Australia records over 500 diphtheria cases as outbreak spikes, officials warn under-reporting

Australia is confronting its biggest diphtheria outbreak since records began, with 538 confirmed cases across several jurisdictions, chiefly the Northern Territory and Western Australia. The surge, which peaked between late May and early June, has since eased but uneven testing rates in remote communities may mean the true number of infections is larger. The disease has largely manifested as skin lesions, disproportionately affecting Aboriginal and Torres Strait Islander populations living in overcrowded, substandard housing.

Federal and state authorities have pledged a $13 million response package to fund surge staffing, additional vaccines, antibiotics and community liaison work, including $3 million for the National Aboriginal Community Controlled Health Organisation. Health officials urge residents with skin sores or sore throats to seek early testing and vaccination, noting a roughly 20 percent hospitalisation rate. Experts attribute the outbreak to waning vaccine immunity, poor housing conditions and limited testing, and call for sustained immunisation efforts alongside improvements to living environments.