Post by Nadica (She/Her) on Jul 9, 2024 20:26:32 GMT
Serologic Testing of US Blood Donations to Identify Severe Acute Respiratory Syndrome Coronavirus-2 and other Coronaviruses, December 2019-July 2020 - Published June 28, 2024
Abstract
Background
The first COVID-19 case in the United States was recognized on January 19, 2020, but the time of introduction of the virus into the US is unknown. An existing sample cohort was examined for serologic evidence of early SARS-CoV-2 infections.
Material and Methods
A repository of 46,120 samples from healthy routine blood donors, representing 46 States and DC were tested for total antibodies to SARS-CoV-2 nucleocapsid (anti-N) using a commercial test. All reactive samples were further tested using an experimental receptor-binding-domain (RBD)-specific IgG ELISA. Further testing was also conducted for anti-spike (anti-S) by commercial tests, experimental anti-S immunologic blocking, and for antibodies to the four human cold coronaviruses.
Results
Anti-N reactivity was observed in 92 (0.2%) tested samples, 91 which had adequate volume for further testing; of these, 55 confirmed positive by anti-RBD. None of these reactive findings were attributable to the other human coronaviruses tested. Confirmed-positive frequency increased over time paralleling patterns observed for COVID-19 cases reported in the US (in contrast to stable patterns over time for the cold coronaviruses). Nine (0.07%) confirmed-positives were identified among the 13,364 donations collected between December 13, 2019 and January 22, 2020. None of these early confirmed-positive samples was reactive by commercial anti-S tests suggesting very recent infection.
Discussion
The samples tested in this study were broadly representative of the US and all were from individuals who had successfully given blood. The reactive results of this study suggest that SARS-CoV-2 was likely present in the US prior to January 19, 2020.
Abstract
Background
The first COVID-19 case in the United States was recognized on January 19, 2020, but the time of introduction of the virus into the US is unknown. An existing sample cohort was examined for serologic evidence of early SARS-CoV-2 infections.
Material and Methods
A repository of 46,120 samples from healthy routine blood donors, representing 46 States and DC were tested for total antibodies to SARS-CoV-2 nucleocapsid (anti-N) using a commercial test. All reactive samples were further tested using an experimental receptor-binding-domain (RBD)-specific IgG ELISA. Further testing was also conducted for anti-spike (anti-S) by commercial tests, experimental anti-S immunologic blocking, and for antibodies to the four human cold coronaviruses.
Results
Anti-N reactivity was observed in 92 (0.2%) tested samples, 91 which had adequate volume for further testing; of these, 55 confirmed positive by anti-RBD. None of these reactive findings were attributable to the other human coronaviruses tested. Confirmed-positive frequency increased over time paralleling patterns observed for COVID-19 cases reported in the US (in contrast to stable patterns over time for the cold coronaviruses). Nine (0.07%) confirmed-positives were identified among the 13,364 donations collected between December 13, 2019 and January 22, 2020. None of these early confirmed-positive samples was reactive by commercial anti-S tests suggesting very recent infection.
Discussion
The samples tested in this study were broadly representative of the US and all were from individuals who had successfully given blood. The reactive results of this study suggest that SARS-CoV-2 was likely present in the US prior to January 19, 2020.