CDC withdraws guidance on airborne spread of SARS-CoV-2

The US Centers for Disease Control and Prevention (CDC) recently released new guidance, recognizing that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be spread through aerosols. Now, the health agency retracts its statement by removing the updates published on September 18.

Transmission electron micrograph of SARS-CoV-2 virus particles isolated from a patient. Image captured and color enhanced at NIAID’s Integrated Research Facility (IRF) at Fort Detrick, Maryland. Credit: NIAID

The first update to the page said that coronavirus disease (COVID-19) spreads most often between people who are in close contact with each other and that the virus can be spread through respiratory droplets or small particles, such as those from aerosols produced when a person sneezes, coughs, talks, sings, or breathes.

In addition, the health agency said that these aerosols could be suspended in the air and inhaled through the nose, mouth, airways and lungs. The CDC also recognized that there is mounting evidence that droplets and aerosols can remain suspended in the air, that people can breathe.

Particles in the air can travel beyond six feet, such as in choir practice situations, gym classes, and restaurants, particularly areas without adequate ventilation.

Many health experts applauded the CDC for acknowledging the spread of the virus in the air. They said the CDC update on Friday was one of the clearest acknowledgments by a public health organization that SARS-CoV-2 can spread through airborne particles and travel long distances.

However, a few days later, the health agency retracted its first update and removed parts where it recognized the airborne spread of the new coronavirus.

New update

In the new page update on September 21, the CDC removed the part where it says that SARS-CoV-2 can spread through airborne particles. Instead, the CDC said COVID-19 will be spread primarily through close person-to-person contact.

“A draft version of the proposed changes to these recommendations was mistakenly posted on the agency’s official website. CDC is updating its recommendations regarding airborne transmission of SARS-CoV-2 (the virus that causes COVID-19). Once this process is complete, the updated language will be published, ”the agency said.

Additionally, the CDC said the virus is most often transmitted through respiratory droplets that are produced when an infected person coughs, sneezes or talks. The agency removed the part that the virus can spread when infected people sing or breathe.

“These droplets can fall into the mouth or nose of people who are close or possibly be inhaled into the lungs,” said the health agency, removing the part where it said that the droplets or virus particles could enter the body through of the eyes.

The CDC still recognized that asymptomatic spread is present, where the virus can spread even if people have no symptoms.

“We are still learning about how the virus spreads and the severity of the disease it causes,” he added.

No change in COVID-19 transmission guidelines: WHO

Meanwhile, the World Health Organization (WHO) said it would change its policy on airborne transmission of SARS-CoV-2, noting that the main mode of transmission of the virus is through respiratory droplets. However, Mike Ryan, executive director of the WHO emergency program, said that in confined and crowded spaces with inadequate ventilation, aerosol transmission can occur.

The move to recognize the possibility of airborne transmission was promoted by a group of more than 200 scientists from around the world, and they said there is evidence that the virus can hang in the air and travel certain distances.

“COVID-19 outbreaks have been reported in some closed places, such as restaurants, nightclubs, places of worship or workplaces where people were perhaps shouting, talking or singing. In these outbreaks, the transmission of aerosols cannot be ruled out, particularly in these indoor places where there is overcrowding and spaces with inadequate ventilation where infected people spend long periods with other people, ”says the WHO on its website.

“More studies are urgently needed to investigate such cases and assess their importance for COVID-19 transmission,” he added.

The coronavirus pandemic has reached 188 countries, infecting more than 31.4 million people and claiming at least 967,000 lives. The United States has the highest number of cases, with more than 6.88 million infections and more than 200,000 deaths. They are followed by India and Brazil, with more than 5.56 million and 4.55 million cases, respectively.