Buruli ulcer
The Buruli ulcer ( ulcer tropicum ) is a common infectious disease in the tropics of the skin and soft tissue with the formation of extensive ulcers in part. Pathogen is the atypical mycobacterium ( MOTT ) Mycobacterium ulcerans, which is related to the causative agents of tuberculosis and leprosy.
Epidemiology
Spread the disease is present in many countries in Western, Central and East Africa, but also occurs in South Asia, Latin America and Australia. Often, the rural population is affected in the vicinity of water or marsh lands. For example, the prevalence was in several rural areas of the Democratic Republic of Congo from 0 to 27.5 per 1000th
The transmission mechanisms are not fully understood. Seems possible transmission by certain types of mosquitoes.
Clinic
In most cases, the affected limb, in children ulceration may appear anywhere. From a papelartigen to nodular skin swelling out the ulcer, which can take considerable extent developed. Is disastrous that the lesion is painless and is therefore often very late by a doctor. After months or years they occasionally heals by itself, but it can also lead to severe mutilations, scarred contractures or lymphedema.
Diagnosis and treatment
In endemic areas, the diagnosis is usually made clinically and supported by means microscopy of wound swabs or fine needle aspirates for acid-fast bacilli by Ziehl- Neelsen as a first-line test in the field. Histopathological examination of excised tissues or 3 mm punch biopsies represents a highly sensitive and specific method, but in endemic areas is usually not available. The laboratory diagnostic detection methods with the highest sensitivity and specificity represents the PCR of repetitive insertion sequence IS2404 of M. ulcerans genome, and is available as conventional PCR or real-time PCR only in national reference laboratories. The cultural cultivation of the bacterium is characterized by a low sensitivity ( 40-70%) and a long incubation period of at least 6 weeks; Thus, this method is unsuitable for the timely diagnosis and initiation of therapy, however, is currently the only way to Viabilitätsnachweis the pathogen is, which is particularly necessary for treatment failures and recurrences for further treatment decisions.
The treatment was carried out until 2004 largely by surgical excision, with recurrence rates were up to 30 % have been reported since the mycobacteria penetrate far into the macroscopically healthy appearing tissue. A purely surgically curative therapy is promising mainly in pre - ulcerative forms of the disease. Since 2004, the WHO recommends a standardized antimycobacterial therapy with rifampicin po and streptomycin i.m. for 8 weeks, which is currently regarded as high efficiency. Since the introduction of this treatment regimen relapse rates are reported by less than 2%. Antibiotic resistance have only been reported in monotherapy with rifampicin from Ghana and currently represent yet not a limiting factor for successful chemotherapy dar. First clinical studies on the use of a purely oral regimen with rifampicin and clarithromycin showed promising results primarily in early diagnosed disease cases.
Consistent heating the affected area to temperatures of 40 ° C inactivates the bacteria and is currently being field tested. In a first study, six Buruli patients were given several weeks associations with corresponding packages launched. All ulcers healed, relapses were observed even 18 months after completion of treatment. Now the method are tested on a larger number of patients on the function and mechanisms are being investigated in detail. As recently noted scientists observed curative effect of certain illite ( clay minerals ) could be due to antibacterial chemical processes and thus enable future cost preparations.