A Norovirus-Related Gastroenteritis Outbreak Stemming from a Potential Source of Infection - Pudong New Area, Shanghai Municipality, China, April 2024.

What is already known about this topic?: Noroviruses are highly infectious with rapid transmission capabilities, causing illness for an average duration of 12-60 hours. In China, individuals in educational agencies may return to class 72 hours after symptom resolution.

What is added by this report?: This outbreak was precipitated by a potential source of infection in a child resuming class after a 72-hour quarantine post-symptom resolution, leading to a cluster of cases within the class.

What are the implications for public health practice?: While extending the quarantine period for children may be considered from a safety perspective, it is a challenge for educational agencies. The outbreak is deemed a low-probability event; however, further investigation into the detoxification period of asymptomatic patients is warranted.