Two childhood viruses close to zero, ‘good side effect of COVID-19’, says pediatrician in Utah

Two illnesses that typically hit children hard in winter – pediatric flu and RSV – are virtually non-existent this year due to the COVID-19 pandemic, a leading pediatrician in Utah said.

The bad news: The two could return with a vengeance next year.

At Intermountain Primary Children’s Hospital, doctors haven’t hospitalized any children with RSV this season – and only one child in Utah has been hospitalized with the flu, said Dr. Andrew Pavia, director of epidemiology at Primary Children’s and Head of Pediatric Infectious Diseases at the University. of Utah Health.

In most years, according to Pavie, 80 children a week would be admitted to Primary for children with RSV, with a third of them going to the intensive care unit.

As for the flu, Pavia said, the Federal Centers for Disease Control and Prevention have reported around 1,400 cases of pediatric influenza nationwide – whereas, in an average year, “that number would be around 500,000, ”he said.

“We are seeing something that I have never seen in the past 35 years,” Pavia said Monday during the Intermountain Healthcare community’s weekly coronavirus briefing on Facebook Live. “This is really, really, one of the good side effects, if you will, of the COVID-19 pandemic.”

Part of the flu drop can be attributed to COVID-19 travel restrictions, Pavia said, as flu strains are typically carried by people from other countries. Pavia added that masks, hand washing and social distancing are known to mitigate the spread of the flu – and taking these public health measures for COVID-19 is “a natural experiment where we are in control. [the flu] really dramatically, ”Pavia said.

The drop in RSV, which stands for respiratory syncytial virus, “is a little more baffling,” Pavie said. A major symptom of RSV is a runny nose, and nasal secretions are the main way the virus is spread – so masks and hand washing are likely to limit the amount of these secretions.

Children under 3, who are most susceptible to RSV, do not congregate as much during the pandemic, with fewer play dates and daycare visits, Pavia said. He also noted that older siblings who are learning online or having fewer days of school in person do not report as many viruses home.

All of this explains why the number of RSVs would drop, Pavie said, but not why “it is practically zero across the country”.

One theory that experts are discussing, although there isn’t much evidence to support it yet, Pavia said, “is that viruses interfere with each other. And when a virus dominates the jungle, it forces all the other animals out, basically. … Viruses have these weird interactions that we don’t fully understand.

Those low flu and RSV rates are unlikely to last for next year, Pavie said.

“It’s very likely that when the flu and RSV have been gone for a while, you’ll have more fully susceptible people,” Pavia said. “So when it happens it spreads more dramatically and we see more serious disease.”

Flu rates tend to fluctuate, Pavie said, with a mild year often followed by a severe year. RSV, on the other hand, “depends a lot on the presence, each year, of a new generation of babies who are completely sensitive to RSV. In Utah, 50,000 other good hosts can be attacked by the virus. This year we’re going to have a whole year of kids who have never seen RSV. So next year we will have twice as many naive infants sensitive to it.

Doctors in Western Australia, Pavia said, noticed that RSV was largely absent in June and July – when it’s winter in the southern hemisphere – as the country brought its spread of COVID under control – 19. Recently, as COVID-19 restrictions were relaxed there, doctors saw a huge increase in RSV during the Australian summer.

“RSV is going to do something really strange when he comes back,” Pavia said. “We really can’t predict that very well. Our instinct is that he will come back and we will have a bad RSV year when he comes back.