Buruli ulcer in Victoria
Buruli ulcer (also known as Bairnsdale ulcer) is an infection of skin and soft tissue caused by the bacterium Mycobacterium ulcerans. The toxin made by the bacteria attacks fat cells under the skin, which leads to localised redness and swelling or the formation of a nodule (lump) and then an ulcer.
Although Buruli ulcer is not fatal, the infection can often leave people with significant cosmetic and sometimes functional damage to limbs.
Buruli ulcer has been reported in 33 countries around the world including rural West Africa, Central Africa, New Guinea, Latin America and tropical regions of Asia. In Australia, Buruli ulcer most commonly occurs in localised coastal areas of Victoria.
The highest risk is associated with the active transmission areas of Rye, Sorrento, Blairgowrie and Tootgarook on the Mornington Peninsula. There is a moderate risk associated with areas in the Bellarine Peninsula (Ocean Grove, Barwon Heads, Point Lonsdale, Queenscliff), Frankston and Seaford areas. There is a low risk associated with the rest of the Bellarine and Mornington Peninsula, the South Eastern Bayside suburbs and East Gippsland. Together, all these areas are considered the endemic parts of Victoria for Buruli ulcer transmission. Recent cases from Aireys Inlet on the Surf Coast and the Geelong suburb of Belmont suggest that these are emerging areas of local transmission. Two cases were identified in residents in Aireys Inlet and two in Belmont during 2019, with no known travel to an endemic area. The risk of transmission in these areas is considered low.
Over the past few years, scientists have been conducting intensive research in a search for answers around the puzzling aspects of this condition. Although it's understood that the infection is picked up from the environment, it's not yet known exactly how humans become infected with the bacteria, or where in the environment the bacteria prefer to live. It is not thought to be spread person-to-person.
Beating Buruli in Victoria research project
Victoria's Department of Health and Human Services (DHHS) has supported research into how Buruli ulcer is transmitted for more than a decade, including providing funding to refine development of an internationally recognized molecular test that has enabled detection of Buruli ulcer in the environment and earlier diagnosis and treatment. Recognising the infection early is important to minimise complications from this infection.
Now, through a substantial National Health and Medical Research grant, a collaborative partnership has been established between DHHS, the Doherty Institute, Barwon Health, Austin Health, CSIRO, Agriculture Victoria, the University of Melbourne and Mornington Peninsula Shire, to undertake an ambitious and innovative two-year project to better understand how Buruli ulcer is transmitted and determine effective ways to prevent infections and reduce infections.
Based on a series of epidemiological, field and laboratory-based studies, the Beating Buruli in Victoria project hopes to actively disrupt disease transmission for the first time and lead to the development of evidence-based policies and guidelines that can help stop the spread of Buruli ulcer around Victoria and even globally.
Beating Buruli: a case-control study
The Beating Buruli case control study is the first research component of the overall Beating Buruli in Victoria project that aims to investigate a range of risk and protective factors associated with Buruli ulcer.
It uses a case control study design which involves asking people with Buruli ulcer (cases) and people without it (the 'controls') to complete a short questionnaire. Field surveys will also be conducted at the properties of study participants where a range of environmental samples will be collected and then tested for Mycobacterium ulcerans at the laboratory.
Comparing questionnaire responses and field survey results from both cases and controls, the team hope to identify factors that increase a person's risk for getting Buruli ulcer and factors that can protect against getting the disease.
The study will run for a total of two years from September 2018.
Who is conducting the study?
The study is being jointly conducted by Barwon Health and the CSIRO with additional support being provided by the Department of Health and Human Services, Mornington Peninsula Shire Council, Deakin University, University of Melbourne and Agriculture Victoria.
Read more about the Beating Buruli: case control study.
Beating Buruli: the mosquito control study
Findings from a previous case-control study conducted in 2004 on the Bellarine Peninsula showed that getting bitten by mosquitoes, as well as gardening, were possible risk factors for getting Buruli ulcer, while wearing insect repellent protected against infection. Further research, including laboratory studies and mapping the distribution of Buruli ulcer lesions in case, has strengthened the evidence that mosquitoes might play a significant role in transmission.
These findings are the basis for the second major research focus of this project, the Beating Buruli mosquito control study which aims to investigate the effect of mosquito control on the transmission of Buruli ulcer.
Through the Beating Buruli mosquito control study, the research team will test the idea that a multifactorial mosquito control program will reduce Buruli ulcer in humans. It will use a cluster randomised control trial where small residential areas are identified and randomly selected to be either 'intervention' or 'control' areas.
Everybody living in the study areas will receive information on how to protect themselves from mosquito bites and the diseases mosquito bites might transmit - like Buruli ulcer. Some areas will also receive an intensive mosquito control program, which will involve mosquito surveillance, mosquito control activities and mosquito trapping. The exact mosquito control activities are being worked out in consultation with the local community and Mornington Peninsula Shire council.
The Beating Buruli mosquito control study will be conducted over two years, targeting specific areas along the Mornington Peninsula where human cases of Buruli ulcer occur.
Who is conducting the study?
The study is being jointly conducted by the Doherty Institute, the University of Melbourne and the Department of Health and Human Services, in collaboration with Austin Health, Mornington Peninsula Shire Council and Agriculture Victoria.
Read more about the Beating Buruli: mosquito control study.
Symptoms and transmission
What are the symptoms of Buruli ulcer?
Buruli ulcer usually progresses slowly over several weeks. Occasionally it can develop more rapidly. An ulcer may not be initially present. It can occur anywhere on the body but it is most common on exposed areas of the limbs, such as ankles, back of calf, around the knee, or forearms or around the elbow.
- Initially, a spot that looks like a mosquito or spider bite forms on the skin. This is usually painless or can be itchy. Some patients do notice pain initially however. Small skin spots and bites are common but a feature of Buruli ulcer is that it doesn't settle with short courses of standard antibiotics and worsens instead of healing naturally.
- The spot usually gets bigger over days or weeks and may form a crusty, non-healing scab.
- Over time, the scab turns into a nodule (lump) then an ulcer that continues to increase in size and is surrounded by a ring of red swelling.
- Sometimes an ulcer does not form, with the infection presenting as persistent localised pain and swelling (cellulitis), thickened or raised flat areas of red skin with pain and fever.
How long does it take for the symptoms of Buruli ulcer to appear?
It is estimated that in Victoria, the average time from exposure to the bacteria to the onset of first symptoms is about four and half months but can range from two to nine months. There is a peak in diagnoses in Victoria between June and November each year; however cases are diagnosed year round.
How is Buruli ulcer transmitted?
Buruli ulcer is an infection acquired from the environment. It is not yet known exactly how humans become infected with the bacteria, or where in the environment the bacteria prefer to live. The bacteria may enter through broken skin, and both mosquitoes and some water-dwelling insects have been implicated in the transmission pathway. Most cases report some form of skin trauma, including insect bites, prior to the development of the lesion. It is not thought to be spread person-to-person. The highest risk for infection is during the warmer months, but the disease can be acquired at any time of the year.
What is the treatment for Buruli ulcer?
Buruli ulcer can be treated with a course of special oral antibiotics. Surgery is sometimes used in combination with antibiotic therapy. Regular dressings are usually required. Complete healing usually takes between three and six months depending on the size of the ulcer.
As ulcers get bigger over time, early diagnosis and effective treatment are important to minimise tissue loss and reduce the time until the ulcer heals.
Read more disease information and advice on Buruli ulcer.
Who is at risk?
People of any age can get infected. People who live in or visit the affected areas of Victoria (see below) are considered at greatest risk. Buruli ulcer is rare outside these areas.
The highest risk is associated with the active transmission areas of Rye, Sorrento, Blairgowrie and Tootgarook on the Mornington Peninsula. There is a moderate risk associated with areas in the Bellarine Peninsula (Ocean Grove, Barwon Heads, Point Lonsdale, Queenscliff), Frankston and Seaford areas. There is a low but material risk associated with the rest of the Bellarine and Mornington Peninsula, the South Eastern Bayside suburbs and East Gippsland. Together, all these areas are considered the endemic parts of Victoria for Buruli ulcer transmission. Recent cases from Aireys Inlet on the Surf Coast and the Geelong suburb of Belmont suggest that these are emerging areas of local transmission. Two cases were identified in residents in Aireys Inlet and two in Belmont during 2019, with no known travel to an endemic area. The risk of transmission in these areas is considered low.
Map of affected areas in Victoria
Evidence to date suggests that mosquitoes play a role in the transmission of M. ulcerans. Exposures to contaminated soil or water following outdoor activities have also been identified as possible sources for transmission. Therefore, the best way to prevent infection is through the use of simple precautionary measures.
Suggestions to reduce the risk of infection include:
- Wear gardening gloves, long-sleeved shirts and trousers when gardening or working outdoors.
- Avoid insect bites by using suitable insect repellents and long clothing, especially during the warmer months.
- Protect cuts or abrasions with sticking plasters.
- Promptly wash and cover any scratches or cuts you receive while working outdoors.
See your doctor if you have a skin lesion and mention the possibility of Buruli Ulcer.
Advice for health professionals
Early diagnosis is critical to prevent skin and tissue loss - consider the diagnosis in patients with a persistent ulcer, nodule, papule, or oedema and cellulitis especially on exposed parts of the body.
Follow the guidance in the Chief Health Officer Advisory on diagnosis and testing, making sure to take a dedicated swab or fresh tissue sample reserved for polymerase chain reaction (PCR) testing for the infection.
People of any age can get infected, and symptoms can occur four weeks to nine months after exposure to any endemic area; however there are very different levels of risk associated with the parts of Victoria that are endemic.
Buruli ulcer is a routine notifiable condition and must be notified to the Department within five days of diagnosis.
Referral for treatment to doctors experienced in the management of this condition is recommended. The current mainstay of treatment is rifampicin-containing combination oral antibiotic therapy. Surgery may be used in combination with antibiotic therapy where indicated.
About the study
Beating Buruli: case control study
Beating Buruli: mosquito control study
For the Victorian public
Buruli ulcer: community information sheet
Possible new transmission areas for Buruli ulcer in Victoria
Disease information and advice: Buruli ulcer
Notifying Buruli ulcer cases
RACGP training module on Buruli (membership required to access)
Buruli ulcer in @ Professor Paul Johnson's website
Buruli @ Better Health Channel
Beat the Bite @ Better Health Channel