The US Centers for Disease Control and Prevention has updated guidelines on their website to say that coronavirus can commonly spread “through respiratory droplets or small particles, such as those in aerosols,” which are also produced when a person breathes. .
“Airborne viruses, including COVID-19, are among the most contagious and easily spread,” the site now states.
Previously, the CDC page stated that Covid-19 was thought to spread mainly among people in close contact – around 6 feet – and “through respiratory droplets produced when an infected person coughs, sneezes or talks.”
The page, updated on Friday, still says Covid-19 is most commonly spread among people who are in close contact with each other, and now says the virus is known to spread “through respiratory droplets or small particles, such as those in aerosols, produced. when an infected person coughs, sneezes, sings, talks or breathes. “
These particles can cause infections if “inhaled into the nose, mouth, airways and lungs,” he says. “This is thought to be the primary way the virus spreads.”
“There is growing evidence that droplets and airborne particles can remain suspended in the air and be breathed in by others, and travel distances greater than 6 feet (for example, during choir rehearsals, in restaurants, or in dance classes. fitness), “the page now says. “In general, indoor environments without good ventilation increase this risk.”
The CDC has also added new measures to its information about protecting yourself and others.
Previously, the CDC suggested maintaining a “good social distance” of about 6 feet, washing hands, cleaning and disinfecting surfaces regularly, and covering the mouth and nose with a mask when around others.
Now it says “stay at least 6 feet away from others whenever possible” and continues to direct people to wear a mask and clean and disinfect regularly. However, he now also says that people should stay home and isolate themselves when they get sick and “use air purifiers to reduce airborne germs in indoor spaces.”
Masks, he notes, shouldn’t replace other preventative measures.
The update also changed the language about asymptomatic transmission from saying “some people without symptoms may be able to spread the virus” to saying “people who are infected but show no symptoms can spread the virus to others”.
Scientists pushed for recognition of airborne transmission
For months, scientists have noticed the likelihood of coronavirus transmission through airborne viral particles and have prompted health agencies to recognize it.
In April, a prestigious panel of scientific experts told the White House in a letter that research showed that the coronavirus can be spread not only by sneezing or coughing, but also by simply talking, or perhaps even just breathing.
“While the current [coronavirus] specific research is limited, available study results are consistent with the aerosolization of the virus from normal breathing, “according to the letter, written by Dr. Harvey Fineberg, former dean of the Harvard School of Public Health and chair of the NAS Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats.
“The research currently available supports the possibility that [coronavirus] it could be spread via bioaerosols generated directly from patients’ exhalation, “the letter said.
And in July, 239 scientists published a letter urging the World Health Organization and other public health organizations to be more open to the likelihood that people could contract the virus from droplets floating in the air.
“Current guidance from numerous international and national bodies focuses on hand washing, social distance maintenance and droplet precautions,” the scientists wrote in the letter, published in the journal Clinical Infectious Diseases.
“Most public health organizations, including the World Health Organization, do not recognize airborne transmission except for aerosol-generating procedures performed in health care facilities. Hand washing and social distancing are appropriate, but at our opinion is insufficient to provide protection from the respiratory tract carrying micro-drops viruses released into the air by infected people, “they added.
Following the published letter, WHO released a report detailing how coronavirus can pass from one person to another, including through the air during some medical procedures and possibly the air in crowded indoor spaces.
On Sunday one of the letter’s lead authors, Donald Milton, a professor of environmental health at the University of Maryland who studies how viruses are transmitted, said the CDC’s new language was a “major improvement.”
“I am very encouraged to see that the CDC is paying attention and moving with science. The evidence is piling up,” Milton wrote in an email to CNN.
He described a pre-press paper published in August – in which scientists described the cultivation of viable viruses from the air in a hospital – as “an important addition to reports of major epidemics that were clearly the result of aerosol transmission. traveling more than 6 feet. ”
“It is time for the WHO to recognize these advances in science,” said Milton.
Video: CDC updates guidelines for asymptomatic Covid-19 test (CNN)
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