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The United States is the country with the highest number of new coronavirus infections
About a year ago, after the emergence of the new coronavirus Sars-CoV-2 was reported in China, scientists first learned of the existence of this virus. But a new study shows that the virus that caused this global epidemic, Sars-CoV-2, may have coexisted with us for quite some time.
The World Health Organization (WHO) has confirmed that the virus causing a new large-scale corona disease (COVID-19) worldwide is Sars-CoV-2 (Sars-CoV-2).
Scientists from the Centers for Disease Control and Prevention (CDC) published the results of their research in the journal Clinical Infectious Diseases.
The official timeline for the new coronavirus pandemic began on December 31, 2019, when health authorities in Wuhan, China issued an alert that a series of cases related to a mysterious respiratory virus had emerged.
But today, 11 months later, researchers retrospectively discovered that 39 people from three US states had developed antibodies to the coronavirus two weeks before China’s alert.
In the United States, the first case of Sars-Cov-2 was not confirmed until January 21, 2020.
However, the study is based on 7,389 blood samples donated and regularly collected from across the United States from December 13, 2019 to January 17, 2020, and 106 blood samples were found to have antibodies to the coronavirus.
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This study analyzed more than 7,000 blood samples collected by the American Red Cross in different parts of the country.
The appearance of antibodies in people’s blood means that they have been exposed to viruses, which triggers a defensive response from the immune system.
Among them, 39 blood samples donated in California, Oregon and Washington from Dec. 13-16 contained antibodies against the coronavirus.
The study also found antibodies in 67 blood samples collected in early January before the widespread outbreak in Connecticut, Iowa, Massachusetts, Michigan, Rhode Island and Wisconsin.
According to this study, the majority of people infected before the outbreak in the United States were men, with an average age of 52 years.
The author of this study believes that the appearance of these antibodies may in part be the response of the human immune system to resist other types of coronavirus circulating in the world, but the author said the discovery of so many people with antibodies in the study indicates Some of them are probably suffering from Covid-19 disease at the time.
Researchers still insist that even if someone is infected, widespread community transmission in the United States is unlikely to occur before the end of February 2020.
But how will these findings change our understanding of the origin of this pandemic?
When did the coronavirus appear?
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Studies in Spain and Brazil found that the new coronavirus in wastewater sampling predates reports of infection in Wuhan.
The exact time the Sars-Cov-2 virus appeared is a question we may never be able to answer.
There are several signs that the virus has been circulating for weeks, even months, before the first outbreak in Wuhan became public in December 2019.
However, researchers from the U.S. Centers for Disease Control and Prevention said that one of the limitations of their research is that it is impossible to determine whether these people in the United States who have developed antibodies were infected on their own. country or during a trip.
The Red Cross, which collects blood samples for research, said that only 3% of these blood donors reported traveling abroad in the month before donating blood. Among these people, only 5% said they had been to Asia.
There are also studies elsewhere that have found evidence of the virus before China officially issued an epidemic alert. In May of this year, French scientists stated that sample tests showed that a patient who was treated for suspected pneumonia near Paris on December 27 was actually infected with the coronavirus.
Researchers in some countries have also found traces of coronavirus in wastewater collected weeks or months before the official timeline of the new coronavirus pandemic.
In June this year, Italian scientists said that coronavirus residues appeared in wastewater from the two cities of Milan and Turin on December 18 last year, long before the first confirmed case in Italy.
Furthermore, a Spanish study also found virus residues in wastewater collected in Barcelona in mid-January, which was about 40 days before the date the first COVID-19 case was detected there.
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A month before Brazil reported the first case of new corona patients, there were already examples of the virus.
In Brazil, there are also new questions about when the new corona virus will arrive in Brazil.
On February 26, the first person diagnosed in the area was a 61-year-old businessman from São Paulo who was returning from a trip to Italy. At that time, Italy had become the second focus of the new crown disease outbreak.
But a research team from the Federal University of Santa Catarina (UFSC) found the virus in wastewater on November 27, 2019.
In addition, a research report conducted by the Oswaldo Cruz Foundation (Oswaldo Cruz Foundation) indicated that a month before the first officially confirmed cases, that is, between January 19 and 25, Brazil There is at least one case of infection by Sars-Cov-2.
It is not clear if the first cases are related to the trip of the infected person abroad.
Unanswered question
There are many unanswered questions, such as how the Sars-CoV-2 virus began to spread, when it began to spread, and from which animal the virus “jumped” into the human body.
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The novel coronavirus outbreak was initially thought to be related to the South China Seafood Wholesale Market in Wuhan, China
People initially turned their attention to a market in Wuhan that sells fresh and slaughtered wild animals, because a large number of early cases may be related to the area, but researchers are not sure whether the virus appeared there or “used” the virus. market. The conditions of the transmission.
Yuan Guoyong, a microbiologist at the University of Hong Kong, told the BBC: “If you ask me which one is more likely, I would say that the virus is more likely to come from markets where wild animals are sold.”
China has advanced the timeline for the emergence of domestic viruses, which is not unusual in the process of researching fast-spreading diseases such as the new corona disease.
An earlier research report published by a Wuhan doctor in The Lancet medical journal earlier this year stated that the first known case of the new crown was discovered on December 1, 2019 and that there was no obvious connection to the market. seafood from southern China.
Some experts believe that a virus that can become a pandemic is difficult to spread globally for months without being detected.
However, the virus has escaped the surveillance system’s radar, and it is not entirely possible that it will be circulating for several weeks, especially in the northern hemisphere when it is winter.
