Recurrent Melioidosis in the Darwin Prospective Melioidosis Study: Improving Therapies Mean that Relapse Cases Are Now Rare

The Darwin Prospective Melioidosis Study has documented 785 melioidosis cases over 23 years. Recurrent melioidosis occurred in 39/679 (5.7%) patients surviving initial infection; 29 patients suffered relapse of the original infection, and 10 presented with a new Burkholderia pseudomallei infection. With improved therapy, relapse has become rare in recent years. Burkholderia pseudomallei, the causative agent of melioidosis, isendemic to the environment of Southeast Asia and northern Australia. Almost all B. pseudomallei infections are caused by en-vironmental exposure to contaminated water or soils, with the commonest route being skin inoculation or, less frequently, inha-lation or ingestion (1). Melioidosis can present as an acute, sub-acute, chronic, or recurrent disease and is fatal in between 10 and 50 % of cases, depending on geographical region (2). Melioidosis treatment is protracted, and recurrent disease is a well-recognized concern, being documented for 13 to 23 % of patients in Thailand (3–7) and in 6 % of patients in Australia (3, 8, 9). Recurrent me-lioidosis can result either from relapse due to failure to clear an infection or from reinfection with a new B. pseudomallei strain