A case of COVID-19 infection was discovered in the US prior to the mass outbreak in Wuhan last year, a report by a US research team claims.
According to a report published on Dec. 1 in the medical journal “Clinical Infectious Diseases” by a research team from the US Centers for Disease Control and Prevention (CDC), the first confirmed COVID-19 case in the US was diagnosed on Jan. 19. A mass outbreak of the virus had previously begun in Wuhan, a city in China’s Hubei Province, in late December 2019.
To examine whether any COVID-19 infections had occurred in the US prior to the first confirmed case, the team conducted serum tests on blood acquired by the US Red Cross from blood donors. The examination covered a period from Dec. 13, 2019, to Jan. 17, 2020, with tests of 7,389 blood samples gathered from nine states, including California, Iowa, and Massachusetts.
In the report, the team said the serum tests showed COVID-19 antibodies in 106 of the samples, or 1.4%. Antibodies are formed in the process of the immune system fighting pathogens (antigens) such as viruses that have infiltrated the body; the presence of antibodies means that a person has been infected in the past.
In its report, the team explained that COVID-19 serum was found in 39 out of 1,912 samples (2%) collected between Dec. 13 and 16 in California, Oregon, and Washington. On this basis, it concluded that isolated cases of COVID-19 infection may have occurred in the western US a month before the first case was officially confirmed.