CDC broadens definition of who's at risk of getting coronavirus

The CDC on Wednesday ramped up its criteria for who's at risk of contracting the coronavirus, in a move with major implications for school and workplace reopenings.

The updated guidance defines a “close contact” as anyone who spends at least 15 minutes within six feet of an infected individual over a 24-hour period. The agency previously applied that designation to people who spent 15 consecutive minutes within six feet of someone with Covid-19.

"Individuals who had a series of shorter contacts but over time added up to more than 15 minutes became infected," CDC Director Robert Redfield said at a briefing, citing a study of multiple non-consecutive exposures. Redfield was joined by HHS Secretary Alex Azar and Jay Butler, the CDC's deputy director for infectious diseases, who warned that the U.S. is showing a "distressing trend" with cases surging over 75 percent of the country.

The details: The guidance is based on a study out today showing brief exposures to infected individuals and resulted in virus spread. The study involved a Vermont correctional facility employee who tested positive after short interactions with multiple inmates who were infected.

The study said the correctional officer was never with the inmates for 15 consecutive minutes. The Vermont Department of Health said the officer wore a cloth mask, gown and goggles and had 22 interactions totaling about 17 minutes with six unmasked inmates who tested positive for the virus.

What's next: The updated guidance could change how public health departments across the country conduct their contact tracing, by increasing the pool of potentially infected individuals. It also could upend plans to reopen schools and businesses that had been based around the earlier guidance, as President Donald Trump continues to call for a return to pre-pandemic conditions. The CDC in May released guidelines for reopening schools that Trump later disavowed, saying they were too burdensome.

The U.S. is reporting an average 60,000 cases per day with the Midwest seeing the largest increases in cases. Officials warned conditions could get worse as the cold weather sends people indoors, where the virus can spread more rapidly.

So far, there have been 8.3 million reported cases in the U.S. and more than 221,000 deaths.