Child transmission of SARS-CoV-2: a systematic review and meta-analysis.

BACKGROUND: Understanding of the role of children in COVID-19 transmission has significant implications for school and childcare policies, as well as appropriate targeting of vaccine campaigns. The objective of this systematic review was to identify the role of children in SARS-CoV-2 transmission to other children and adults. METHODS: MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, and Web of Science were electronically searched for articles published before March 31, 2021. Studies of child-to-child and child-to-adult transmission and quantified the incidence of index and resulting secondary attack rates of children and adults in schools, households, and other congregate pediatric settings were identified. All articles describing confirmed transmission of SARS-CoV-2 from a child were included. PRISMA guidelines for data abstraction were followed, with each step conducted by two reviewers. RESULTS: 40 of 6110 articles identified met inclusion criteria. Overall, there were 0.8 secondary cases per primary index case, with a secondary attack rate of 8.4% among known contacts. The secondary attack rate was 26.4% among adult contacts versus 5.7% amongst child contacts. The pooled estimate of a contact of a pediatric index case being infected as secondary case was 0.10 (95% CI 0.03-0.25). CONCLUSIONS: Children transmit COVID-19 at a lower rate to children than to adults. Household adults are at highest risk of transmission from an infected child, more so than adults or children in other settings.

Higher Hospitalization Rates in Children Born HIV-exposed Uninfected in British Columbia, Canada, Between 1990 and 2012.

BACKGROUND: Compared with children who are HIV-unexposed and uninfected (CHUU), children who are HIV-exposed and uninfected (CHEU) experience more clinical complications. We investigated hospitalizations among CHEU by antenatal antiretroviral therapy (ART) exposure, in British Columbia, Canada. METHODS: This retrospective controlled cohort study used administrative health data from 1990 to 2012. CHEU and CHUU were matched 1:3 for age, sex and maternal geographical area of residence. We determined adjusted odds ratios (aORs) via conditional logistic regression, adjusting for maternal risk factors. RESULTS: A total of 446 CHEU and 1333 CHUU were included. Compared with CHUU, more CHEU experienced one or more lifetime hospitalization (47.3% vs. 29.8%), one or more neonatal hospitalization (40.4% vs. 27.6%), and any intensive care unit admission (28.5% vs. 9.2%). In adjusted analyses, CHEU experienced higher odds of any lifetime hospitalization (aOR 2.30, 95% confidence interval 1.81-2.91) and neonatal hospitalization (aOR 2.14, 95% confidence interval 1.68-2.73), compared with CHUU. There was, however, no difference in infection-related hospitalizations (9.0% vs. 7.5%), which were primarily respiratory tract infections among both CHEU and CHUU. CHEU whose mothers-initiated ART preconception showed lower odds of infection-related hospitalizations than children whose mothers initiated ART during pregnancy or received no ART. CONCLUSIONS: CHEU experienced increased odds of hospitalization relative to CHUU. A substantial number of CHEU hospitalizations occurred within the neonatal period and were ICU admissions. Initiating ART preconception may reduce the risk of infection-related hospitalizations. These findings reinforce the benefit of ART in pregnancy and the need for ongoing pediatric care to reduce hospitalizations.