For the time being, the first case registered in the United States was considered to be a case attended by a doctor from China on 19 January this year. However, a study published in the journal Clinical Infectous Diseases postpones the date of first appearance a month earlier.
Of the 7389 samples analyzed, 106 showed the presence of anticoronavirus IgG antibodies. These antibodies may not in themselves indicate the presence of SARS-CoV-2, they may be raised against other coronaviruses (such as those that cause colds). Therefore, the researchers performed further tests, and the antibodies detected in 84 samples neutralized SARS-COV-2.
One of the samples was able to neutralize SARS-CoV-2 very safely, the other responded to parts of the glycoprotein S that are very specific for the new coronavirus. “So at least two samples can be considered evidence of infection,” co-author Susan Stramer said in the New York Times.
The positive samples are from December 30 to January 17, and because igG antibodies are formed several days after infection, the researchers estimate that the coronavirus occurred in the United States at least in the first half of December.
The coronavirus study is still on the rise last year
According to Stramer, antibody blood tests may not always be useful for individuals because they do not detect the presence of the virus as such. However, antibodies that stay in the body longer than the virus itself can, among other things, provide important epidemiological guidance and allow monitoring of wider patterns of disease transmission.
Studies showing that the virus began spreading earlier this year are gradually increasing. On December 31, China officially confirmed the emergence of “unknown causes of pneumonia.” But an Italian study, similar to the American study, found 23 cases of blood containing antibodies to SARS-CoV-2 collected as early as last September.
Another method of counter-testing is the analysis of effluents containing human faeces which may contain coronavirus.
Samples from the Santa Catalina regions of Brazil and the city of Florianopolis came from 30 October 2019 to March this year. All coronavirus samples tested have been positive since 27 November 2019 (Brazil reported the first case of coronavirus on 26 February 2020). In Spain, similar tests revealed the presence of SARS-CoV-2 on 15 January this year, with the country notifying the first case until 31 January.
References still point to China
All these indications support the assertion that the infamous Wuchan market was not the place where the coronavirus gradually spread throughout the world. China is trying to prove that the coronavirus does not come from it and, on the contrary, it was introduced there.
The most reliable Chinese experts believe the Indian subcontinent, where there was a lot of heat last year and people and animals used the same water sources. However, the study that claims this has not been revised, and it is not clear if and when it will actually come out. The Chinese authorities often use research to suggest that the country had a coronavirus last year.
However, the studies themselves do not prove this in any way. If he claims that the coronavirus entered the country earlier, it could mean that it started spreading from China long before the Chinese authorities confirmed the disease.
If we focus on the virus itself, it is still true that most scientists assume its natural origin. The genetic composition of SARS-CoV-2 is 80 percent consistent with the coronaviruses found in bats in Yunnan province.
Another reference to China is the leaked documents released by CNN this week. The documents not only show that the Chinese authorities have underestimated the number of infected and victims, but also shed light on the possible beginning of a pandemic.
An extremely severe flu epidemic was reported in Hubei Province last December. Compared to the previous year, the number of patients in hospitals increased twenty times. However, according to the documents, many tests did not show influenza. At that time, according to documents, the coronavirus had to spread in the country for some time. And thousands of tourists flew to all over the world.