Leptospirosis in the Platypus () in Australia: Who Is Infecting Whom?

The platypus () is an amphibious, egg-laying mammal of high conservation value that is found only in Australia. The zoonotic bacterium serovar Hardjo was discovered in platypuses in prior studies, but little is known about its epidemiology. Samples in the Platypus Serum Bank were tested in 2023 and the results were combined with historical records.