Buruli Ulcer is spreading

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. As of 17 December, there have been 344 cases notified so far in 2024 compared to the same time in 2023 (362 cases), 2022 (338 cases), 2021 (286 cases), and 2020 (217 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
• The Surf Coast Shire towns of Breamlea, Torquay, Anglesea and Aireys Inlet.
• 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, Ascot Vale and Strathmore

The disease is not transmissible from person to person, however there is evidence that both mosquitoes and possums play a role in disease transmission in Victoria. The bacterium that causes the ulcer is also found in possum excrement and possums have been observed with ulcers and open sores. It is advised not to handle possums and avoid contact with their faeces.

Household members of people with Buruli ulcer should 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.

Symptoms

When recognised early, diagnostic testing is straightforward. If guidelines are followed, prompt treatment can significantly reduce skin loss and tissue damage, and avoid the need for more intensive treatment.

The incubation period varies from 4 weeks to 9 months, with an average of 4 to 5 months. The lesion of Buruli ulcer may occur anywhere on the body, but it is most common on exposed areas of the limbs. In 1 or 2 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.

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.

Recommendations

For the general public

Your only protection against mosquitoes and the diseases they can carry is to avoid mosquito bites. Preventive measures include:

• 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 being outdoors during peak biting times, especially at dusk and dawn.
  • Use 'knockdown' fly spray, mosquito coils or plug-in repellent where you gather to sit or eat outdoors.
• Reduce mosquito breeding sites around houses and other accommodation by changing water weekly or reducing areas where water can pool (including pot plant saucers, bird baths, dog bowls, buckets, ponds, open tins or cans, discarded tyres, stored trailers or boats, and untreated pools and spas).
• Mosquito proof your home by securing insect screens on windows and doors.
• 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.
• Do not handle sick possums, especially if they are displaying signs of open sores or ulcers. Seek advice from wildlife assistance services or veterinarians who are experienced in dealing with sick and injured animals.

More detailed advice on how to prevent mosquito bites and other tips can be found at on the Better Health Channel.

Early recognition, diagnosis and treatment can prevent serious complications from the ulcer. It is important to remember: skin lesions that progress rather than heal over weeks to months should always be assessed by a doctor and tested for Buruli ulcer.

For health professionals

M. ulcerans should be suspected in any patient with a non-healing ulcer who has been present in endemic areas as listed above.

• 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), ulceransPCR 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 ulcerans. The biopsy should be sent for histology, and fresh tissue should be sent for AFB staining, M. ulcerans PCR and mycobacterial culture.

Testing

• Please specify on the specimen request form that Buruli ulcer or ulceransis suspected so that one swab is reserved for PCR testing by 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 the 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.

Notification of disease

Under the Public Health and Wellbeing Regulations 2019, Buruli ulcer is a notifiable disease that must be notified within 5 days of diagnosis.

Management of infection

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.