After COVID, WHO Defines Disease Spread ‘Through Air
The World Health Organization and 500 specialists have defined airborne disease transmission for the first time to avoid the uncertainty early in the COVID-19 epidemic, which some scientists say killed lives.
Thursday saw the Geneva-based U.N. health agency produce a technical document. It stated it was the first step in preventing this type of transmission for measles and future pandemics.
The document concludes that “through the air” can be used for infectious diseases where the pathogen is transmitted through the air or suspended in the air, similar to “waterborne” diseases, which are understood across disciplines and by the public.
Nearly 500 physicists, public health professionals, and engineers, many of whom had previously disagreed, helped define the term.
Before labeling diseases airborne, agencies required high levels of proof and strict containment procedures. The new definition considers risk of exposure and disease severity.
Previous debates focused on whether infectious particles were “droplets” or “aerosols” based on size, but the new definition eliminates that.
Early in 2020, 200 aerosol scientists publicly criticized the WHO for failing to warn about the potential of airborne COVID-19. The focus on hand cleaning to stop the infection overshadowed ventilation, they said.
The WHO reported “evidence emerging” of airborne spread in July 2020, but its then-chief scientist Soumya Swaminathan, who started the defining process, later admitted the WHO should have been more assertive “much earlier”.
In an interview, her successor, Jeremy Farrar, said the new definition was about more than COVID, but he noted that at the start of the pandemic, experts like the WHO acted in “good faith” due to a lack of evidence He headed the Wellcome Trust and advised the British government on the epidemic.
Farrar said a consensus on the term would allow professionals from all fields to discuss ventilation concerns in hospitals and schools.
It was like realizing that doctors without gloves could spread HIV or hepatitis B.
“When I started out, medical students, nurses, doctors, none of us wore gloves to take blood,” he said. “Not wearing gloves is unthinkable now. The consensus on the topic and language led to this outcome. Change in practice came later.”
