No Spread of SARS-CoV-2 From Infected Symptomatic Children to Parents: A Prospective Cohort Study in a Controlled Hospital Setting

Abstract

Introduction: The transmission rates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from children to adults are unclear due to a lack of controlled conditions.Materials and Methods: We investigated the occurrence of SARS-CoV-2 transmission among 12 discordant child-parent pairs in our ward. In each hospital isolation room, caregivers and children lived in close contact during the entire hospitalization period.Results: A total of 136 swab-positive children (mean age, 3.6 ± 4.9 median age, 1; IQR 0–6.2, range 0.1–17) attended by their caregivers were hospitalized. Of those, 12/136 (8.8%, mean age, 6.1 ± 5.3 median age, 4.5) were attended by caregivers who were swab and serology negative at admission despite previous close contact with positive children at home. Three children were completely dependent on their mothers, one of whom was being breastfed. The mean duration of overall exposure to the index case was 20.5 ± 8.2 days.Conclusion: None of the infected children transmitted SARS-CoV-2 infection to their caregivers, raising the hypothesis of a cluster of resistant mothers or of limited transmission from children to adults despite prolonged exposure and close contact. These data might provide reassurance regarding school openings and offer the chance of investigating SARS-CoV-2 variants in the future under the same quasi-experimental conditions.

A systematic review on outbreaks of COVID-19 among children within households in the European region

“…Regarding the transmissibility of SARS-CoV-2 from children to other household members, the SARs detected in the studies of this review ranged between 13% and 75%, while two studies showed no secondary transmission from child index cases (18,20). Our results are similar to a recent meta-analysis of 18 studies with a more global scope, which estimated the SAR of child index cases at 20% (95% CI: 15-26, I2 = 100%), indicating that child index cases were significantly associated with a lower possibility to transmit SARS-CoV-2 to their family members (RR = 0.64, 95% CI: 0.50-0.81, I2 = 96%) compared with the adult index cases (36).…”

“…The lowest SARs, ranging from 13% to 15% were detected by Charbonnier et al (2021) 9 and Galow et al (2021) (11), while Maltezou et al (2020) (17) and Nunziata et al (2021) (20) found no secondary SARS-CoV transmission from paediatric index cases. Similarly, in the study published by Maltezou et al (2021) (18) none of the six paediatric index cases from 23 family clusters transmitted SARS-CoV-2 to any of the household contacts, while children were more likely to have an asymptomatic SARS-CoV-2 infection compared to adults (40% vs 10.5%; P⍰= ⍰.021) and were significantly more likely to have a low viral load.…”

“…Of the 25 studies, 16 were cohort studies (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24), five were cross-sectional (25)(26)(27)(28), two were case reports (29,30), one was a case series (31) and one was a case-control (32). Real-time polymerase chain reaction (RT-PCR) was used in 17 studies to diagnose COVID-19.…”

“…Of the 25 studies included in the analysis, 18 provided adequate contact tracing data for estimating the SAR from paediatric index cases to adult and/or child household contacts (Table 1). Overall, SAR ranged from 13% to 75% in 23 studies, while in two studies there was no evidence of secondary transmission from children to other household members (18,20). The highest SARs (67% and 75%) were found in studies examining single-family clusters with symptomatic paediatric index cases (29,30).…”

Nosocomial transmission of SARS-CoV-2 from infected children to uninfected caregivers: A retrospective cohort study in a Japanese tertiary children's hospital

“…Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can spread from infected children to adult caregivers in the ward room unless they are already infected with SARS-CoV-2 at admission. However, few reports have evaluated the risk of transmission of SARS-CoV-2 within discordant pairs (a child positive for SARS-CoV-2 with a negative caregiver) [ 1 ]. Therefore, we investigated SARS-CoV-2 transmission from infected children to adult caregivers in our hospital.…”