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

Abstract

Objective

To describe the epidemiological, clinical, and household transmission characteristics of pediatric coronavirus disease 2019 (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, 2,620 cases (age range, 24 days-17 years) were enrolled in this study. Of these, 1,011 (38.6%) were asymptomatic, whereas 1,415 (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 0-3 years, those unvaccinated, with underlying diseases, and overweight/obese children, had a higher risk of developing moderate to severe disease than children 12-17 years, those vaccinated, without any underlying disease, and with normal weight, respectively (all p<0.05). Prolonged duration of viral shedding was associated with disease severity, presence of underlying diseases, vaccination status, and younger age (all p<0.05).

Conclusions

Children younger than 3 years old 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.