Researchers from the National Centre for Infectious Diseases have confirmed that the transmission mechanism of COVID-19 is different from SARS and in fact more similar to H1N1 or influenza. Like influenza, COVID-19 is infectious when symptoms are mild.
Assistant Professor Clarence Tam stressed that even if the risk of mortality from a virus is low, it can still cause a large number of deaths if it spreads easily.
“The available data indicate that this new virus is not as deadly as SARS, but spreads much more readily from person to person. Consequently, the number of reported deaths has already surpassed deaths from SARS in less than two months,” he said.
“The same applies for influenza viruses. Even though the proportion of all influenza cases that succumb to the disease is low, an estimated 300,000-500,000 people worldwide die each year from influenza,” he added.
Some experts believe the coronavirus causing the COVID-19 outbreak will mutate to something milder, stabilise and eventually disappear from public consciousness.
“This is the historical pattern of past pandemics, and happens because the virus ‘burns out’ and runs out of people to infect as a result of many factors. There is a possibility that the virus could mutate into something more ‘sinister’, that spreads faster or cause more severe disease, but, so far, we have not seen any evidence of this happening,” said Professor Tikki Pangestu, visiting professor at the Lee Kuan Yew School of Public Policy.
Dr Leong Hoe Nam, infectious disease specialist at Mount Elizabeth Novena Hospital, added, “If the virus is too pathogenic and it kills its host, it is unable to continue spreading. But if it is mild, it can continue to propagate and pass on to other individuals, eventually picking up mutations that reduce the virus’ ability to cause disease.”
Dr Tam said it is quite difficult to predict whether the COVID-19 will take the same route as the H1N1 pandemic.
“The concern is that if current efforts to contain the virus aren’t ultimately enough to stamp out human transmission, it could spread rapidly across the globe causing many more hospitalisations and deaths before a vaccine can be developed or enough immunity builds up in the population to bring the epidemic under control,” he said.
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