'Strong evidence' COVID-19 predominantly spreads through air: Lancet study
New Delhi, Apr 16: There is consistent, strong evidence to prove that the SARS-CoV-2 virus, behind the COVID-19 pandemic, is predominantly transmitted through the air, according to a new assessment published on Friday in The Lancet journal.
The analysis by six experts from the UK, the US and Canada says public health measures that fail to treat the virus as predominantly airborne leave people unprotected and allow the virus to spread.
Although some studies in the past have suggested that COVID-19 may spread through air, overall scientific literature on the subject has been inconclusive.
In July last year, over 200 scientists from 32 nations wrote to the WHO, saying there is evidence that the coronavirus is airborne, and even smaller particles can infect people.
"The evidence supporting airborne transmission is overwhelming, and evidence supporting large droplet transmission is almost non-existent," said Jose-Luis Jimenez, from the University of Colorado Boulder in the US.
"It is urgent that the World Health Organization and other public health agencies adapt their description of transmission to the scientific evidence so that the focus of mitigation is put on reducing airborne transmission," Jimenez said.
The team, led by researchers at the University of Oxford in the UK, reviewed published research and identified 10 lines of evidence to support the predominance of the airborne route.
The researchers highlighted the super-spreader events such as last year's Skagit Choir outbreak in the US, in which 53 people became infected from a single infected case.
Studies have confirmed these events cannot be adequately explained by close contact or touching shared surfaces or objects, the researchers said in their assesment.
They noted that transmission rates of SARS-CoV-2 are much higher indoors than outdoors, and transmission is greatly reduced by indoor ventilation.
The team cited previous studies estimating that silent -- asymptomatic or presymptomatic -- transmission of SARS-CoV-2 from people who are not coughing or sneezing accounts for at least 40 per cent of all transmission.
This silent transmission is a key way COVID-19 has spread around the world, "supporting a predominantly airborne mode of transmission," according to the assessment.
The researchers also highlighted work demonstrating long-range transmission of the virus between people in adjacent rooms in hotels, who were never in each other's presence.
On the contrary, the team found little to no evidence that the virus spreads easily via large droplets, which fall quickly through the air and contaminate surfaces.
"We were able to identify and interpret highly complex and specialist papers on the dynamics of fluid flows and the isolation of live virus," said study lead author Trish Greenhalgh.
"While some individual papers were assessed as weak, overall the evidence base for airborne transmission is extensive and robust," Greenhalgh added.
He noted that there should be no further delay in implementing measures around the world to protect against such transmission.
The assessment has serious implications for public health measures designed to mitigate the pandemic, the researchers said.
They said "droplet measures" such as handwashing and surface cleaning, while important, should be given less emphasis than airborne measures, which deal with inhalation of infectious particles suspended in the air.
According to the researchers, if an infectious virus is primarily airborne, someone can potentially be infected when they inhale aerosols produced when an infected person exhales, speaks, shouts, sings, or sneezes.
They noted that some airborne control measures include ventilation, air filtration, reducing crowding and the amount of time people spend indoors.
Wearing masks whenever indoors, attention to mask quality and fit, and higher-grade PPE for healthcare and other staff when working in contact with potentially infectious people are some of the other control measures, according to the researchers.
"It is quite surprising that anyone is still questioning whether airborne transmission is the predominant transmission pathway for this virus or not," said study co-author Professor Kimberly Prather, from the University of California San Diego, US.
"Only by including inhalation of aerosols at both close and long range can we explain the many indoor outbreaks that have occurred around the globe. Once we acknowledge this virus is airborne, we know how to fix it, Prather said.
The researchers added that there are many examples of places that have fared much better by acknowledging this virus is airborne from the start, adding the world needs to follow their lead as soon as possible.
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Modi should leverage his ties with world leaders to de-escalate war in West Asia: Omar Abdullah
Jammu (PTI): Jammu and Kashmir Chief Minister Omar Abdullah on Monday said India can play a meaningful role in de-escalation in West Asia, given Prime Minister Narendra Modi's strong relations with the warring countries and their neighbours.
He said Pakistan was leveraging ties with Iran and the United States, and that any effort towards ending the war should be welcomed.
"As I said in the House (Assembly), we would like the war to end as soon as possible. The role that the prime minister can play may not be possible for anyone else because of his good relations with all these countries," Abdullah told reporters on the sidelines of a function here.
He, however, said any escalation would not be easy to manage.
"Any such move by US President Donald Trump, despite the long history of Iran resisting external domination, would not be easy," the chief minister said.
Asked about Pakistan mediating in the war, he said, "I will simply say that if any country can play a role in preventing this war, no one should have any objection to it."
He added, "I will repeat what I said … our prime minister has good and close relations with all countries — whether it is Israel, the United States, Iran, or the countries around Iran. If those relationships can be used to make some progress and help ease the situation, it would be a good thing."
Abdullah said attacks by terror groups like Lashkar-e-Taiba and Jaish-e-Mohammed in India, as suggested by a report from the United States, are not unlikely.
Meanwhile, he asserted that any efforts to end the war, be it from Pakistan, must not be resisted.
"Pakistan is using its good relations with Iran and the United States to its advantage, and it has done so. How can we object to that? If that angle helps in stopping the war, would you want them not to act and let the war continue? We want the war to stop. If any country can play a role in that, it should. And if we can play an even better role, then we should do so," he said.
On unemployment in J-K, the chief minister said the issue cannot be resolved overnight, and government jobs alone are not the solution.
He stressed the need to explore alternative avenues, highlighting the importance of Mission Yuva in promoting entrepreneurship.
"Mission Yuva provides not just funding but also support in preparing DPRs and post-startup assistance, such as marketing. In just nine months, distributing Rs 1,000 crore and approving numerous schemes is a significant achievement," he said.
Abdullah credited the coordination between the government and Jammu and Kashmir Bank for the scheme's progress.
