Preliminary Clinical and Epidemiological Analysis of the First 1,000 Pediatric COVID-19 Cases in Moscow Region

Abstract

Rationale. The novel coronavirus infection caused by SARS-CoV-2 (COVID-19) continues to spread worldwide, though the epidemiological situation varies across countries. It is of interest to estimate the pediatric incidence in a separate constituent entity of the Russian Federation, Moscow Region (MR) closely connected with Moscow (accounting for the highest number of COVID-19 cases in Russia). Assessment of the epidemiological data is interesting due to the late onset of the epidemic outbreak, the preventive lockdown imposed during the early stages, and extensive testing of all the identified contacts.Purpose of the study: Assessment of the pediatric incidence of COVID-19, including identification of its main clinical and epidemiological characteristics, based on the monitoring data for the current situation in MR.Materials and methods. A retrospective analysis of all pediatric cases of laboratory-confirmed COVID-19 in MR (1,047 children of all ages) was performed. The time span covered the data of the daily monitoring of the epidemiological situation from the beginning of reporting (53 days in total). The information was obtained from the database of the Rospotrebnadzor Territorial Administration of MR and collected in compliance with the regulations on Daily Monitoring of Children with Coronavirus Infection, Management Section, State Information System, MR.Results. The pediatric cases of COVID-19 accounted for 6.3% (95% CI2 5.9–6.7) of all the cases reported by 6/5/2020 (16,590); the total infection rate of the pediatric population in the region was 0.07% (0.06–0.09). The basic reproduction number ranged from 4.8 (during the two-week exponential growth phase) to 2.7 (during the later period characterized by a slowdown in the incidence rate) and averaged 3.8 (3.0–4.57). The clustering rate of COVID-19 among children was high, reaching 82.8% (79.7–85.6) with a small average number of cases detected in the cluster — 1.21 (1.16–1.26). Asymptomatic COVID-19 cases prevailed significantly, amounting to 62.2% (59.2–65.1), including 73.1% in newborns; severe cases accounted for 0.38% (0.35–0.41) and hospitalized cases totaled 12.0 (10.1–14.2). No death cases were reported. The mean age of the diseased and infected was 8 [4; 13] years old. Boys prevailed insignificantly (53.2%).Conclusion. There is a distinct stage-by-stage development of the epidemic situation among children in MR. In the pediatric population, COVID-19 was generally acquired from a secondary household transmission within family clusters. Early preventive measures and extensive testing helped to reduce the period of exponential growth and, therefore, to avoid large clusters of infection. In addition, 17.2% of the COVID-19 clusters were identified as those where the child was the first to become sick. In the future, it is necessary to practice distancing and provide effective isolation of diseased children and adults, since the high rate of incidence in children can lag behind the incidence rate in adults.