Salmonella javiana infection in an infant associated with a marsupial, the quokka, Setonix brachyurus, in Western Australia

Abstract

Salmonella javiana, a serotype rarely isolated in Australia, has been recovered from the faeces of a 14-month-old infant with symptoms of enteritis.The child had been closely associated with a marsupial species, the quokka, during a vacation on Rottnest Island in Western Australia, and S. javiana was isolated from faecal pellets from adult quokkas, and also from a snake collected on the island.Sampling revealed a high incidence of Salmonella infection in the quokkas. In all, 62 out of 87 animals (71%) were found to be infected, and 17 Salmonella and 3 Arizona serotypes were identified from 100 isolations comprising 92 salmonellas and 8 arizonas. Multiple infections were frequently detected and up to four serotypes were recovered from individual animals. S. javiana was isolated from four quokkas.A close parallel was observed between the serotypes isolated from quokkas and sea-gulls on the island, and abattoir effluents, lake waters, bird droppings and reptiles sampled on the adjacent mainland.The epidemiological significance of Salmonella and Arizona infections in the quokka population and their possible association with the seasonal decline in condition and numbers of animals on Rottnest Island is discussed.