Animal melioidosis in Australia

Melioidosis was first diagnosed in Australia in sheep in 1949. While it has been considered endemic in tropical Australia, there have been animal outb reaks in southwest Western Australia and southern Queensland. Infection occ urs in many species, with both latency and a wide range of clinical manifes tations. Some species may develop melioidosis only if immunocompromised. Sh eep and goats are particularly susceptible, resulting in the requirement fo r pasteurisation of tropical commercial goat's milk. Nine out of 43 (21%) g oats had aortic lesions at autopsy and seven died from aortic aneurysm rupt ure. Transplacental transmission in goats has also been documented. Asympto matic organ abscesses are common in pigs but bovine melioidosis is very rar e. Camels moved north and an alpaca brought to Darwin have died from melioi dosis. It also occurs in wildlife, including birds, crocodiles and kangaroo s. Zoonotic transmission to humans is extremely unusual, but there are many similar epidemiological and clinical features of melioidosis in animals an d humans. There have been three possible zoonotic cases in Australia. Molec ular typing has found identical Burkholderia pseudomallei organisms from an imals, humans and soil. The study of melioidosis in animals, especially the use of molecular genetic techniques for organism identification and typing , will continue to unravel aspects of the disease that remain unclear in hu mans. (C) 2000 Elsevier Science B.V. All rights reserved.