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 2 Related definitions of study indicators.
| Indicators | Definition of molecule | Definition of denominator | Formula of calculation |
|---|---|---|---|
| Vomiting rate | Number of vomiting cases during the outbreak | Total number of cases during the outbreak | (Number of vomiting cases/ total number of cases)×100% |
| Diarrhea rate | Number of diarrhea cases during the outbreak | Total number of cases during the outbreak | (Number of diarrhea cases/ total number of cases)×100% |
| Attack rate | Number of cases during the outbreak | Total number of individuals exposed during the outbreak | (Number of cases/ total number of individuals exposed)×100% |
| Asymptomatic prevalence []17 | Number of norovirus nucleic acid positive but asymptomatic individuals during the outbreak | Total number of asymptomatic individuals for norovirus nucleic acid testing during the outbreak | (Number of norovirus positive but asymptomatic individuals/ total number of asymptomatic individuals for norovirus testing)×100% |
| Norovirus detection rate | Number of norovirus nucleic acid positive cases during the outbreak | Total number of cases for norovirus nucleic acid testing during the outbreak | (Number of norovirus positive cases/ total number of cases for norovirus testing)×100% |