Investigation of an outbreak of sapovirus infection in a middle school in Chaozhou City,Guangdong Province in 2022
Objective To comprehend the gastroenteritis outbreak triggered by sapovirus(SaV)in a middle school located in Chaozhou City in 2022,ultimately providing a scholarly reference for the implementation of preventive and control measures against contagious diarrhea within educational institutions.Methods Descriptive epidemiological methods were employed to analyze the epidemiological characteristics of the outbreak.A 1∶3 case-control study was conducted to identify potential correlation factors.Anal swab specimens from students and kitchen workers,food samples from the cafeteria,and environmental swab samples were collected for nucleic acid PCR testing of Sapovirus,Norovirus,Staphylococcus aureus,five types of enterotoxigenic Escherichia coli,Salmonella,and Bacillus cereus.One SaV-positive nucleic acid sample was randomly selected for VP1 capsid protein sequencing.Results A total of 148 sapovirus cases and 6 asymptomatic infections were reported in this outbreak.The predominant clinical manifestations were vomiting(83.1%),nausea(38.5%),and vertigo(24.3%),with no fever symptoms reported.The peak incidence was recorded on March 20,showing a propagative and point source exposure pattern.Cases were distributed across 83.3%of the classes in the school,with the highest incidence rate of 32.69%in Class 311.The case-control study revealed that having lunch on campus on March 18 was a significant correlation factor for the disease(OR=4.17,95%CI:1.58-11.00).A total of 43 students and 23 kitchen workers anal swab specimens,7 food samples,and 9 cafeteria environmental swab samples were collected.Of these,20 students and 6 kitchen workers anal swab specimens tested positive for SaV nucleic acid,while the remaining samples returned negative results.Gene sequencing indicated the presence of the GI.6 genotype.Hygiene investigation exposed improper food handling practices among some kitchen workers.Conclusions This outbreak was caused by a GI.6 genotype SaV infection,with exposure in the cafeteria on March 18 being the primary contributing factor for the outbreak and subsequent spread.
NETL
NSTL
万方数据
