Buruli ulcer

Diagnosis

Clinical

In general, with trained health professionals in endemic areas, clinical diagnosis is reliable.

Depending on the patient’s age, the patient’s geographical area, the location of lesions, and the extent of pain experienced, other conditions should be excluded from the diagnosis. These other conditions include tropical phagedenic ulcers, chronic lower leg ulcers due to arterial and venous insufficiency (often in the older and elderly populations), diabetic ulcers, cutaneous leishmaniasis, extensive ulcerative yaws and ulcers caused by Haemophilus ducreyi.

Early nodular lesions are occasionally confused with boils, lipomas, ganglions, lymph node tuberculosis, onchocerciasis nodules or other subcutaneous infections such as fungal infection.

In Australia, papular lesions may initially be confused with an insect bite.

Cellulitis may look like oedema caused by M. ulcerans infection but in the case of cellulitis, the lesions are painful and the patient is ill and febrile.

HIV infection is not a risk factor, but in co-endemic countries HIV infection complicates the management of the patient. The weakened immune system makes the clinical progression of Buruli ulcer more aggressive, and as a result the treatment outcomes are poor.

Laboratory

Four standard laboratory methods can be used to confirm Buruli ulcer; IS2404 polymerase chain reaction (PCR), direct microscopy, histopathology and culture. PCR is the most commonly used method. WHO has recently published a manual on these 4 methods to guide laboratory scientists and health workers.