Buruli Ulcer: A misunderstood mycobacterial disease

Martin Tako (inset) shows his scarred left leg which is healing after a buruli ulcer operation. His biggest complaint is that the leg still swells. Dr Dominic Drametu (R) says the disease is very common during the rainy season. photos by PAUL MENYA

What you need to know:

Buruli ulcer is caused by a germ that mainly affects the skin but which can also affect the bone. Left untreated, the disease leads to functional disability, loss of economic productivity, and social stigma.

May 2012 evokes sad memories for Martin Tako. It was the month when something pricked the lower limb of his left leg, resulting in buruli ulcer.

At the time, he did not know what was ailing him even when the affected spot got swollen and developed blisters which eventually turned into a wound.

The father of eight says, “I then sought medical attention. I first used local herbs and therapeutic cuts were done with no change.” He was referred to Adjumani Hospital. “I would feel pain right to my bones in the affected leg. My left leg would swell even after a short walk. The swelling would only reduce when I raised the leg.”

Moment of truth
On June 17, 2012, he was admitted to Adjumani Hospital where he was told he had buruli ulcer.

This diagnosis was then followed with surgery and then skin grafting was done. He was discharged on July 30, 2012. That gave him a new lease of life because the pain disappeared and he was able to wear closed shoes again.

Although he does not know what causes buruli ulcer, his advice to victims is to seek medical attention.
Tako says he did not react to drugs but he complains of the swelling of his left leg. “I can’t say I have completely healed because my left leg occasionally swells. I hope for complete recovery,” he says. As a result, Tako’s farming activities have retarded yet this is his only source of income.

He owns 11 acres of land, five in Pakele Sub-county and six in Adjumani Municipality where he used to grow ground nuts, rice, cassava and maize.

“I can’t do anything on my farm for fear of harming my leg. A stone or any other object could hit the leg and cause another wound,” Tako says.

Prevalence
According to the World Health Organisation (WHO), buruli ulcer is caused by infection with mycobacterium ulcerans, an organism which belongs to the family of bacteria that causes tuberculosis and leprosy.

It is a chronic debilitating skin and soft tissue infection that can lead to permanent disfigurement and disability.
Infection leads to destruction of skin and soft tissue with large ulcers usually on the legs or arms. Patients who are not treated early suffer long-term functional disability. Early diagnosis and treatment are the only ways to minimise morbidity and prevent disability.

Buruli ulcer has been reported in 33 countries in Africa, America, Asia and the Western Pacific. Most cases occur in tropical and subtropical regions except in Australia, China and Japan. Between 5,000 and 6,000 cases are reported annually from 15 of the 33 countries.

Most cases occur in rural communities in sub-Saharan Africa and nearly half of the people affected are children under 15. West Africa, Benin, Côte d’Ivoire and Ghana report most cases, with Côte d’Ivoire reporting almost half of the global cases.

According to statistics from Ministry of Health, the disease is the third most common mycobacterial infection after tuberculosis and leprosy.

It is also the most misunderstood of the three human mycobacterial diseases. The disease affects men and women equally.
About 75 per cent of those affected are children under 15 years of age and 90 per cent of the lesions are on the limbs; mostly lower limbs. There is little seasonal variation in the incidence of the disease.

Impact
The ministry adds that buruli ulcer imposes a serious economic burden on the affected household and on health systems that are involved in the diagnosis of the disease and treatment.

Although the disease was initially identified in Buruli (Nakasongola District), a recent survey found no cases there. They also add that the disease is prevalent in areas near rivers, swamps and wetlands. Some cases of the disease, however, were recorded in Adjumani and Moyo districts.

WHO observes that buruli ulcer often starts as a painless swelling (nodule). It can initially also present as a large painless area of induration (plaque) or a diffuse painless swelling of the legs, arms or face (oedema).

Local immunosuppressive properties of the mycolactone toxin enable the disease to progress with no pain and fever.

Without treatment or sometimes during antibiotics treatment, the nodule, plaque or oedema will ulcerate within four weeks with the classical, undermined borders. Occasionally, the bone is affected causing gross deformities.

The Adjumani Hospital Medical Superintendent, Dr Dominic Drametu, says he has on average been treating 2 – 3 people per month.
According to Drametu, cases of buruli ulcer are common during the rainy season between the months of April and October. The disease is so prevalent around the shores of River Nile in Adjumani District and also South Sudan.

“One of the features of a nodule is that it is usually painless, unless there is a secondary bacterial infection. Otherwise, people don’t come for treatment. They usually dress the wound themselves along with herbs for a long time. It is only when the wound fails to heal that they come to hospital,” Drametu says.

A combination of rifampicin and streptomycin/amikacin for eight weeks as a first line treatment for all forms of active disease is being used. Nodules and uncomplicated cases can be treated without hospitalisation. For complicated cases, the only treatment available is surgery to remove the lesion, followed by a skin graft if necessary.

Health workers in Adjumani and Moyo hospitals have been trained in diagnosis and management, including skin grafting. In addition, village health teams were trained in case detection and referral to health facilities.

WHO notes that the exact mode of transmission of mycobacterium ulcerans is still unknown. However, it appears that different modes of transmission occur in different geographic areas and epidemiological settings.

There may be some role for living agents as reservoirs and as vectors of mycobacterium ulcerans, in particular aquatic insects, adult mosquitoes or other biting arthropods.

The health ministry on its part admits that the major gap in the management of the disease is the absence of a well-established national control programme.

Currently, there is limited data available on buruli ulcer. Routine surveillance needs to improve for early detection.