Coronavirus was likely present in US from December 2019: Study

A new antibody testing study published on June 15 has found further evidence that the coronavirus was present in the United States from at least December 2019, weeks before the first confirmed case was announced on January 21, 2020.

The National Institutes of Health study analyzed 24,000 stored blood samples contributed by volunteers across the country from January 2 to March 18, 2020.

Antibodies against the SARS-CoV-2 virus were detected via two different serology tests in nine patient samples, according to the paper, which was published in the journal Clinical Infectious Diseases.

The participants were outside the major hotspots of Seattle and New York City, thought to be the key entry points of the virus to the United States.

The first positive samples came from participants in Illinois and Massachusetts on January 7 and 8, 2020, respectively, suggesting that the virus was present in those states in late December.

"Antibody testing of blood samples helps us better understand the spread of SARS-CoV-2 in the U.S. in the early days of the U.S. epidemic, when testing was restricted," said lead author Keri Althoff, an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.

The research builds on a similar investigation published by the Centers for Disease Control and Prevention last November that reached the same conclusion.

But since there are uncertainties surrounding serology testing, further confirmation builds extra confidence in the finding.

To help minimize the possibility of false positives, the team used two separate tests on each sample, searching for antibodies that bind to different parts of the virus.

The types of antibodies they were looking for are...