Real touch behaviors and control strategies of norovirus transmission among young children in kindergarten: An on-site investigation and intervention study

Abstract

Fomite transmission represents a major route for norovirus outbreaks, especially in kindergartens, where children’s frequent and complex touch behaviors, immature immunity, and extendedindoor stays increase infection risks. However, empirical data on children’s touch behaviors remain scarce. In this study, red-green-blue-depth cameras were employed to monitor 26 children (aged 2.5–7 years) across five kindergarten scenarios in China, recording more than 1.08 million touch events. A Markov chain model based on real touch data was developed to evaluate infection risks and the effectiveness of interventions. Children touched public surfaces (i.e., shared objects such as books and toy cars) more frequently than personal surfaces (i.e., items assigned to individual children). On average, children touched their mouths 39 times per hour in the dining area. Virus transmission ability (VTA) — defined as the percentage of viral load transferred through a surface relative to the total viral load generated by the infected individual, was positively correlated with touch frequency on public surfaces (r = 0.862, p < 0.001), with sensory integration training equipment exhibiting the highest VTA (382.7 %). Assuming the presence of one infected child per scenario, the classroom exhibited the highest infection rate (1.0 %/min) among young children. Handwashing reduced infection risk among susceptible children by up to 51.5 % (efficiency = 99 %), making it considerably more effective than surface disinfection. This study provides quantitative evidence linking children’s touch behaviors to norovirus infection risks via fomite transmission, thereby supporting targeted prevention strategies in kindergarten settings.