SHIGELLOSIS IN THE UNITED STATES: FIVE-YEAR REVIEW OF NATIONWIDE SURVEILLANCE, 1964–1968

Abstract
Reller, L B., E. J. Gangarosa and P. S. Brachman (National Communicable Disease Center, Atlanta, Ga. 30333). Shigellosis in the United States: five-year review of nationwide surveillance, 1964–1968. Amer. J.Epid., 1970, 97: 161–169.—The National Communicable Disease Center received reports of 45, 263 isolations of shigella during the first 5 years (1964–1968) of a national system of shigella surveillance. Two-thirds of these isolates were from children under 10 years of age. Differences in the age and sex distribution of patients showed a predominance in infant males and women of childbearing age. A seasonal distribution persisted with the greatest number of isolates being reported each autumn. Although not a leading cause of food poisoning in this country, 25 common-source outbreaks of shigellosis were reported during the 5-year period. In each of these outbreaks the source of contamination was a proven or suspect human carrier, again emphasizing the high degree of host specificity of this organism. Over the 5-year period S. sonnei has replaced the S. flexneri serotypes as the most frequently isolated subgroup and accounted for 54% of the total isolates in 1968 compared with 36.7% in 1964. The percentages of reported isolates of S. dysenteriae and S. boydii subgroups have been stable, each contributing less than 1% to the isolates each year. These unusual serotypes often signify disease acquired abroad. The following high-risk population areas have been identified: mental institutions, Indian reservations, and urban low socio-economic communities.