Explainer: Is tracking daily case numbers still relevant as Singapore lives with endemic Covid-19?
SINGAPORE — Experts are split on whether the Government should continue publishing daily figures on Covid-19 cases since it has said that the country will move to treating the disease as endemic and circulating in the population like influenza. The latest moves to impose social and workplace restrictions suggest that the Government is not ready yet for the country to live with the virus in its midst, they observed.
- The recent rise in unlinked cases here is due to the higher transmissibility of the Delta variant, experts noted
- The high rate of vaccination means that it is harder to detect milder or asymptomatic coronavirus infections
- However, it is not a cause for concern as the number of serious cases remains low
- Experts are mixed on how MOH’s daily reports on Covid-19 should be revised
- Some said the daily case numbers should remain until the disease is “truly endemic” here, another said data on clusters can go
SINGAPORE — Experts are split on whether the Government should continue publishing daily figures on Covid-19 cases since it has said that the country will move to treating the disease as endemic and circulating in the population like influenza.
Two infectious diseases experts told TODAY that the latest moves by the national task force against Covid-19 to impose social and workplace restrictions suggest that the Government is not ready yet for the country to live with the coronavirus in its midst.
Associate Professor Alex Cook from the National University of Singapore Saw Swee Hock School of Public Health said that a spike in cases is expected as restrictions are relaxed, but the latest announcements by the task force show that “a surge is less palatable than keeping control measures in place”.
Health Minister Ong Ye Kung last month described Singapore’s approach towards Covid-19 as “a middle course” — where there are social restrictions in place, even as life continues normally with schools and restaurants in operation.
The views of infectious diseases experts reflect a larger division among the public on whether Singapore will be able to arrive at a truly endemic state, especially after social gatherings and interactions at workplaces will not be permitted from Wednesday (Sept 8) and people were told to reduce their social interactions in general.
The number of infections spreading locally has risen dramatically in the last month, along with an alarming spike in the number of cases with no known sources of infection despite a robust contact-tracing programme.
On Tuesday, the number of locally transmitted cases with no links to reported ones was a record 185, out of 328.
Unlinked cases have also breached the 100-figure mark in the last six days.
TODAY looks at why there is a surge in unlinked cases recently, and if Singapore is ready to stop reporting the daily number of Covid-19 cases.
WHY CONTACT TRACING IS SLOWER NOW
Experts said that the transmissibility of the Delta variant of the virus had made it harder to detect the sources of infection.
This is despite efforts by the Ministry of Health (MOH) to increase the number of contact tracers from 330 to 480 as of Aug 12.
TraceTogether, the contact-tracing system and application used on mobile devices and tokens issued by the Government, has also been adopted by more than 90 per cent of people in Singapore, its website shows.
Assoc Prof Cook said that there are “fundamental changes” in the epidemic situation here.
With more than 80 per cent of the population fully vaccinated, those who are infected usually have mild or no symptoms, making it harder to link cases to clusters.
The Delta variant of the coronavirus also spreads more easily, even through fleeting contact. This makes it harder to link cases, he added.
Lastly, with Singapore opening up, individuals also come into contact with people outside of their households, making it less straightforward to trace the source of their infections.
IS TRACETOGETHER STILL EFFECTIVE OR NOT
Experts said that the highly transmissible nature of the Delta variant limited the effectiveness of TraceTogether.
Dr Leong Hoe Nam, an infectious diseases expert from Rophi Clinic, said that the TraceTogether app “is being made irrelevant” by the Delta variant, given that contact with an infectious person from 10 to 15 seconds is enough to spread the virus.
Dr Paul Tambyah, president of the Asia Pacific Society of Clinical Microbiology and Infection, said that TraceTogether may not be able to trace cases that are spread through contact with surfaces or objects.
However, Dr Ling Li Min of Rophi Clinic, said that technology has sped up the time required for contact tracing from four to fewer than two days and it is manual contact tracing that is the “rate-limiting step”.
“A contact tracer has to ask each and every infected individual and their close contacts for detailed information on their movements and interactions over the past week or so,” Dr Ling explained.
SHOULD THE PUBLIC BE WORRIED
At a press conference last Friday, Associate Professor Kenneth Mak, director of medical services at MOH, said that the large number of unlinked cases are “not necessarily a cause for worry” because they are eventually linked.
He added that the higher caseloads recently had made it more difficult for the authorities to establish the links in time for the daily reporting cycle.
Experts who spoke to TODAY agreed that the rise in unlink cases was not a major cause for concern.
Dr Tambyah said that although unlinked cases indicate that more new clusters are likely to arise, the high vaccination rate of above 80 per cent in Singapore means that the number of severely ill people will remain very low.
Likewise, Assoc Prof Cook pointed out that most of those in the older age group are protected by the vaccine, which was the main reason for trying to prevent the virus’ transmission in the past.
As of Monday, at least 85 per cent of each age group eligible for vaccination, including those aged 70 and above, had been fully immunised.
Overall, 81 per cent of the population had completed their full regimen or received two doses of Covid-19 vaccines, and 83 per cent had received at least one dose.
HOW DAILY REPORTS MAY REFLECT ENDEMIC SITUATION
Mr Ong, who is also co-chair of the task force, said last Friday that it was timely for MOH to revamp the format of its daily reports and reduce the importance of linking cases.
He said that daily reports should include more timely information about the emerging clusters so that the public may regulate their own activities and avoid certain places.
However, the experts contacted had mixed views on whether daily Covid-19 numbers should remain or if emerging clusters should be highlighted in the reports.
Dr Leong said that Singapore has yet to go “truly endemic” given that the Government is still actively contact tracing.
Therefore, unlinked cases are still important to track because it will help people anticipate the number of Covid-19 cases in subsequent weeks.
Publishing the daily Covid-19 numbers will also allow people to appreciate the Government’s decision to open up or impose restrictions, Dr Leong added.
The ministry can stop reporting daily numbers when the country truly reaches an endemic state, where the demand for intensive care services stops going up consistently and averages one or two cases a day.
Last Friday, Assoc Prof Mak said that admissions to intensive care units have “held relatively steady” at around six to seven in the last week, with those requiring oxygen support trending downwards.
However, Dr Leong’s view is that it is not relevant to include information on emerging clusters in the reports because there will always be a risk of infection when people are out and about.
Dr Tambyah, on the other hand, said that it is important to still track cases to identify clusters in high-risk settings such as schools or nursing homes.
Similarly, Assoc Prof Cook is in favour of keeping information on clusters in the report because it will allow people to make informed choices about how to protect their health.
He said: “As we move into the endemic state and remove restrictions imposed by the Government, shifting responsibility to the individual to protect oneself from Covid would require that they be provided with useful information to make choices aligned with their risk tolerance.”
However, he questioned the value of reporting unlinked cases and said that he expects the reporting of daily numbers to stop in the long run, similar to other major infectious diseases such as dengue.