Airborne transmission of Covid-19 plausible factor in Tan Tock Seng Hospital cases: MOH

SINGAPORE - Reports have emerged suggesting a stronger possibility of airborne transmission of Covid-19 in certain settings, particularly closed environments with limited airflow and poor ventilation, said Ministry of Health (MOH) director of medical services Kenneth Mak on Tuesday (May 18).

However, droplets and contaminated surfaces remain the dominant ways by which the virus can transmit, Associate Professor Mak said during a press conference by the multi-ministry task force tackling the pandemic.

"We're adding on now the possibility in specific settings (that) some level of aerosolised transmissions can also take place," he added.

As for the Tan Tock Seng Hospital (TTSH) cluster which saw 46 cases, Prof Mak said the authorities are still studying how the virus spread in the hospital.

He noted there may not be one single factor that contributed to the virus spreading among hospital staff and patients, but it is plausible that some form of airborne transmission could have taken place.

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There would need to have been an infected person with a high viral load emanating a large amount of the virus, Prof Mak said, and this could have been supplemented by an environment associated with airborne transmission.

He said: "We are in the midst of completing the epidemiological investigations together with (TTSH) and we hope to have further information that will allow us to assess for this possibility."

The authorities are also looking how the virus could have spread in other clusters and settings.

Health Minister Ong Ye Kung said the most common mode of transmission is still among people without masks in crowded environments with a lot of vocalisation and interaction, and in an enclosed space with poor ventilation.

"These are the conditions that usually lead to big spreading events and I think these are the settings that we should be most careful about," Mr Ong said, adding that this is why the latest set of Covid-19 measures deliberately stopped such activities from taking place in such settings.

This article was first published in The Straits Times. Permission required for reproduction.