Buruli ulcer - Infectious dermatological disease caused by lesions of the skin one of the species of mycobacteria. Mainly prevalent in hot tropical countries, humid climate. Symptoms of this condition are ulcers with necrotic content at the bottom, arising mainly on the extensor surfaces of the skin of the knee and elbow joints. Diagnosis of Buruli ulcer is carried out by dermatological examination, study the history of the patient, bacteriological examination of discharge from the ulcer lesions. Treatment of the disease is done with antibiotics, but their efficacy may be insufficient for a full recovery. Also, use a topical treatment antiseptic solutions, in severe cases, surgical removal of lesions.
tuberculosis and leprosy), Mycobacterium ulcerans is the acid-resistant microorganism with a very slow development. Growth notable colonies when plated on nutrient medium takes 7-12 weeks. This pathogen Buruli ulcer is unable to parasitize within macrophages and other cells, like other mycobacteria, and unlike them are active exotoxin (mycolactone), which has a cytolytic effect (particularly with regard to the adipocytes - fat cells present in the subcutaneous adipose tissue). There are indications that the toxin produced by Mycobacterium ulcerans has immunosuppressive properties, which facilitates infection and considerably complicates the course of the disease when there are multiple ulcerative lesions.
Reservoirs of mycobacteria in the wild are not defined to date. It is assumed that it may be water from stagnant ponds, some plants and aquatic animals - especially exciter Buruli ulcer was found on wool koala and kangaroo in Australia. This uncertainty makes it difficult to epidemiologists to develop preventive and anti-epidemic measures in endemic regions. Unexplained at the moment as the explosive growth in the incidence of Buruli ulcer in the second half of the XX century, when the pathology of several small foci in Africa spread to a vast territory from Uganda to Australia - it is believed that this was a consequence of increased migration flows and trade between the countries.
Infection of the causative agent of Buruli ulcer occurs through the "entrance gate" - the skin as such may be abrasions, cuts, insect bites and other injuries. Especially dangerous deep injury, reaching the subcutaneous fat, as Mycobacterium ulcerans has an affinity specifically to lipid-rich tissues. Long-term study of Buruli ulcer have revealed the fact that the development of this disease often requires a previous weakening of the body due to various factors. These may act as a chronic lack of protein in the diet (starvation), hypovitaminosis, infestation (helminth infections), debilitating diseases (eg, malaria). This explains why Buruli ulcer is mainly prevalent in poor developing countries with low levels of health and social protection of the population.
lymphadenitis - lymph nodes were not enlarged and painless on palpation.
If left untreated, complications develop Buruli ulcer. Most often joined by secondary bacterial infection, usually purulent character. Symptoms of this complication may be the appearance of a pulsating pain skin ulceration area, putrid odor and the presence of pus. There lymphadenitis may rise in temperature. In the absence of such an ulcer complications Buruli around the primary tumor can be formed child elements - as a rule, they are somewhat smaller, but also to pass all stages of the development of infiltration to ulcers. Lesions are separated by strips of compacted skin, dermatologists called "skin bridges." In severe cases of Buruli ulcer combination of secondary infection and multiple lesions may threaten the patient's life and become a reason for amputation.
dermatology, microscopic and bacteriological examination of discharge from skin erosions. Dermatologic examination reveals painless infiltration (in the early stages of the disease) or ulcers, covered with dried black scab, preferential localization - the hand (wrist, forearm) and leg. Always (except joining a secondary infection) there is no response from the regional lymph nodes. On questioning the patient Buruli ulcer, in most cases it appears that the development of the disease was preceded by noticeable or deep skin injury. Often in the same way can be detected and the source of infection - the existence of such a disease in relatives or friends, developing symptoms after swimming in stagnant freshwater, etc.
For the microscopic examination of the material at the Buruli ulcer trying to take the edge of the hearth - it forms a niche where there is an accumulation of dead skin tissue. The most informative method of diagnosis is a painting of smear Ziehl-Nielsen - with Mycobacterium ulcerans turn red. Mycobacteria that are Buruli ulcer agents, are normally located in a smear singly, in pairs or in long chains. Sowing samples on nutrient media (Lowenstein-Jensen) and its storage at a temperature of 30-32 degrees in 7-12 weeks leads to the appearance of small colonies rozovatovogo color. Differentiation of Buruli ulcer agents from other mycobacteria produced by Mycobacterium ulcerans inability to to the splitting of urea and hydrogen peroxide, and resistance to traditional anti-TB drugs - p-aminosalicylic acid (PAS), isoniazid. In recent years, for the determination of the disease began to use the technique of polymerase chain reaction that allows you to identify the DNA of the pathogen - this method is considered the most accurate.
closing wounds or defects by skin plasty.
Prediction and prevention of Buruli ulcer
Forecast Buruli ulcer is usually uncertain, as the severity of disease symptoms depends on many factors -. Values "entry gate" resistance to infection, the patient's age, etc. With time begun treatment is sometimes seen fairly rapid ulcer healing with scarring, but most cases of skin ulceration persist for many weeks. In particularly severe cases (with multiple lesions of Buruli ulcer and the accession of secondary infection) may develop toxic shock, gangrene of the extremities, sepsis, which threatens the life of the patient. Methods of prevention of this disease is being developed, there have been attempts to use BCG vaccine in endemic areas. This gave a temporary immunity against Buruli ulcer, but its duration was only 4-6 months. Currently, WHO continues to search for an effective vaccine, as well as the study of Mycobacterium ulcerans to reduce the incidence of this disease.