Longitudinal study of rotavirus infection in child-care centres

Objective: To describe the epidemiology of symptomatic and asymptomatic rotavirus infection among young children attending Sydney child-care centres during the 1994 rotavirus season. Methods: Children aged 0-36 months in 11 child-care centres participated in the study. A weekly stool specimen was collected from each subject and tested for rotavirus antigen by commercial enzyme immunoassay. Results: One hundred and seventy-eight children (76 girls and 102 boys) with a mean age of 18.2 +/- 6.5 (SD) months were enrolled for a total of 2249 child-weeks. Of 1653 weekly faecal specimens, 59 (3.6%) were positive for rotavirus antigen. Positivity for rotavirus antigen peaked at 8.0% and 7.4% of specimens in weeks 6 and 7, respectively. The 59 positive specimens were obtained from 44 children in eight of the 11 study centres. One child appeared to suffer a second episode. Eighty-two per cent of episodes were associated with symptoms of gastroenteritis. Overall, 32% of the children in the eight affected centres were infected; 52% or those < 12 months were infected compared to 26% of alder children. Secondary spread to household contacts was also documented. Conclusions: Rotavirus infection poses a significant health problem in under-3-year-old children attending child-care centres in Sydney, We believe that these results are applicable to all Australian children of this age attending group child care.