Recovered Covid-19 death rate tapering off

‘a better understanding of the disease has led to a decrease in mortality’

The mortality rate of Covid-19 in Malaysia at 1.4% is among the lowest in the world.

Globally, the death rate is gradually going down despite the number of infections being on an upward trajectory in many other countries.

Explaining the lower rate of fatalities, Universiti Malaya dean of faculty of medicine and infectious diseases specialist Datuk Prof Dr Adeeba Kamarulzaman said: “It is more likely that recovery and survival of patients is related to better patient care and management.”

She said there was currently no data to suggest that the mutation of SARS-CoV-2 (Covid-19) had led to a loss in potency.

“SARS-CoV-2 belongs to a family of viruses that mutates frequently, as seen with SARS and MERS,” she said.

On June 1, Alberto Zangrillo, head of intensive care at Italy’s San Raffaele Hospital in Lombardy, sparked a debate when he claimed that Covid-19 had been losing its potency, noting that the coronavirus “clinically no longer exists”.

However, the World Health Organisation (WHO) and other scientists have refuted his assertions.

WHO epidemiologist Maria Van Kerkhove was quoted in Reuters as saying that Zangrillo’s comments “were not supported by scientific evidence”.

Health experts here in Malaysia also cautioned that the coronavirus had not lost its potency.

Universiti Sains Malaysia medical epidemiologist and biostatistician Assoc Prof Dr Kamarul Imran Musa said that it was an undeniable fact that viruses would undergo mutation which resulted in the change of potency – viruses could be more lethal or less lethal.

However, Dr Kamarul said studies on Covid-19 suggested that even though there had been mutations in the SARS-CoV-2 virus genetics, the virus was “still potent and life-threatening”.

As Covid-19 cases continue to rise in the world, death rates have, however, slowed down, as seen in a Covid-19 graph that monitors worldwide daily cases.

The graph shows that daily Covid19 cases since March 4 have continued to steadily rise until June 24.

However, comparatively, the graph shows that from May 21 to June 26, the daily Covid-19 death rate has tapered off as it hovers around 5,000 deaths a day.

Dr Adeeba said that over the last few months, there has been a much better understanding of the clinical disease associated with SARS-CoV-2.

She said questions such as who were at risk of the disease, the nature of the disease itself, how to better monitor and manage those at risk and who develop severe diseases, were studied.

“For example, some of the advances include studies that have shown that delaying mechanical ventilation and supporting those who develop respiratory failure with non-invasive methods is associated with better outcomes.

“We are also beginning to understand the mechanism behind some of these complications – the cytokine storm phenomena, the thromboembolic (clots) complications that can develop – which have led to recommendations such as managing patients with drugs to prevent these clots and of course the most recent study that showed that treating patients with severe Covid-19 with corticosteroid results in good response and outcome,” she said.

Dr Kamarul, however, believed that the number of deaths was “not a good indicator of disease spread” but the number of cases through surveillance and active case detection, was.

“I see this as a condition epidemiologists describe as a bias.

“As a result of outbreaks, sicker individuals will seek treatment quicker from hospitals or clinics. Hence, they will get more prompt treatment. At the same time, more active contact tracing and tests are conducted.

“After a certain time, a large proportion of these sicker Covid-19 patients would have been treated.

“But new cases – from active case detection (ACD) and testing – will result in the spike in the number of confirmed cases, and many of them have milder Covid-19 symptoms,” he said.

As a result of this, Dr Kamarul said the rate of deaths which was the number of deaths over positive cases, over time, would bias towards a smaller number of death rates.

“This happens because you simply have a larger denominator – that is the number of cases detected from ACD and testing,” he said.