Covid-19 was present in the United States before the pandemic in China, concludes a US study

15:57 02.12.2020Short URL

An American study showed signs of the coronavirus in the United States before the announcement of the first case in China.

A retrospective study of blood samples taken by Americans in December 2019 found that some of them had been infected with Covid-19 even before the first case was announced in China. The article was published in the journal Clinical Infectious Diseases.

Chinese officials first reported a mysterious case of pneumonia in Wuhan on December 31, 2019. In the United States, the first confirmed case of coronavirus in a newly arrived Washington state resident was reported on January 20, 2020. from China.

Researchers from the U.S. Centers for Disease Control and Prevention (CDC) analyzed more than 7,000 blood samples collected by the American Red Cross in nine states between December 13, 2019 and January 17, 2020.

Of these, 106 samples tested positive for antibodies to SARS-CoV-2: 39 in California and 67 in Connecticut, Iowa, Massachusetts, Michigan, Rhode Island and Wisconsin.

The scientists ran further tests on 90 of these samples to confirm that the antibodies did not belong to other coronaviruses, such as those that cause cold snaps. According to the report, a total of 84 people, or about 93%, had Covid-19 specific antibodies. Even taking into account possible false positives, the study says the virus was already present in the United States in early December.

“These findings suggest that SARS-CoV-2 may have been introduced in the United States before January 19, 2020,” the study says, adding that it could not be determined whether the infections were linked to people who had recently traveled or to the spread. of the virus.

Similar cases in France and Italy

Previous retrospective studies conducted in France and Italy also found antibodies against SARS-CoV-2 in blood samples taken from residents in early December 2019.

US scientists plan to continue the study by contacting people whose blood showed the presence of antibodies to find out if they traveled in late 2019 and had symptoms similar to Covid-19.

Additionally, the authors hope to find tissue, saliva, or blood samples from these people from this period for testing.