Infectious diseases experts say a new requirement, in which Singapore citizens and permanent residents (PRs) must test negative for Covid-19 before being allowed to return home from high-risk countries, will help to protect front-line staff at the airport.
It could also ease the load on Singapore's healthcare system.
But the measure has its limits.
With the recent spate of unlinked community cases, Dr Ling Li Min, an infectious diseases physician from Rophi Clinic, said the authorities have several fires to fight and the new requirement will help to minimise the risk of the virus spreading in Singapore.
While polymerase chain reaction (PCR) tests may not pick up every single case, Dr Ling said the mandatory pre-departure tests will at least help to identify those who are infectious and prevent the virus from spreading on board flights into Singapore.
Professor Paul Tambyah, deputy director of the National University of Singapore's (NUS) Yong Loo Lin School of Medicine's Infectious Diseases Translational Research Programme, said it would also be logical to extend the testing requirement to Singaporeans and PRs returning from lower-risk places.
"Taiwan and Vietnam were previously considered low-risk places, as was the state of Victoria in Australia. These classifications can change rapidly."
Professor Teo Yik Ying, dean of NUS' Saw Swee Hock School of Public Health, said implementing the new measure may be more challenging than expected.
He said not every jurisdiction will have commercial PCR testing capacity that is accredited and trustworthy.
There is also the issue of the Government's responsibility towards citizens who test positive and cannot return on a commercial flight. The Health Ministry said Singaporeans who test positive while overseas can still return home via a medevac flight or equivalent forms of transport if they require urgent medical care.
Singapore Management University (SMU) assistant professor of law Benjamin Joshua Ong noted that Article 13(1) of the Constitution states that no citizen shall be "banished or excluded" from Singapore.
"It is possible that those words mean that anything preventing a citizen of Singapore from travelling to Singapore would be unconstitutional. On the other hand, a court might also hold that it is acceptable for certain requirements to be imposed," he said.
"I think it is at least arguable that, if the restrictions are too onerous, then those restrictions would in substance amount to banishment or exclusion."
SMU law don Eugene Tan said while it might appear that the new requirement is in breach of Article 13(1), this is not the case. "A citizen who is not in Singapore voluntarily cannot be said to be banished or excluded."
The new requirement means a citizen will not be allowed to board a flight or ferry to Singapore unless he has a negative Covid-19 test result. If he does somehow make the journey, he is unlikely to be denied entry, Associate Professor Tan added.
"In other words, the pre-departure test requirement imposes a duty on the flight or ferry operator to ensure that all passengers travelling to Singapore have the necessary negative test results based on their travel histories. The constitutional guarantee provided by Article 13(1) is in no way under threat," he added.
Prof Tambyah said there seems to be a reluctance to ban flights and replace them with evacuation flights, as was done with Wuhan early last year. Hence, the new measure is a logical option despite its limitations.
Prof Teo believes the Government will not leave any citizen in the lurch, but said individuals need to be responsible. "This is really a reminder to Singaporeans and PRs that they should avoid unnecessary travel out of Singapore during this period, and if they choose to do so, to ensure they have the necessary insurance coverage for Covid-19 medical evacuation if infected."
