Shigellosis in Kentucky, 1986 through 1989.

A marked increase in the number of cases of shigellosis was reported in Kentucky in 1988. To examine reasons for this increase, we reviewed the 389 cases of shigellosis reported from 1986 through 1989. Ninety-three percent (285/305) of cases due to known species were due to Shigella sonnei. Sixty-two percent (243/389) of cases occurred in children less than 10 years of age. The annual incidence for blacks (6.8 cases per 100,000) was nearly four times that for whites (1.8 per 100,000). The increased number of cases in 1988 was due to outbreaks in five areas of the state, which accounted for 85% (200/234) of the cases. Three of the five outbreaks involved day-care centers. The primary mode of transmission appeared to be person-to-person; there was no evidence of a common source of infection from food or water. To prevent future outbreaks, cases of shigellosis need to be reported promptly to ensure appropriate investigation and control by local health departments.