A three-year prospective study of streptococcal infections in a population of rural Egyptian school children.

Abstract

SUMMARY Epidemiological and clinical observations on streptococcal infections in 156 Egyptian school children aged 6 to 12 yr were obtained by prospective bacteriological, serological and clinical surveys from 1967 to 1970. The yearly recovery rate of group-A streptococci from the throat varied from 13 per cent. to 24 per cent. The seasonal variations showed a peak during the late autumn and winter and a minimal rate in the summer months. The carrier rate in each of four school grades varied independently, an indication that the classroom, more than any other area of the school, is a primary locus of exposure and transmission. The prevalence of the group-A streptococcal carrier state was assessed from the long-term observation of the study population. In 7 per cent. of the children, more than 25 per cent. of the monthly throat cultures were positive in a 3-yr period. Thirteen per cent. of the children had fewer than 5 per cent. of throat cultures positive. In most of the children, however, there were marked shifts in the percentage of positive monthly throat cultures from one year to the next. The attack rate of streptococcal infections, defined as a throat culture positive for group-A streptococci with a concomitant rise of ASO, was 6 per 1000 per week.