Superspreaders might be unknowingly driving the COVID-19 pandemic

On Monday, California reported more than 7,000 new COVID-19 cases, and other parts of the U.S. are seeing COVID-19 spikes too, including Texas, Arizona, and Florida.

This might be due to a small fraction of people infecting the majority of the population, according to James Lloyd-Smith, a professor of ecology and evolutionary biology at UCLA. He’s been studying superspreader events since the SARS outbreak.

The large daily jumps shows how much of the U.S. hasn’t been exposed to the virus, he says.

“We're still a big pile of fuel that the virus still has the potential to burn through. … We need to keep up with the precautions and not let our eye off the ball. Because there is still the risk of some pretty awful outcomes,” he says.

He says at least two factors define a superspreader: their innate biology and their behavior. Superspreaders might be able to hold larger amounts of the virus inside their bodies. Despite the biological component, Lloyd-Smith says it comes down to how much contact superspreaders have with others.

“A significant part of it has to come from contact and getting into situations where there are other so-called susceptible people around ... and where you're contacting them at close enough distance and for a long enough duration that a significant fraction of them get infected,” he says.

The one thing that helps prevent potential superspreaders from infecting others? Masks, Lloyd-Smith says.

—Written by Danielle Chiriguayo and Amy Ta, produced by Angie Perrin