05 November 2025 : Clinical Research
Epidemiology of Norovirus Outbreaks in Kindergartens, Primary Schools, and Junior High Schools in Xi'an, China, From October 2020 to February 2023
Hui Zhang
ABCDEF 1, Xin-qian Gu BCDF 1, Lei-le Zhang BCDF 2, Chun-juan Wang BCDF 1, Zheng Wei ABCDEFG 3*
DOI: 10.12659/MSM.949902
Med Sci Monit 2025; 31:e949902
Table 1 Related definitions of norovirus outbreaks.
| Defining elements | Acute gastroenteritis case [8] | Clinically confirmed case [8] | Laboratory-confirmed case [8] | Asymptomatic infected individuals [8,17,18] | Exposed individual* |
|---|---|---|---|---|---|
| Clinical symptoms | At least one of the following items must be included: | At least one of the following items must be included: | At least one of the following items must be included: | No clinical symptoms during the outbreak | None required |
| Laboratory detection | None required | None required | Stool/vomit/ rectal swab positive for norovirus nucleic acid (RT-PCR) or for norovirus antigen (ELISA) | Stool/ rectal swab positive for norovirus nucleic acid (RT-PCR) | None required |
| Epidemiologic associations | None required | Clear exposure history (eg, contact with cases, or shared-location exposure) during the outbreak | Clear exposure history (eg, contact with cases, or shared-location exposure) during the outbreak | Clear exposure history (eg, contact with cases, or shared-location exposure) during the outbreak | Clear exposure history (eg, contact with cases, or shared-location exposure) during the outbreak |
| RT-PCR – Reverse Transcription-Polymerase Chain Reaction; ELISA – enzyme-linked immunosorbent assay. * If an acute gastroenteritis case caused by norovirus occurs in a class, all students in the class and the teacher who was present in the class at the time of the case’s vomiting or diarrhea are considered exposed individuals. | |||||