"Coronavirus is Airborne", Scientists tell WHO! Is this a new Threat? Report

More than 200 scientists from 32 countries have written to the World Health Organization (WHO) stating that there is evidence that the coronavirus is airborne and that smaller particles can spread through air and infect people. 

However, WHO has been claiming so far that COVID19 primarily spreads only through coughs and sneezes. 

A report in The New York Times cites that clusters of infections are rising globally as the lockdowns are being removed and people are slipping back to normalcy. 

"In an open letter to the WHO, 239 scientists in 32 countries have outlined the evidence showing that smaller particles can infect people, and are calling for the agency to revise its recommendations," the report said and also added that researchers are planning to publish their letter in a scientific journal next week.

"If airborne transmission is a significant factor in the pandemic, especially in crowded spaces with poor ventilation, the consequences for containment will be significant. Masks may be needed indoors, even in socially-distant settings. Health care workers may need N95 masks that filter out even the smallest respiratory droplets as they care for coronavirus patients," the NYT report said.

What does Airborne Transmission Mean? 

Respiratory infections such as COVID19 spread through droplets of different sizes. When the droplets particles are larger than 5-10 microns in diameter, they are called respiratory droplets and if they are smaller than 5 microns in diameter, they are called as droplet nuclei. “According to current evidence, Covid-19 virus is primarily transmitted between people through respiratory droplets and contact routes,” the WHO states.

However, the letter which was written by scientists state that aerosol transmission too can happen. WHO is of the view that if the droplets are larger than 5-10 microns in diameter, it will eventually fall to the ground due to gravity, after travelling for less than 1 metre.

Whereas, the scientists believe that even droplet nuclei that are less than 5 microns in diameter can have the virus and travel for longer than 1 metre and eventually stay in air for a longer time. If this is true, the risk of transmission will be higher than what it was previously. 

What is the evidence so far on the aerosol transmission?

A study conducted in Renmin Hospital and Wuchang Fangcang Field Hospital in Wuhan found that the concentration of the virus in aerosols detected in isolation wards and ventilated room was very low, whereas it was “higher in the toilet areas used by the patients”. “Levels of airborne SARS-CoV-2 RNA in the most public areas was undetectable, except in two areas that were prone to crowding,” the study stated.

“Although we have not established the infectivity of the virus detected in these hospital areas, we propose that SARS-CoV-2 may have the potential to be transmitted through aerosols,” the study mentions. 

WHO’s response to the scientists is awaited.