Burden of RSV falls mainly on youngest children, study finds, stressing need for better prevention

Nearly half of children hospitalized for RSV in Canada's pediatric hospitals in recent years were under six months of age, a new study has found, calling attention to the need for preventative options to ease the pressure on intensive care units caring for the sickest.

In research published Wednesday in JAMA Network Open, Dr. Jesse Papenburg and his team from the Canadian Immunization Monitoring Program Active (IMPACT) looked at the number and severity of hospital admissions associated with respiratory syncytial virus (RSV) at 13 pediatric hospitals, from 2017 to 2022.

Infections in that period resulted in 11,000 hospitalizations, with nearly half — or 5,488 — being children under six months of age. Doctors in other countries, such as the U.S. and Denmark, noticed a similar trend.

Hospitalizations also increased in the most recent year of the study, compared to pre-pandemic times, with nearly a quarter of the kids needing ICU care, like mechanical ventilation.

RSV causes infection of the lungs and the respiratory tract. The virus generally leads to cold-like symptoms, such as runny nose, cough and fever, but it can be severe in some people, including children under two and older adults with pre-existing conditions.

In babies, mucus and other secretions can plug up small airways and make it hard for them to breathe, pediatricians say. They might need oxygen or become dehydrated and need hospitalization.

"Last season … was really incredible in terms of how, across the country, we saw an early and very intense RSV season, with peak levels of activity occurring [in] late October, November and then trailing off," said Papenburg, one of the study's senior authors and a pediatric infectious diseases specialist at the Montreal Children's Hospital.

"RSV typically affects us mostly during the dark months of winter."

Mila Olumogba's infant son, Adeyemi, spent two weeks in the ICU at CHEO in Ottawa last year, recovering from RSV, when he was only 10 weeks old. One of Olumogba's older children likely brought the virus home.

Olumogba said she hadn't even heard of RSV until the baby became lethargic and the normally voracious eater stopped breastfeeding. When he appeared limp and his whole body struggled just to take a breath, Olumogba took him to the emergency department.

When the test came back positive for RSV, he was moved to the ICU, put in an induced coma and was on mechanical ventilation that resembled scuba gear, she recalled.

"The staff kept telling me, it's gonna get really bad before it gets better and you just need to prepare yourself for that," Olumogba said.

When Adeyemi's breathing stopped, Olumogba watched staff resuscitate her baby. "It's honestly the most traumatic experience that you can go through," she said.

Prior to infection, doctors planned to offer Olumogba a preventive treatment for Adeyemi, because he was considered to be high risk, born with a small hole in the lower chambers of his heart that's now closed.