- Advisory number:
- Date issued:
- 08 Nov 2022 - (update to Advisory issued 4 May 2022)
- Issued by:
- Associate Professor Deborah Friedman, Deputy Chief Health Officer (Communicable Disease)
- Issued to:
- Victorian residents and health professionals
- Buruli ulcer is a bacterial skin infection.
- Lesions typically present as a slowly enlarging painless lump or wound which can initially be mistaken for an insect bite.
- Case numbers are increasing this year.
- The disease is spreading geographically across Victoria and is no longer restricted to specific coastal locations. Most recently, there has been an increase in cases linked to several suburbs in greater Geelong.
- Early recognition and diagnosis is critical to prevent skin and tissue loss – consider the diagnosis in patients with a persistent ulcer, nodule, papule, or oedema and cellulitis not responding to usual treatments, especially on exposed parts of the body.
- Public health laboratory testing for Buruli ulcer is free for patients. A handling fee may be charged by private pathology companies.
- Buruli ulcer must be notified to the Department within five days of diagnosis.
- There is increasing evidence that mosquitoes and possums play a role in disease transmission.
- Prevention measures include reducing mosquito breeding sites, avoiding mosquito bites and covering cuts and abrasions with a dressing when spending time outdoors.
What is the issue?
Buruli ulcer is a skin infection caused by the bacterium Mycobacterium ulcerans (M. ulcerans). Patients usually develop a painless lump or wound (known as a nodule or papule) which can initially be mistaken for an insect bite. Over time the lesion can slowly progress to develop into a destructive skin ulcer which is known as Buruli or Bairnsdale ulcer.
Cases of Buruli ulcer are increasing. There have been 266 cases notified so far in 2022 compared to the same time in 2021 (227 cases), 2020 (165 cases) and 2019 (247 cases).
There are many areas where the disease has been found. These include:
- Mornington peninsula region
- Bellarine peninsula region
- Westernport region
- Frankston/Langwarrin region
- South Eastern Bayside suburbs
- East Gippsland
- Phillip Island (particularly Cowes), although much less common now
- Aireys Inlet and the Surf Coast
- Several suburbs of Greater Geelong, in particular Belmont, Highton, Newtown, Wandana Heights, Grovedale and Marshall
- Inner Melbourne suburbs of Essendon, Moonee Ponds, Brunswick West, Pascoe Vale South and Strathmore
The disease is not transmissible from person to person. While there is no clear evidence of transmission from possums directly to humans, the bacteria that causes the ulcer is found in possum excrement. Local research has found both mosquitoes and possums play a role in disease transmission in Victoria.
Household members of people with Buruli ulcer should self-monitor for any non-healing skin lesions and seek early medical assessment as they may have been exposed to the same environmental source.
Who is at risk?
Everyone is susceptible to infection. Disease can occur at any age, but Buruli ulcer notifications are highest in people aged 60 years and above in Victoria. The risk of contracting Buruli ulcer, however, is still considered low.
When recognised early, diagnostic testing is straightforward. If guidelines are followed, prompt treatment can significantly reduce skin loss and tissue damage, as well as lead to more simplified treatment.
The incubation period varies from four weeks to nine months, with an average of four to five months. The lesion of Buruli ulcer may occur anywhere on the body, but it is most common on exposed areas of the limbs. In one or two months the lesion may ulcerate, forming a characteristic ulcer. Some people initially develop a painful lump, limb swelling (oedema) or cellulitis without an ulcer. Occasionally people develop severe pain and fever. People of any age can be infected.
In patients with a lesion or cellulitis that does not respond as expected to usual antibiotics, the diagnosis of Buruli ulcer should be considered, especially in those with reported exposure to an endemic area.
Preventive measures include:
- Reduce mosquito breeding sites around houses and other accommodation by reducing areas where water can pool (including pot plant containers, buckets, open tins or cans, discarded tyres, and other untreated, freshwater pools).
- Mosquito proof your home by securing insect screens on accommodation.
- Avoid mosquito bites by:
- Using personal insect repellents containing diethyltoluamide (DEET) or picaridin
- Covering up by wearing long, loose-fitting, light-coloured clothing
- Avoiding mosquito-prone areas and vector biting times, especially at dusk and dawn.
- When gardening, working or spending time outdoors:
- Wear gardening gloves, long sleeved shirts and trousers
- Wear insect repellent on any exposed skin
- Protect cuts and abrasions with a dressing
- Promptly wash any new scratches or cuts you receive with soap and apply a topical antiseptic and dressing.
- Exposed skin contaminated by soil or water should be washed following outdoor activities.
Early recognition, diagnosis and treatment can prevent serious complications from the ulcer. It is important to remember: The presence of skin lesions that progress rather than heal over weeks to months, should be assessed by a doctor and tested for Buruli ulcer.
Diagnostic information for health professionals
If an ulcer is present or if a scabbed lesion can be deroofed, two dry swabs (or pre-moistened with sterile saline) from beneath the undermined edges of the lesion should be sent for staining for acid-fast bacilli (AFB), M. ulcerans PCR and culture. It is essential that there is visible clinical material on the swab. The key to accurate diagnosis is that M. ulcerans is found in the subcutaneous fat layer. This can only be accessed with a swab if an ulcer has already formed.
If an eschar cannot be deroofed or in the event of atypical presentation with plaque, oedema and/or cellulitis, a superficial swab will likely return a false negative and will not be useful. In these cases, a fine needle aspirate (FNA), punch biopsy, or skin biopsy will be required for diagnosis. Repeat testing or punch biopsy should be undertaken if initial PCR is negative and clinicians have a high clinical suspicion for M. ulcerans. The biopsy should be sent for histology, and fresh tissue should be sent for AFB staining, M. ulcerans PCR and mycobacterial culture.
Please specify on the specimen request form that Buruli ulcer or M. ulcerans is suspected so that one swab is reserved for PCR testing by our public health reference laboratory, the Victorian Infectious Diseases Reference Laboratory (VIDRL) and not split for other laboratory testing such as culture.
PCR testing at VIDRL for Buruli ulcer can confirm diagnosis in a few days and is free for patients (a handling fee may still apply for private pathology collection services). General practitioners should include their patient’s Medicare details so that the test can be bulk billed. Public hospitals can also test for Buruli ulcer free of charge.
Under the Public Health and Wellbeing Regulations 2019, Buruli ulcer is a notifiable disease that must be notified within five days of diagnosis.
Referral for treatment to infectious diseases doctors experienced in the management of this condition is strongly recommended. The current mainstay of treatment is a combination of two specific oral antibiotics for approximately 8 weeks. Surgery is sometimes required in combination with antibiotic therapy.
Reviewed 09 November 2022