El Sheikh Mahgoub

Mycetoma: a unique neglected tropical disease

Mycetoma can be caused by bacteria (actinomycetoma) or fungi (eumycetoma) and typically affects poor communities in remote areas. It is an infection of subcutaneous tissues resulting in mass and sinus formation and a discharge that contains grains. The lesion is usually on the foot but all parts of the body can be affected. The causative microorganisms probably enter the body by a thorn prick or other lesions of the skin. Mycetoma has a worldwide distribution but is restricted to specific climate zones. Microbiological diagnosis and characterisation of the exact organism causing mycetoma is difficult; no reliable serological test exists but molecular techniques to identify relevant antigens have shown promise. Actinomycetoma is treated with courses of antibiotics, which usually include co-trimoxazole and amikacin. Eumycetoma has no acceptable treatment at present; antifungals such as ketoconazole and itraconazole have been used but are unable to eradicate the fungus, need to be given for long periods, and are expensive. Amputations and recurrences in patients with eumycetoma are common.

Mycetomas caused by Curvularia lunata, Madurella grisea, Aspergillus nidulans and Nocardia brasiliensis in Sudan

Four cases of mycetoma are described from the Sudan. The first is an authentic case due to Curvularia lunata. The others were due to Madurella grisea, Aspergillus nidulans and Nocardia brasiliensis.

Merits and Pitfalls of Currently Used Diagnostic Tools in Mycetoma

Treatment of mycetoma depends on the causative organism and since many organisms, both actinomycetes (actinomycetoma) and fungi (eumycetoma), are capable of producing mycetoma, an accurate diagnosis is crucial. Currently, multiple diagnostic tools are used to determine the extent of infections and to identify the causative agents of mycetoma. These include various imaging, cytological, histopathological, serological, and culture techniques; phenotypic characterisation; and molecular diagnostics. In this review, we summarize these techniques and identify their merits and pitfalls in the identification of the causative agents of mycetoma and the extent of the disease. We also emphasize the fact that there is no ideal diagnostic tool available to identify the causative agents and that future research should focus on the development of new and reliable diagnostic tools.

Mycoses of the Sudan.

Mycoses in the Sudan are still significant and, as well as mycetoma, there are a number of fungal diseases: paranasal aspergillus granuloma, which came into eminence in 1966; actinomycosis; subcutaneous phycomycosis; systemic phycomycosis; post-operative opportunistic infection of the eye with Trichosporon cutaneum and rhinosporidiosis. Mycetoma and paranasal aspergillus granuloma are discussed in detail.

A new model for management of mycetoma in the Sudan.

Patients with mycetoma usually present late with advanced disease, which is attributed to lack of medical and health facilities in endemic areas, poor health education and low socio-economic status. With this background, an integrated patient management model at the village level was designed to address the various problems associated with mycetoma. The model was launched in an endemic village in the Sudan, between 2010 and 2013. This model is described in a prospective, descriptive, community-based study, aimed to collect epidemiological, ecological, and clinical data and to assess knowledge, attitude and practice (KAP) in order to design effective and efficient management measures. In this study, the prevalence of mycetoma was 14.5 per 1,000 inhabitants. The patients were farmers, housewives and children of low socio-economic status, and no obvious risk group was detected. All had surgery performed in a mobile surgical unit in the village which encouraged patients to present early with small early lesion leading to a good clinical outcome. The close contact with the Acacia tree thorns, animals and animal dung, walking bare footed and practising poor hygiene may all have contributed to the development of mycetoma in the village. Knowledge of mycetoma was poor in 96.3% of the study population, 70% had appropriate attitudes and beliefs towards interaction with mycetoma patients and treatment methods, and 49% used satisfactory or good practices in the management of mycetoma. Knowledge and practices on mycetoma were found to be significantly associated with age. Based on the KAP and epidemiological data, several health education sessions were conducted in the village for different target groups. The integrated management approach adopted in this study is unique and appeared successful and seems suitable as an immediate intervention. While for the longer term, establishment of local health facilities with trained health staff remains a priority.

Lymph node involvement in mycetoma.

Abstract Lymphatic spread of mycetoma agents to regional lymph nodes with consequent enlargement is reported in 13 cases. 9 of these were due to Streptomyces somaliensis , 3 Madurella mycetomi and 1 to Nocardia species. Fungal grains were seen inside lymphatic tissue. The pathological changes of lymph nodes involved in mycetoma are described.

Mange in domestic animals in the Sudan

Bovine demodicidosis, caused by Demodex folliculorum var. bovis, was diagnosed for the first time in the Sudan; it occurred in 10% of 10 000 cattle surveyed in Kordofan Province. A new technique is described for the isolation of this mite. Other mange mites responsible for severe skin lesions were Sarcoptes scabiei var. cameli (camels) and S. scabiei var. caprae (goats). Psoroptes communis var. ovis (sheep) and P. communis var. cuniculi (donkeys and rabbits) were also identified. A detailed histopathological description is given of the skin changes associated with these mange conditions. Effective treatments were given to the goats, donkeys and rabbits, but treatment of the camel mange was not successful.

Experimental infection of domesticated animals and the fowl with Dermatophilus congolensis.

Abstract Rabbits, camels, calves, sheep, goats and donkeys were successfully infected by skin scarification with Dermatophilus congolensis. This is the first time that the camel has been shown to be susceptible to experimental infection. In contrast to the natural disease the lesions did not spread and regressed after 20 to 52 days. The histological changes were scab formation and degeneration, necrosis and micro-abscess formation in the superficial epidermal layer and the hair follicle sheaths. The fowl was refractory to infection by this route. Cutaneous lesions and foreign body granulomas were induced by embedding infected thorns in the skin of calves and rabbits. A tuberculin-type reaction was induced when the organism and Freunds adjuvant were inoculated intradermally. Calves and rabbits injected s.c. and rabbits i.p. failed to develop cutaneous lesions. The i.v. route also failed to produce skin lesions except at the site of injection in rabbits. Various gross internal lesions were observed in calves and rabbits inoculated i.v. and rabbits i.p. An anaphylactic-like reaction occurred in calves repeatedly inoculated i.v. Resistance to reinfection by scarification occurred. The histological changes in internal organs indicated severe inflammatory responses.

Dermatophilus Congolensis. A Bacteriological, In Vitro Antibiotic Sensitivity and Histopathological Study of Natural Infection in Sudanese Cattle

SUMMARY Dermatophilus congolensis was isolated in culture from 36 of 39 field cases of streptothricosis in cattle in the Sudan. The morphological and cultural characteristics and the in vitro sensitivity of the organism to antibiotics are outlined. The lesions were characterised by thick scab, degeneration of the epidermis and a granulomatous reaction in the dermis.

Ringworm infection among Sudanese school children

Abstract 8,443 schoolchildren were examined for ringworm infection and the causal organisms were identified by cultural methods for the first time in Sudanese history. Certain areas were not visited because of transport difficulties. For the same reason towns rather than villages were visited, and the impression given is therefore urban. A rural survey might have changed the picture, because, in general, rural ringworm tends to be of animal origin and does not occur in epidemics, whereas urban ringworm is caused by anthropophilic species and can occur in epidemics ( George, Hand and Manges , 1956 ). Despite this, the results are considered important because they reveal an overall incidence of ringworm infection of 4·2%, rising to 17% in certain schools. Tinea capitis presented the main problem, 3·2% of the children having this infection. Fungi were isolated from 172 scalp specimens; of these 79 (46%) were M. audouinii, 75 (43·6%) T. violaceum, 13 (7·5%) T. soudanense, and 5 (2·9%) M. canis. Tinea corporis was far less common, amounting to 0·88% of the total cases. But still the infection was mainly caused by T. violaceum (42%) and M. audouinii (32%). M. canis was responsible for 5%. Although 7 children had lesions that looked like tinea unguium, no organism could be isolated from the nail scrapings. The infection rate in this series was high in boarding schools. Tinea capitis was seen more often in boys than girls, but tinea corporis was nearly equal among both sexes. Pityriasis versicolor was definitely more common in girls than boys—a ratio of 21 to 1—and one may reasonably assume that the constant oiling of skin by girls provides nourishment for M. furfur. An important point about this survey is that it throws some light on the distribution of T. soudanense by showing that the intermediate zone of the Sudan may be the dividing line between the Mediterranean countries of North Africa where T. violaceum is the main organism ( Ajello , 1960 ) and tropical Africa where T. soudanense prevails. Some of the strains diagnosed as M. audouinii did not altogether show the characteristic picture of M. audouinii as seen in European countries; but they were called M. audouinii to avoid confusion.