Buruli ulcer in Victoria: why cases keep rising and how to protect yourself this summer

By The Rundowns News Desk · Published 1 November 2026

Victoria recorded a record 426 confirmed Buruli ulcer cases in 2025, and the skin infection is no longer confined to the bayside peninsulas. With the higher-risk warmer months starting, here's where it's turning up, what the early signs look like, and what actually lowers your risk.

What's happening

The 426-case figure for 2025 is reported by ABC News, The Age and researchers writing for SBS News / The Conversation. The ABC describes Victoria as now the Buruli ulcer centre of the world. The Age reported in late August that more than 100 cases had already been notified in 2026. For comparison, The Age says there were 32 cases in 2010.

The Western Public Health Unit told The Age that cases across Melbourne's north-west and western suburbs rose from 35 in 2021 to 123 in 2025, and that Parkville and Williamstown had emerged as new hotspots.

Where it's found in Victoria

The Victorian Department of Health says the disease is spreading geographically and is no longer restricted to coastal areas. Its list of affected areas includes:

• the Mornington Peninsula and Frankston/Langwarrin
• the south-eastern bayside suburbs
• the Bellarine Peninsula, Aireys Inlet and the Surf Coast
• Geelong suburbs including Belmont, Highton, Newtown, Wandana Heights, Grovedale and Marshall
• inner Melbourne: Essendon, Moonee Ponds, Brunswick West, Pascoe Vale South and Strathmore

Outside Victoria it occurs in Far North Queensland, around Darwin and, more recently, on the NSW south coast near Batemans Bay. Genomic analysis cited by the Conversation researchers suggests the NSW cases come from a separate outbreak rather than spreading from Victoria.

What it is and how people catch it

Buruli ulcer is a skin infection caused by the bacterium Mycobacterium ulcerans. It isn't known to spread from person to person (Department of Health). In Victoria, research points to ringtail and, less often, brushtail possums as a major reservoir of the bacteria, with mosquitoes playing a key role in getting it to people. The exact route of human infection still isn't fully understood. The one established risk factor is spending time in an area where it's endemic. Risk is highest in the warmer months, but infection can happen year-round.

Early signs to watch for

• It usually starts as a painless lump or bump, often mistaken for an insect or spider bite, most commonly on the arms or legs (Department of Health, ABC News).
• Over weeks to months the skin over it can break down into an ulcer that keeps growing if untreated.
• Symptoms show up late. The department puts the average incubation period at 4 to 5 months, with a range of 1 to 9 months. That means a summer holiday infection may not appear until autumn or winter.

Infectious diseases physician Daniel O'Brien told the ABC that outcomes are better with early diagnosis. He advises seeing a doctor about any suspicious lump, especially if you live in or have visited an affected area, and asking specifically about Buruli ulcer. Diagnosis is usually by a PCR swab test. Treatment is typically a six-to-eight-week antibiotic course, sometimes with surgery, and healing can take months.

How to lower your risk

The Department of Health's prevention advice centres on mosquitoes:

• Empty or remove anything that holds standing water around the house: pot plant saucers, buckets, tins and old tyres.
• Keep insect screens in good repair.
• Use a repellent containing DEET or picaridin on exposed skin.
• Wear long, loose, light-coloured clothing, and avoid mosquito-prone spots at dawn and dusk.
• Wear gloves, long sleeves and long pants when gardening or working outdoors.

There's evidence that mosquito control works. In a trial by the Doherty Institute and the University of Melbourne, almost 600 mosquito-control stations were installed across parts of Merri-bek and Moonee Valley. The Age reports that residents in the treated zones were 83 per cent less likely to get an ulcer than people in nearby comparison areas.

Don't take matters into your own hands with possums. Not every possum in an affected area carries the bacteria, and the ABC notes it's illegal to trap, relocate or cull possums without a licence. Researchers are working on an edible possum vaccine.

What's next

Summer and autumn are the main transmission seasons, so expect case numbers to keep climbing into 2027. A shorter, gentler 10-day antibiotic treatment is being trialled, according to the ABC. If you develop a lump that doesn't heal in the months after time on the peninsulas, in Geelong or in Melbourne's north-west, mention it to your GP. If you're in Victoria, also check our guide to thunderstorm asthma season.

This article is general information, not medical advice. See your doctor about any skin lesion that isn't healing.