Diarrheal illness among infants and toddlers in day care centers. I. Epidemiology and pathogens.

We conducted a 2-year prospective study of diarrheal illness in children ages 0 to 36 months in 22 day care centers in Maricopa County, Arizona. In 7464 child-months of observation, 465 sporadic cases and 170 outbreak-associated cases of diarrhea were identified. Enteric pathogens were identified in 20% of diarrhea episodes. Giardia lamblia, rotavirus, and Campylobacter jejuni were the most common pathogens. Giardia was significantly more common in toddlers than in infants and was found in 19% of asymptomatic child contacts of symptomatic infected children. Rotavirus was significantly more common in infants than in toddlers. In outbreaks, shorter duration of child enrollment was associated with illness. Comparison of day care center characteristics revealed that only a lower score in standardized observations of hygiene and child-handling practices was associated with greater risk of diarrhea. Infectious diarrhea appears to be common in diaper-age children in day care centers, but the patterns of disease differ for different pathogens and for the infant and toddler age groups.