Melioidosis in Africa: Time to Uncover the True Disease Load.

Melioidosis is an often fatal infectious disease with a protean clinical spectrum, caused by the environmental bacterial pathogen Burkholderia pseudomallei. Although the disease has been reported from some African countries in the past, the present epidemiology of melioidosis in Africa is almost entirely unknown. Therefore, the common view that melioidosis is rare in Africa is not evidence-based. A recent study concludes that large parts of Africa are environmentally suitable for B. pseudomallei. Twenty-four African countries and three countries in the Middle East were predicted to be endemic, but no cases of melioidosis have been reported yet. In this study, we summarize the present fragmentary knowledge on human and animal melioidosis and environmental B. pseudomallei in Africa and the Middle East. We propose that systematic serological studies in man and animals together with environmental investigations on potential B. pseudomallei habitats are needed to identify risk areas for melioidosis. This information can subsequently be used to target raising clinical awareness and the implementation of simple laboratory algorithms for the isolation of B. pseudomallei from clinical specimens. B. pseudomallei was most likely transferred from Asia to the Americas via Africa, which is shown by phylogenetic analyses. More data on the virulence and genomic characteristics of African B. pseudomallei isolates will contribute to a better understanding of the global evolution of the pathogen and will also help to assess potential differences in disease prevalence and outcome.