Control of cerebrospinal meningitis epidemics with sulfadimidine and penicillin; report on an experiment in mass chemoprophylaxis in the Sudan.

Four villages in Kordofan Province of the Sudan were selected by the authors to determine the effectiveness of mass prophylactic treatment with sulfa drugs and penicillin in controlling cerebrospinal meningitis epidemics in rural areas with highly primitive living conditions. Sulfadimidine was given orally in two of the villages, and procaine penicillin G in oil with 2% aluminium monostearate (PAM) was given intramuscularly in the other two. The population of the villages was classified by age and by sex and given the following prophylactic doses: in Kaldung village, where 93% of the population was treated, 4 g of sulfadimidine were given to persons over 15 years of age, 2.5 g to those between 15 and 5, and 1.5 g to those under 5; in Korongo Abdulla, the same age-groups received 2.0 g, 1.0 g, and 0.5 g, respectively, and 34% of the population was treated; in El Machicha and Miri Bara villages, PAM was given to 38% and 90% of the respective populations in the dosage of 150,000 units to those over 15 years of age, 100,000 units to those between 15 and 5, and 75,000 to those under 5.In this campaign, some 4,000 people were examined daily and, where necessary, treated by a medical staff of four with five trained assistant dressers. The drugs had a noticeable influence on the number of cases in the protected groups, which showed an incidence of 4.86 cases per 1,000 of the total population of the 4 villages against 17.68 cases per 1,000 in the unprotected groups. The authors point out that in the Sudan it is not possible to take a neighbouring village as the control unit, since each village is an epidemic unit in itself and the results from treated and untreated would thus not be comparable. It was therefore decided to take that portion of the village population which did not receive treatment as the control series. The conditions under which the controls lived were, as regards environment and exposure to infection, strictly comparable to those of the treated persons. The results were similar with sulfa drugs and with penicillin.The authors conclude that mass chemoprophylaxis with sulfonamides or penicillin of populations living under primitive conditions is effective in the group treated, whatever the stage of the epidemic at the time of treatment, but that there is no reason to assume that it influences the development of the epidemic. There is no clear explanation why the groups protected did not become reinfected, but it is thought that this was perhaps due to the development of a low-grade immunity in previous carriers cleared by the prophylactic treatment.