STANFORD (CBS SF) — A new study authored by a Stanford computer scientist found that indoor businesses were the biggest spreaders of COVID-19 — providing bad news for a restaurant industry struggling during the pandemic.
The study, published Tuesday in the weekly scientific journal Nature, found that around eight in every ten COVID cases diagnosed during the first months of the pandemic were infected while inside a public venue such as a restaurant or gym.
“Restaurants were by far the riskiest places, about four times riskier than gyms and coffee shops, followed by hotels,” Jure Leskovec, a Stanford computer scientist and lead author on the study, told the New York Times.
With help from researchers at Northwestern University, and San Francisco’s Chan Zuckerberg Biohub, Leskovec’s team used cell phone mobility data to follow the movements of 98 million people in and out of indoor public spaces over the earliest months of the pandemic. The data came from cell phone users in cities such as Atlanta, Chicago, Houston, Dallas, Los Angeles, Miami, Philadelphia, New York City, San Francisco and Washington D.C.
While virologists and health officers already believed that crowded indoor spaces increased the spread of COVID-9, the study provided hard data to back such claims, down to the hourly movements of subjects and the size of the indoor spaces they entered.
Nature published the study just as San Francisco Mayor London Breed announced that the city would shut down all indoor dining in the city by Friday night in order to stem off another spike in coronavirus cases — a 250% increase in cases since early October.
“I know this is not the news our residents and businesses wanted to hear, but as I’ve said all along, we’re making decisions based on the data we’re seeing on the ground,” Breed said when announcing the restaurant reopening rollback on Tuesday.
A local restaurant lobbying group, the Golden Gate Restaurant Association (GGRA), lightly pushed back against Breed’s order while promoting compliance with indoor dining rules in a statement <a href=”http://” rel=”noopener” target=”_blank”>to Eater SF. While insisting that there’s no casual link between COVID cases and indoor dining, the association “continues to remind our members to follow all COVID-19 safe practices and guidelines.”