Saliva Droplets Could Transmit Coronavirus – Coronavirus Study
The US government scientists have found that when people speak, the tiny droplets of saliva that are sprayed into the air may be sufficient to spread coronavirus.
In Maryland, the US National Institutes of Health (NIH) researchers found that if a speaker were infected with the virus, there would be thousands of fine droplets released into the air when the speaker talks, which could pose a risk to others.
In normal speech, even in short phrases such as “stay healthy”, there are thousands of droplets that are too small to see with the naked eye are emitted. High-speed videography and laser imaging were used by scientists to show how the droplets are emitted.
In a report, the scientists claim that the findings may have vital implications for containing the pandemic, and the work is still preliminary and has not yet been peer-reviewed.
The researchers write, “The transmission rate can be significantly decreased, and the pandemic can be contained until a vaccine is available if every person adheres to social distancing and handwashing, and is made to wear any kind of cloth mouth cover in public as speaking and oral fluid viral loadcan prove to be a major mechanism of Sars-CoV-2 transmission.”
The ongoing debate over whether or not healthy people should wear face masks in public will be fueled by the results of this research. The US Centers for Disease Control and Prevention gave recent advice for people to wear cloth face covers when they visit places where it is hard to maintain physical distancing, such as grocery stores and pharmacies.
However, the World Health Organization had previously reviewed its stance on face masks and the US advice contrasts with this. WHO had restated that there was no evidence that people could be prevented from picking up infections such as Covid-19 by wearing a mask in public in its updated guidance published on Monday.
The WHO concedes that a mask may reduce the number of droplets they spray into the air and that the people who are infected with the virus but do not show symptoms can still spread the virus. Viruses can penetrate cloth masks, and can still invade the body through the eyes, and thus wearing a mask in public is unlikely to protect the wearer from the virus was their primary argument.
To detect otherwise invisible mists of droplets that are released when people speak, the US team, led by Adriaan Bax at the NIH’s Laboratory of Chemical Physics, repurposed laser instrumentation. As many as 360 saliva droplets when the phrase “stay healthy” was spoken was counted by them in a single 17-millisecond frame.
The scientists said the droplets are sufficiently large to carry a variety of respiratory pathogens, including the measles and influenza viruses though they have not analyzed the droplets for their ability to carry coronavirus particles.
The scientists said, “none of the spoken words would be causing a droplet to rise above the background if a damp homemade cloth mask is used and it can dramatically reduce droplet excretion.”
Saliva Droplets Could Transmit Coronavirus