Buruli ulcer is spreading through Australian suburbs — act now

What just happened

University of Melbourne researchers have documented a significant geographic expansion of Buruli ulcer in Australia, with cases moving out of coastal Victorian regions into Melbourne’s inner suburbs — Essendon, Brunswick West, Moonee Ponds — and appearing for the first time on the NSW south coast. Victoria recorded 426 cases in 2025. NSW genomic analysis confirms the south coast cases represent a separate outbreak, not Victorian spillover.

Buruli ulcer is caused by Mycobacterium ulcerans, a bacterium that starts as a painless lump after a mosquito bite and, if untreated, can progress to a disfiguring, slow-healing ulcer that may require reconstructive surgery. The primary vector in Australian urban environments is the backyard mosquito Aedes notoscriptus — the mosquito that breeds in the water containers most suburban gardens contain.

Both-and

A condition that rewards early recognition — and punishes late diagnosis

The clinical trajectory of Buruli ulcer is one of those stories where timing changes everything. Caught early — treated with an eight-week course of rifampicin combined with clarithromycin or moxifloxacin — the infection resolves with limited tissue damage. Left untreated, the bacteria produce a toxin called mycolactone that destroys skin, fat, and muscle, resulting in deep ulcers that can take more than four months to heal.

The challenge is that the early presentation is deceptively minor. A small, painless nodule or lump. The kind of thing someone might ignore for weeks. And because the lag between mosquito bite and visible symptom can be months, the connection to a bite is not always obvious. In suburban Melbourne and the NSW south coast — where clinicians and patients are less familiar with the diagnosis than those in the Mornington Peninsula — that recognition gap is a real risk.

The Victorian Department of Health has noted the disease is spreading to local government areas not previously considered affected. If you live in inner Melbourne and your GP has not encountered a case before, the right move when you present with a persistent, non-healing skin lesion is to name the possibility explicitly.

Diagnosis requires PCR confirmation, ideally from a swab of ulcer fluid or tissue biopsy; wound culture alone has poor sensitivity for M. ulcerans. The condition is notifiable in Victoria.

The new vector data changes the suburban risk calculation

The reason Buruli ulcer was historically associated with specific coastal environments is that earlier research pointed to water environments, possums, and less common mosquito species as part of the transmission chain. New data published in Nature Microbiology confirms the backyard mosquito Aedes notoscriptus as the primary urban vector. This matters because A. notoscriptus is not a coastal specialist — it is a generalist suburban mosquito that breeds wherever water sits undisturbed.

Bird baths. Roof gutters with leaf litter. Rainwater tanks without proper covers. Plant saucers. Any container that holds water for more than a week. These breeding sites exist in equal density in Brunswick West as they do in Barwon Heads.

The same Melbourne research team trialled autodissemination stations — devices that attract mosquitoes and coat them with a growth-regulating agent — in an affected Victorian neighbourhood. A randomised trial found a 70% reduction in mosquito egg counts after eight weeks, with an estimated 83% lower infection incidence in treatment areas. That is a promising public health tool, though not yet widely deployed. The accessible, immediate intervention is habitat removal in your own garden.

The patient population at highest risk of late presentation

The patients most likely to present late are older adults who live alone, tend to minimise symptoms, and do not connect a garden mosquito bite from three months ago to the lesion on their shin. The lower limbs are the most common site — often attributed to a garden scratch or an unremembered knock.

GPs in newly affected areas in inner Melbourne and the NSW south coast who are seeing slow-healing, painless lower limb lesions in this demographic are worth having Buruli ulcer on their differential.

2 cents

If you live anywhere in greater Melbourne or the NSW south coast and your garden has water containers, now is the time to act. Refill bird baths weekly. Clear gutters. Cover rainwater tanks. Empty anything that holds standing water. This is low-effort and the risk it addresses is now confirmed in inner-suburban areas that were not part of this conversation two years ago.

Use insect repellent with DEET or picaridin, wear long sleeves and pants around dawn and dusk, and if you or a family member develops a persistent, slow-growing skin lump that does not resolve — particularly on the lower limbs — mention Buruli ulcer to your GP. It is a condition that rewards prompt attention.

This is general information. For assessment of a specific skin lesion, your GP is the appropriate place to start.

Verdict: yes — worth knowing about. The suburban spread of Buruli ulcer is new, the vector is the common backyard mozzie, and prevention is genuinely achievable with simple household changes.

---

Sources cited

1. Paris V, Buultjens A, et al. Mozzies are causing Buruli ulcers in more parts of Australia. The Conversation, 11 September 2026.
2. Paris V, et al. Autodissemination station trial for Buruli ulcer vector control, Victoria. Nature Microbiology, 2026.
3. NSW Buruli ulcer genomic surveillance. PLoS Neglected Tropical Diseases, 2025.
4. Mycobacterium ulcerans infection (Buruli ulcer). Victorian Department of Health.
5. Buruli ulcer. NSW Health.