Buruli ulcer in Australia (Buruli ulcer, Bairnsdale ulcer, Daintree ulcer, Mossman ulcer, Flesh Eating Bug, Mycobacterium ulcerans infection) (last update April 12th 2015).
What is Buruli ulcer? Buruli ulcer, Bairnsdale ulcer, Mossman ulcer and Daintree ulcer are all local names given to the same disease that is caused by Mycobacterium ulcerans--a mycobacterium related to those that cause TB and leprosy. “Buruli ulcer” or just “Buruli” is the official name preferred by WHO. Mycobacterium ulcerans produces a toxin that damages skin and subcutaneous fat tissue. The infection occurs in humans in more than 32 countries.
Which areas in Australia and New Zealand are endemic? Buruli is a geographically restricted infection (GRI). The means it occurs following contact with specific “endemic” areas. In Australia endemic areas include coastal Victoria, north Queensland near Mossman, the Capricorn Coast of Queensland near Yeppoon and the tropical north coast near Darwin (see map). So far no cases have been linked to Tasmania, South Australia, southern Western Australia or the ACT. Buruli does not occur in New Zealand.
How do you get infected? Travel to an endemic area even for just a few hours is enough to pick up the infection. The median incubation period is 4.5 months with a range of 3 weeks to almost a year. Hence visitors to endemic areas may notice something wrong when they have returned home. In Victoria (southeastern Australia) there is evidence that mosquitoes transmit the infection, but other biting arthropods may be involved, or there may be more than one mode of transmission. Mycobacterium ulcerans does not appear to spread from person to person.
How common? In 2013-14 there were 163 confirmed cases of Buruli ulcer in Australia, giving an annual national incidence of < 1 per 100,000. However in endemic regions this can be up to 100 times higher. Overseas there have been thousands of cases of Buruli, predominantly in rural areas in west and central Africa.
Map: Confirmed cases Australia since 1939 (Courtesy A/Prof John Hayman: circle radii estimates only).
Map: Confirmed cases Australia, 2013-14 (WHO Meeting on Buruli ulcer, March 2015, Geneva). Circle radii are to scale.
Graph: Confirmed cases in Australia by year and state, 2004-2014 (WHO Meeting on Buruli ulcer, March 2015, Geneva).
Graph: Confirmed cases in Victoria by year (WHO Meeting on Buruli ulcer, March 2015, Geneva). [Acknowledgement: A/Prof John Hayman, cases prior to 1993].
Figures: Overlaid Google Earth image, likely place of infection, confirmed cases Victoria, 2013-14 (WHO Meeting on Buruli ulcer, March 2015, Geneva).
When to suspect Buruli ulcer? The infection usually starts as a small spot (lesion) on or under the skin that enlarges over days to weeks. Lesions are typically solitary and mostly occur on the lower leg or arm. However, they can be anywhere. A nodule (mobile lump) beneath the skin may be the first sign. Sometimes an insect bite or episode of trauma is recalled. Lesions are usually painless, and fever or other symptoms are usually absent. Eventually the spot breaks down at the centre and a slowly enlarging undermined ulcer appears but appearances can be variable and Buruli ulcer is difficult to diagnose if your doctor is not familiar with the condition. Some patients present with a plaque rather than an ulcer or develop swelling of the whole limb or whole abdominal wall, without there initially being an identifiable nodule, plaque or ulcer. The disease progresses over days to weeks (not hours). Most severe cases of Buruli ulcer result from delayed diagnosis.
IMPORTANT NOTE: Some patients have said that the term “Buruli ulcer” is misleading, as an ulcer is not always present leading to delayed diagnosis. “Buruli” may be a better descriptor than “Buruli ulcer” to remind clinicians of these variations in presentation.
How is Buruli ulcer treated? Buruli ulcer is slow moving and always curable although it can be quite destructive. A 2-month course of antibiotics appears able to kill the bacteria. Lesions may paradoxically worsen during antibiotic treatment. Surgery and antibiotics are often used in combination to achieve optimal outcomes. Recently updated treatment guidelines for Australian clinicians are available here.
Pictures (confirmed cases from Australia)
Ear: 2 year-old child, coastal Victoria, Australia [Photo Clinical Photography, Royal Children’s Hospital, Melbourne]
Leg, adult female, early diagnosis. [Photo: Dr. Paul Flood, Phillip Island].
Elbow ulcer, 9 year-old girl, delayed diagnosis. [Photo: Clinical Photography, Royal Children’s Hospital, Melbourne]
Ankle - 23 year-old woman, plaque lesion (no ulcer apparent when diagnosed by biopsy)
[Photo: Dr. Paul Johnson, Austin Hospital, Melbourne]
Lower back ulcer - 12 year-old boy. The markings show the area of palpable induration (swelling) that is more extensive than the ulcer itself.
[Photo: Mr. John Buntine, Melbourne]
Notes on diagnosis for clinicians
Rapid accurate diagnosis can be made by PCR directly from swab.
Specify “Mycobacterium ulcerans” or “Bairnsdale/Buruli ulcer” and “PCR” clearly in clinical notes on the request slip.
Details--DIAGNOSIS FROM A SWAB...PCR can be performed straight from the swab
Microscopy: Acid-fast bacilli (Mycobacterium ulcerans) in a smear taken directly from a swab of an ulcer. The bacteria can be clearly seen as red clumps on a blue background.
If not ulcerated, or an acute oedematous presentation is being considered perform an incisional biopsy, punch biopsy, fine needle aspirate or excisional biopsy, and remember to ask for Mycobacterium ulcerans PCR microscopy and culture. Histology is also very helpful.
Links to guidelines, articles and useful sites
Department of Health (Victorian State Government)
Publications about Buruli ulcer in Victoria, Australia
Buruli ulcer in Far North Queensland
Buruli ulcer in central Queensland
World Health Organization
Public Library of Science (Journal)
Medical Journal of Australia
Proceedings of the National Academy of Science (Journal)
Stop Buruli (NGO)
Genome Research (Journal)
About this website
This is a privately funded website provided as a community service. The information is intended as a guide only and should not replace personalised medical advice from your doctor. Latest update April 2015.If you have questions/concerns about the contents or accuracy of this website please contact me by email: Paul.JohnsonATaustin.org.au (this email address is disguised to avoid automated SPAM; it can be recreated by replacing AT with the @ symbol). Professor Paul Johnson (Austin Health Link)
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