Objective: To analyze the epidemiological and molecular characteristics of norovirus outbreaks in schools in Xicheng District of Beijing from 2017 to 2022, so as to provide evidence for the prevention and control of norovirus outbreaks in schools. Methods: Data of norovirus outbreaks in schools in Xicheng District, Beijing during 2017 to 2022 were collected and analyzed by descriptive epidemiological methods. Realtime PCR was used to detect the nucleic acid of group GⅠand GⅡnorovirus, the positive norovirus nucleic acid samples were sent to Beijing Center for Disease Control and Prevention for molecular typing. Results: From 2017 to 2022, 185 norovirus outbreaks were reported in schools in Xicheng District, including 166 cluster outbreaks and 19 outbreaks. A total of 2 044 cases were reported, with a total attack rate of 13.92%. There were two peaks in the outbreak time, which were from March to June after the spring semester and from October to December after autumn semester. Primary schools were the most common place of occurrence (101 cases), followed by nursery institutions (68 cases) and secondary schools (16 cases). There were statistically significant differences in the incidence rates among different sites(12.37%, 22.78%, 8.47%, χ2=263.34, P<0.01). There were significant differences in the incidence of vomiting, diarrhea, nausea and stomachache among different students (χ2=263.33, 90.58, 20.42, 30.29, P<0.01). Vomiting was the main symptom in primary school and nursery school children (96.41%, 98.28%), and the diarrhea rate was higher in middle school students (68.22%). The outbreaks were mainly caused by type GⅡ norovirus. The genotype from 2017 to 2021 showed the characteristics of diversity, mainly GⅡ.2[P16], but there was no significant advantage for the GⅡ.2 [P16] during 2019 to 2021. Conclusions The norovirus outbreak in schools in Xicheng district of Beijing from 2017 to 2022 are mainly caused by GⅡ type genome. The main genotype is GⅡ.2[P16]. Norovirus infection mainly occurred in primary schools and kindergartens. For the vulnerable populations, it is necessary to improve the capacity to early identification, student infectious disease management, active infection control and prevention measures, and pathogen surveillance and sporadic case monitoring.

Objective To explore the feasibility of a modified technique of extracorporeal appendectomy assisted by transumbilical single-site laparoscopy for non-encapsulated appendicitis in children.Methods Between June 2022 and December 2023,extracorporeal appendectomy assisted by transumbilical single-site laparoscopy was performed in our department for non-encapsulated appendicitis in 30 children(aged from 2 to 6 years old).A 5 mm trocar and a 30° laparoscope were inserted in the center of the umbilicus,and a 5 mm trocar and operating forceps were inserted at the lower edge of the umbilicus.The diseased appendix was explored and located.Non-invasive laparoscopic grasping forceps were used to clamp the head or center of the appendix.The tissue between the two trocar ports was cut open with the use of an electric knife.The appendix and distal cecum were pulled out of abdominal cavity to ligate the appendix root and mesentery.Then the appendix was disconnected with an electric hook.Results The operating time of the 30 cases was 15-22 min(average,18.0±2.5 min).Patients got out of bed and walked around at 6-8 h after surgery,and passed flatus and consumed liquid food within 1 d after surgery.Postoperative hospitalization was 2-5 d(average,3.5 d).Follow-ups for 1-15 months(average,4.5 months)showed no complications such as incision infection,adhesive intestinal obstruction,or pelvic abscess.Conclusion Transumbilical single-site laparoscopy assisted extracorporeal appendectomy is an effective procedure to resect the appendix,with characteristics of handy and convenient performance,being suitable for non-encapsulated appendicitis.