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.