• COVID-19 festers in New York City due to its huge population density
  • The largest city in the U.S. has a population density of  27,000 people per square mile
  • It also had 23,112 confirmed COVID-19 cases and 365 deaths as of Thursday evening

New York City is the largest and most densely populated city in the United States. Its population of 8.4 million persons is crammed into an area of only 468,000 square miles.

This means a population density of 27,000 people per square mile. This density is more than double the density of Chicago and Philadelphia and more than three times the density of Los Angeles.

These facts make The City That Never Sleeps the always-on, happy hunting ground for any contagious human virus such as SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) -- the virus that causes COVID-19.

NYC had 23,112 confirmed cases and 365 deaths as of Thursday evening. It accounted for 28% of all confirmed COVID-19 cases (82,547) in the U.S. The city's huge casualties led New York state governor Andrew Cuomo to describe the Big Apple as the epicenter of the epicenter.

"We're used to crowds," said Mayor Bill de Blasio, who first refused to recognize the danger to his city presented by COVID-19. "We're used to lines. We're used to being close together."

New York's very high number of SARS-CoV-2 cases is just a reflection of its size, said Dr. Kent Sepkowitz, a professor of Medicine and Infectious Diseases at the Weill Cornell Medical College in the city. Dr. Sepkowitz told CNN New York state will likely lead the country in SARS-CoV-2 cases even if its infection rate per person isn't the highest.

The accelerated pace of coronavirus testing is another reason for New York City reporting the huge numbers that it does. The huge results revealed by testing make the city look bad to the rest of the world, but provide invaluable information for doctors seeking to combat and isolate the coronavirus.

Cuomo said more than 100,000 people have been tested for coronavirus in New York state but didn't give any figure for the city. He said 25% of all testing nationwide took place in the state.

"We're hunting positives," said Cuomo. "We're hunting positives so we can isolate them and reduce the spread."

The city has made a concerted push to boost testing at hospitals, labs and new drive-through centers. New York state also authorized 28 public and private labs to begin testing for SARS-CoV-2, the first state to do so.

"It's higher (the infection numbers) in New York because it started here first, because we have global travelers coming here first, because we have more density than most places, but you will see this in cities all across the country," said Cuomo. "And you will see this in suburban counties all across the country. We are just a test case."

A nearly empty Times Square is seen on March 23, 2020 in New York City
A nearly empty Times Square is seen on March 23, 2020 in New York City AFP / Angela Weiss