LONDON: The World Health Organisation and around 500 experts have agreed for the first time what it means for a disease to spread through the air, in a bid to avoid the confusion early in the Covid-19 pandemic that some scientists have said cost lives.

The Geneva-based UN health agency released a technical document on the topic on Thursday. It said it was the first step towards working out how to better prevent this kind of transmission, both for existing diseases like measles and for future pandemic threats.

The document concludes that the descriptor “through the air” can be used for infectious diseases where the main type of transmission involves the pathogen travelling through the air or being suspended in the air, in line with other terms such as “waterborne” diseases, which are understood across disciplines and by the public.

Almost 500 experts contributed to the definition, including physicists, public health professionals and engineers, many of whom disagreed bitterly over the topic in the past.

Agencies have historically required high levels of proof before calling diseases airborne, which required very stringent containment measures; the new definition says the risk of exposure and severity of disease should also be considered.

Published in Dawn, April 19th, 2024