Household transmission of SARS-CoV-2 during the Omicron wave in Shanghai, China: A case-ascertained study.

OBJECTIVES: We used a case-ascertained study to determine the features of household transmission of SARS-CoV-2 Omicron variant in Shanghai, China. METHODS: In April 2022, we carried out a household transmission study from 309 households of 335 SARS-CoV-2 pediatric cases referred to a designated tertiary Children's Hospital. The detailed information can be collected from the 297 households for estimating the transmission parameters. The 236 households were qualified for estimating the secondary infection attack rates (SARI ) and secondary clinical attack rates (SARC ) among adult household contacts, characterizing the transmission heterogeneities in infectivity and susceptibility, and assessing the vaccine effectiveness. RESULTS: We estimated the mean incubation period and serial interval of Omicron variant to be 4.6 ± 2.1 and 3.9 ± 3.7 days, respectively, with 57.2% of the transmission events occurring at the presymptomatic phase. The overall SARI and SARC among adult household contacts were 77.11% (95% confidence interval [CI]: 73.58%-80.63%) and 67.03% (63.09%-70.98%). We found higher household susceptibility in females. Infectivity was not significantly different between children and adults and symptomatic and asymptomatic cases. Two-dose and booster-dose of inactivated COVID-19 vaccination were 14.8% (5.8%-22.9%) and 18.9% (9.0%-27.7%) effective against Omicron infection and 21.5% (10.4%-31.2%) and 24.3% (12.3%-34.7%) effective against the symptomatic disease. CONCLUSIONS: We found high household transmission during the Omicron wave in Shanghai due to presymptomatic and asymptomatic transmission despite implementation of strict interventions, indicating the importance of early detection and timely isolation of SARS-CoV-2 infections. Marginal effectiveness of inactivated vaccines against Omicron infection poses a great challenge for outbreak containment.

Effective multidimensional approach for practical management of the emergency department in a COVID-19 designated children's hospital in east China during the Omicron pandemic: a cross-sectional study.

Background: Characterized by rapid transmission but lower severity, the new Omicron wave brought about an acute increase in local corona virus disease 2019 (COVID-19) cases in Shanghai, followed by stricter infection prevention and control strategies. Inevitably, more time was required for emergency consultation and treatment of children with critical illnesses. Therefore, a multidimensional approach was designed to streamline the emergency service and reduce the incidence of nosocomial infection of sever acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the Omicron wave for the emergency department (ED) at the Children's Hospital of Fudan University (CHFU). Methods: A multidimensional approach was implemented in the ED to help achieve a balance between the demand for emergency services and pandemic control, consisting of ED layout adjustment; electronic screening (E-screening) measures; standard management processes for patients, medical staff, and goods transfer; reliable disinfection measures; and a surveillance system for infection prevention and control. To evaluate the effect of the management strategy, the data on nosocomial infection cases and occupational exposure episodes among staff in the ED were collected. The demographic and clinical characteristics of level I/II children by the five-level pediatric triage tool and their mean duration of stay in the resuscitation room were collected. Results: There were 12,114 ED visitors from March 1 to May 31 in 2022, among which 53.24% were medical emergencies (6,449/12,114) and 46.76% were surgical emergencies (5,665/12,114). Twenty-nine patients were sent to the buffer zone, four of whom were transferred to the pediatric intensive care unit (PICU) because of the critical situation. Six patients tested positive for COVID-19 after entering ED, including three in the buffer zone and three in the ED clinic, causing a temporary closure of the ED for disinfection. There were no reports on medical care delays, unintended deaths, staff with COVID-19 infection, or occupational exposures to COVID-19. Conclusions: Our findings highlight the effectiveness of the multidimensional approach, which can simultaneously meet the emergency care needs of patients as well as pandemic prevention and control. However, the results were obtained against the proportional decrease in clinic visitors due to the Shanghai lockdown. Dynamic assessment and further optimization may be adopted to cope with the pre-pandemic visit volume.

Epidemiological and clinical features of SARS-CoV-2 infection in children during the outbreak of Omicron variant in Shanghai, March 7-31, 2022.

OBJECTIVES: This study aimed to understand the epidemiological and clinical characteristics of pediatric SARS-CoV-2 infection during the early stage of Omicron variant outbreak in Shanghai. METHODS: This study included local COVID-19 cases <18 years in Shanghai referred to the exclusively designated hospital from March 7 to March 31, 2022. Clinical data, epidemiological exposure, and COVID-19 vaccination status were collected. Relative risks (RRs) were calculated to assess the effect of vaccination on symptomatic infection and febrile disease. RESULTS: A total of 376 pediatric cases of COVID-19 (median age: 6.0 ± 4.2 years) were referred to the designated hospital, including 257 (68.4%) symptomatic cases and 119 (31.6%) asymptomatic cases. Of the 307 (81.6%) children ≥3 years eligible for COVID-19 vaccination, 110 (35.8%) received two doses of vaccines. The median interval between the completion of two-dose vaccination and infection was 3.5 (interquartile range [IQR]: 3, 4.5) months. Compared with no vaccination, two-dose COVID-19 vaccination reduced the risks of symptomatic infection and febrile disease by 35% (RR 0.65, 95% confidence interval [CI]: 0.53-0.79) and 33% (RR 0.64, 95% CI: 0.51-0.81) among confirmed cases. Eighty-four percent of symptomatic cases had fever (mean duration: 1.7 ± 1.0.8 days), 40.5% had cough, and 16.4% had transient leukopenia. Three hundred and seven (81.6%) had an epidemiological exposure in household (69.1%), school (21.8%), and residential area (8.8%). CONCLUSION: The surge of pediatric COVID-19 cases and multiple transmission model reflect wide dissemination of Omicron variant in the community. Asymptomatic infection is common among Omicron-infected children. COVID-19 vaccination can offer some protection against symptomatic infection and febrile disease.

Point-of-care training program on COVID-19 infection prevention and control for pediatric healthcare workers: a multicenter, cross-sectional questionnaire survey in Shanghai, China.

BACKGROUND: To evaluate the effectiveness of training on knowledge and practice of infection prevention and control (IPC) among pediatric health care workers (HCW) in Shanghai, China, in the context of COVID-19 pandemic. METHODS: An online training program was designed by the Shanghai Pediatric Clinical Quality Control Center (SPQCC) during the early phase of COVID-19 pandemic on disease knowledge and practice of IPC. Training took place in the 81 partner hospitals affiliated with SPQCC. A multicenter, cross-sectional questionnaire survey was designed with a 25-item self-administered questionnaire to evaluate the knowledge gained from the training. Stratified-random sampling was used to select HCW according to three professionals (i.e., pediatricians, nurses and administrators) within each partner hospital. Awareness and knowledge of COVID-19 and its related infection control and practice were assessed by comparing survey results between different types of hospitals, professionals and professional ranks. A higher survey score meant that the respondent was more prepared and knowledgeable about COVID-19 and its infection control measures. RESULTS: Completed questionnaires were returned from 1,062 subjects (385 pediatricians, 410 nurses, and 267 administrators), giving a response rate of 96.5%. Overall, awareness of clinical information related to COVID-19, importance of personal hygiene and isolation policy was high among the respondents. No statistical difference of scores on knowledge of COVID-19, IPC and relevant practice between the tertiary and peripheral hospitals. Among all respondents, middle-ranked health care personnel were most knowledgeable and achieved the highest score. CONCLUSIONS: Majority of pediatric HCW showed good recognition and practice in infection protection and control measures. The online training was able to achieve its aim to enhance knowledge and awareness and could have contributed to the zero infection rate among HCW caring for confirmed COVID-19 cases in Shanghai.

A quickly, effectively screening process of novel corona virus disease 2019 (COVID-19) in children in Shanghai, China.

BACKGROUND: A recent cluster of pneumonia cases in China was caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report the screening and diagnosis of corona virus disease 2019 (COVID-19) in our hospital. METHODS: Developed a procedure for the identification of children cases with COVID-19 in outpatient and emergency department of our hospital, then we observed how this process works. RESULTS: (I) There were 56 cases considered suspected cases, and 10 cases were confirmed as COVID-19. (II) Of the 10 confirmed COVID-19 cases admitted in our hospital, 5 were males and 5 were females, aged from 7 months to 11 years, the average age is 6.0±4.2 years, 6 cases were mild pneumonia, the others were upper respiratory tract infection. (III) We followed up 68 patients in isolation at home until symptoms disappeared. Non were missed in the patient's first visit. The sensitivity of this method is 100% and the specificity is 71.3%. CONCLUSIONS: Our screening process works well, and it is also necessary to establish a screening network in the hospital.