Speed at which airport cluster grew is worrying: Prof Teo
Also concerning is how virus has hit high number of elderly workers after infiltrating other places in airport
In less than two weeks, the Changi Airport cluster has emerged as the country's largest community cluster to date - second only to the outbreak at the workers' dormitories last year - with a total of 78 Covid-19 cases linked to it.
What is even more worrying is how the virus has hit a large number of elderly workers, as much as it has also infiltrated visitors at Jewel and other public places within the airport.
Professor Teo Yik Ying, dean of the National University of Singapore's Saw Swee Hock School of Public Health, said the most striking thing about this cluster is how rapidly the virus has spread between the cases.
"We have seen not just two generations of spread - but up to three and even four generations that happened within a matter of less than two weeks," he told The Straits Times yesterday.
Health Minister Ong Ye Kung said last Friday that the workers who were infected with Covid-19 mainly received travellers from high-risk countries.
The zone includes a conveyor belt and an immigration area that passengers have to pass through.
Workers who were in charge of this area would then go on to have their meals at the Terminal 3 Basement 2 commercial area and foodcourt, where they were likely to have passed on the virus to the community.
Prof Teo said the areas where people are more likely to come together, such as immigration checkpoints and baggage collection areas, are where the risks of transmission are higher.
"The fact is that these areas are indoors and air-conditioned, thus meaning the air is cooler and less humid, creating an environment that likely permits the coronavirus to stay viable for longer, whether it is as droplets, aerosols, or on surfaces," Prof Teo said.
With emerging variants such as the B1617 strain being more transmissible than what was seen last year, it could mean that even transient exposure through close contact with someone contagious or an increased survivability of the coronavirus would be sufficient to infect, added Prof Teo.
This is even as infection prevention and control (IPC) protocols - such as the wearing of personal protective equipment (PPE) and ensuring the frequent disinfecting of surfaces - continue to remain in place, suggesting that these measures may no longer be as adequate.
Associate Professor Kenneth Mak, director of medical services at the Ministry of Health, said last Friday that the PPE regime for front-line workers will be reviewed, starting with the hospitals before this is extended to other sectors.
As such, while it is important to investigate any lapses in the existing protocols, Prof Teo said ramping up crowd segregation and IPC protocols should also be considered.