Use this pediatric COVID calculator to measure back-to-school risk

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A team of medical researchers at UC San Francisco Benioff Children's Hospital have created an interactive calculator to estimate, for any county in the U.S., the likelihood that a group of asymptomatic children will contain at least one child with COVID-19.

“[The calculator] uses publicly available data on COVID rates in the general population,” says Dr. Dylan Chan, a pediatric ear, nose and throat doctor at UC San Francisco Benioff Children's Hospital. “We wanted to use that data, which is readily available, to help provide an estimate for asymptomatic pediatric infection rates, which is not readily available.”

This information could prove valuable as teachers and school officials decide whether it’s safe for kids to return to the classroom, and in what numbers.

Dr. Chan gives an example: If a group of 26 asymptomatic kids in LA County met up this past week, there’s a 67% likelihood that at least one of those kids would have been COVID positive. He says that seems like a high risk level, but it doesn’t necessarily mean the student will spread it.

“This is providing the chance that one of these kids would be positive for the virus. And what we mostly know is that kids actually are very inefficient at transmitting COVID infections to other people,” he says.

He hopes the calculator will help educators make data-driven decisions surrounding class size, social distancing, and enforcing masking among kids and teachers. For example, cutting the class size in half cuts the likelihood percentage in half.

“It is never going to be possible to completely eliminate risk. [We should be] focusing our efforts and resources into constructing safe environments, using tried and true things like masks and social distancing and reduced class size to minimize that risk rather than eliminate the risk.”



  • Dylan Chan - MD, PhD - pediatric ear, nose and throat doctor, UCSF Benioff Children's Hospital