort and nested seroprevalence study.

This article focuses on estimating the COVID-19 morbidity and mortality burden in a rural health district of Madagascar using a population-representative seroprevalence study nested within a longitudinal cohort. By April–June 2021, about 18% of the population had been infected, with infections initially concentrated along the main paved road and in towns before spreading to more remote areas. Wealthier individuals and those in commerce or formal employment faced higher infection risk during the first wave. Adult mortality increased notably in 2020, especially among older men, but only a small fraction of this excess mortality could be directly attributed to COVID-19 based on known infection fatality ratios, suggesting substantial indirect effects or underestimation of COVID-19 deaths. The study highlights that COVID-19's true burden in poor, rural sub-Saharan African settings may be considerably underestimated due to limited data and complex local factors.