Melioidosis in Australia

Abstract

Melioidosis is a potentially fatal bacterial infection caused by the Gram-negative bacillus, Burkholderia pseudomallei following contact with a contaminated environmental source, normally soil or water in tropical and subtropical locations. The disease spectrum varies from rapidly progressive bacteraemic infection with or without pneumonia, to focal lesions in deep soft tissues and internal organs to superficial soft tissue infection and asymptomatic seroconversion with possible long-term dormancy. Most infections occur with a background of chronic illness such as diabetes, chronic kidney disease and alcoholic liver disease. Improvements in diagnosis, targeted antimicrobial treatment and long term follow up have improved clinical outcomes. Environmental controls following rare point source case clusters and heightened awareness of melioidosis appear to have reduced the disease burden in some parts of northern Australia. However, the impact of climate change on dispersal of environmental B. pseudomallei, and changing land use in tropical Australia is expected to change the epidemiology of melioidosis in future.

Melioidosis in northern Australia

“…In high-volume centres, laboratory scientists are adept at identifying B. pseudomallei; however, laboratories unfamiliar with the organism may disregard it as an environmental contaminant. 5 There is interest in the use of lateral flow immunoassay testing, PCR and MALDI-TOF to expedite the diagnosis of melioidosis, however PCR has not been sufficiently sensitive or specific for direct detection from clinical samples, and while the lateral flow immunoassay shows promise for the rapid diagnosis of melioidosis directly from pus and urine, it is not yet widely available, nor incorporated into validated diagnostic algorithms. [25][26][27] Serology has very limited utility in the diagnosis of the disease as it has poor sensitivity and may be positive in healthy individuals in endemic areas.…”

“…4 In humans, melioidosis can involve almost any organ, with the clinical presentation a result of the complex interplay between host, pathogen, and the environment. 5,6 B. pseudomallei can also infect animals, with pigs, goats, sheep, and camels among the most susceptible. 4…”