On Thursday (12 March), a South China Morning Post (SCMP) story revealed that researchers now believe that the mass quarantine measures taken to limit the spread of the deadly coronavirus in China may have changed its genetic course, potentially making it more “insidious” and harder to detect.
Clinical researchers are now under the impression that the new strain of the coronavirus, which first emerged in December, will mutate and continue to spread.
Clinical researchers in Wuhan submit that the precautionary measure of locking down millions of people by the Chinese government may have caused mutations in the genetic make-up of the coronavirus, to the extent that it could have resulted in causing only milder symptoms of the pneumonia-like illness, or with no initial symptoms at all in the early stage of infection.
A respiratory specialist at the Renmin Hospital of Wuhan University, Dr Zhang Zhan, has noticed recently that there is an unusual trend among patients with the Covid-19 virus now, compared to the earlier cases.
Dr Zhang and his colleagues have found that the initial clinical characteristics of patients admitted after 23 January has begun to differ from those of patients admitted before that. And this, they believe has brought new diagnostic challenges.
His team of medical researchers inform that “some common systemic symptoms of Covid-19, such as fever, fatigue, phlegm, and muscle pain, were more prominent in patients admitted before 23 January, but more insidious in later patients”.
According to the researchers, the current strain of virus after 23 January does not overtly contribute to these symptoms as much. The team has discovered that there was a 50 per cent decrease in fever, 70 per cent decline in fatigue, and an 80 per cent drop in muscle pain, says their research paper.
Meanwhile, a separate study published on 3 March by researchers from Peking University and the Chinese Academy of Sciences, reached a similar conclusion on the effect of quarantines.
Here, the research team led by Dr Lu Jian, a bioinformatics researcher at Peking University, analysed genomic sequence data of the virus from 103 samples collected from patients in China and other countries. They found the earliest cases in Wuhan might have evolved into two competing strains – an earlier one and a newer, “more aggressive” one.
In another study by the Hubei Provincial Centre for Disease Control and Prevention, led by Dr Jiang Yongzhong, researchers claim that based on an analysis of 146 samples, the virus had split into two major types.
Overall, the studies disclose that the genetic make-up of the virus had changed after quarantine measures were imposed, and mutations had “occurred across the world … providing the possibility of widespread adaptation”.
However, Professor Paul Young, the head of School Chemistry & Molecular Biosciences at the University of Queensland suggests, “This is normal for a virus that contains an RNA genome [like Sars-CoV-2]. They naturally acquire mutations as they replicate.”
“Most of these mutations, being random, have nothing to do with adaptation to the host and are simply a reflection of the high error rate in copying the viral genome,” he added.
However, other medical professionals working on the virus are undeterred by the findings. They treat these findings with caution and believe the current studies on the mutation of the virus are still far away from being conclusive.
