COVID-19: Circuit breaker might be lifted when community cases fall to zero or single digits over sustained period

COVID-19: Circuit breaker might be lifted when community cases fall to zero or single digits over sustained period

A woman wearing a face mask queue to enter a wet market Singapore safe distancing
A woman wearing a face mask is given direction by safe distancing ambassadors as others queue to enter a wet market in Singapore on Apr 22, 2020. (Photo: AFP/Roslan Rahman)

SINGAPORE: For Singapore to lift COVID-19 "circuit breaker" measures, the number of community cases daily should fall to zero or single digits over a sustained period of time, said Health Minister Gan Kim Yong in Parliament on Monday (May 4).

This is one of three factors being considered when deciding on how to open up again and emerge from strict measures put in place.  

READ: 66 COVID-19 cases among healthcare workers and support staff: Gan Kim Yong

"Numbers are important. We need to be assured that community transmission locally is stemmed, or very low," said Mr Gan in his ministerial statement.

“Community cases should ideally fall to zero or single-digits daily, with very low numbers of unlinked cases, not just for one day, but sustained over a period of time."

There also needs to be a fall in the number of migrant worker cases, Mr Gan added, noting that this will take "a while longer". The vast majority of Singapore's COVID-19 cases are work permit holders living in dormitories.

READ: Situation at larger foreign worker dormitories stable, but COVID-19 picture in smaller dorms ‘mixed’: Josephine Teo

“It is equally important to reduce the migrant worker cases over time, though it will take a while longer. Otherwise we will continue to be at risk of a spillover from the dormitories into the wider population,” Mr Gan said.

START "SMALL AND SELECTIVELY" IN REOPENING BORDERS

Apart from tracking the daily infection numbers, Mr Gan added that the Government needs to make an assessment of the situation globally in order to decide on its approach in reopening Singapore's borders. 

“We would review the rate of transmissions in other countries, as well as what they have done to contain spread," he told the House. 

"For any reopening of our borders, we are likely to start small and selectively, and to continue to impose a mix of isolation and test requirements, to protect ourselves from new imported cases leading to community spread.

Singapore must also put in place a system to be able to open up safely such as stepping up COVID-19 testing, said Mr Gan, as there will be a higher risk of transmission when businesses are social activities are allowed to resume.

READ: Government has debunked 40 instances of fake news on COVID-19: Iswaran

 “Therefore we need to step up our capability and capacity to test and detect cases early, contact trace quickly, promptly ringfence close contacts, and establish the original source of the infection to stop other undetected transmission chains, if any," he explained.

“These are the key enablers which give us confidence to reopen.”

TESTING CAPACITY

To date, Singapore has conducted more than 140,000 tests for COVID-19, which works out to 2,500 tests per 100,000 people in Singapore, said Mr Gan.

Responding to Members of Parliament who asked about the different tests available, the Health Minister said Singapore uses mainly the polymerase chain reaction (PCR) test to detect confirmed COVID-19 cases. PCR tests work by detecting the virus RNA from a nose or throat swab, and is the gold standard for detecting current infection, Mr Gan explained.

PCR testing is done to diagnose suspect cases to provide early treatment and isolate close contacts, as well as to do screening and active case finding of individuals at risk, such as migrant workers moved from their dormitories before they return to work.

This kind of testing is also used in conducting surveillance to monitor undetected cases in the community.

Inside one of the Tan Tock Seng Hospital laboratory rooms, where testing for Covid-19 is done.
Inside one of the Tan Tock Seng Hospital's laboratory rooms, where testing for COVID-19 is done.

Currently, Singapore has the capacity to conduct more than 8,000 PCR tests a day, up from 2,900 a day in early April.

Authorities are working with various private and public sector partners to further increase the testing capacity to up to 40,000 a day.

"With this increase, we will widen the net that we cast for diagnostic testing for symptomatic cases, active case finding, screening and surveillance testing in our community and among workers, including migrant workers," said Mr Gan.

“We will also do more testing and monitoring to pick out asymptomatic and pre-symptomatic cases among priority groups such as nursing home residents and staff, to prevent clusters from developing. Testing is crucial as risk of infection will increase when we allow more economic and social activities to resume."

READ: Singapore to start gradual easing of circuit breaker measures as COVID-19 community cases decline

ASYMPTOMATIC TESTING

Amid questions about whether asymptomatic testing can be done for the entire population, Mr Gan said his ministry will study this. However, he said the yield will be very low if asymptomatic testing is done indiscriminately, as there is no widespread community transmission.

"It may also need to be done repeatedly as it does not reflect immunity and those tested can be infected after the test," he explained. "It may not be best way to use testing resources."

Instead, the authorities will and have started doing asymptomatic testing selectively, for priority groups.

READ: Stretched but coping: How Singapore's healthcare system has cranked up efforts to deal with COVID-19

“For example, we currently test asymptomatic young children, if they are in the same household as COVID-19 patients, since they may not be able to articulate their symptoms well,” Mr Gan said.

“As more businesses reopen, we may also do more tests for essential service workers. At our borders, we can also deploy tests for arrivals to reduce the risk of local transmission from imported cases.”

Dr Partha Pratim De and a colleague from the TTSH laboratory check the results of the PCR test.
Dr Partha Pratim De and a colleague from the TTSH laboratory check the results of a PCR test.

Mr Gan also pointed to a study by the National Centre of Infectious Diseases (NCID) that showed that while the infection rate among healthcare workers and the general population is extremely low, among close contacts, around 2.5 per cent had antibodies despite not having had symptoms during their quarantine period.

“That means they had been infected earlier but recovered, and remain well without any symptoms. This points to the need to continue our efforts to quickly isolate close contacts of confirmed cases,” he added.

“We will continue to do more of these studies, to help us understand the extent of spread and immunity in the community. I should add that scientific evidence on protective immunity is still under intensive study currently."

READ: Singapore developing nationwide COVID-19 testing strategy to better detect unlinked cases in community: Lawrence Wong

Testing more people and for more purposes will be important as Singapore starts to open up, “so that we can pre-emptively detect and break any potential transmission chains”, said Mr Gan.

SEWAGE TESTING, PROLONGED STAY AT CCFs

Apart from swab tests, the ministry is conducting trials of sewage testing, Mr Gan said in response to a question by Non-Constituency MP Leon Perera on whether Singapore is looking into this as a way to determine possible clusters of infection.

Mr Gan said authorities are doing trials to see if they can pick up fragments to assess whether particular locations like dormitories, housing estates or nursing homes have outbreaks.

"There are challenges because sewage, by nature, would have been significantly diluted because it’s a collection of a large population, so we will need to test the sensitivity and see whether we are able to pick up sufficient fragments to be able to determine whether there is significant infection in particular target area," he explained.

The inherent challenges mean that such tests may not be able to be used, but the authorities continue to study the method to assess if it can be deployed in a "meaningful way", he said.

Mr Gan also touched on why some patients at community care facilities are being kept there for more than a month, in response to a question from MP Cheryl Chan.

Authorities have found many patients in community care facilities, hospitals and isolation facilities who continue to test positive.

"The theory is that many of these tests in the end are picking up fragments of the virus and some of this virus may no longer be viable," Mr Gan said. 

Nonetheless, the test is able to pick up the virus, and the test is not conclusive on whether these fragments are viable, he added.

EXPO interior COVID-19 community isolation facility (1)
A community isolation facility for COVID-19 patients at Singapore EXPO.

USING "REPRODUCTION NUMBER" AS AN INDICATOR

MP Sylvia Lim asked why Singapore is not using what's known was the "reproduction number" as an indicator in easing circuit breaker measures, like New Zealand did.

The reproduction number is a measure of a virus' transmission potential, meaning how many people an infection person is likely to pass on COVID-19 to.

Mr Gan explained that circuit breaker measures mean that an infected person is not likely to infect more people, keeping this number low.

"Once you remove these circuit breaker measures, you have more interaction and the risk of you transmitting that infection to other people will go up and therefore the reproductive number will go up," he said. 

While Singapore is tracking the number, Mr Gan said: "I would prefer not to produce one single number and try to peg our matrix on that number, so I think we need to take into account all the factors in order for us to be able to restore some of the activities safely."

Earlier in his ministerial statement, Mr Gan gave updates on the capacity in hospitals. The number of isolation beds has increased from around 550 in January to close to 1,500 as of May 2, he said. NCID has also increased its capacity from about 100 to more than 500 negative pressure isolation beds in the same period, he said. 

A total of 22 COVID-19 patients are in intensive care. Hospitals have almost 150 vacant beds in the intensive care units, and the healthcare system can “quickly bring another 300 online”, Mr Gan said. 

Additionally, the public hospitals have put in place plans to ensure that their infrastructure, equipment, medications and manpower are in place to add another 450 ICU beds by mid-May if needed, he added.

“We have also ensured a sufficient supply of ventilators and other ICU accessories to support the care of ICU patients."

IMPORTANCE OF HEALTHCARE WORKERS

Beyond the hardware and technology needed to handle COVID-19, Mr Gan underscored the importance of healthcare workers.

“They are at the centre of our fight against this COVID-19 outbreak. We deeply appreciate their sacrifices, long hours as well as personal and professional commitment to care for each patient. This will be a long campaign, and we need to support our healthcare workers and take care of their needs,” he said.

Responding to MPs who asked about the well-being of healthcare workers, Mr Gan gave assurance that the Government is committed to taking care of them “in every way”.

"The many gifts and words of encouragement from members of the public to our healthcare workers mean a lot to them and have helped to keep up their morale," said the Health Minister, noting that members of the public have been writing thank you messages and buying breakfast for Singapore's healthcare workers. 

"As part of the SG United initiative, close to 9,000 messages for our healthcare workers were collected from appreciation zones around Singapore,” he said.

“On behalf of our healthcare workers, let me thank you for your continued support.”

Mr Gan said that the Government recognises the “invaluable contributions of our workers” and will ensure that they receive due recognition for stepping up during this challenging period.

“We recognise that no monetary compensation is ever enough. I want to again acknowledge and thank our healthcare workers for their hard work and dedication,” he said.

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Source: CNA/ja(gs)

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