Plasma analysis shows that 1/5 of New Yorkers were infected with Coronavirus
4th by the physicist organization network, researchers at the Icahn Medical College of Mount Sinai in the United States wrote in the latest issue of “Nature” that they are responsible for more than 10,000 diseases.
A retrospective analysis of the patient’s plasma samples revealed that the virus had been latent in New York City before the first case of Coronavirus Pandemic infection was reported in New York on March 1.
Studies have shown that 1.7 million New Yorkers about 20% of the city’s population—have been infected with the new coronavirus, which has a fatality rate close to 1%, 10 times that of influenza.
From February 9th to July 5th this year, researchers obtained 10,691 patient plasma samples from the Mount Sinai Health System and tested them every week.
The first set of samples consisted of 4101 samples, obtained from patients who were admitted to the emergency department of Mount Sinai. This group is called the “emergency care group”, which is a positive control group.
The purpose is to detect changes in the infection status of patients with moderate to severe Coronavirus with changes in the local pandemic.
The second group of samples consisted of 6590 samples, called the “routine care group”, obtained from patients in childbirth, surgery, hospitalized patients, cardiology and other routine departments.
In the emergency care group, 45.5% were women, and most of them were over 61 years old; 67.6% in the routine care group were women, with a more balanced age distribution and more similar to the distribution of the average adult population.
In order to estimate the true infection rate, researchers measured whether antibodies were present in patients infected with the new coronavirus in the past.
This enzyme-linked immunosorbent assay (ELISA) antibody test was developed by the hospital with high sensitivity and high specificity (false The negative and false positive rate is very low) and other characteristics, it is the first test method authorized by New York State and the US Food and Drug Administration for emergency use. The researchers said: “Our two-step ELISA test confirmed the presence and level of antibodies, with sensitivity as high as 95% and specificity as high as 100%.”
According to the researchers, the seroprevalence rates of the two groups increased at different rates, and the increase was faster in the emergency group.
It is worth noting that the researchers found samples that were seropositive as early as mid-February (a few weeks before the first official case report).
From May to July, the seroprevalence rate and antibody titers remained stable, indicating the continued existence of antibodies in the population.
Dr. Florian Cramer, professor of vaccinology at Mount Sinai at Icahn School of Medicine, said: “The seroprevalence rate in New York City is about 22%, which shows that so far, at least 1.7 million New Yorkers have been infected with Coronavirus, and After the first wave of the pandemic hit New York, the infection mortality rate was 0.97. Understanding the detailed dynamics of Coronavirus Pandemic in this study is very important for simulating the spread of the pandemic in other parts of the United States.”