CDC updates guidelines with airborne transmission
Agency: 6 feet is not necessarily far enough
The Centers for Disease Control and Prevention has updated its website to warn that the coronavirus can spread through the air, something public health experts have been warning about for months but went unacknowledged by the agency until Monday.
The CDC says people can be exposed to the virus in small droplets and particles that can linger in the air for minutes to hours, potentially infecting people who are farther than 6 feet away and even people who come into the area after an infected person has left.
“There is evidence that under certain conditions, people with COVID-19 seem to have infected others who were more than 6 feet away,” the CDC says on its website.
The CDC’s previous guidance said the virus spreads primarily among people who are in close contact with one another – within about 6 feet – through respiratory droplets produced when an infected person coughs, sneezes or talks. The current guidance says that’s still the greatest risk.
Scientists have warned for months that the virus could be spread through tiny aerosols that spread farther and hang in the air longer than previously known. The World Health Organization, lobbied by hundreds of scientists, noted that risk in July.
In September, the CDC attempted to address airborne transmission, revising its guidelines to say, “There is growing evidence that droplets and airborne particles can remain suspended and be breathed in by others, and travel distances beyond 6 feet (for example, during choir practice, in restaurants, or in fitness classes).”
However, a few days later the language on the CDC’s website was switched back to the previous information, without mention of airborne transmission. A note was added to say the agency was still working on its recommendations regarding the airborne transmission of SARS-CoV-2, the virus that causes COVID-19.
The CDC has not responded to USA TODAY’s request for comment on the
latest revision.
The CDC’s update on airborne transmission follows a string of confusing changes to its guidelines on testing of people who don’t show symptoms.
The agency once said testing was recommended “for all close contacts of persons with SARS-CoV-2 infection.” In August, that was updated to say people do not “necessarily need a test” if they don’t show symptoms, even if they’ve been in close contact with an individual with a confirmed or suspected case of COVID-19.
That change spurred widespread criticism because people often don’t develop symptoms for a couple of days, but they can still transmit the disease to others during that time.
In September the CDC changed course again, saying if you’ve been in close contact with an infected person and don’t have symptoms, “you need a test.”
“Inconsistent messaging is always a drawback in public health interventions, including in our response to COVID-19,” Ogbonnaya Omenka, an assistant professor who specializes in public health at Butler University’s College of Pharmacy and Health Sciences, told USA TODAY. “It can breed suspicion and distrust from the public.”
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