Students: Long Yin Cheung (Cyrus), Tik Yan Lim (Didi) (University of Adelaide)
Supervisor: Darren Trott (University of Adelaide)
Pasteurella multocida is the causative agent of avian cholera which affects a wide variety of domestic and wildlife avian species worldwide. This project documented the avian cholera outbreak which was first detected among waterfowl in the Coorong RAMSAR wetland, South Australia in January 2024.
Post-mortem examination of collected carcasses was undertaken for gross pathology, bacterial culture, and histopathology. Frozen liver samples were sent to the Veterinary Pathology unit at the University of Melbourne for isolation and sequence typing of P. multocida to compare with other Australian isolates. Stakeholders relevant to the outbreak, including from management agencies, the local community, and First Nations, were interviewed to gain their perspectives on the outbreak.
The outbreak occurred from January 9th, 2024, to approximately March 24th, 2024; carcasses were mainly observed at the Pelican Point, North Lagoon, Coorong. The number of deaths was estimated between 500 to 1200 birds. The Coorong P. multocida isolates and previously sequenced avian isolates across Australian belonged to sequence type (ST) 20.
The outbreak emphasised the need to implement preventative measures and raise public awareness to help manage outbreaks that may occur in the future. Genetic similarities of P. multocida across Australian states suggests the possible transmission between wildlife and free- range poultry farms, with the direction and mechanism of transmission not fully understood. Further study on potential risk factors specific to the nature of wetland and the importance of biosecurity is essential to maintain this valuable ecosystem in the future
