Kids under 3 with COVID-19 more likely to spread virus within household than teens, study finds

Kids under 3 with COVID-19 more likely to spread virus within household than teens, study finds

Younger children may be more likely to transmit COVID-19 to caregivers and other siblings in the house than older kids, a new study out of Canada found, with researchers pointing to their behavior while sick as a possible driving factor. 

The study, published in JAMA Pediatrics, examined 6,280 households between June 1 and December 31, 2020, that reported a pediatric COVID-19 case. Older children were more likely to be involved in the initial case, and 27% of the 6,280 households reported a secondary infection involving another member. 

Data revealed that children ages 0 to 3 years old, although less likely to bring the infection into the house, were more likely to spread the virus to another member than those ages 14 to 17 years old. Children ages 4 to 8 also had increased odds to spread the virus, as did those ages 9 to 13, but the greatest was among the younger population. 


“Differential infectivity of pediatric age groups has implications for infection prevention controls within households and schools/childcare to minimize risk of household secondary transmission,” the researchers who were supported by Public Health Ontario, wrote. “Although children do not appear to transmit infection as frequently as adults, caregivers should be aware of the risk of transmission while care for sick children in the household setting.” 

Researchers noted that it’s “challenging and often impossible” to isolate from sick children, and as such caregivers should implement other infection control measures like wearing masks, washing hands and keeping them separate from siblings. 

The researchers noted that the role of young children in the pandemic is not well known, as early on testing was reserved for health care workers and symptomatic patients. Interaction during lockdown was also limited to household members, meaning children were kept out of daycares and school settings. The study also noted conflicting findings by other researchers regarding viral loads in younger patients, and whether that may impact infectiousness.


The team called for additional population-based studies to better establish the risk of transmission with younger COVID-19 patients.