Nearly half of household members become infected with COVID-19 after exposure, study finds

New research suggests that the transmission of COVID-19 within a household could be more than 50 per cent and that children play a “important” role in its spread through the home.

The peer-reviewed study, published earlier this week in the Canadian Medical Association Journal, analyzed the transmission of COVID-19 in 180 homes in the Ottawa, Ont. area between September 2020 and October 2021, and found that after the first person in the home tested positive for COVID-19, 49.1 per cent of people in the same home would later test positive as well.

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In all, 239 of the 487 people in the same household as someone with COVID-19 would later test positive for the virus.

Dr. Maala Bhatt, an associate professor of Pediatrics at the University of Ottawa and the study’s lead author, believes this study is a reminder that Canadians need to continue with the proper precautions.

“I know many want to ‘live with COVID’ and abandon the layers of protection that were previously mandated, but it’s important to be aware of the high transmissibility of this virus in closed, indoor settings, such as schools,” she said in a news release.

“Our most vulnerable and our youngest children who are not yet able to be vaccinated are still at risk for COVID infection.”

Maala also notes that this study was conducted before the emergence of the highly transmissible Omicron variant, meaning the transmission rate in the household is likely higher than this research shows.

“While we’re lucky hospitals aren’t currently overloaded, emergency departments are and positivity rates are on the rise, even amongst children,” Bhatt said.

“As significant COVID-19 transmission continues within households and throughout the community, it’s important to continue doing what you can to keep yourself and those around you safe – mask while indoors, wash your hands, get vaccinated with all the doses you are eligible for, stay home if you’re sick, and limit close contacts.”

While the study showed that adults were more likely to spread the virus to others in the home, the study stated that children were “were an important source of spread” and accounted for about a third of household transmission.

“The role of children in transmission warrants attention, since they are often asymptomatic or have mild symptoms,” the study noted.

“Addressing this gap in the literature would allow a more evidence-based approach to public health initiatives, given that COVID-19 pandemic control strategies have often affected the lives of children and youth, as well as negatively affecting their overall well-being.”