The WHO has long held that the coronavirus is spread primarily by large respiratory droplets that, once expelled by infected people in coughs and sneezes, fall quickly to the floor.
But in an open letter to the W.H.O., 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 researchers plan to publish their letter in a scientific journal.
Whether carried 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, the coronavirus is borne through air and can infect people when inhaled, the scientists said, according to the NYT.
However, the UN health agency said the evidence for the virus being airborne was not convincing, according to the NYT.
“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,” Dr. Benedetta Allegranzi, the WHO’s technical lead of infection prevention and control, was quoted as saying by the NYT.
We summarize below some of the other publications that have recently discussed the significance of considering airborne transmission and taking those factors into account.
In this study, from medRxiv. Santarpia, J.L. et al. ”Aerosol and Surface Transmission Potential of SARS-CoV-2”, June 3, 2020
“During the initial isolation of 13 individuals with COVID-19 at the University of Nebraska Medical Center, we collected air and surface samples to examine viral shedding from isolated individuals. We detected viral contamination among all samples, indicating that SARS-CoV-2 may spread through both direct (droplet and person-to-person) as well as indirect mechanisms (contaminated objects and airborne transmission). Taken together, these finding support the use of airborne isolation precautions when caring for COVID-19 patients.”
From medRxiv. Ma, J. et al. “Exhaled breath is a significant source of SARS-CoV-2 emission”, June 2, 2020
“Here, 35 COVID-19 subjects were recruited; exhaled breath condensate (EBC), air samples and surface swabs were collected and analyzed for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR). EBC samples had the highest positive rate (16.7%, n=30), followed by surface swabs (5.4%, n=242), and air samples (3.8%, n=26). COVID-19 patients were shown to exhale SARS-CoV-2 into the air at an estimated rate of 103-105 RNA copies/min; while toilet and floor surfaces represented two important SARS-CoV-2 reservoirs. Our results imply that airborne transmission of SARS-CoV-2 plays a major role in COVID-19 spread, especially during the early stages of the disease.”
From medRxiv. Ma, J. et al. “Exhaled breath is a significant source of SARS-CoV-2 emission”, June 2, 2020
“Here, 35 COVID-19 subjects were recruited; exhaled breath condensate (EBC), air samples and surface swabs were collected and analyzed for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR). EBC samples had the highest positive rate (16.7%, n=30), followed by surface swabs (5.4%, n=242), and air samples (3.8%, n=26). COVID-19 patients were shown to exhale SARS-CoV-2 into the air at an estimated rate of 103-105 RNA copies/min; while toilet and floor surfaces represented two important SARS-CoV-2 reservoirs. Our results imply that airborne transmission of SARS-CoV-2 plays a major role in COVID-19 spread, especially during the early stages of the disease.”
From SciTech Daily. Queensland University of Technology. “Indoor Precautions Essential to Stem Airborne COVID-19 – The World Should Face the Reality”, April 16, 2020
“Airborne transmission of COVID-19 must be taken into account.”
“Likely COVID-19 spread to cruise ship passengers through ventilation system even when passengers confined to their cabins.”
“Viable airborne viruses can travel beyond 1.5m on airflow when exhaled by an infected person.”
“Virus air transmission research must begin now not retrospectively.”
From Emerging Infectious Diseases Journal (Centers for Disease Control and Prevention) Vol 26; No. 7. Guo, Z-D. et al. “Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China 2020”, April 10, 2020
“SARS-CoV-2 was widely distributed in the air and on object surfaces in both the ICU and GW [COVID-19 General Ward], implying a potentially high infection risk for medical staff and other close contacts.” The maximum transmission distance of SARS-CoV-2 aerosol was measured at up to 4 metres. […]
“Half of the samples from the soles of the ICU medical staff shoes tested positive. Therefore, the soles of medical staff shoes might function as carriers.”
Source: APP, NYT, Online journals/publications
