Students and staff who ate at a high school cafeteria on February 6, 2017 experienced gastroenteritis. A total of 36 students and 5 staff me the case definition for an outbreak case. Illness onsets for cases were February 7-8. Three staff returned stool specimens. Two were positive for norovirus GII.4. No one was hospitalized and no one died.

The school used a contract caterer to provide food service at the cafeteria. Most foods were prepared on site by the kitchen staff. Among the 36 student cases, meal transaction records indicated that 35 (97%) had a lunch meal in the cafeteria on February 6. Among the approximately 278 students known not to be ill, 228 (82%) had a lunch purchase on Monday. Odds of a Monday lunch transaction were 7.7 times higher among cases than those not known to be ill (95% confidence interval, 1.4 to 160.5, p=0.016).

The six kitchen employees were interviewed. Two reported recent gastrointestinal illness. One reported onset of illness on February 8. A chef who worked making salad and pizzas became ill on February 6. This food worker was suspected to be infectious while working on Monday as the likely source of the outbreak.