Scientists warn airborne transmission of COVID-19 is possible

Date:7 July 2020 Author: Kirsten Jacobs

A group of more than 200 scientists representing over 30 countries are urging the World Health Organisation (WHO) to address the possibility that the novel coronavirus can be spread via the air, and for the organisation to revise its safety recommendations.

In an open letter titled “It is Time to Address Airborne Transmission of Covid-19”, 239 scientists detailed growing evidence that the virus may be airborne. According to the paper, the virus can spread indoors through aerosols that linger in the air. Even in small quantities, this has the potential to be infectious.

“We appeal to the medical community and to the relevant national and international bodies to recognise the potential for airborne spread of COVID-19. There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale), and we are advocating for the use of preventive measures to mitigate this route of airborne transmission,” reads the paper.

“Studies by the signatories and other scientists have demonstrated beyond any reasonable doubt that viruses are released during exhalation, talking, and coughing in microdroplets small enough to remain aloft in air and pose a risk of exposure at distances beyond 1 to 2 m from an infected individual.”

The paper also says that several retrospective studies conducted after the SARS-CoV-1 epidemic demonstrated that airborne transmission was the most likely mechanism explaining the spatial pattern of infections.

The scientists claim that WHO and most other public health organizations are not taking the potential of airborne transmission as seriously as they should. They say that while the promoted hand washing and social distancing measures are appropriate, they are insufficient to provide protection from virus-carrying respiratory microdroplets released into the air by infected people.

The paper suggests a number of practical measures to mitigate this risk, including:

– Provide sufficient and effective ventilation (supply clean outdoor air, minimize recirculating air) particularly in public buildings, workplace environments, schools, hospitals, and aged care homes.

– Supplement general ventilation with airborne infection controls such as local exhaust, high-efficiency air filtration, and germicidal ultraviolet lights.

– Avoid overcrowding, particularly in public transport and public buildings.

“We are concerned that the lack of recognition of the risk of airborne transmission of COVID-19 and the lack of clear recommendations on the control measures against the airborne virus will have significant consequences: people may think that they are fully protected by adhering to the current recommendations, but in fact, additional airborne interventions are needed for further reduction of infection risk,” concludes the paper.

“This matter is of heightened significance now, when countries are re-opening following lockdowns – bringing people back to workplaces and students back to schools, colleges, and universities. We hope that our statement will raise awareness that airborne transmission of COVID-19 is a real risk and that control measures, as outlined above, must be added to the other precautions taken, to reduce the severity of the pandemic and save lives.”

In March, WHO said they have found no reported cases of airborne transmission, but do assert that it may be possible in very specific circumstances.

“According to current evidence, COVID-19 virus is primarily transmitted between people through respiratory droplets and contact routes. In an analysis of 75,465 COVID-19 cases in China, airborne transmission was not reported,” they wrote.

“In the context of COVID-19, airborne transmission may be possible in specific circumstances and settings in which procedures or support treatments that generate aerosols are performed; i.e., endotracheal intubation, bronchoscopy, open suctioning, administration of nebulized treatment, manual ventilation before intubation, turning the patient to the prone position, disconnecting the patient from the ventilator, non-invasive positive-pressure ventilation, tracheostomy, and cardiopulmonary resuscitation.”

This paper follows after much criticism has been targetted at WHO for their handling of the COVID-19 pandemic.

Read the full paper here: ciaa939

Image: Pixabay

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