Effect of total attending period on infection episode rate in a child-care center

Background: Attendance to a child-care facility is known to be associated with increased rate of episodes of infectious diseases in children. This retrospective cohort study investigates the infection episode rate and the effect of total attending period on infection episode rates in a child-care center (Gulveren Child-Care Center, Ankara, Turkey), at a stable environmental condition, over a 7-year follow-up period. Methods: During the study period, 288 children attended the center and enrolled. Sex, total duration of breastfeeding, starting age at the center, total duration of attendance, and the type and frequency of infections diseases were recorded. Episode rates were calculated for each child. Results: The mean starting age at the child care center was 4.1 +/- 0.7 years (range: 2.5-5.8 years); the mean total duration of attendance at the center was 20.4 +/- 9.9 months. Over the study period, 1000 infection episodes were detected. The general infection episode rate was calculated as 2.04/child per year. In bivariate analysis, children with longer attendance period (greater than or equal to12 months), and a younger starting age at the center (<4 years of age) had lower 'moderate general infection' (greater than or equal to3 episode/child per year) episode rates than those of other groups. In multiple logistic regression analysis, only total attending period in the center was significantly associated with 'moderate' level general infection episode rate. The presence of asthma slightly increased the lower respiratory tract infections episode rate in bivariate analysis, and was the only significant predictor of LRTI episode rate in multivariate analysis. Conclusions: The results of the present study show that among children attending a single facility, longer periods of attendance at the facility was associated with a decreased risk of general infection episode, regardless of starting age at the center. Additional cohort studies are needed to determine whether this reduction in general infection episode rate extends into school-age years and whether children moving between different centers affects the incidence of infectious episodes.