Wednesday, December 16, 2020

mapping sars-cov-2 strains

 3-11-20   After extensive analysis, the Milan team has not yet identified the individual at the root of the worst outbreak in Europe, but they have matched the Italian genetic sequencing of the virus here to a case that emerged in Munich, Germany ~January 19-22.  Galli added that the German patient had caught the virus after contacting someone who came from Shanghai.  https://www.reuters.com/article/us-health-coronavirus-italy-scientists/coronavirus-may-have-reached-italy-from-germany-scientists-say-idUSKBN20Y35B

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6-24-20  The G strain is predominantly on the East Coast of the United States, and the D strain is predominantly on the West Coast.   https://pubmed.ncbi.nlm.nih.gov/32311094/

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7-23-20  After analyzing more than 300 blood samples of COVID-19 patients from Lombardy between February and April, researchers found that the variant of the virus is observed frequently in European countries, such as the Netherlands, Switzerland and France but seldom observed in China, said a non-peer-reviewed paper published Monday on medRxiv.org, a preprint server for health sciences.  fter analyzing more than 300 blood samples of COVID-19 patients from Lombardy between February and April, researchers found that the variant of the virus is observed frequently in European countries, such as the Netherlands, Switzerland and France but seldom observed in China, said a non-peer-reviewed paper published Monday on medRxiv.org, a preprint server for health sciences….

  According to a report by Sputnik also released on Monday, Skolkovo Institute of Science and Technology (Skoltech) found that there were at least 67 coronavirus strains spreading in different Russian cities between late February and early March.  researchers found that the viruses causing COVID-19 outbreak in Russia were mainly from Europe instead of China, Skoltech said to Sputnik.  https://newsghana.com.gh/new-study-shows-italys-earliest-coronavirus-strains-not-from-china/

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  U. of Bologna report.  Currently there are six strains of coronavirus.  The original one is the L strain, that appeared in Wuhan in December 2019.  Its first mutation--the S strain--appeared at the beginning of 2020, while since mid-January 2020 we have had strains V and G.  To date strain G is the most widespread:  it mutated into strains GR and GH at the end of February 2020.

"Strain G and its related strains GR and GH are by far the most widespread, representing 74% of all gene sequences we analysed," says Giorgi.  "They present four mutations, two of which are able to change the sequence of the RNA polymerase and Spike proteins of the virus.  This characteristic probably facilitates the spread of the virus."

If we look at the coronavirus map, we can see that strains G and GR are the most frequent across Europe and Italy.  According to the available data, GH strain seems close to non-existence in Italy, while it occurs more frequently in France and Germany.  This seems to confirm the effectiveness of last months' containment methods.

In North America the most widespread strain is GH, while in South America we find the GR strain more frequently.  In Asia where the Wuhan L strain initially appeared, the spread of strains G, GH and GR is increasing.  These strains landed in Asia only at the beginning of March, more than a month after their spread in Europe.  https://webcache.googleusercontent.com/search?q=cache:a5k1g8O2Ux8J:https://www.sciencedaily.com/releases/2020/08/200803105246.htm+&cd=3&hl=en&ct=clnk&gl=us

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11-25-20  Before March most of the SARS-CoV-2 genomes that researchers worldwide isolated and sequenced encoded an aspartic acid (D) at residue 614 of the viral spike protein.  By April the majority of viral sequences harbored a single mutation in the genome converting the D to a glycine (G). Presently, the 614D variant has been all but replaced by the 614G variant globally.

These findings, described in a study published in Cell in August, and corroborating evidence from other groups have led scientists around the world to investigate whether the rapid shift in representation of circulating viral strains is based on random introduction by a group of mobile founders or if it indicates that 614G provides some sort of selective advantage to the virus—making it more infective, for instance. 

The authors also confirmed that 614G is not associated with infection severity and observed that younger patients were more likely to have 614G and have higher viral loads.  Their results support the idea that 614G is under positive selection and likely affects virus transmissibility.   https://www.the-scientist.com/news-opinion/sars-cov-2-genetic-variant-may-be-more-transmissible-68201

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flawed virus testing:   https://pandemic.news/2020-12-11-scientists-show-covid-tests-are-useless.html

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