Ho Ching feels unlinked cases should still be reported. Should they, though?

OUTGOING Temasek CEO Ho Ching is known to be quite vocal online, especially on Facebook, where she frequently puts up more than 50 posts in a single day — not all without commentary.

Pertaining to the Covid-19 pandemic especially, despite not being a known certified public health or infectious diseases expert herself, she appears to have taken it upon herself to study developments in epidemiology quite judiciously over the past year and eight months or so, and has commented and posted quite extensively in various phases of the epidemic as it unfolded here and in the rest of the world.

She has also played a very active role in Temasek Foundation’s multiple nationwide charity drives to distribute various iterations of free reusable and single-use face masks over the past year and a half too. Suffice to say, Ms Ho has really been quite involved in looking into and talking about Covid-19.

Her latest comments on Facebook regarding the Ministry of Health (MOH)’s effort to shift its reporting data on new daily Covid-19 cases signal a shift, however — in her stance on how things should be done, and whether the government is doing it right.

“We are not there yet; unlinked cases are still relevant”

In a Facebook post on Thursday morning, Ms Ho directly responded to MOH’s Sunday post, saying, “We are not there yet, and unlinked cases are still relevant for the purpose of getting a sense whether we are having a runaway gallop or a steady trot.”

GET BT IN YOUR INBOX DAILY

Start and end each day with the latest news stories and analyses delivered straight to your inbox.

Sign UpVIEW ALL

A day prior, she had also written at length why in her view daily unlinked cases continues to be “a good indicator to track”.

Using the terms Rt (which indicates the virus’s actual transmission rate at a given time) as well as R0 (a figure that refers to the number of people who could catch the disease from a single infected person in a previously-unexposed population. The lower, the better, but if it’s above 1 it could grow exponentially), she warned of the recent new case report trend of the past two weeks possibly being “the start of an explosion that would seep into many homes with old folks who are yet to be vaccinated”.

Ms Ho argued that the number of unlinked cases, as well as unquarantined linked cases, are indicative of the number of “community nodes” from which more infections can arise.

She said her calculations hadn’t taken into account superspreader clusters, or the Delta variant, which has 1,000 times more viral load and speedier infectious rates than older variants of the virus.

She also said Singaporeans should “tap on the brakes early” in order to avoid more superspreader events or ripples.

Infectious disease & public health experts respond

So should Singapore continue to keep the public apprised of the number of unlinked cases reported daily?

Two experts in infectious disease and public health The Business Times spoke to roundly disagree with Ms Ho.

Jeremy Lim, who teaches global health systems reforms at the NUS Saw Swee Hock School of Public Health, noted firstly that the number of daily unlinked cases reported when they are first confirmed are subsequently re-classified as linked after contact tracing.

He explains that from a public health perspective, data collection and analyses do exert strain on resources, so decisions on which data to collect must be driven by whether they will be used practically in policymaking.

“This is a lot of work and if it has marginal impact on actual practice, then the limited resources might be better deployed elsewhere,” he said. “I suspect the management of cases would be the same anyway — isolate the cases and their close contacts with release when tests return negative. Given how many cases there are, the utility of chasing every last case contact in detail may not be worthwhile.”

No strong correlation exists between spikes in unlinked cases and spikes in infections: public health expert

Responding to Ms Ho’s view that unlinked cases indicate how many there might be in time to come, Dr Lim said he has not yet seen empiric data to show any strong correlation between the number of reported unlinked cases and future infectious figures.

To him, therefore, the useful figures for the public to be kept informed of would be those concerning health system utilisation — ICU, bed occupancy rates, and the number of infected cases warded in hospital.

“The rest seem superfluous. On the public wanting to know (the number of unlinked cases), I’m reminded of the comment that just because the public is interested doesn’t mean it is in the public interest.”

MTF’s moves to evolve data reported are “absolutely appropriate”: infectious disease expert 

Senior consultant in NUH’s infectious diseases division Dale Fisher, who also teaches at NUS’s school of medicine, takes this further, arguing that if we are transitioning to Covid-19 being endemic, the number of cases will have to eventually stop being counted as well — not just the number of unlinked cases.

“The number of daily unlinked cases was an important indicator but it no longer is,” he told BT. “The end-point of this in the Covid-endemic state, as with flu, will be monitoring genetic movements of Covid, and monitoring hospitalisations, and sentinel surveillance for overall prevalence within acute respiratory infections.”

He agrees with MOH’s position that “taking away irrelevant measures is an appropriate step”.

“We actually expect a lot of unlinked cases now, because with so many people vaccinated the disease is mild and asymptomatic. So of course it can go through two or three transmissions, and then reappear with someone who goes for a test in a completely different part of Singapore, and that's called unlinked. But we know most people are not getting symptoms like they did pre-vaccinations.

“So what the multi-ministry taskforce has recently brought in is absolutely appropriate as we transition (to endemic) in every possible way. We're not just transitioning the restrictions, we're also transitioning in surveillance.”

“The future won’t be in counting every case or doing mass testing”

Prof Fisher agrees with Dr Lim’s view that a further reason for not bothering with unlinked cases is that the authorities are not acting to change or reduce that figure.

“We can’t live in a world where the restrictions are maintained and unnecessary surveillance is a focus. You do surveillance to give you information that you will act on. Things that matter to you. And when you know half the cases every day are going to be unlinked and we're not trying to change that... but the future won't even be counting every case and it won't be doing mass testing. That won't be the future. When that future point is, is yet to be determined, but we're moving in that direction.”

Choosing not to report figures like unlinked cases in Singapore sends a signal to the public to temper the value of the information that is not reported, Prof Fisher concluded.

“What we don’t want is people inflating the value of what is an unnecessary measure,” he said.

That being said, Dr Lim notes that a matrix that maps actions to be taken against health system capacity will be helpful for the public to get a better sense of the MTF’s logic and timelines, given how disruptive lockdowns, circuit breakers and movement restrictions are.

READ MORE: How readable is the roadmap to endemic Covid-19?

“It's really like the pre-Covid days when the public was informed routinely of hospital bed occupancy rates, waiting times for specialist appointments, et cetera. We are all users of the health system and so just want to be assured that if we ever need healthcare, there is capacity for us.”

He also stresses that the majority of new cases found now continue to be “very mild”.

“Something the naysayers seem to forget is that most cases are very mild and if there are lots of asymptomatic cases already in the community, then there are fewer people left to infect,” he said. “Hence, these doom and gloom scenarios may be premised on inaccurate assumptions.”

READ MORE: 

• MOM to allow up to 500 migrant workers to move within the community each week
• Lawrence Wong urges companies, directors to start thinking ahead, restructure