Younger children appear to be more likely than their older siblings to spread COVID-19 infection in the households, suggested an analysis of public health records in Ontario, Canada.

Researchers from Public Health Ontario noted that teenagers, aged 14- to 17 years, were more likely to bring the virus into the household, compared to their younger siblings. However, infants and toddlers had around 43% higher likelihood than the older siblings to transmit it to others in the household. Children or teens were identified as the source of the virus in about 1 in 13 Ontario households from June through December 2020, noted researchers in the study published in JAMA Pediatrics. 

Researchers had analyzed the health records from 6280 households with a case of COVID-19 in a child and a subset of 1717 households where a child up to 17 years of age was the source of transmission in a household… (Medscape)