Objective: To investigate the epidemiological characteristics of cluster vomiting diarrhea outbreaks caused by Sapovirus infection in Baoshan District, Shanghai, and to provide reference for the standardized management of cluster vomiting diarrhea events in schools. Methods: The cluster of vomiting and diarrhea outbreaks in Baoshan District from 2017 to 2019 were collected, and the basic information and scene of each cluster were summarized. Sample results were collected and descriptive epidemiological methods were used to analyze the epidemiological characteristics of the outbreak. Results: From 2017 to 2019, a total of 100 cluster vomiting and diarrhea events were reported in Baoshan District, including 9 cases caused by Sapovirus, 120 cases of cluster vomiting diarrhea caused by Sapovirus, with an average incidence rate of 2.37%, including 39 laboratory confirmed cases, the epidemic epidemic time was mainly concentrated in September to November, the places were distributed in 4 primary schools and 5 kindergartens, the main clinical manifestations were vomiting (112/120, 93.33%), abdominal pain (27/120, 22.50%), diarrhea (26/120, 21.67%), compared with Norovirus events, the positive rate, vomiting and fever ratios of Zarovirus were lower than those of Norovirus( χ 2=8.32, 4.52, 14.20, P <0.05). Conclusion In school cluster vomiting and diarrhea events, the positive detection rate of Sapovirus is second enteric vinus behind Norovirus, and it s recommended to formulate a prevention and control plan for Sapovirus infection diarrhea to provide a basis for the on site treatment of school cluster vomiting diarrhea events.

Objective: To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai. Methods: Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing. Results: A total of 16 influenza like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59% (15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone( P <0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled. Conclusion This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.

ObjectiveTo investigate the influenza virus infection status of influenza-like illness (ILI) at a sentinel hospital in Baoshan District of Shanghai, to explore the seasonal patterns of influenza, so as to provide a scientific basis for influenza prevention and control in Baoshan District of Shanghai. MethodsSurveillance data and pathogenic testing results of ILI from the monitoring year of 2015 to 2023 were collected from the sentinel hospital to describe the seasonal epidemic characteristics of influenza in this district. ResultsThe proportion of ILI visits to sentinel hospital in Baoshan District of Shanghai showed an upward trend from 2015 to 2023 (Z=2.598, P=0.09). The positive rate of influenza virus in ILI was 20.43% (1 761/8 621), of which 14.17% were positive for influenza A virus, including 8.43% for influenza A/H3N2 and 5.74% for influenza A/H1N1. The positive rate of influenza B virus was 6.25%, of which the positive detection rate of influenza B/Victoria virus was 5.35%, while that of influenza B/Yamagata virus was 0.90%. Influenza B/Yamagata virus was not detected in 2019‒2023. The highest positivity rate was observed in the 5‒<15 years age group (25.57%). The positive rate of ILI was lower in males (19.90%) than that in females (20.90%). There were three patterns of influenza epidemic in the district: with year-round circulation in 2016‒2017 and 2021‒2022; with bimodal peaks in 2015‒2016, 2017‒2018 and 2022‒2023; and with one peak in 2018‒2019 and 2019‒2020. The positive rate of influenza virus exhibited seasonal variations, with influenza A virus predominated in summer and autumn. However, influenza B virus showed an increase in spring and winter. ConclusionThe influenza epidemic in Baoshan District, Shanghai exhibits diverse patterns with heterogeneous epidemiological characteristics across different age groups and seasons. Notably, children and adolescents aged 5‒<15 years constitute the key target population for influenza prevention and control. Enhanced surveillance and targeted control measures against influenza A/H3N2 lineage viruses are particularly warranted during summer and autumn seasons.