Covid was circulating in five US states as early as December 2019, new research suggests

Cases were found in Illinois, Massachusetts, Mississippi, Pennsylvania, and Wisconsin

New study finds Covid cases were potentially ciruclating in US as early as December 2019 (AFP via Getty Images)

The Covid-19 virus was circulating in the United States in multiple states as early as December 2019, weeks ahead of the first reported case, according to a new research study by the National Institutes of Health.

Scientists analysing blood samples from the NIH’s “All of Us” research program, which was developed to advance “precision medicine” by gathering health data of a diverse group of people, discovered nine people who tested positive for Covid-19 antibodies.

Seven of the recorded people gave blood in five states – Illinois, Massachusetts, Mississippi, Pennsylvania, and Wisconsin – prior to the first recorded Covid-19 case.

The report, published in the journal Clinical Infectious Diseases on Tuesday, noted that seven of the nine people were racial minorities, with five of the subjects Black and two who were “Hispanic, Latino or Spanish”. Some of these subjects experienced mild Covid-19 symptoms.

The earliest recorded blood samples were taken from Illinois and Massachusetts on 7 January, 2020 and 8 January, 2020, respectively, the researchers said.

Typically Covid-19 antibodies take about 14 days to develop, the report said, which “suggests the virus may have been present in Illinois as early as 24 December, 2019.”

This suggests that the timeline for when Covid-19 first entered the United States could be different from what scientists and researchers initially estimated.

The first case of a coronavirus infection in the country was recorded on 20 January, 2020, after a patient in Everett, Washington, experienced symptoms from the novel virus on 14 January. This patient had previously travelled to Wuhan, China – where Covid-19 was believed to have originated.

But the Centers for Disease Control and Prevention (CDC) did not identify community spread of the novel virus until 26 February, meaning only infections found in connection with someone who previously travelled to China were only discovered up to that point.

In total, nine cases of Covid-19 were detected in 24,079 volunteers whose blood samples were taken between from 2 January, 2020, to 18 March, 2020.

Researchers said this suggested that while the virus was circulating earlier than anticipated, it was more sporadic within communities.

One shocking factor of the study was that no blood samples from California, New York, or Washington within the January to March timeframe showed Covid-19 antibodies. This despite the three locations being the first hotspots for the novel virus in the US.

The study comes as researchers are working to learn more about the novel virus and how it spread through the country.

An earlier study published at the end of 2020 from the CDC and American Red Cross revealed isolated Covid-19 cases in the US as early as mid-December. The researchers found evidence of a Covid-19 infection in a man from California who gave blood in December, as well as an individual in Connecticut who gave blood on 10 January, 2020.

Another study published by the scientific journal Nature Communication in December 2020 found that Covid-19 cases were likely circulating in New York City at least one month before the first infection was detected.

Researchers said that these studies don’t indicate that the virus originated in the US, but instead suggest that Covid-19 developed and circulated around the world earlier than initially estimated.