A large-scale survey revealed that the actual number of people infected with the new coronavirus may exceed the officially confirmed number by several tens of times



With the epidemic of novel coronavirus infection (COVID-19) in the world, it has been

suggested that the infection may be spread by asymptomatic infected persons who have no subjective symptoms. A new study from the University of Southern California has revealed that the actual number of people infected with the new coronavirus may well exceed the officially confirmed and published numbers.

What a USC-LA County antibody study can teach us about COVID-19-Press Room USC
https://pressroom.usc.edu/what-a-usc-la-county-antibody-study-can-teach-us-about-covid-19/

Coronavirus may have infected hundreds of thousands in LA County-Los Angeles Times
https://www.latimes.com/california/story/2020-04-20/coronavirus-serology-testing-la-county



Persons infected with the novel coronavirus have been identified mainly by PCR tests through medical institutions, but PCR tests should only be performed on patients with subjective symptoms or severe illness, or those who die due to suspicious symptoms. Hmm. As a result, infected persons who are infected with the novel coronavirus but who are asymptomatic or who have recovered mild symptoms before going to a medical institution will be overlooked without undergoing a PCR test.

It has been confirmed that more than half of the infected persons were asymptomatic, although the infection of the new coronavirus has spread in

Theodore Roosevelt , an American nuclear aircraft carrier. Therefore, it was thought that there may be more infected people than the actual number of infected people.

The mystery that `` most are asymptomatic '' of the aircraft carrier's crew with a large number of new coronavirus infected people, the Secretary of Defense is also puzzled-GIGAZINE


by US Pacific Fleet

Therefore, a research team at the University of Southern California, in cooperation with public health authorities in Los Angeles County , California, surveyed about 1000 randomly selected residents for `` antibody of new coronavirus contained in blood '' I'm doing research. Since an antibody to the virus is made in the body of a person infected with the virus, it can be understood by investigating the antibody contained in the blood whether the person has been infected with the new coronavirus. The research team will conduct similar surveys every few weeks and will continue for several months.

An antibody test developed by a company called Premier Biotech seems to detect people with new coronavirus with 90-95% accuracy, and the probability of diagnosing negative people as positive is very low, led the study. Said Neeraj Sood, professor at the University of Southern California. By conducting a large amount of testing on a general population as a sample, we analyze the difference between the number of official reports and the actual number of infected people, and more accurately measure the actual mortality rate, hospitalization rate, ICU probability, etc. of COVID-19. It is possible to estimate.

In addition, the research team also investigates how the people surveyed 'how they took measures to prevent infection with the new coronavirus', how effective the action to prevent the infection is actually I think that you can also measure. If we compare 'areas where social distances were kept appropriately' and 'areas where social distances were not kept', the rate of increase in infected persons was higher in 'areas where social distances were kept appropriately'. It is expected to be low, Sood said.



And from the results of the antibody survey conducted by the research team of the University of Southern California for the first time on April 10 and 11, 2020, '4.1%' of all the adults surveyed have the new coronavirus antibody It turned out. The population of Los Angeles County is about 10 million, and 221,000 to 442,000 people in Los Angeles County may have been secretly infected with the new coronavirus and have already recovered even if misdiagnosis is taken into consideration. The research team pointed out. As of April 10, the official number of people in Los Angeles County was less than 8,000, so the study suggests that far more people than previously thought were infected with the new coronavirus. It was.

A similar study is being conducted by

Stanford University in Santa Clara County , California. Similar to the University of Southern California study, Stanford University research suggests that the actual number of people infected in Santa Clara County may be tens of times higher than the officially announced number.

Deborah Barks, a member of the Trump administration's new anti-coronavirus team, said, 'I'm concerned about the spread of infection by asymptomatic people,' according to a study from the University of Southern California. He pointed out that the infectivity of the new coronavirus is extremely high.



If the actual number of people infected is higher than reported, the actual mortality and hospitalization rates due to COVID-19 will decrease. But that doesn't mean that the risk of COVID-19 is reduced, the researchers argue. Paul Simon, chief science officer in the public health department of Los Angeles County, noted that nearly 50 COVID-19 people die in Los Angeles County each day. This number is higher than heart disease, which was the number one cause of death in the past, and `` If the death rate of COVID-19 lasts for one year, COVID-19 will be the leading cause of death in Los Angeles County. 'Simon said.

Data from a study conducted in Los Angeles County showed that men were more likely to be infected with the new coronavirus than women, and that there were differences in infection rates among different races. The prevalence of infection was 7% in blacks, 6% in whites, 4% in Asian Americans and 2.5% in Latin Americans. The results depend on where you live and public transportation. It is unknown whether it is due to frequency or genetic / biological factors.

In addition, although it was suggested that the actual number of people infected was much higher than expected, the research team pointed out that it has not yet acquired the collective immunity to suppress the epidemic of infectious diseases in the population . In addition, at the time of writing the article, it was not confirmed that people who were once infected with the new coronavirus would not be infected with the new coronavirus again, so even if more people than expected were infected with the new coronavirus, never It seems that the threat of COVID-19 is not diminished.



in Science, Posted by log1h_ik