People wearing face masks to help curb the spread of the coronavirus walk on a pedestrian crossing in Tokyo.
Hundreds of health experts including scientists, researchers in a big claim based on evidence have said that coronavirus is an airborne disease and have urged the World Health Organisation (WHO) to review its guidance, advisories on how the disease is transmitting. In a report published in the New York Times, it says cases of coronavirus are increasing as people have started going back to restaurants, bars, offices, markets and casinos, leading to an increase in clusters of the virus. As people continue to get infected, the trend confirms that the virus lingers in the air indoors, infecting those nearby.
Coronavirus is airborne: What is an airborne disease
People wearing face masks to help curb the spread of the coronavirus walk through a shopping street in Tokyo. Japan lifted a seven-week pandemic state emergency in late May, and social and business activity have since largely resumed.
An Airborne disease is any disease that is caused by pathogens that can be transmitted through the air over time and distance by small particles. Such diseases include many of considerable importance both in human and veterinary medicine.
Is coronavirus airborne: What we know
- "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 New York Times report said.
- The report said the researchers plan to publish their letter in a scientific journal next week.
- WHO has long held that coronavirus spreads through large respiratory droplets coming out of mouth or nose whenever a person sneezes, coughs or speaks that are inhaled by another person.
- In its latest update dated June 29 on the coronavirus, the WHO said airborne transmission of the virus was possible only after medical procedures that produce aerosols, or droplets smaller than 5 microns.
- The guidance that the health agency (WHO) has given to deal with the virus, such as wearing masks, maintaining social distance and frequent handwashing, since the pandemic first broke is based on its claim that the virus spreads through large droplets when an infected person coughs and sneezes. Therefore, scientists have now urged the world health body to review its advisories on how the disease is spreading.
- As the pandemic spread across the world, a lag by the global health agency in issuing critical guidelines was seen as hampering efforts to control the outbreak.
- It lagged behind most of its member nations in endorsing face coverings for the public.
- While many organisations, including The Centers for Disease Control and Prevention have long since acknowledged the importance of transmission by people without symptoms, the WHO still maintains that asymptomatic transmission is rare.
- The NYT report says that many experts said the WHO should embrace what some called a "precautionary principle” and others called "needs and values" — the idea that even without definitive evidence, the agency should assume the worst of the virus, apply common sense and recommend the best protection possible.
- "There is no incontrovertible proof that SARS-CoV-2 travels or is transmitted significantly by aerosols, but there is absolutely no evidence that it's not," said Dr Trish Greenhalgh, a primary care doctor at the University of Oxford in Britain.
- "So at the moment we have to make a decision in the face of uncertainty, and my goodness, it’s going to be a disastrous decision if we get it wrong. So why not just mask up for a few weeks, just in case?" Dr Trish said.
What if coronavirus is airborne?
People put on masks while walking their dog, Boker, on Sunset Blvd, in West Hollywood, Calif. Sheriff's deputies in West Hollywood will issue citations to people who are not wearing masks in public, ramping up enforcement that previously had largely been imposed without penalties.
- "If airborne transmission is a significant factor in the pandemic, especially in crowded spaces with poor ventilation, the consequences for containment will be significant", say scientists according to NYT report.
- 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.
- The report said that ventilation systems in schools, nursing homes, residences and businesses may need to minimise recirculating air and add powerful new filters.
- "Ultraviolet lights may be needed to kill viral particles floating in tiny droplets indoors," the report says.
What WHO's technical lead on infection control says
WHO’s technical lead on infection control Dr Benedetta Allegranzi, however, said in the report that the evidence for the virus spreading by air was unconvincing.
"Especially in the last couple of months, we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence. There is a strong debate on this," she said.
Scientists, WHO consultants on whether coronavirus is airborne
Scientists urge WHO to review its coronavirus guidance. (Representational image)
- Interviews with nearly 20 scientists, including a dozen WHO consultants and several members of the committee that crafted the guidance, and internal emails "paint a picture of an organization that, despite good intentions, is out of step with science," the report said.
- "Whether carried aloft by large droplets that zoom through the air after a sneeze, or by much smaller exhaled droplets that may glide the length of a room, these experts said, the coronavirus is borne through air and can infect people when inhaled," it said.
- Experts pointed out that WHO's infection prevention and control committee is "bound by a rigid and overly medicalized view of scientific evidence, is slow and risk-averse in updating its guidance and allows a few conservative voices to shout down dissent".
- "They’ll die defending their view," one longstanding WHO consultant was quoted as saying in the report.
- The WHO was relying on a dated definition of airborne transmission. The agency believes an airborne pathogen, like the measles virus, has to be highly infectious and to travel long distances, said Linsey Marr, an expert in airborne transmission of viruses at Virginia Tech.
WHO's chief scientist on coronavirus
WHO’s chief scientist Dr Soumya Swaminathan said in the report that agency staff members were trying to evaluate new scientific evidence as fast as possible, but without sacrificing the quality of their review. She said the UN health agency will try to broaden the committees’ expertise and communications to make sure everyone is heard.
"We take it seriously when journalists or scientists or anyone challenges us and say we can do better than this. We definitely want to do better," she said.
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