Surveillance to estimate the burden of rotavirus gastroenteritis in children aged less than 3 years attending day care centers in Paris, France.

Between December 2006-May 2007, 371 children aged <3 years attending 15 day care centers (DCCs) in Paris, France were actively followed for acute gastroenteritis [GE; diarrhea (≥3 loose stools/24 hours with or without vomiting) for <14 days] and outbreaks of acute GE (≥3 cases in a DCC with onset within 11 days). Demographic, clinical and cost-related information was collected for all acute GE episodes. All children with acute GE and all participating attendees at affected DCC s during an outbreak (irrespective of symptoms) provided stool samples for rotavirus (RV) testing (RotaStrip™). RV-positive samples were typed by polymerase chain reaction (PCR). Overall incidence of RVGE among DCC attendees <3 years was 46.7 cases/100,000 person-days (95% CI: 26.7, 75.8) and was highest among children aged 5-11 months [139.2 cases/100,000 person-days (95% CI: 60.1, 274.2)]. 16/69 (23.2%) GE episodes were RV-positive by PCR, with 50% of RV-positive episodes occurring in children aged <1 year. G1P[8] was the most common RV type (12/16). Over half of the RVGE episodes that could be evaluated scored severe on the Vesikari scale and most RVGE episodes resulted in parents/guardians accessing health care services. We found 10 children with RVGE to be the likely origin of outbreaks in 3 DCCs, in which 5/10 (50.0%), 6/21 (28.6%) and 7/23 (30.4%) children tested RV-positive. One in 25 DCC attendees exposed to RVGE developed RVGE and 1 in 9 contracted asymptomatic RV infection. RV-positive episodes had higher mean total costs than RV-negative episodes (€484.00 versus €182.80, respectively). Results highlight the ease with which RV can spread in a day care setting and the resulting burden on DCC attendees and their families. The introduction of new RV vaccines into national immunization programs should help prevent similar outbreaks and protect DCC attendees.