'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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Trouble ‘Miyas’ everywhere only then they will leave Assam: Himanta Biswa Sarma
Says “Himanta Biswa Sarma, BJP are openly against them, we are saying it openly
New Delhi: Assam Chief Minister Himanta Biswa Sarma on Tuesday said that four to five lakh “Miya voters” would be removed from the electoral rolls in the state once the Special Intensive Revision (SIR) of voter lists is carried out. He also made a series of controversial remarks openly targeting the Miya community, a term commonly used in Assam in a derogatory sense to refer to Bengali-speaking Muslims.
Speaking to reporters on the sidelines of an official programme in Digboi in Tinsukia district, Sarma said it was his responsibility to create difficulties for the Miya community and claimed that both he and the BJP were “directly against Miyas”.
“Four to five lakh Miya votes will have to be deleted in Assam when the SIR happens,” Sarma said, adding that such voters “should ideally not be allowed to vote in Assam, but in Bangladesh”. He asserted that the government was ensuring that they would not be able to vote in the state.
The chief minister was responding to questions about notices issued to thousands of Bengali-speaking Muslims during the claims and objections phase of the ongoing Special Revision (SR) of electoral rolls in Assam. While the Election Commission is conducting SIR exercises in 12 states and Union Territories, Assam is currently undergoing an SR, which is usually meant for routine updates.
Calling the current SR “preliminary”, Sarma said that a full-fledged SIR in Assam would lead to large-scale deletion of Miya voters. He said he was unconcerned about criticism from opposition parties over the issue.
“Let the Congress abuse me as much as they want. My job is to make the Miya people suffer,” Sarma said. He claimed that complaints filed against members of the community were done on his instructions and that he had encouraged BJP workers to keep filing complaints.
“I have told people wherever possible they should fill Form 7 so that they have to run around a little and are troubled,” he said, adding that such actions were meant to send a message that “the Assamese people are still living”.
In remarks that drew further outrage, Sarma urged people to trouble members of the Miya community in everyday life, claiming that “only if they face troubles will they leave Assam”. He also accused the media of sympathising with the community and warned journalists against such coverage.
“So you all should also trouble, and you should not do news that sympathise with them. There will be love jihad in your own house.” He said.
The comments triggered reactions from opposition leaders. Raijor Dal president and MLA Akhil Gogoi said the people of Assam had not elected Sarma to keep one community under constant pressure. Congress leader Aman Wadud accused the chief minister of rendering the Constitution meaningless in the state, saying his remarks showed a complete disregard for constitutional values.
According to the draft electoral rolls published on December 27, Assam currently has 2.51 crore voters. Election officials said 4.78 lakh names were marked as deceased, 5.23 lakh as having shifted, and 53,619 duplicate entries were removed during the revision process. Authorities also claimed that verification had been completed for over 61 lakh households.
On January 25, six opposition parties the Congress, Raijor Dal, Assam Jatiya Parishad, CPI, CPI(M) and CPI(M-L) submitted a memorandum to the state’s chief electoral officer. They alleged widespread legal violations, political interference and selective targeting of genuine voters during the SR exercise, describing it as arbitrary, unlawful and unconstitutional.
