According to a new immunology study, the new coronavirus had spread in New York before the first cases of COVID-19 were diagnosed,media BGR reported. The findings come as a surprise to many, but they are consistent with similar studies that say the new coronavirus spread much earlier than expected in communities in the United States and Europe. The new study from Mount Sinai Hospital also suggests that as many as 22 percent of New York City residents may have been infected.
A new study by researchers at Mount Sinai Hospital shows that the virus was quietly spreading in New York City as early as early February, just weeks before PCR testing confirmed the first case. This will surprise many people, who believe that most of the early undiagnosed transmission occurs on the West Coast. The researchers also provided additional conclusions about antibody testing, COVID-19 immunity, and population immunity.
Researchers at Mount Sinai Hospital analyzed more than 10,600 plasma samples from patients who visited the health system in the weeks from February 9 to July 5. They divided patients into two groups, including the “Emergency Care” group of 4,101 patients and the “General Care” group of 6,590 patients. The emergency care group is a positive control group for new coronavirus infection in patients who come to the hospital to seek coVID-19 emergency care. The General Care Group represents patients who have been to the hospital for non-COVID-19 problems, including obstetrics and gynecology, childbirth, surgery, oncology, and any other conditions that do not involve the presence of pathogens.
The researchers believe that routine care will represent a better image of the general population. They found that most people in the emergency care group were over 61 years old, while the regular care group was more balanced in terms of age. The researchers designed their own antibody tests to detect infection. Mount Sinai tests are highly specific and sensitive, which means the chance of misdiagnosis is very low. They also measured the presence of antibodies and the amount of antibodies in a person.
“Our two-step ELISA test confirms the presence and level of antibodies. The use of two sequential tests can reduce the false positive rate, conducive to high specificity, so that sensitivity of 95%, specificity of 100%. Viviana Simon, a professor of microbiology who was involved in the study, said.
The researchers observed a sharp increase in the number of positives in both groups, with different frequency in the emergency group. Researchers at Mount Sinai Hospital discovered the virus spreading in New York in early February. The first positive antibody test dates back to mid-February. These proteins can be detected in the blood a few weeks after a person is infected with a new pathogen. This indicates that the virus has been coming to New York for several weeks – at least until health officials confirm the spread of COVID-19. In the first week of March, there was a marked increase in the number of COVID-19 cases, and on 22 March, the city implemented a “home order”.
Using antibody tests, researchers at Mount Sinai Hospital were able to measure the number of people infected in the first wave of the COVID-19 outbreak in New York. The researchers concluded that a significant number of New Yorkers were infected, but not enough to make the city immune to the population.
“Our data show that antibody titration is stable over time, with a seropositivity rate of about 22 percent in New York City, with at least 1.7 million New Yorkers infected with SARS-CoV-2 so far, and a 0.97 percent mortality rate after the first wave of infection in New York City,” said Dr. Florian Krammer. “Our study shows that during the first wave of epidemics in New York City, infection rates were relatively high, but far from seroposive rates that might indicate community immunity (group immunity). Understanding the detailed dynamics of serum prevalence shown in this study is important for simulating serum prevalence in other parts of the country. “
But the study has good news about COVID-19 immunity, suggesting that antibody titration remained stable from May to July. A growing body of research suggests that the new coronavirus immunity may last at least six months in most people.
The full study is available in the journal Nature.