A new study published in the medical journal Lancet claimed that SARS-CoV-2 virus that causes Covid-19 is primarily transmitted through the air. It went on to say that failing to treat the virus as primarily airborne leaves people vulnerable and allows the virus to spread.
According to the medical journal, six experts from the United Kingdom, the United States, and Canada have stated that “consistent and strong evidence” is available to support this claim.
Jose-Luis Jimenez, a chemist at the Cooperative Institute for Research in Environmental Sciences (CIRES) and the University of Colorado Boulder, said, “The evidence supporting airborne transmission is overwhelming, and evidence supporting large droplet transmission is almost non-existent.”
“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 experts, led by Trish Greenhalgh of the University of Oxford, reviewed published research and found ten lines of evidence to support the airborne route’s supremacy. Super-spreader cases, such as the Skagit Choir epidemic, where 53 people were infected from a single infected case, are at the top of their list. Near contact or touching shared surfaces or objects cannot sufficiently describe these cases, according to studies.
SARS-CoV-2 transmission rates
Furthermore, SARS-CoV-2 transmission rates are much higher indoors than outdoors, and indoor ventilation significantly reduces transmission.
Silent (asymptomatic or presymptomatic) transmission of SARS-CoV-2 from people who are not coughing or sneezing accounts for at least 40% of all transmission, according to reports. According to the assessment, COVID-19 has spread around the world primarily through silent transmission, “supporting a predominantly airborne mode of transmission.”
The researchers also cited studies that showed long-distance transmission of the virus between people in adjacent hotel rooms who had never met before.
The team, on the other hand, found little to no evidence that the virus spreads rapidly through the air and contaminates surfaces through large droplets.
“We were able to identify and interpret highly complex and specialist papers on the dynamics of fluid flows and the isolation of live virus,” lead author Greenhalgh said. “While some individual papers were assessed as weak, overall the evidence base for airborne transmission is extensive and robust. There should be no further delay in implementing measures around the world to protect against such transmission.”
The new research has major consequences for public health efforts to combat the pandemic. First, while “droplet measures” like handwashing and surface cleaning are essential, they should be prioritized over airborne measures, which address inhalation of infectious particles suspended in the air.
Someone can become infected by inhaling aerosols created when an infected person exhales, talks, yells, sings, or sneezes if an infectious virus is mainly airborne. Ventilation, air filtration, minimizing crowding and the amount of time people spend indoors, wearing masks while indoors (even if not within 6 feet or 2 metres of others), paying attention to mask consistency and fit, and higher-grade PPE for healthcare and other workers working in contact with potentially contagious people are all examples of airborne control steps.
“It is quite surprising that anyone is still questioning whether the airborne transmission is the predominant transmission pathway for this virus or not,” said co-author Professor Kimberly Prather, an aerosol scientist from the University of California San Diego. “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. There are many examples of places that have fared much better by acknowledging this virus is airborne from the start. The world needs to follow their lead as soon as possible.”