Tuesday , August 16 2022

The Covid-19 would have arrived earlier than expected in the United States


Researchers at the Centers for Disease Control and Prevention (CDC) carried out a study of 7,000 blood bags. They were collected by the American Red Cross between December 13, 2019 and mid-January 2020. This was well ahead of the official release of the first Covid-19 outbreak in the United States, dating from January 20, 2020. Now, 106 samples among the 7,000 were labeled positive for Covid-19-associated antibodies.

Note that the samples are from nine American provinces. More than half of the patients who test positive for the disease are from Massachusetts, Michigan, Connecticut, Rhode Island, Iowa and Wisconsin. The remaining 39 come from Washington, California and Oregon.

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The results of this new study question the date when the virus actually spread on American soil.

False positives or positive cases?

As a reminder, the Chinese state declared the first cases of this disabling pneumonia in late December 2019. It was in Wuhan, the capital of Hubei.

It should be noted that a positive test for coronavirus antibodies only suggests infection with the Cov-2 of SARS. The possibility of the existence of false positives should not be excluded from the samples. They are mainly due to the host’s response to other types of coronavirus.

Therefore, to refine their results, the CDC researchers conducted further tests. They analyzed the samples collected seeking antibody responses to SARS Cov-2. Finally, 84 out of 90 analyzes are positive. “The results make it highly unlikely that all samples are false positives”, they concluded. That is, the team is almost certain that a good number of these patients are infected with Covid-19.

Also read: Covid-19 vaccine, the 5 steps recommended by the HAS

Still some gaps to fill

University of California epidemiologist Dr George Rutherford, who is also a professor of biochemistry in San Francisco, highlighted the limitations of the study. For him, apart from the possibility of cross-reacting with other types of coronavirus, the research has another flaw. This is data on the exact places where the virus found those who tested positive. For example, the study questionnaire does not consider potential trips abroad.

Also read: We know who the first doses of the anti-Covid-19 vaccine will go in the United States

Dr Rutherford argued that more studies are needed to verify these results. He specifically recommended that Cov-2 genetic material from SARS be searched for on these positive samples. This should be based on an analysis of the saliva, blood and tissue of the first Americans who test positive.

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