Buruli Ulcer

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Key facts

- Buruli ulcer is a chronic disease caused by Mycobacterium ulcerans, a bacterium that produces a toxin leading to skin damage.

- It is endemic in at least 33 countries in tropical, subtropical, and temperate regions, primarily in Africa, the Americas, Asia, and the Western Pacific.

- Buruli ulcer can lead to permanent disfigurement and long-term disability, often affecting the skin and occasionally bones.

- The mode of transmission is still unknown, and no primary prevention measures exist.

Overview

Buruli ulcer is caused by Mycobacterium ulcerans, which produces a toxin responsible for tissue destruction. The disease, if untreated, can cause significant disability. It belongs to the same family of bacteria responsible for tuberculosis and leprosy, but the way it spreads from the environment to humans remains unclear.

Scope of the Problem

Buruli ulcer has been reported in 33 countries, mostly in tropical and subtropical climates, with 14 regularly reporting data to WHO. The exact transmission method is still unknown.

Signs and Symptoms

- It begins as a painless swelling, nodule, plaque, or swelling of limbs or face, which can eventually ulcerate if untreated.

- The disease progresses with little to no pain or fever.

- The severity is classified into three categories based on lesion size and involvement:

- Category I: Small lesions (<5 cm).

- Category II: Plaque or oedema between 5-15 cm.

- Category III: Large lesions (>15 cm), including bone involvement.

Diagnosis

- Diagnosis is usually made clinically by experienced health professionals in endemic areas.

- Laboratory confirmation can be done with PCR, direct microscopy, histopathology, or culture.

- Differential diagnoses include tropical ulcers, leprosy, diabetic ulcers, and leishmaniasis, among others.

Treatment

- Treatment consists of a combination of antibiotics, typically rifampicin (10 mg/kg daily) and clarithromycin (7.5 mg/kg twice daily), with a typical duration of 8 weeks.

- Other treatments include wound management, debridement, skin grafting, and physiotherapy.

- Research is ongoing to shorten the treatment duration.

Prevention and Control

- No primary prevention exists, but Bacillus Calmette–Guérin (BCG) vaccination provides limited protection.

- The focus is on early detection and treatment with antibiotics to prevent severe disability.

- Community health workers play a crucial role in case detection.

WHO's Response

WHO provides technical guidance, coordinates control efforts, and supports research to understand transmission, improve diagnostic methods, and establish optimal treatments. They also advocate for integrating Buruli ulcer control within broader skin NTD (neglected tropical diseases) initiatives. WHO’s Skin App assists health workers in diagnosing skin-related NTDs, including Buruli ulcer.