Buruli Ulcer: Causes, Symptoms & Treatment

Buruli ulcer, also known as tropical ulcer, is a tropical disease that occurs mainly in Africa, South Asia, and Latin America. In the disease, ulcers form in various parts of the body. However, the legs are particularly frequently affected by these ulcerations. The exact mechanism of transmission is as yet unclear.

What is Buruli ulcer?

Buruli ulcer is a tropical disease caused by the bacterium Mycobacterium ulcerans. The bacterium causes a chronic skin infection to develop with extensive ulcers. These not infrequently lead to disfigurement and subsequent stigmatization of those affected. The disease is estimated to be prevalent in 30 African countries, but cases have also been observed in New Guinea or Australia. Worldwide, about 20,000 people become infected with the bacterium each year. Buruli ulcer affects children under the age of 15 in about 70 percent of all cases. The World Health Organization (WHO) counts the disease among the neglected diseases. The ulcers are only diagnosed too late and can then often only be removed in a complicated operation. It is not uncommon for patients to be maimed by the ulcers even before they are diagnosed. For this reason, WHO established the Global Buruli Ulcer Initiative in 1998, which aims to raise awareness of the disease.

Causes

The causative agent of Buruli ulcer is Mycobacterium ulcerans, as mentioned earlier. It is a gram-positive, acid-fast, and slow-growing rod bacterium. Mycobacterium ulverans is distributed primarily in humid tropical and subtropical regions. Stagnant waters are probably the habitat of the bacterium. Therefore, people living near lakes or in swampy areas are particularly frequently affected. The mechanism of transmission is not yet fully understood. Transmission via mosquitoes is conceivable. In Africa, the pathogen has been detected in some mosquito species. However, other small aquatic insects or a smear film on the water may also be sources of infection. However, it is considered virtually certain that the disease does not spread from person to person. Unlike tuberculosis, which is also caused by a Mycobacterium, HIV-positive people do not appear to be strikingly susceptible to Buruli ulcers.

Symptoms, complaints, and signs

Mycobacterium ulverans produces the cell toxin mycolactone. This damages the tissue and simultaneously weakens the immune system. Buruli ulcer usually begins with painless swelling, nodules, or induration. There is no fever. The infection spreads on the surface of the skin and also eats into deeper and deeper layers of the skin. Mycobacterium ulverans produces the cytotoxin mycolactone. The pathogen destroys more and more tissue and large ulcers develop. Even the bones can be literally eaten away by the bacterium. Pain is rare despite the ulcers, and there is no fever later in the course of the disease due to the immunosuppressive effect of the pathogen toxin. The disease process can last for months to years.

Diagnosis and course

Buruli ulcer sufferers go to the doctor very late or not at all. There are several reasons for this. First, the first symptoms are rather unspecific and are sometimes not noticed at all. Then, even the larger ulcers are usually not associated with pain. As a result, the condition is often not taken seriously until it is usually too late for treatment. However, even when patients suspect they are suffering from the tropical disease, they do not go to the doctor. Infection with Burili is a stigma, especially in Africa, and those affected suffer from ostracism. For this reason, the ulcers are often hidden under long clothing. Decisive clues for diagnosis are provided by the typical symptoms themselves. In endemic areas, an initial diagnosis can be made directly in the field using a microbiological method, the Ziehl-Neelsen staining test. The required tissue material is obtained from wound swabs. A newer and more specific method for pathogen detection is PCR (polymerase chain reaction). Another method of diagnosis is the cultivation of the bacterium in a culture. For a result to be found here, the infection must have occurred at least six weeks before the test is performed. A timely and early diagnosis is therefore not possible.The most specific determination can be made by histopathological examination of punch biopsied tissue. However, in most endemic areas, the material needed for this examination is not available.

When should you see a doctor?

This disease definitely needs to be evaluated and treated by a physician. There is no self-healing. As a rule, a doctor should be consulted when the affected person suffers from a significantly weakened immune system. Swelling appears on the skin, but it is not associated with pain. Fever may also indicate the disease. If various skin complaints suddenly occur, a doctor must be consulted in any case. Ulcers must also be examined to avoid further complications. In many cases, unfortunately, the complaints are very unspecific, so that no doctor is consulted. However, if the complaints persist for a long time, medical treatment is necessary. The diagnosis of the disease is usually made by a general practitioner or by a dermatologist. However, for further treatment, patients depend on surgical removal of the affected skin areas. To prevent scars, a doctor should be consulted at an early stage for this reason.

Complications

As a rule, Buruli ulcer causes severe ulcers that can appear on different areas of the body. Most often, these spread to the patient’s legs and can lead to serious complications if left untreated. There is usually swelling, which is initially painless. As Buruli ulcer progresses, pain and nodules appear on the skin. There is often also induration on the legs. In the worst case, the pathogen penetrates directly into the lower layers of the skin and eats its way to the bones. This can also cause severe damage to the bones. Often, those affected also suffer from fever. The disease itself requires a relatively long treatment of about half a year. In most cases, the treatment is carried out with the help of a surgical intervention, in which all the affected tissue is removed. Amputation may also be necessary, after which the patient suffers from severe limitations in everyday life. Mostly, the affected person has to take antibiotics for a longer period of time after the operation. Except for the scars of the surgery, there are usually no other complications if the treatment is performed early.

Treatment and therapy

Because Buruli ulcer is often diagnosed very late, the treatment of choice is usually surgical removal of the infected tissue. However, this method results in recurrences in 30 percent of cases because bacteria have often already spread even in healthy-appearing tissue. Depending on the size of the ulcerations, skin and tissue grafts may have to be used. If the disease is already very advanced, amputation of the affected limb is often the only option. In addition to surgical removal of the pathogen and infected sites, the World Health Organization recommends eight weeks of therapy with specific antibiotics. This can reduce the recurrence rate to two percent. In many cases, however, functional limitations and large scars remain. Rarely, the disease also heals without treatment.

Outlook and prognosis

In many cases, the prognosis of Buruli ulcer is unsatisfactory. In principle, the disease can be cured, but this requires a very experienced medical team because the treatment is very complicated and lengthy. Only a combination of intensive wound care, antibiotic treatment and surgical intervention can prevent severe consequences. Although the disease is rarely fatal, it can cause loss of limbs and severe joint stiffness, eventually leading to limited mobility. Without treatment, the responsible bacterium, Mycobacterium ulcerans, destroys subcutaneous tissue. Progressive ulcers penetrate to the bones and muscles and destroy them. Since the immune system‘s defense cells are also attacked, the bacterium can survive in the body and further destroy the affected tissue. The ulcers come to a halt only after many months or even years. Uncontrolled scarring of entire parts of the body forms, which can lead, among other things, to deformities of the limbs and other parts of the body or even to the loss of the eyes.Furthermore, the risk of secondary infections increases, which in severe cases can be fatal. Often, the only option is to surgically remove affected tissue to prevent the disease from spreading. Amputation of limbs is also sometimes necessary. Shrinkage and stiffening of joints occur as serious complications of ulcers, which must later be treated by plastic surgery.

Prevention

Currently, Buruli ulcer disease cannot be prevented. According to the WHO, the Bacillus Calmette-Guérin (BCG) vaccine, which is actually used for tuberculosis prophylaxis, offers brief protection against Mycobacterium ulcerans. However, longer-term protection could only be achieved with a special vaccine against Buruli ulcer. Research on this vaccine is currently underway.

Follow-up

Buruli ulcer always requires comprehensive follow-up after drug and surgical treatment. After surgical treatment, the affected skin area must be protected from pathogens and other external influences. The bandage can be removed after a few days in consultation with the physician. The physician will check a few days after the surgery to see if the wound has healed as expected. If no complications are found, no further follow-up is normally required. However, if the wound does not heal as expected, the doctor will need to perform further tests. Often, a change in medication is necessary or surgery must be performed again because the infection has not completely subsided. In case of a complicated course, further control examinations are necessary. The patient must visit the dermatologist once or twice a month so that the necessary examinations can be performed. In addition, other physicians must be involved, since a repeated occurrence or a complicated course of Buruli ulcer indicates a serious underlying condition. Follow-up care also includes good wound care. The patient should contact the physician after completion of treatment so that the necessary measures can be initiated.

What you can do yourself

Buruli ulcer is often diagnosed late and must always be removed by chemotherapy or surgery. The surgical or chemotherapeutic procedure puts a great strain on the affected organism, which is why those affected must pay particular attention to good preparation and aftercare. To prepare for the operation, first of all the doctor’s instructions must be followed. In most cases, an adapted diet is suggested; especially shortly before the operation, no stimulants or overly fatty foods should be consumed. Patients who regularly take medication should inform the doctor. In most cases, the medications do not need to be adjusted, but in the case of a heart condition, at least a check-up is indicated. After surgery, rest and bed rest are indicated. The affected person should also make sure that the wound is well cared for. Otherwise, pathogens can enter the wound and cause serious complications. If any unusual symptoms develop, the doctor must be informed immediately. In general, good monitoring by the physician is indicated for Buruli ulcer, as the tropical disease may continue to occur for weeks or months after the diseased tissue has been removed.