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On the origin and continuing evolution of SARS-CoV-2
The SARS-CoV-2 epidemic started in late December 2019 in Wuhan, China, and has since impacted a large portion of China and raised major global concern. Herein, we investigated the extent of molecular divergence between SARS-CoV-2 and other related coronaviruses. Although we found only 4% variability in genomic nucleotides between SARS-CoV-2 and a bat SARS-related coronavirus (SARSr-CoV; RaTG13), the difference at neutral sites was 17%, suggesting the divergence between the two viruses is much larger than previously estimated. Our results suggest that the development of new variations in functional sites in the receptor-binding domain (RBD) of the spike seen in SARS-CoV-2 and viruses from pangolin SARSr-CoVs are likely caused by mutations and natural selection besides recombination. Population genetic analyses of 103 SARS-CoV-2 genomes indicated that these viruses evolved into two major types (designated L and S), that are well defined by two different SNPs that show nearly complete linkage across the viral strains sequenced to date. Although the L type (∼70%) is more prevalent than the S type (∼30%), the S type was found to be the ancestral version. Whereas the L type was more prevalent in the early stages of the outbreak in Wuhan, the frequency of the L type decreased after early January 2020. Human intervention may have placed more severe selective pressure on the L type, which might be more aggressive and spread more quickly. On the other hand, the S type, which is evolutionarily older and less aggressive, might have increased in relative frequency due to relatively weaker selective pressure. These findings strongly support an urgent need for further immediate, comprehensive studies that combine genomic data, epidemiological data, and chart records of the clinical symptoms of patients with coronavirus disease 2019 (COVID-19).
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B.C. identifies 3 more cases of COVID-19, bringing total to 12
All new cases announced Tuesday are connected to Iran, which is now the source of majority of B.C. cases.
All three of the new cases are connected to the outbreak in Iran, provincial health officer Dr. Bonnie Henry told reporters Tuesday afternoon. It was her second news conference of the day concerning the coronavirus — another new case was announced in the morning.
The new cases involve three people who recently travelled to Iran: a man in his 60s, an adult woman living in the Vancouver Coastal Health region and a man in his 50s who lives in the Fraser Health region. The fourth patient is a woman in her 30s who contracted the coronavirus in the household of the eighth patient, a woman in her 60s who is visiting the Vancouver Coastal Health region from Iran.
All of the new patients are now in self-isolation at home, and their close contacts are being monitored, Henry said. None of the B.C. cases has become severely ill and four patients have recovered fully.
Henry said she believes the spike in cases reflects the fact that officials have urged people who've travelled to Iran to monitor themselves for symptoms.
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TV Station empties shelves to run a story on shortages
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Pope tested for coronavirus after suffering cold symptoms and cancelling retreat
The number of deaths in Italy has leapt to 52 with more than 2,000 people diagnosed
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More than 100 cases confirmed across the U.S., with current death toll at 6
On Monday, U.S. authorities confirmed more than 100 cases across the country, while in Seattle, officials announced four more deaths, bringing the total in the U.S. to six. However both numbers are expected to rise dramatically.
Critics have raised additional problems, along with delays in testing. A government whistleblower has filed a complaint alleging that some federal workers did not have the necessary protective gear or training when they were deployed to help Americans evacuated from China during the coronavirus outbreak.
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’We Simply Do Not Understand Why’: Coronavirus Is Sparing Kids, Puzzling Experts
As the novel coronavirus spreads around the globe, sickening more than 90,000 people and killing about 3,000, doctors have noticed something curious: Very few children have been diagnosed with it. And of those who have, most have had mild cases, NBC News reports.
In China, where the outbreak started, children comprise just 2.4% of all reported cases of COVID-19, the illness caused by the new coronavirus, a World Health Organization-China Joint Mission report from last month found. Of those, only a sliver — 2.5% — experienced severe symptoms, and an even tinier proportion — 0.2% — became critically ill. Worldwide, there have been no deaths reported so far in young children.
The coronavirus' mercy on children is a relief and a mystery to pediatric infectious diseases experts, who have a handful of working theories but no definitive answers for why.
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