The Buruli Mysteries
Unanswered Questions Surround a Growing Epidemic 

Buruli ulcer, which is sweeping across Africa now, is a cruel disease which silently eats through skin, muscle and bone and, in its worst form, leaves victims with disfiguring and debilitating craters. But the list of questions surrounding Buruli is daunting. No one is sure where the bacterium lives in the environment. It's also a mystery how it enters the body, although it is clear the bacterium is unable to do so by itself. 

No one knows why the tropical disease can spontaneously erupt in temperate climates like Australia or any of 25 other countries where Buruli has been spotted. It's also unclear if everyone infected with Buruli develops the disease and, if not, why some are able to fight it off. There is no diagnostic tool, other than straight visual observation. Incubation periods are a matter of guesswork. And for unknown reasons, drugs frequently fail.

- More than 50% of the cases are in children under 15 years of age, and yet we know more about most veterinary diseases than we do about Buruli ulcer," says Kingsley Asiedu who is responsible for the World Health Organization's Buruli Ulcer Program. "At the dawn of the 21st century, when scientists have decoded the entire human genome, it is surprising to have so little knowledge about such a debilitating disease."

Finding answers to the Buruli mysteries is becoming urgent. Buruli roams unchecked in more than two dozen countries. In West Africa, thousands of cases are being reported every year. These mysteries form the backdrop to a meeting of most of the world's Buruli experts as they gather next week at a WHO meeting in Geneva, Switzerland, 11-14 March 2002 to sort through the latest research.

Somehow, the bacteria pass through the protective barriers of the skin. And, in a way that is not well understood, they then disable the alarms of the immune system. Once under the skin, the bacteria release a corrosive toxin. As Buruli does its work, the normal warnings of fever and pain, which are common with other infections, rarely appear. 

Without these alarms to suggest a problem or an immune response to keep it in check, Buruli can eat its way through flesh for weeks or even months. Eventually, a crater, known as an ulcer, appears in the surface of the skin. A small ulcer becomes larger. So it grows until, for whatever reason, it stops. Drugs are generally ineffective in advanced cases, but can stop the disease if given early.

Some features of Buruli are known or strongly suspected. Much has been discovered by the work of a small band of dedicated Buruli experts over the last 30 years. But because of poor funding and low visibility, compared to diseases like AIDS and malaria, there are vast areas involving spread, cause and treatment where little is certain.

An Australian physician discovered that Buruli ulcer is caused by Mycobacterium ulcerans, a member of a family that includes the bacteria which cause tuberculosis and leprosy. But inside the body, the Buruli bacteria do not dwell inside cells which is unusual but rather live in the material surrounding cells.

Some scientists strongly suspect a link between changes in the environment and the spread of the disease. Support for this belief comes from studies on a well-documented outbreak on an island resort in Australia in 1997. There, 29 cases appeared in a region that had never seen Buruli. Says the physician who documented the outbreak, Paul Johnson: "This thing is environmental. The question we need to ask is 'What are we doing to the environment to make it more and more common.'"

For victims with advanced disease, the only therapy is to cut away the diseased tissue. Sometimes this involves amputation. Surgery for advanced Buruli always means a lengthy hospitalisation and life-long disability. Patients are kept in hospitals for an average of three months after an operation, but in some cases rehabilitation can take as long as 18 months. Thus Buruli is inflicting not only a harsh physical toll but a brutal economic one as well. 

In Ghana, the average cost of Buruli treatment is US$ 780. This is an extraordinary amount in a country where the majority of the population lives on less than a dollar a day. Even so, surgery does not always provide a cure. In 30% of the surgery patients, Buruli returns.

With information lacking in so many key areas, WHO's strategy has been to focus on early intervention. Identification and treatment of small ulcers and nodules can be done at the local level with relatively little cost. WHO has launched an effort to raise awareness of the disease and to encourage those who even suspect they have it to seek medical treatment quickly. The goal is to prevent the widespread progression and the disabilities caused by the disease.

Early indications are that some of the mysteries will fall away at this year's meeting on Buruli.

Sources: Based on WHO

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