Norovirus and Shigella spp. are the leading causes of acute gastroenteritis outbreaks in schools and child care settings, according to a new study.
Researchers from the Centers for Disease Control and Prevention (CDC) set out to characterize these outbreaks using data from the National Outbreak Reporting System. They reported the findings today in “Childcare and School Acute Gastroenteritis Outbreaks: 2009-2020,” (Mattison CP, et al. Pediatrics. Oct. 24, 2022).
Acute gastroenteritis symptoms include bloody stools, diarrhea, gastroenteritis, nausea, vomiting and abdominal cramps. The reporting system defines an outbreak as at least two cases of similar illness with common exposure. Since reporting is voluntary, the case counts do not represent all cases.
From 2009-’19, 4,633 outbreaks were reported in child care or school settings. There were 166,787 illnesses, 1,604 emergency department visits, 694 hospitalizations and five deaths, according to the study.
The median number of outbreaks for either setting was 457 per year. Median counts for schools were 280 outbreaks a year involving 29 cases each, lasting nine days. Medians for child care settings were 230 outbreaks a year with 10 cases each, lasting 15 days.
About 65% of school outbreaks were viral, and 10% were bacterial. In child care settings, about 37% were viral, and 41% were bacterial. Norovirus accounted for about 51% of the outbreaks, while Shigella spp. caused about 16%. About 86% of the outbreaks were spread person-to-person, while 3% were foodborne.
Authors of the study also looked at 2020 outbreaks in comparison to the decade prior. There were only 123 acute gastroenteritis outbreaks reported in schools and child care settings, most of which were in the first quarter before school closures due to the COVID-19 pandemic.
Authors emphasized the importance of preventive measures to protect children from acute gastroenteritis.
“Outbreak prevention and control in these settings should focus on handwashing, cleaning and disinfection with effective products, and the exclusion of ill children and staff,” they wrote.