The infection was announced a day after President Donald Trump allowed the ship to begin accepting patients who were infected with the coronavirus.
"The ship is following protocols and taking every precaution to ensure the health and safety of all crew members and patients on board," said the official.
On Thursday, the 1,000-bed ship only had 20 patients, while hospitals in New York were overwhelmed with COVID-19 patients, according to The New York Times. By Tuesday, this number had increased to 44 patients.
Originally, restrictions on patients were exceedingly strict, causing some hospital officials complaining that they were so onerous that only healthy people would be allowed on board. The Defense Department later eased the restrictions.
The infected crew member was not a medical worker and had no contact with patients.
"The ability to take COVID-19 patients on board USNS Comfort provides increased capability to care for high severity COVID-positive cases, allowing the Javits New York Medical Station to focus on lower severity COVID-positive patients," said a spokesperson for the 2nd Fleet, according to Politico.
Although the ship originally was meant for patients who weren't infected with the coronavirus, five patients who originally tested negative for the virus developed symptoms and were confirmed as infected after being transferred to the Comfort.