STATEN ISLAND, NY – Data released Tuesday by the Centers for Disease Control and Prevention (CDC) showed that actual coronavirus infections (COVID-19) in New York City were at least 10 times higher than reported cases.
Preliminary findings published by the CDC looked at seroprevalence, the presence of a virus in a population based on blood samples, in 10 different cities and states, and found that the actual number of people infected with the virus in this region was actually between two and 13 times greater than previously confirmed through positive test results.
CDC data suggests that large sections of the population in these areas were asymptomatic or not seeking medical attention, which could unknowingly spread the virus.
Using antibody tests, the CDC analyzed blood samples from each of the 10 areas at least once. Data from eight of the 10 sites, including the New York City metropolitan area, was also collected for the second time at a later date.
The CDC’s first round of data collection took place in New York between March 23 and April 1, about a week before the city’s highest number of daily deaths during the coronavirus outbreak.
At that time, nearly 54,000 cases were confirmed in the area. However, CDC analysis showed that approximately 7% of the region’s population had antibodies against the virus during that period.
The CDC estimates that 642,000 people were actually infected at the time, the data shows, indicating that the actual number of infections during the aforementioned period was at least 12 times greater than the confirmed cases.
“These data continue to show that the number of people who have been infected with the virus that causes Covid-19 far exceeds the number of reported cases,” Dr. Fiona Havers, a CDC researcher who led the report, told the New York Times. study. . “It is likely that many of these people had no symptoms or mild illness and had no idea that they were infected.”
The second round of data collection in the New York City metropolitan area, meeting between April 25 and May 6, showed that approximately 23% of the population had antibodies to the coronavirus present in the blood samples. , which is consistent with the timing of the outbreak throughout New York. The results also coincided with a statewide survey conducted at approximately the same time.
As diagnostic tests increased across the city and state, the gap between actual infections and confirmed cases narrowed, CDC data shows.
While 281,000 confirmed cases were recorded in early May, the CDC estimates that 2,832,000 people had actually been infected by that date, about 10 times more than the reported cases.
In another part of the country, the data painted a similar image.
Initial data collected from Minnesota showed that actual coronavirus infections exceeded reported cases ten times, based on blood samples taken between April 30 and May 12. The second round of tests in the state, gathered more than a month later, showed that the antibodies were present in approximately 2.2% of the population – reducing the disparity between actual infections and confirmed cases.
The CDC antibody survey is the largest of its kind, but it has its limitations.
Some antibody test results could be false positives or false negatives, the agency said in the study, and the analysis does not take into account a variety of factors, including the occupation of the people tested or the underlying health conditions.
Furthermore, the study is concise to point out that antibody test surveys should not be interpreted as meaning that people who tested positive for the virus are immune to future infections.
The CDC is conducting additional analyzes to assess how changes in seroprevalence estimates over time could be affected by collecting samples from different populations or geographic areas in each state, the CDC said, adding that it is possible that Antibody levels may decrease over time.
Several recent studies indicate that antibody levels rapidly faded in individuals who recovered from the virus.
Despite having the highest seroprevalence of any tested state at around 23%, New York is well below the bar that experts believe should be reached to achieve herd immunity. Some experts believe that approximately 70% of the population would need to be exposed to the virus to achieve a sustainable level or protection.
The CDC aims to process approximately 1,800 samples from each of the 10 sites every three to four weeks, the agency said, which will allow its data to be updated regularly.
