Melioidosis in northern Australia

Abstract

Burkholderia pseudomallei, the environmental bacterium that causes melioidosis, is endemic to northern Australia. Melioidosis is a strongly seasonal disease, occurring predominantly in individuals with specific comorbidities that include diabetes mellitus, chronic kidney disease, chronic lung disease, immunosuppresion, malignancy and hazardous alcohol use. Most patients are bacteraemic and the majority have pneumonia, however, the infection can involve almost any organ, with the skin, soft tissues, genitourinary system, bones, and joints frequently affected; multi-organ involvement is also common. Central nervous system involvement is less frequent but is more likely to cause death and long-term disability. The incidence of melioidosis is increasing in Australia, but improvements in management have resulted in the local case- fatality rate declining to approximately 10%. Further progress requires greater awareness of the disease and the development of technologies that might expedite diagnosis. A deeper understanding of the disease’s pathophysiology – particularly the role of virulence factors – may also help define optimal management strategies, including the duration of antimicrobial therapy and the role of adjunctive treatments. Public health strategies that address the risk factors for this opportunistic infection – and the social inequity that drives them – would also reduce the morbidity and mortality of this life-threatening disease.