Factors associated with negative conversion of viral RNA in hospitalized children infected with SARS-CoV-2 Omicron variant in Shanghai, China: a retrospective analysis.

OBJECTIVES: This study aimed to identify the related risk factors and potential predictors of SARS-CoV-2 RNA negative conversion by describing the dynamics of viral shedding in infected children admitted to two hospitals from Shanghai during the Omicron variant outbreak. METHODS: This retrospective cohort included laboratory-confirmed cases of SARS-CoV-2 infection from Shanghai between March 28 and May 31, 2022. Clinical characteristics, personal vaccination, and household vaccination rates were collected through electronic health records and telephone interviews. RESULTS: A total of 603 paediatric patients confirmed to have COVID-19 were included in this study. Both univariate and multivariate analyses were performed to filter independent factors for the duration to viral RNA negative conversion. Data on the redetection of SARS-CoV-2 in the patients after they showed negative results on the RT‒PCR test (intermittent negative status) were also analysed. The median duration of virus shedding was 12 (interquartile range, IQR: 10-14) days. The severity of clinical outcome, personal vaccination-2doses, household vaccination rates, and abnormal defecation were factors indecently affecting negative conversion of SARS-CoV-2 RNA, suggesting that patients who had abnormal defecation or with more severe conditions would have delayed virological clearance, while patients who previously had 2 doses of vaccination or had higher household vaccination rates would have accelerated virological clearance. Loss of appetite (odds ratio (OR): 5.343; 95% CI: 3.307-8.632) and abnormal defecation (OR: 2.840; 95% CI: 1.736-4.645) were significantly associated with intermittent negative status. CONCLUSION: These findings could provide clues for the early identification of paediatric patients with prolonged viral shedding and could enrich the evidence for the development of prevention and control strategies, especially vaccination policies for children and adolescents.

Epidemiological, clinical, and household transmission characteristics of children and adolescents infected with SARS-CoV-2 Omicron variant in Shanghai, China: a retrospective, multicenter observational study.

OBJECTIVES: To describe the epidemiological, clinical, and household transmission characteristics of pediatric COVID-19 cases in Shanghai, China. METHODS: Pediatric patients with COVID-19 hospitalized in Shanghai from March-May 2022 were enrolled in this retrospective, multicenter cohort study. The symptoms and the risk factors associated with disease severity were analyzed. RESULTS: In total, 2620 cases (age range, 24 days-17 years) were enrolled in this study. Of these, 1011 (38.6%) were asymptomatic, whereas 1415 (54.0%), 190 (7.3%), and 4 (0.2%) patients developed mild, moderate, and severe illnesses, respectively. Household infection rate was negatively correlated with household vaccination coverage. Children aged 0-3 years, those who are unvaccinated, those with underlying diseases, and overweight/obese children had a higher risk of developing moderate to severe disease than children aged 12-17 years, those who were vaccinated, those without any underlying disease, and those with normal weight, respectively (all P <0.05). A prolonged duration of viral shedding was associated with disease severity, presence of underlying diseases, vaccination status, and younger age (all P <0.05). CONCLUSION: Children aged younger than 3 years who were not eligible for vaccination had a high risk of developing moderate to severe COVID-19 with a prolonged duration of viral shedding. Vaccination could protect children from COVID-19 at the household level.