WASHINGTON HEIGHTS, NY — Slightly more than 33 percent of Washington Heights and Inwood residents tested for antibodies showed signs they were previously infected with the coronavirus that causes COVID-19, according to new city data.
Out of the 47,603 residents tested in the four Zip Codes that make up the two neighborhoods, roughly 33.15 percent tested positive for antibodies, according to data released by the Department of Health on Tuesday.
The positive antibody test rate for the four Upper Manhattan Zip Codes is significantly higher than the borough's rate of 19 percent.
Washington Heights is home to the Zip Code with the highest rate of positive antibody tests in all of Manhattan, 10032, which contains the downtown section of the Washington Heights. About 33.7 percent of antibody tests came back positive for residents in that area.
Percent positive antibody tests by Washington Heights and Inwood ZIP Code:
10032: 33.7 percent (13,465 tested, 4,538 positive)
10033: 33.4 percent (13,934 tested, 4,648 positive)
10034: 32.2 percent (9,982 tested, 3,214 positive)
10040: 33.3 percent (10,222 tests, 3,399 positive)
Residents in Harlem ranked second in Manhattan for the highest positive antibody test rate, with just under 27 percent of people in the neighborhood who were tested for antibodies showing they had been infected with COVID-19.
The Bronx led the way out of the five boroughs for the highest rate, at about 33 percent.
An antibody test indicates if a person has been exposed to the coronavirus by measuring their bloodstream for signs that their immune system produced proteins called antibodies to fight off the virus.
On Tuesday, Mayor Bill de Blasio announced that the city's website for coronavirus data would start, including the results of antibody tests.
Additionally, a positive test result could mean the person has antibodies from an infection with a virus in the same family as the coronavirus, according to the U.S. Centers for Disease Control and Prevention.
The chance of receiving a false negative can be as high as 30 percent, depending on when the test is conducted, according to a Harvard Medical School blog post.
The data may not accurately reflect the prevalence of antibodies among all neighborhood residents or New York City residents, because people who have been ill with COVID-19 symptoms or were exposed to the virus may be likelier to seek out antibody testing, the city wrote in a disclaimer about the dataset.
"We will be the first jurisdiction in the nation to present our antibody data this way," de Blasio told reporters. "While there is still much to learn about the science of COVID-19 antibody testing, it is an important element to consider when understanding the epidemiology of COVID."
Patch reporter Maya Kaufman and Nick Garber contributed to this report.