A cluster of leptospirosis cases associated with crocodile workers in the Northern Territory, Australia, 2022

Leptospirosis is a worldwide zoonotic waterborne disease endemic in tropical and subtropical climates. Outbreaks have been observed in the Northern Territory (NT) of Australia. We briefly described the epidemiology of leptospirosis in the NT between 2012 and 2022, and undertook an investigation of a cluster of three leptospirosis cases observed in crocodile workers between January and December 2022 in the Top End of the NT. A descriptive case series was conducted to investigate the cluster; all three cases were male and non-Aboriginal with a median age of 46.5 years; none took chemoprophylaxis; only one of the three cases reported wearing appropriate protective attire; all reported receiving limited to no education about personal protective measures from their associated workplaces. Higher than average rainfall in both February and December 2022 likely contributed to the increased risk of infection in those months. Changing climate patterns are likely to result in more frequent periods of heavy rain, and risk of contracting leptospirosis in the NT may increase, particularly for those who work in wet and muddy conditions. Promoting the use of protective workplace clothing and equipment, the use of waterproof dressings for skin abrasions, regular hand hygiene, and the consideration of chemoprophylaxis in certain circumstances may prevent future cases.