- We continue to see more and more conclusive evidence that the novel coronavirus is spreading through the air.
- Airborne COVID-19 transmission occurs through tiny droplets and aerosols that disperse infected people when they cough, sneeze, cry, or even just talk.
- A new study shows that coronavirus aerosols contain the live virus that can infect and multiply in cells, and it proves that the pathogen can travel much farther through the air than the six-foot recommendation for social distance.
It is not only when we cough and sneeze that we release invisible projectiles from the mouths that may contain pathogens such as the novel coronavirus. It also happens when you cry, sing, or even just talk. But there is an enormous difference between the types, size, and behavior of these drops. Coughing and sneezing project larger droplets that generally lie on the ground within six feet of the infected person as gravity pulls them down. But the microdroplets that arise during the conversation are much smaller and their water content can evaporate quickly, and they convert into aerosols. The aerosols can then move freely in the air, hang for longer periods and travel much farther than the six feet we have all been told.
More than 200 scientists asked the World Health Organization (WHO) a few weeks ago to recognize the aerosol transfer of COVID-19. The organization eventually did, but insisted that drip transmission is the most important way COVID-19 is distributed. Since then, we have seen an increasing number of studies that prove the least about the new coronavirus: The virus ends up trapped in aerosols, and these aerosols are highly infected.
Scientists from the University of Nebraska were able to collect virus samples from the air in hospital rooms and showed that some of the aerosols had live viruses that could replicate in cells. Another study that looked at the outbreak of the Diamond Princess coronavirus from early February concluded that airborne transmission was a major factor in COVID-19 spread on board the ship. Finally, a separate study showed that numerous people may be at greater risk for the disease, and transmission in the air is the only thing that can explain the phenomenon.
This brings us to the latest investigation into the case, a University of Florida study that not only showed that the virus is infected in aerosols, but it can spread through the air well beyond the six feet that authorities remain called as a safe distance.
Researchers invented a new method for capturing aerosols from the air, which could be better than alternatives. May The New York Times, they have a sampler that uses pure water vapor to increase the aerosols so that they can be collected from the air. Then the equipment transports them to a liquid rich in salt, sugar, and protein.
Using the device, the researchers collected samples from a room in a COVID-19 ward at the University of Florida Health Shands Hospital. None of the patients in the room were subjected to any medical procedure that could generate aerosols. The WHO and others say it would be the primary source for airborne transmission in a hospital.
The samplers were placed at about seven feet and 16 feet of the patients, and both collected infection for virus in a dish. The researchers found that the genomic sequence of the isolated virus was identical to that from a swab of a newly admitted asymptomatic patient in the room.
Of note, the room was equipped with efficient air filters and ultraviolet radiation that should inactivate the virus before the air is re-introduced into the room. That may be why the researchers found only 74 virus particles per liter of air.
If this is not a smoke pistol, then I do not know what is. Successful isolation (cytopathic effect) of SARS-CoV-2 in aerosols collected 2-5 m from patients, genome identical to NP swab, TCID50: genomic copies close to 1: 1! / 1 https://t.co/OJ7jo2P2a0
– Linsey Marr (@linseymarr) August 6, 2020
This is definitive evidence that aerosolized virus is still viable, and that it can travel well over six feet. What no study has found out is the amount of virus in the aerosol that needs to be inhaled to induce an infection. But the findings are relevant to managing the pandemic, especially when it comes to indoor activities and re-education. Places that do not lack good ventilation may have an increased amount of coronavirus aerosols floating in the air.
The Times points to one discrepancy in this study. The scientists found as much viral RNA as they did infected viruses. Other methods discovered 100 times more genetic material than the viral load. As with other coronavirus studies, more research may be needed to verify these findings. And this is not peer-reviewed at the time of this writing.
But other experts agree that the conclusions are important. “This is what people have known themselves for,” said Drs. Linsey Marr. “There is clear evidence that there is an infected virus in aerosols.” Marr is an expert in spreading airbus virus, but was not involved in the investigation.
Columbia University virologist Angela Rasmussen said The Times that while she was not sure that the amount of virus in that hospital room “is high enough to cause an infection”, the conclusion that you can culture viable virus from the air “is not a small thing.”
The full study is available at this link.
Chris Smith began writing about gadgets as a hobby, and before he knew it, he was sharing his views on tech things with readers all over the world. Every time he does not write about gadgets, he manages to get away with it, even though he tries desperately. But that’s not necessarily a bad thing.
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