Objective: To analyze the epidemiological characteristics and genetic characteristics of sapovirus (SaV) in a cluster of schools in Changzhou, so as to provide a reference for the treatment of clustered vomiting and diarrhea events in schools. Methods: The epidemiological data and laboratory test data of sapovirus clusters in Changzhou from 2019 to 2022 were collected and analyzed. Partial VP1 genes of SaV positive samples were amplified and sequenced for phylogenetic analysis. Results: A total of 8 cases of clusters of SaV epidemics were reported in Changzhou City from 2019 to 2022, with 118 reported cases. The total attack rate was 1.47%, and the median of the attack number was 15. There were 6 outbreaks in kindergartens and 2 outbreaks in primary schools, which were reported in the epidemic period from September to December. The main clinical manifestations were vomiting (113 cases, 95.76 %), abdominal pain (39 cases, 33.05%), and diarrhea (16 cases, 13.56%). Among the 8 outbreaks, 17 sample strains were successfully sequenced. 5 outbreaks were GII.3 , and the other 3 outbreaks were GI.1, GI .3 and GII.2. GI and GII were the main genotypes in this area, and GII .3 was the predominant strain. Conclusion SaV is an important pathogen in the clusters of vomiting and diarrhea in schools after the transmission of norovirus. Continuous surveillance of SaV should be carried out to further understand its epidemiological characteristics and genotype distribution, so as to provide scientific basis for the prevention and control of the epidemic in schools.

Objective To investigate the source of microbial contamination in the clean room of the workshop. Methods Microbiological sampling was carried out from the air, environment and personnel of the workshop. The samples were cultivated, the microorganisms were detected by MALDI-TOF-MS, and homology analysis was performed with the microbial identification system of the instrument. Results A total of 14 species and 41 strains of bacteria were detected. Nine strains of Staphylococcus epidermidis were selected for homology analysis, and the Staphylococcus epidermidis from personnel gloves and headgear had 94% homology. There was 83% homology among the staphylococcus epidermidis derived from the sedimentation bacteria, the ground environment and personnel, which was higher than the 71% of the standard strain. Conclusion The homology analysis demonstrates that the pollution in the clean room of the workshop mainly comes from personnel, and secondly comes from the environment outside the workshop. Enterprises need to strengthen management to prevent the occurrence of microbial contamination. MALDI-TOF-MS can be used for rapid detection of complex environmental bacteria and for homology analysis.

Objective To understand the epidemiological characteristics and variation of H3N2 influenza virus hemagglutinin (HA) gene in Changzhou from 2017 to 2018. Methods Throat swab specimens of the influenza-like cases were collected from Changzhou Influenza Monitoring Sentinel Hospital from April 2017 to March 2018. RNA was extracted from the specimens for influenza diagnosing and genotyping using real-time RT-PCR．H3N2 positive samples were isolated, and extracted RNA was used for amplification, sequencing and phylogenetic analysis of HA gene. Results From April 2017 to March 2018, 28 strains of influenza A (H3N2) virus were isolated. After gene sequencing, a phylogenetic tree was constructed. It was found that all of the strains belonged to Group3C.2a, which was similar to the vaccine strain A/Hong Kong/4801/2014. The HA amino acid sequence difference was analyzed and compared between the H3N2 influenza virus strains isolated in Changzhou and the vaccine strain A/Hong Kong/4801/2014. It was found that the epidemic strain isolated in Changzhou was in the HA epitope (A-E) region. Ten amino acid site mutations in the HA epitope (A-E) region and two amino acid site mutations in the stem region of HA antigen were found. Conclusion From April 2017 to March 2018, the influenza virus H3N2 prevalent in Changzhou was distributed on the same evolutionary branch with the vaccine strain A/Hong Kong/4801/2014 (group 3C.2a), rendering the popular trend of one subgroup. However, some amino acid sites of the HA epitope had variations, suggesting that mutations may occur, which may affect the immune effect of the vaccine. Monitoring needs to be strengthened in the future work.