- COVID 19 MUTATIONS BAFFLE SCIENTISTS.
Coronavirus’s ability to mutate has been vastly underestimated, and mutations affect deadliness of strains, Chinese study finds
- The most aggressive strains of Sars-CoV-2 could generate 270 times as much viral
load as the least potent type - New York may have a deadlier strain imported from Europe, compared to less deadly viruses elsewhere in the United States
Professor Li Lanjuan and her colleagues from Zhejiang University found within a small pool of patients many mutations not previously reported. These mutations included changes so rare that scientists had never considered they might occur.
They also confirmed for the first time with laboratory evidence that
than others.
“Sars-CoV-2 has acquired mutations capable of substantially changing its pathogenicity ,” Li and her collaborators wrote in a non-peer reviewed paper released on preprint service medRxiv.org on Sunday.
Li’s study provided the first hard evidence that mutation could affect how severely the virus caused disease or damage in its host.
Li took an unusual approach to investigate the virus mutation. She analysed the viral strains isolated from 11 randomly chosen Covid-19 patients from Hangzhou in the eastern province of Zhejiang, and then tested how efficiently they could infect and kill cells.
The deadliest mutations in the Zhejiang patients had also been found in most patients across Europe, while the milder strains were the predominant varieties found in parts of the United States, such as Washington state, according to their paper.
Coronavirus can survive long exposure to high temperature, a threat to lab staff around world : paper
- French scientists had to bring the temperature to almost boiling point to kill virus
Results have implications for the safety of lab technicians working with the virus
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The French team found a higher temperature could help solve the problem. For instance, heating the samples to 92 degrees Celsius for 15 minutes could render the virus completely inactive.
However, such high temperatures could also severely fragment the virus’ RNA and reduce the sensitivity of the test. The researchers therefore suggested using chemicals instead of heat to kill the virus and strike a balance between the safety of lab workers and detection efficiency.
“The results presented in this study should help to choose the best suited protocol for inactivation in order to prevent exposure of laboratory personnel in charge of direct and indirect detection of Sars-CoV-2 for diagnostic purpose,” wrote the authors.
A microbiologist studying the coronavirus at the Chinese Academy of Sciences in Beijing said Chinese test facilities were aware of the risk to lab workers and took extra precautions.
All staff must dress in a full hazmat suit when handling the virus samples, even after deactivation, among other measures.
The French experiment provided valuable information but the situation in real life could be much more complex than the lab simulations, according to the scientist.
“The virus behaves quite differently with a change in environment. Many research projects are still under way to solve these puzzles,” he said.
There was hope that the pandemic in the northern hemisphere would ease
with the change of seasons. Some studies suggested that tropical countries reported fewer confirmed cases.
These observations were nonetheless hampered by other factors at play, such as the strength of government mitigation efforts and testing capabilities. Some recent research detected an alarming signal that the Covid-19 could continue to spread through summer .
In a paper published in journal JAMA Network Open earlier this month, a team of Chinese researchers reported a cluster outbreak at a public bath in Huaian, in the eastern province of Jiangsu.
A patient visited the centre on January 18 for a bath and sauna. Eight people, including a staff member, were subsequently infected over about two weeks.
The bath had a temperature higher than 40 degrees Celsius and an average 60 per cent humidity.
That study had some limits. Without a surveillance camera in the bath, it was impossible to determine whether the transmission was caused by airborne droplets or contaminated surfaces, such as a doorknob. But the researchers said the cluster outbreak sounded an alarm bell.
“The transmissibility of Sars-CoV-2 showed no signs of weakening in warm and humid conditions,” the peer-reviewed paper said.
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