To stop Covid-19 from entering the country, Singapore shut its doors to travellers. But in the last three months, it has gradually reopened its borders, increasing the risk of infections creeping into the community. To beat the virus while trying to revive the hard-hit travel and aviation industries, the Republic has set up numerous safeguards - to keep cases low, even as numbers surge in some other countries.
A BALANCING ACT
The risk from imported cases is not new, and in fact, border controls have always been a cornerstone of the Republic's defence strategies, experts told The Straits Times.
But the challenge now is to reopen borders in a safe and controlled way amid a pandemic that is still raging in other parts of the world, said Associate Professor Josip Car, director of the Centre for Population Health Sciences at Nanyang Technological University's Lee Kong Chian School of Medicine. The growing knowledge of how to stop the virus spread would help the country reopen its borders smartly, he noted.
But as more countries experience worsening outbreaks, including India and those in Europe, the Middle East and the Americas, it becomes more important to be prudent and cautious when arranging travel green lanes, to protect the fragile local situation that has been brought under control after much effort, said Professor Teo Yik Ying, dean of the National University of Singapore's (NUS) Saw Swee Hock School of Public Health.
Conversely, said Prof Teo, priority for travel arrangements should be given to countries with a stable local situation and which have similarly put in place strict public health measures.
The biggest benefit, when it comes to aviation and travel, will be through the resumption of mass market tourism, but it comes at a price: It poses the greatest risk to the country.
"Governments worldwide will really need to decide whether regaining the economic activity from tourism justifies the risk to the rest of the local economy," said Prof Teo.
For some countries, this decision is a difficult one as tourism drives a major segment of the local economy, but for many others, shutting down mass market tourism to safeguard the rest of the economy and allow the rest of the community and society to function is a necessary compromise.
Singapore does not expect "no new cases", and there would be a tolerance for a small number of imported cases, said Professor Dale Fisher, a senior consultant in the infectious diseases division at the National University Hospital.
He said it is crucial that visitors entering the country continue to obey the rules on mask wearing and safe distancing, and not having gatherings of more than five in a group.
Asked about the speed at which Singapore is reopening its borders, Prof Fisher suggested that the country could afford to quicken its pace.
"I am sure there is a lot of behind-the-scenes work between governments, health insurers and those in the travel industry to make it happen. Any country that has few cases, does contact tracing quickly and has few unlinked cases should be 'approved'."
If there are additional risks, stricter restrictions such as a week-long stay-home notice and wearing a contact-tracing device can then be added, Prof Fisher said.
FACTORS TO CONSIDER
It is useful to break down the importation risk into three components, said Associate Professor Alex Cook, vice-dean of research at NUS Saw Swee Hock School of Public Health.
First, assessing the level of risk of an arriving passenger being infected from that particular country, which would determine which countries to prioritise having travel arrangements with.
Second, determining how much of this risk of virus spread to the community can be reduced through the nation's "fences", such as having a two-week quarantine compared with a week-long quarantine, or even a rapid test at the airport.
The fence is an approach highlighted by coronavirus analyst Tomas Pueyo in a New York Times article this month. Fences are necessary to control the virus, and are effective if enforced, he said.
Finally, the third component is that should infections creep into the community, how much of this spillover is considered tolerable, Prof Cook said.
"(Having) no spillover infections would be perfect, but of course, we might tolerate one spillover infection, or five, if it helps to reinvigorate the economy. The combination of these three components determines which countries and how many travellers we can accommodate," added Prof Cook.
Prof Car noted that the kinds of tests and the respective thresholds should also be considered. For example, the amount of genetic material that is detected before a test is considered positive and how accurate a test is are different depending on the test used.
Ultimately, Prof Fisher said, one has to look beyond case numbers.
"It is about whether the country knows where its cases are."
Most Malaysian cases were recently from two clusters in Sabah and Kedah, while most Australian cases lately have been in Victoria. Having a handle on where the cases originated and being able to effectively contact trace and quarantine these cases would make the country an unlikely source of infected travellers, Prof Fisher said.
Prof Teo agreed, adding that a well-established and functional surveillance and management protocol, and having the political will to isolate and quarantine whenever necessary, will be enduring aspects in keeping the Covid-19 situation under control.
Another aspect worth noting is whether a country is transparently reporting the local situation, or whether there is a considerable degree of under-reporting due to insufficient testing capacity or incomplete surveillance - for instance, when certain segments in the community are overlooked, such as those living in informal dwellings like slums, and unregistered migrant workers, Prof Teo said.
Given how complex the pandemic has been, risk needs to be managed with multifarious strategies, ranging from the individual (being vigilant and adhering to protocols, for instance) to the government level, said Prof Car.
Government processes such as rigorous protocols for testing, guidance on pre-arrival tests and quarantine would be necessary, and these need to be tailored to balance risk, inconvenience and cost for travellers, Prof Car explained.
What works in one country may also not be transferable to another due to cultural, social, scale or economic factors, he added.
"Individuals also need to be reminded that there is no perfect test and a negative result is not a 100 per cent guarantee that they cannot spread the virus."
Relying on testing to shorten the quarantine period will always result in some leakage and this risk increases if the traveller is coming from a location with a severe outbreak, Prof Teo said.
However, a strict quarantine effectively stops many short trips, Prof Cook said, stressing that testing travellers remains key to reducing risk.
"The question is how and when to test to keep the risk tolerable. For instance, if they are tested before they arrive in Singapore, they could still be infected after the test. I'm inclining towards a rapid test on arrival, followed by a repeat test a few days later to confirm negativity," said Prof Cook.
Ultimately, Singapore's aim has always been to live with the virus, Prof Fisher said, unlike some countries such as New Zealand, China and Vietnam, which aim for eradication.