https://www.wwno.org/post/coronavirus-was-us-weeks-earlier-previously-known-study-says
New analysis of blood donations finds virus was present on West Coast earlier than previously believed
The new coronavirus infected people in the U.S. in mid-December 2019, a few weeks before it was officially identified in China and about a month earlier than public health authorities found the first U.S. case, according to a government study published Monday.
The findings significantly strengthen evidence suggesting the virus was spreading around the world well before public health authorities and researchers became aware, upending initial thinking about how early and quickly it emerged.
Scientists at the U.S. Centers for Disease Control and Prevention found evidence of infection in 106 of 7,389 blood donations collected by the American Red Cross from residents in nine states across the U.S., according to the study published online in the journal Clinical Infectious Diseases.
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In analyzing the blood samples, the CDC scientists found antibodies in 39 samples from California, Oregon and Washington state collected between December 13 and December 16.
The findings suggest there were isolated cases of coronavirus infection on the U.S. West Coast in mid-December, the scientists wrote.
They also found 67 samples with antibodies in Massachusetts, Michigan, Wisconsin or Iowa, and Connecticut or Rhode Island collected between Dec. 30 and Jan. 17.
Those findings indicated that cases were more dispersed—yet still isolated—by early this year.
PS
The research article
https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1785/6012472
Methods
To determine if SARS-CoV-2 reactive antibodies were present in sera prior to the first identified case in the U.S. on January 19, 2020, residual archived samples from 7,389 routine blood donations collected by the American Red Cross from December 13, 2019 to January 17, 2020, from donors resident in nine states (California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin) were tested at CDC for anti-SARS-CoV-2 antibodies. Specimens reactive by pan-immunoglobulin (pan Ig) enzyme linked immunosorbent assay (ELISA) against the full spike protein were tested by IgG and IgM ELISAs, microneutralization test, Ortho total Ig S1 ELISA, and receptor binding domain / Ace2 blocking activity assay.
Results
Of the 7,389 samples, 106 were reactive by pan Ig. Of these 106 specimens, 90 were available for further testing. Eighty four of 90 had neutralizing activity, 1 had S1 binding activity, and 1 had receptor binding domain / Ace2 blocking activity >50%, suggesting the presence of anti-SARS-CoV-2-reactive antibodies. Donations with reactivity occurred in all nine states.
Conclusions
These findings suggest that SARS-CoV-2 may have been introduced into the United States prior to January 19, 2020.
