An epidemic due to sulphonamide-resistant group A meningococci in the Helsinki area (Finland). Epidemiological and clinical observations.

An epidemic due to sulphonamide-resistant group A meningococci started in Finland in January 1973. By the end of 1974 the number of cases exceeded 1300. This report describes epidemiological and clinical observations in 370 patients treated in Helsinki 1973-1974. The incidence was about 65 per 100 000 per year in children under 7 years of age and about 10 per 100 000 in adults. More than one case occurred in 3.8% of the families and in 36% of the lodging-houses of the lowest social group. The fatality rate of patients treated in hospital was 4.1%. Persistent neurological damage was noticed in 4.6%.