SINGAPORE - A week after Singapore entered a stabilisation phase on Sept 27, it saw new Covid-19 infection numbers breach the 3,000 figure for the first time, sparking concern among some of the impact on the healthcare system.

But the multi-ministry task force tackling the pandemic also noted that the reproduction rate has slowed, with the doubling of cases now taking longer.

Experts The Straits Times spoke to say the higher number of infections is not unexpected, but whether the pace of increase now dovetails with what the task force views as a stable number to stay the course towards reopening is unclear.

Associate Professor Hsu Li Yang, an infectious diseases expert at the NUS Saw Swee Hock School of Public Health, said the task force has not given any indication that the rise in case numbers is beyond the projections that they are using.

"It may be a bit difficult to use the daily case numbers to estimate whether the trends are stabilising, because it is plausible that many cases of Covid-19 are diagnosed by ART (antigen rapid test) alone now, and these cases are not reported to the Ministry of Health (MOH)," added Prof Hsu.

Finance Minister Lawrence Wong, who co-chairs the task force, highlighted the challenge in predicting a peak, saying on Oct 2 that there was a range of views with some thinking the current wave will peak at about 5,000 new daily cases while others think it will be around 10,000 daily cases.

"No model can predict with absolute certainty what the epidemic curve will look like in the next few weeks. It just simply means that we have to be prepared for this range of possible outcomes," he added.

One figure to look out for is the reproduction rate, said Dr Leong Hoe Nam, an infectious diseases specialist from the Rophi Clinic at Mount Elizabeth Novena.

He highlighted the longer duration between the doubling period seen here recently, which suggests the daily number of new cases could plateau soon.

"If we can keep it under 6,000 daily cases, we should be fine... I am hoping the United States experience will be repeated with us," added Dr Leong.

After almost three months of a rapid rise in new infections, US last week reported a decline in coronavirus-related hospital admissions and daily cases with the Centres for Disease Control and Prevention projecting the number of new infections to plunge further.

The task force had noted that the doubling of daily cases in Singapore was taking longer. From Sept 3, cases had doubled every seven days, with the Republic reporting over 840 cases on Sept 16.

It then took about 10 days for the cases to hit just over 1,700 cases.

Singapore's strategy in tackling the pandemic has been to test, trace and vaccinate. Although more than 80 per cent of the population is fully vaccinated, with booster shots rolled out for those above 50 years old, the number of new cases continue to climb.

Prof Hsu said local and international data show that the efficacy of current Covid-19 vaccines at preventing infection drops substantially after several months, especially against the Delta variant, although their efficacy at preventing severe infection and death has not changed significantly.

"That accounts for the increasing case numbers even though approximately 83 per cent of our population have received both doses of the vaccine. This does not mean we cannot open up, but that we must still take care to prevent our hospitals and primary care clinics from being overwhelmed," he added.

The pace at which Singapore reopens will depend on the hospital load, said Dr Leong.

"If it gets worse, even regular medical services may be compromised. This will be disastrous. Hence, MOH is taking a pre-emptive approach in building community treatment facilities.

"But if these facilities get overwhelmed, the hospitals will be under heat again," he added.

These community care facilities provide clinical care to Covid-19 patients who are stable, have mild symptoms or who may have underlying conditions that require a closer monitoring.

In anticipation of higher numbers, MOH last month also set up the Covid-19 Treatment Facility - to care and manage elderly patients who are stable, mildly symptomatic, clinically-well but with some underlying chronic illnesses or comorbidities.

The occupancy of community care facility beds has gone from 10 per cent to 35 per cent, Senior Minister of State for Health Janil Puthucheary told Parliament on Oct 4.

The occupancy rate of isolation beds has also risen from 58 per cent to 86 per cent, and in the intensive care units (ICU) of public hospitals, it was up from 26 per cent to 53 per cent over the last three months.

Prof Hsu said the task force has indicated that it will be unnecessary for another lockdown, noting that the experience of countries with high vaccination rates such as Denmark, Norway and Britain support that.

But as he pointed out at a recent discussion held by ST: "We haven't talked about what we might want to accept in terms of the cost of living with Covid-19."

Currently, about two people a day die due to influenza. To open up faster, Prof Hsu said at the discussion that Singapore has to accept six or seven Covid-19 deaths a day.