To beat 'sneaky' coronavirus, test more and lift circuit breaker gradually when time is right: Experts
SINGAPORE: Five weeks from now, if the number of daily COVID-19 cases in the community falls to single digits and the situation in the foreign worker dormitories improves, “circuit breaker” measures in Singapore may ease gradually, experts said.
Key indicators of whether Singapore is in a position to consider such a move include the number of new community cases falling to single digits per day and a “very clear decline” in new cases in the dormitories, said Saw Swee Hock School of Public Health dean Teo Yik Ying.
Besides a fall in the total number of cases, the number of unlinked cases should go down to near zero, added Professor Paul Tambyah of the Yong Loo Lin School of Medicine at the National University of Singapore.
Another indicator of community transmission of the coronavirus would be the numbers from the Health Ministry’s surveillance programmes. Such random testing of flu-like illnesses in the community aims to pick up cases that otherwise would not have not been detected.
READ: COVID-19: Support staff at Singapore hospitals work quietly behind the scenes as cases increase
“The key is to look at the sentinel surveillance data – from the influenza-like illness surveillance done in polyclinics and general practitioner clinics – to see how much coronavirus is circulating in the community, as well as pneumonia surveillance in hospitals,” said Prof Tambyah.
Trade and Industry Minister Chan Chun Sing said on Thursday said the sentinel programme is an example of how authorities are trying to "pre-empt the situation going forward".
"For example at this point in time, while the numbers are coming down, we are also making sure that we have background sentinel checks to make sure that we are not caught blindsided by some other hidden cases in the community," he said in an interview with Bloomberg.
Health Minister Gan Kim Yong said on Tuesday that authorities have been picking up COVID-19 cases from its surveillance, and that was one of the reasons Singapore’s circuit breaker was extended to Jun 1. “This indicates that there is continued seeding in the community, many of them undetected because their symptoms are mild but they are still infectious,” he said.
Earlier that day, Prime Minister Lee Hsien Loong said in a televised address that Singapore’s circuit breaker would be extended from May 4 to Jun 1. Authorities also announced tighter measures, two weeks after Singapore closed most workplaces and schools.
COVID-19 circuit breaker extended until Jun 1 as Singapore aims to bring down community cases ‘decisively’: PM Lee
UNLINKED CASES, ORIGIN OF INFECTIONS
As of Saturday (Apr 25), Singapore has reported 12,693 cases of COVID-19 in total. The majority of the cases have been found in migrant worker dormitories, while cases in the general population have been levelling off.
The number of new cases in the community has decreased, from an average of 31 cases per day in the week before to an average of 23 per day in the past week. The number of unlinked cases in the community has also decreased, from an average of 21 cases per day in the week before to an average of 15 per day in the past week.
However, new cases among work permit holders living outside dormitories have increased, from an average of 21 cases per day in the week before to an average of 26 per day in the past week.
While the average number of daily cases in the community has fallen from the start of the circuit breaker, the number was still high, said Prof Teo on Thursday when asked why the circuit breaker was extended.
Infectious diseases expert Dr Piotr Chlebicki said that the number of community cases should include work permit holders living outside dormitories - which would make the number of community cases even higher. "If migrant workers are living in the community, for all practical purposes, they are community cases," said Dr Chlebicki, who runs the Infectious Diseases Medical Clinic at Mount Alvernia Hospital.
Beyond the total number, experts are also concerned about the number of unlinked cases even after contact tracing.
"The unlinked cases are the concern as we would have hoped that these would have gone down significantly with the circuit breaker measures," said Prof Tambyah.
Prof Teo said that one of the reasons for the extension of the circuit breaker to Jun 1 was that some of the transmissions originated from workers in essential services, including those in the F&B sector and in construction. "It is more prudent to extend the circuit breaker to resolutely contain the situation in all segments in Singapore, than to risk easing the circuit breaker prematurely only for the outbreak to flare up again," he said.
Along with the extension, Singapore also announced that essential services would be further limited, and hair salons as well as some food outlets have had to suspend operations from Wednesday. In addition, foreign workers have been confined to their dormitories and large numbers of workers in construction and their dependents have been put on mandatory stay-home notices from Apr 20 to May 4.
Mr Gan has also said that as the country eases circuit breaker measures, it will need to increase testing capability, to make sure that there is no community spread of the virus.
“In order to make sure that there's no transmission in the community, we need to test a lot more,” he said at a virtual press conference held on Tuesday by the multi-ministerial task force tackling COVID-19.
Mr Chan made a similar point in on Thursday, saying: "We hope that in a month's time we will be able to progressively reopen the economy with much more testing for the entire population and at the same time to take on additional safe distancing measures."
READ: COVID-19: Concern over unlinked cases even as daily average number of community cases falls, says Health Minister
Dr Chlebicki said that one of the objectives of the extending the circuit breaker could be to ramp up testing to see if infections are really decreasing in the community. If there is more testing, then “most people with respiratory symptoms should be able to be tested to see whether they really have COVID-19 or another respiratory tract infection”, he said.
Testing in the worker dormitories, where the outbreak has surged in recent weeks, has already accelerated and is one of the reasons Singapore’s case numbers have shot up, sometimes by more than 1,000 cases a day.
Prof Teo said that actively testing for people who are infected with SARS-CoV-2, the virus that causes COVID-19, serves two purposes. Identifying infected people early on means they can be isolated and treated early, and contact tracing can be done to isolate other people who may have been infected by them. Also, because asymptomatic infection can happen, Singapore needs to “cast a wider net and test aggressively in the community”, beyond those that exhibit symptoms.
“This is the reason why the World Health Organization has identified testing capacity as an important element to consider prior to easing any measures to allow community and economic activity to resume,” he said.
NO “HAPPILY EVER AFTER”
Even if the signs are all positive, there may not be an immediate lifting of all the measures enacted during the circuit breaker period.
“I actually hope we will have a graduated easing of the different measures,” Prof Teo said.
Mask wearing and safe-distancing requirements, for example, are likely to remain for the foreseeable future even after Jun 1, along with restrictions on large gatherings, said Prof Teo. School may resume but workers from sectors that do not require them to be physically present are likely to continue working from home.
“F&B outlets may need to endure further hardship for a while longer by allowing for only takeaways and delivery, and not dining in – but a bright spot will be bubble tea outlets and McDonald’s should be able to resume takeaway and delivery options,” he added.
Other experts also warned about opening up the country too quickly. By trying to keep transmissions to the lowest level possible, Singapore would be prioritising people’s well-being over the economy, said Dr Chlebicki. “In the end, it will not be the situation where Jun 1 we will wake up and: No more virus, and we will be living happily ever after,” he said.
When asked if there are models around the world which Singapore can look to, Prof Teo said that many countries are experimenting and taking tentative steps.
“I do not think there is a rule book that countries can follow,” he said.
Infectious diseases expert Annelies Wilder-Smith said that every country is using different criteria, depending on the epidemiological and economic situation as well as cultural background.
“For China, they kept the lockdown for four weeks after the last new case. Hong Kong is doing the same,” said the visiting professor at Nanyang Technological University’s Lee Kong Chian School of Medicine.
“Europe will loosen the lockdown as soon as the curve has flattened and there is a consistent decline in new cases and hospitalisations for at least two weeks, but every country within Europe has some nuanced differences.”
That circuit breaker measures can be lifted as scheduled is based on the assumption that there are no new transmission chains.
However, Dr Chlebicki pointed out that any crowded place could be a concern.
“This virus is quite sneaky and it will uncover any blind spots sooner or later,” he said.
Prof Teo said that potential hot spots could be “vulnerable and often-overlooked population segments”, including care homes, nursing homes and orphanages.
“Equally we need to think about other population segments such as prisons, military camps and outfits, mental health institutions … as well as an often-overlooked group such as commercial sex workers,” he said.
“Only by confronting some of the realities that societies have, can we, and other countries, properly and systematically identify any high-risk segment and put in place plans to protect these people.”