A collaborative study conducted by a group of scientists from CSIR-CCMB, Hyderabad and CSIR-IMTech, Chandigarh along with hospitals in Hyderabad and Mohali has confirmed airborne transmission of SARS-CoV-2.
The study is published in the Journal of Aerosol Science.
The exact mechanism of spread of the coronavirus SARS-CoV-2 remains elusive. Previously thought to spread through surfaces, epidemiologists found that countries where people wore masks during the pandemic were less severely affected. However, there was a lack of quantitative evidence showing infectious coronavirus particles in the air.
Scientists analyzed the genome content of the coronavirus from air samples collected from different areas occupied by COVID-19 patients. These included hospitals, closed rooms in which only COVID-19 patients spent less time, and home-stayed homes of COVID-19 patients.
They found that the virus could often be detected in the air around Covid-19 patients and the positivity rate increased with the number of patients present on the premises. They found the virus in ICU as well as in non-ICU sections of hospitals, suggesting that patients shed the virus through the air, regardless of the severity of the infection. The study also found viable coronaviruses in the air that can infect living cells, and that these viruses can spread over long distances. Scientists still recommend wearing a face mask to avoid the spread of the coronavirus.
“Our results suggest that in the absence of ventilation in closed spaces, the coronavirus can remain in the air for some time. We find that the positivity rate for detecting the virus in the air was 75 percent when two or more COVID-19 patients were present in a room, as opposed to 15.8 percent when one or no COVID-19 patients in these studies occupied the room. did not, said Dr. Shivranjani Mohrir, the scientist involved in the study.
“Our observations are concurrent with previous studies showing that concentrations of SARS-CoV-2 RNA are higher in indoor air than in outdoor air; And in indoor, it is higher in hospital and health care settings, which host a larger number of Covid-19 patients than community indoor settings,” he said.
“As we return to conduct in-person activities, aerial surveillance is a useful tool to predict the infection potential of places like classrooms, meeting halls. This may help in refining strategies to control the spread of the infection,” said the work’s lead scientist Dr Rakesh Mishra, CSIR Distinguished Emeritus Professor and Director, Tata Institute for Genetics and Society at CCMB.
He also said that the aerial surveillance technology is not limited to the coronavirus but can be adapted to monitor other air-borne infections as well.