Estimates of the changing age-burden of Plasmodium falciparum malaria disease in sub-Saharan Africa

TLDR

Estimating the changing burden of malaria disease remains difficult owing to limitations in health reporting systems. The study uses a transmission model that incorporates acquisition and loss of immunity to capture age‑specific malaria disease patterns across varying transmission intensities. The model was fitted to age‑stratified data from 23 African sites and used to generate maps and burden estimates. In 2010, an estimated 252 million malaria cases occurred in sub‑Saharan Africa, but only about 34 % would be detected passively; the share of cases in children under five ranges from >60 % in high‑transmission areas to <20 % in low‑transmission settings, suggesting that intervention focus on young children may need to be re‑evaluated based on local transmission intensity.

Abstract

Abstract Estimating the changing burden of malaria disease remains difficult owing to limitations in health reporting systems. Here, we use a transmission model incorporating acquisition and loss of immunity to capture age-specific patterns of disease at different transmission intensities. The model is fitted to age-stratified data from 23 sites in Africa, and we then produce maps and estimates of disease burden. We estimate that in 2010 there were 252 (95% credible interval: 171–353) million cases of malaria in sub-Saharan Africa that active case finding would detect. However, only 34% (12–86%) of these cases would be observed through passive case detection. We estimate that the proportion of all cases of clinical malaria that are in under-fives varies from above 60% at high transmission to below 20% at low transmission. The focus of some interventions towards young children may need to be reconsidered, and should be informed by the current local transmission intensity.