Control of day care shigellosis: a trial of convalescent day care in isolation.

Simultaneous outbreaks of S. sonnei infections occurred in September 1983 at two day care centers in Seattle, Washington. At both centers, there were high rates of diarrheal illness in the children (22/80 and 11/23, respectively), in staff members, and in family members of the ill children. The smaller center was temporarily closed, but the larger one remained open. Convalescent children and staff whose diarrhea had resolved and who were receiving appropriate antimicrobials were allowed to return to the larger center before negative cultures were obtained and were separated in an isolation room. No culture-proven cases of shigellosis occurred at either center in the following two months. Plasmid profile determinations suggested the Shigella were not transmitted from the center that remained open to the community. Estimated need for alternate child care requirements at the closed center were 100-fold greater than at the center with the isolation room. Caring for convalescent children in isolation at day care centers while they receive antimicrobial therapy may be a useful strategy for controlling day care shigellosis.