Buruli ulcer

About Buruli ulcer#

Buruli ulcer (also known as Bairnsdale ulcer) is a skin disease caused by the bacterium Mycobacterium ulcerans. The toxins made by the bacteria destroy skin cells and small blood vessels. These bacteria are found in the environment and have, for example, been detected in mosquitoes.

It is not known exactly how humans become infected. In some affected regions there is increasing evidence that mosquitoes and possums have a role in transmitting the infection.

Buruli ulcer is not known to spread from person to person. However, household members of someone with the disease should watch for any non-healing skin lesions and seek early medical assessment, as they may have been exposed to the same environmental source.

Symptoms of Buruli ulcer#

The progression of symptoms can include the following:

• A spot that looks like a mosquito or spider bite forms on the skin, most commonly on the limbs.
• The spot grows bigger over days or weeks.
• It may form a crusty, non-healing scab.
• The scab then breaks down into an ulcer.
• The ulcer continues to enlarge.

Unlike many other ulcers, a Buruli ulcer is usually painless, and there is generally no fever or other signs of infection. The infection can also appear as raised lumps, or as thickened or raised flat areas of skin. Sometimes it presents with no ulceration but with localized pain, swelling and fever.

Where Buruli ulcer occurs#

Buruli ulcer has been reported in 33 countries around the world. Affected areas include rural West Africa, Central Africa, New Guinea, Latin America and tropical regions of Asia.

Within affected countries, the infection tends to be concentrated in defined endemic areas, where it is constantly present in the community. The level of risk can vary from area to area, and the disease has been observed to spread geographically over time rather than remaining restricted to specific locations. Even in endemic areas, however, the overall risk of infection is considered low.

Incubation period#

The average incubation period is estimated to be between 4 and 5 months, with a range of roughly 1 to 9 months.

Diagnosis of Buruli ulcer#

Buruli ulcer is usually diagnosed by a doctor, based on:

• your medical history
• your travel history, if you have been to an area associated with Buruli ulcer
• a physical examination, to identify a slowly enlarging, painless ulcer
• swabs or a biopsy taken from the ulcer, which are tested in a laboratory

Early recognition and diagnosis is important to prevent skin and tissue loss. See your doctor if you have a non-healing skin lesion, and ask them to consider testing for Buruli ulcer.

Treatment for Buruli ulcer#

Most Buruli ulcers require treatment with a 6 to 8 week course of specific oral antibiotics. Surgery is sometimes used in combination with antibiotic therapy to promote healing. People with Buruli ulcer are typically cared for by infectious diseases specialists who have experience managing the condition. Because untreated ulcers tend to get bigger over time, prompt treatment can minimize skin loss.

Prevention of Buruli ulcer#

Because mosquitoes may play a role in transmission, reducing mosquito breeding and avoiding bites are sensible precautions.

Reduce mosquito breeding sites around the home by removing places where water can pool, such as:

• pot plant containers
• buckets
• open tins or cans
• discarded tyres
• other untreated freshwater pools

Other suggestions to reduce the risk of infection include:

• mosquito-proof your home by securing insect screens
• avoid mosquito-prone areas and biting times, especially at dusk and dawn
• use a personal insect repellent containing diethyltoluamide (DEET) or picaridin on exposed skin
• cover up by wearing long, loose-fitting, light-colored clothing
• wear gardening gloves, a long-sleeved shirt and trousers when gardening or working outdoors
• promptly wash any new scratches or cuts with soap, then apply a topical antiseptic and a dressing
• wash any exposed skin that has been in contact with soil or water after outdoor activities
• protect cuts and abrasions with a dressing

It is important to remember that the risk of infection is low, even in areas where the infection is endemic. See your doctor if you have a slow-healing skin lesion.

Key points#

• Buruli ulcer is a skin disease caused by Mycobacterium ulcerans, found in the environment and detected in mosquitoes.
• It usually begins as a painless, slowly enlarging spot or ulcer, most often on the limbs.
• It occurs in defined endemic areas within affected countries, but the overall risk of infection is low.
• Early recognition and diagnosis is important to prevent skin and tissue loss.
• Most Buruli ulcers require a 6 to 8 week course of specific oral antibiotics, and prompt treatment minimizes skin loss.

Where to get help#