Transmission dynamics of enteric bacteria in day-care centers.

The role of fomites in the transmission of diarrhea in day-care centers was evaluated. During a nine-month period (December 1980-August 1981), inanimate objects and hands of children and staff in five Houston day-care centers were cultured monthly and again during outbreaks of diarrhea. Air was sampled from the classrooms and bathrooms using a single-stage sieve sampler. When a diarrhea outbreak occurred, stool specimens were collected from ill and well children and from staff in the affected rooms. Multiple pathogens accounted for 3 of 11 outbreaks. The rates of isolation of fecal coliforms from hands and classroom objects on routine sampling were 17% (22/131) and 13% (8/64), respectively. During outbreaks of diarrhea, fecal coliforms were recovered with significantly greater frequency from hands (32%; p less than 0.005) and from classroom objects (36%; p less than 0.005). There was no difference in the level of fecal contamination in the toilet areas during outbreak and nonoutbreak periods. Shigella was not isolated in the study; salmonella was isolated on one occasion from a table during an outbreak of salmonellosis. Contamination of hands, communal toys and other classroom objects appeared to play a role in the transmission of enteropathogens in day-care center diarrhea outbreaks and helped to explain the presence of multiple pathogens among those affected.