Features of a large epidemic of group A meningococcal meningitis in Khartoum, Sudan in 1988.

A large epidemic (February-August 1988) of group A sulphonamide resistant, clone III-1 meningococcal meningitis in Khartoum, Sudan is described. A total of 10,099 cases were admitted to treatment centers with 8,397 cases during March and April, corresponding to an annual incidence of 1,679/100,000 inhabitants during this period. The age profile showed a high morbidity in adults (31% of the cases greater than or equal to 20 years). The male dominance was marked especially in the adult cases with a proportion of 3.2:1. The epidemic started during the hot and dry season and declined when the clouds came, humidity rose, temperature fell and a mass vaccination campaign had been implemented together with other epidemic precautions. Vaccination with a combined group A/C polysaccharide vaccine had been given 4 weeks-1 year before hospitalization to 11% of the children, 80% of whom were greater than 18 months of age. The estimated case fatality rate was 6.3%. Since 47% of the cases came from periurban and rural areas, the actual mortality during the epidemic might have been higher when considering those who may have died before reaching any of the treatment centres. Fatal cases had a short history of acute illness and a septic condition. Septicaemia was rare and seen in only 3.7% of the cases, the rest had acute purulent meningitis. Hearing loss/impairment and hemiplegia was diagnosed in 2-3% of the cases. The epidemiology, based on detailed typing/subtyping and restriction enzyme patterns of meningococcal strains, was apparently associated with the Mecca outbreak in August 1987.