WHO reviews ‘available’ evidence of airborne coronavirus infectionExBulletin

A 1940 photograph taken for infection research at the Massachusetts Institute of Technology shows respiratory droplets released through a sneeze.

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Betman / Betman Archive

A 1940 photograph taken for infection research at the Massachusetts Institute of Technology shows respiratory droplets released through a sneeze.

Betman / Betman Archive

who To tell The virus responsible for COVID-19 does not appear to remain in the air, and cannot spread through the air more than about three feet.

However, at least one expert on viral transmission said it was too early to know.

“I think WHO is irresponsible for providing that information. This misinformation is dangerous,” says Dr. Dr. Donald Milton, An infectious disease aerobiologist at the University of Maryland School of Public Health.

The WHO states that the virus, “according to current evidence”, is transmitted via “respiratory droplets and contact routes”. By that, the agency means that the virus was found in a large drop of mucus and saliva created through coughing and sneezing.

These droplets can travel a short distance in the air and either land on a person or later land on a surface that is touched. Stopping this type of transmission is a reason why public health officials urge people to wash their hands and avoid touching the face frequently, as the virus can contact the nose and mouth.

However, other viruses are transmitted to infected people in such a way that the bacteria can actually be suspended in the air for minutes or hours. Then, when others pass by, these airborne viruses can be inhaled. Measles is a good example of this type of transmission-Centers for Disease Control and Prevention To tell “The measles virus can remain infectious in the air for up to two hours after an infected person leaves the area.”

WHO states that this type of airborne transmission of the new coronavirus can be described as “ specific situations and settings under which aerosol-generating procedures are performed, such as when a patient is intubated in a hospital or disconnected from a ventilator. ” “It may be possible.

Based on this, authorities recommend “airborne precautions” when healthcare workers perform these procedures. Otherwise, according to the WHO, healthcare workers who care for COVID-19 patients may not use “droplet and contact precautions” much.

Milton is worried that little is known about this new virus, SARS-CoV-2, but it is inappropriate to draw conclusions about how to transmit it.

“I don’t think they know and they’re talking with hats on,” Milton says.

He states that some sharp black-and-white between the “ airborne ” virus, where people can remain in the air and float, and the virus that spreads only when embedded in larger, moist droplets picked up through close contact. He says he likes to think there is a difference, but the reality of infection is much more subtle.

“Epidemiologists say that if it’s” close contact, “it’s not airborne. It’s ridiculous, “he says.

When epidemiologists are working in the field and trying to understand the outbreak of an unknown pathogen, it is impossible to know exactly what is going on as the pathogen spreads from person to person Milton says. “Epidemiologists cannot tell the difference between droplet and short-range aerosol transmission.”

He says these are difficult questions to answer, and scientists still discuss how much of the flu transmission may be airborne. Some research show Exhaled gas clouds from humans contain a continuum of many droplet sizes, and “high-momentum clouds” created by coughing and sneezing can carry droplets over long distances.

In addition, one study of COVID-19 patients’ rooms found “Swabs taken from the exhaust port tested positive, suggesting that small droplets containing the virus could be displaced by the airflow and attach to equipment such as vents.”

Another study at Wuhan Hospital found In most areas, airborne viruses were either not detected or at low levels.

Faced with this uncertainty, Milton believes that WHO should “adopt precautionary principles and recommend airborne precautionary measures,” according to the CDC example.

“The US CDC has exactly that,” he said. Recommend Airborne precautionary measures for all situations, including COVID-19 patient care.

Of course, the world is suffering from a shortage of the most protective medical masks and gear. For the average person who does not work in the hospital, Milton says recommending 6 feet away from others sounds reasonable.

He says that if someone in the house is sick, it makes sense to have a mask worn and, if possible, break the windows to increase room ventilation. People shouldn’t pack their cars with windows around them, he said, and authorities need to keep crowded with mass transit vehicles like trains and buses.