Improving surveillance of infectious diseases in child daycare settings: insights from a pilot study in the Netherlands.

IntroductionChild daycare centres (DCCs) are high-risk settings for infectious disease transmission. Although Dutch DCCs are legally required to report unusually high numbers of infections to Public Health Services (PHS), underreporting is common. Our pilot study aims to enhance DCC surveillance using a simple paper-based syndromic tool and wastewater monitoring.MethodsLarge DCCs in the Dutch PHS-region Zuid-Holland Zuid were invited. During 16 weeks in summer and winter, DCCs recorded weekly counts of children (0-4 years) and staff with respiratory, gastrointestinal and skin infections using tally sheets. Incidence rates/100 persons/week were calculated and compared between seasons (Wilcoxon signed-rank test; DCC-level). In parallel, feasibility of local wastewater surveillance was assessed in stand-alone DCCs through sewer map review, on-site inspection and dye testing to identify DCC-specific sampling points, with planned analysis for parvovirus B19, norovirus and respiratory syncytial virus.ResultsTwenty-six DCCs participated in summer and 23 in winter. DCCs reported 7 mandatory outbreak notifications in summer and 4 in winter. Tally sheets showed a higher incidence in winter than in summer (20.1 vs. 8.8/100 persons/week; p