Melioidosis in Laos

Abstract

Melioidosis is a serious infectious tropical disease caused by a soil-dwelling bacterium, Burkholderia pseudomallei, transmitted from contaminated soil or surface water. Although endemic in Southeast Asia, it is considered an emerging disease in Lao PDR where it has only been recognised for 15 years, becoming one of the leading causes of community-acquired septicaemia. A research programme has been developed by the Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit in collaboration with the Institut de la Francophonie pour la Medecine Tropicale (IFMT) and the Institut de Recherche pour le Developpement (IRD) to investigate the environmental reservoir of B. pseudomallei in Lao PDR. The first study, conducted in 2009, showed that the geographical distribution of B. pseudomallei was very heterogeneous and not limited to the floodplains of the Mekong River. The soil samples collected in the province of Saravane (southern Laos) was proved the most heavily contaminated. The second study, conducted in 2010, aimed to detect B. pseudomallei in surface water using Moore's swabs. A high proportion of water samples taken from the Sedone River were positive downstream of a heavily contaminated terrestrial site, suggesting contamination by runoff from land reservoirs. Both environmental reservoir studies of B. pseudomallei pave the way for future research in order to clarify the areas at risk of melioidosis to facilitate preventive measures amongst populations at risk and better care for those infected.