Children have been suggested as the facilitators of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and amplification, because many affected children might be asymptomatic. Accordingly, social and public health policies, such as school closure, have been implemented in many countries. However, the role of children in asymptomatically carrying SARS-CoV-2 needs to be further explored. In this study, Milani, et al. (2020) investigated the frequency of individuals carrying SARS-CoV-2 among children admitted for noninfectious conditions and without any SARS-CoV-2–associated symptoms or signs and compare it with the frequency of individuals carrying SARS-CoV-2 among a similar adult population.

At the Fondazione Ca’ Granda Ospedale Maggiore Policlinico in Milan, Italy, all patients who require hospitalization after accessing either the pediatric emergency department (for participants younger than 18 years) or the adult emergency department (for individuals 18 years and older) immediately undergo a nasopharyngeal swab for the detection of SARS-CoV-2, regardless of their symptoms. If the first sample has negative results, a second one is administered within 12 to 48 hours. For this study, eligible patients were those admitted for noninfectious conditions to this hospital from March 1 to April 30, 2020. The researchers excluded individuals presenting with any signs or symptoms possibly associated with SARS-CoV-2 infection and those with a history of close and prolonged contact with individuals who had tested positive for SARS-CoV-2 or had a history of symptoms or signs consistent with COVID-19 in the previous 21 days. Individuals with only 1 nasopharyngeal swab available were also excluded. The Milano Area 2 ethics committee approved the study, which included a waiver of informed consent because of the retrospective nature of the investigation.

Data on age, sex, the reason for admission, and development of any SARS-CoV-2 signs of infection in the following 48 hours were retrospectively collected. A comparison of proportions between the pediatric and adult cohorts was made with the 2-tailed Fisher test. An odds ratio and its 95% CIs were calculated as a measure of risk of carrying SARS-CoV-2. Significance was assumed when P < .05. Statistical analysis was performed using the open-source statistical language R, version 3.5.3 (R Foundation for Statistical Computing).

In the study period, 881 children presented to the pediatric emergency department, and 83 children (34 girls and 49 boys; median [interquartile range] age, 5.3 [1.1-11.0] years) fulfilled the eligibility criteria. In the same period, among the 3610 adults presenting to the adult emergency department, 131 (51 women and 80 men; median [interquartile range] age, 77 [57-84] years) were included. The reasons for admission of the included individuals are given in the Table. Children were found to be less frequently positive than adults (1 in 83 children [1.2%] vs 12 in 131 adults [9.2%]; P = .02), with an odds ratio of 0.12 (95% CI, 0.02-0.95) compared with adults. Eleven of 12 adults were positive for SARS-CoV-2 at the first swab. None of the included individuals developed signs or symptoms of SARS-CoV-2 infection in the 48 hours after the admission.

Reference: Milani GP, et al. Frequency of Children vs Adults Carrying Severe Acute Respiratory Syndrome Coronavirus 2 Asymptomatically. JAMA Pediatr. Published online September 14, 2020. doi:10.1001/jamapediatrics.2020.3595