Coronavirus: Deadly COVID-19 virus has not mutated and changed to something more dangerous, says expert
There has been no change in the DNA of COVID-19, implying that the virus has not mutated and become more dangerous since the outbreak began. Nor has it become milder. This was confirmed by the World Health Organization (WHO)-China joint mission.
Gene-sequencing of 104 novel coronavirus samples collected from different locations shows the virus has not mutated and has no obvious variation, said Liang Wannian, head of the Chinese expert panel on outbreak response and disposal.
He explained that the genetic data of the samples were 99% homogeneous — signs that mutation has not occurred. “We have conducted full genome sequencing on 104 separated strains -- proven homology is 99.9% -- signifying that there is no significant mutation to the virus,” said Wannian during a media briefing.
As far as susceptibility is concerned, Wannian said that the virus is a new pathogen, it is age-impartial, and people of all ages have no special immunity to it. “So it can be inferred that it is universally susceptible,” he added.
The WHO-China team recently inspected various provinces of China, including Wuhan, the capital of Hubei province and the epicenter of the outbreak.
“The WHO-China joint mission concluded its visit and delivered its report. The team has made a range of findings about the transmissibility of the virus, the severity of disease and the impact of the measures taken. They have found that there has been no significant change in the DNA of the virus,” said WHO DIrector-General Tedros Adhanom Ghebreyesus in a statement.
Few experts believe the new coronavirus causing the COVID-19 outbreak may mutate to something milder, stabilize and might eventually disappear.
Citing warmer temperatures, better awareness and public health measures, Professor Tikki Pang, visiting professor at the Lee Kuan Yew School of Public Policy under the National University of Singapore (NUS), told CNA, “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 causes) more severe disease, but, so far, we have not seen any evidence of this happening,” said Professor Pang.
Transmission dynamics
In terms of the demographic characteristics in China, the average age of the confirmed cases was 51, and nearly 80% of these patients aged 30-69. As of February 20, about 78% of the confirmed cases were from Hubei Province. The case-fatality rate is estimated between 3% and 4% nationwide. It is about 0.7% in other cities and provinces outside Wuhan.
The hosts of the new coronavirus remain unclear. However, according to the currently available data in China, bats maybe its host, and pangolin may also be one of the intermediate hosts of this virus. Scientists are still working to further identify the host of the new coronavirus.
Wannian said the coronavirus is mainly transmitted through respiratory droplets and physical contact, and there is a risk for fecal-oral and aerosol transmission. But he noted that fecal-oral and aerosol transmission are not major transmission routes in the Chinese mainland.
Explaining the transmission dynamics, Wannian said that in the early stage, most of the cases in Wuhan had exposure history with the seafood market, where the virus broke the human-animal interface and later triggered human to human transmission.
“However, starting from January 23, after Wuhan started with the traffic bans, and restriction measures, we have seen a decline of confirmed cases and new onsets. We can see this continued trend today when we compare it to the peak time of confirmed cases,” he said.
According to the team, the epidemic peaked and plateaued between January 23 and February, 2 in China, and “has been declining steadily since then.”
Wannian said that transmission in cities outside of Wuhan and Hubei shows significant differences, where early cases were mostly sporadic cases.
The expert said that China also saw transmission in some “special workplaces” such as hospitals. “Over 3000 medical staff got infected and we are still looking into further details as to how many got infected due to community-acquired infections and how many during delivering hospital care to patients,” said Wannian.
Most of the confirmed and suspected cases among medical staff originated in Wuhan, and the reasons could have been fatigue and poor knowledge of the disease during the initial days of the outbreak.
“It was peak hour when there were so many cases and back then, our understanding of the disease was still quite inadequate. The measures adopted by medical staff were not sufficient enough. With the building of many mobile camping hospitals, the medical staff needed time to get acquainted with the measures and environment. Also, they were working for prolonged hours, and they tend to develop fatigue and compromised immune systems,” said Wannian.
On Wednesday, China reported 406 new cases of confirmed infections, 439 new cases of suspected infections, and 52 deaths. The nation's tally now stands at 78,064 confirmed cases and 2,715 deaths.