Older people struck by Covid-19 are at higher risk of dying than others. That is a fact which no one disputes.

But what the experts don't quite agree on is just how high the risk is and what should be done about it.

Understanding this debate in more detail can help individuals and families make better decisions on how to protect their elderly.

In one camp are views like those of Professor Lim Tow Keang, a senior respiratory and critical care consultant at the National University Hospital (NUH). He said Covid-19 is not any more deadly for older people than other respiratory illnesses.

Prof Lim warned against overprotecting the elderly by restricting their movements during the pandemic.

"Keeping them 'safe' through strict isolation in an extended lockdown while the rest of society returns to normal life could be viewed as another version of ageism that needs to be guarded against," he said in an editorial in the latest issue of the Annals, the publication of the Academy of Medicine.

Prof Lim said that while old age is a pivotal risk factor for mortality in respiratory infections, it is not unique to Covid-19.

He wrote: "Most reports of Covid-19, especially in the media, had described it as a deadly respiratory tract infection with the assumption of a high case fatality rate.

"This is a fallacy which might lead, in certain situations, to inappropriate reactions, decisions and actions."

The editorial states that while Covid-19 kills 10 times more infected people than influenza - leading to about 1 per cent of its patients dying compared with 0.1 per cent - community acquired pneumonia, which kills about 13 per cent of those infected, is far more deadly.

So in terms of risk for older people, Covid-19 is somewhere between the flu and pneumonia.

But Prof Lim also pointed out that while fairly common, community acquired pneumonia is not a public health problem since it does not spread easily.

He also questioned the mortality rate of Covid-19, given that many infected people remain asymptomatic - which is unusual for a respiratory disease.

He said that Covid-19's mortality rate may be lower than reported as the number of people who have had the disease is likely to be far higher than acknowledged.

As more evidence surface, Prof Lim said the R0 or transmission rate for Covid-19 is probably double the two, three the world had been working with. He thinks it is more likely that one infected person passes the virus to five, six others.

He said: "One not only fails to consider the total number of infected individuals in those communities, but also fails to appreciate the real denominators of so many deaths for an accurate assessment of how truly lethal Covid-19 is."

Prof Lim said the daily reports of infections and deaths make Covid-19 appear "a deadly disease". But Covid-19 fatalities "form just the tip of an iceberg that comprises a huge number of mild cases below the surface of detection".

Given all this, he said: "There is continuum of risks and appropriate responses. There are also more effective ways of protecting older people than immobilisation."

One such way is protecting nursing homes, which Singapore is doing. He pointed out that more than half the deaths in Europe and the United States comprised nursing home residents.

This will not affect older people who are fit and in good health, he said, though he advised caution among the elderly "against all types of respiratory tract infections".

OTHER VIEWS

However, several infectious diseases experts took issue with his comments.

Dr Asok Kurup, a specialist in private practice who chairs the Academy's Chapter of Infectious Disease Physicians, said it is "foolhardy" to draw conclusions while the pandemic is still raging.

He said: "I don't think anyone has the answer yet to conclude that it's not more dangerous than other respiratory diseases in older persons.

"It's premature to compare case fatality risk with other disease conditions as the pandemic is still evolving."

Singapore has also adopted a calibrated approach to deal with the pandemic and has not immobilised or locked away its elderly. Instead, it has instituted long-term, social distancing measures that require everyone to wear face masks outside the home, and that ban social mixing between large groups, whether it is in private homes, restaurants or public places like parks.

As Associate Professor Hsu Li Yang, an infectious disease expert at the NUS Saw Swee Hock School of Public Health, pointed out: "We aren't quite locking away our elderly, at least not far more than the rest of the population."

But he added that age is currently the "strongest risk for mortality", although younger people with heart or lung problems are also at higher risk. "I think everyone needs to continue to take care, because young, sociable and more mobile people clearly spread the virus better than the elderly and infirm."

Still, he acknowledged: "Unfortunately the elderly are at far higher risk of dying from Covid-19."

Professor Dale Fisher, a senior infectious diseases consultant at the NUH, said: "Indeed the elderly are at risk of many forms of pneumonia, but Covid-19 is different and these times are different."

While he agreed with Prof Lim that "the elderly should not be specifically locked down", he said "they would be wise to adhere to what we know can be protective; that is social distancing, mask wearing, minimising visitors, unnecessary outings and hand hygiene".

BALANCED VIEW

In a sense, despite their disagreements, the experts all made valid points. Over-protecting the elderly may actually do them more harm as social isolation could affect both their mental and physical well-being.

But those who were socially active in the pre-Covid days need to realise that resuming such a lifestyle could place them at risk.

Although the number of infections in the community averages about two a day - which is extremely low given a local population of 3.8 million - it does indicate that transmission is still happening.

It means that there are undiscovered reservoirs of the virus.

Prof Hsu said that while the community cases here are now low, the experiences of Australia, Japan and Vietnam "serve as sobering reminders that things can reverse quickly".

Studies show just how much more dangerous the virus can be for the elderly. A German study of more than 10,000 Covid-19 patients admitted to 920 hospitals, which appeared online in The Lancet journal on July 28, found that mortality was significantly higher for older patients.

The study concluded: "In the German healthcare system, in which hospital capacities have not been overwhelmed by the Covid-19 pandemic, mortality has been high for patients receiving mechanical ventilation, particularly for patients aged 80 years or older and those requiring dialysis, and has been considerably lower for patients younger than 60 years."

For the 1,727 patients who needed ventilator aid, 28 per cent of those 59 years and younger, died. Among older patients, mortality ranged from 45 per cent for those aged 60 to 69 years to 72 per cent for patients 80 years and older.

Age wasn't the only determining factor. Patients with serious underlying medical conditions, such as kidney failure requiring dialysis, also faced higher risk of death.

So while there may be no need for the elderly to continue to lock themselves away, they need to take more precautions than younger people. And so must their family members who may pass the virus to them.

Call it ageism if you want, the virus doesn't care.

People must assess their own risks, decide on the risks they are willing to accept, and act accordingly.