The Upper East Side's Legionnaires' disease outbreak has now caused over 20 hospitalizations, officials say.

The cluster, which is being investigated by NYC's Health Department, continues to grow daily in the area.

Here's what to know as of Friday, July 10.

The city's health department is still investigating a community cluster in Carnegie Hill and Yorkville, two neighborhoods in the Upper East Side. The affected zip codes are: 10028, 10128, and 10075.

Officials emphasized that residents can still do everyday activities with their water supply, like drink tap water, shower, cook and use AC units at home.

People are at risk of getting Legionnaires' disease if they breathe in water vapor contaminated with the bacteria. If multiple people become infected within a neighborhood, a typical source would be a cooling tower, hot tub or spray fountain, NYC Health wrote on its website.Mark Levine, the city's comptroller, said this current cluster of cases is from a contaminated cooling tower, and not a water system. In another post, Levine said that "it takes two weeks or so to grow legionella samples in the lab so we will not get the location of contaminated towers right away."

As of late July 9, the health department said that there were 46 cases, with 22 currently hospitalized.

So far, there have been zero deaths.

Those with symptoms who have been in the area are urged to receive medical attention promptly.

Per Mayo Clinic, symptoms include:

headaches and muscle aches

fever

coughing and shortness of breath

chest pain

nausea

confusion

Amethyst Martinez is a New York City-based journalist covering politics, life, culture and trends in the city for USA TODAY.

This article originally appeared on USA TODAY: NYC's Legionnaires' disease outbreak continues to grow. What to know