Officials said Monday night there has been an uptick in Legionnaires' disease cases in Central Harlem.

The New York City Department of Health said there are now 90 confirmed cases, including three deaths. Currently, there are 17 people hospitalized.

So far, Legionnaires' cases have been found in these Central Harlem zip codes: 10027, 10030, 10035, 10037 and 10039. Officials said anyone with symptoms in these neighborhoods should see a health care provider and not assume they simply have a cold.

NYC unveils amended and new rules on cooling towers  

Officials believe they traced the outbreak to cooling towers on 11 buildings in Central Harlem. Last week, the infected towers underwent antibacterial treatments to stop the Legionella bacteria from spreading, said Dr. Michelle Morse, the city's interim health commissioner.

The city is proposing stricter rules for cooling towers, with health officials saying the guidelines were in development before the cluster was identified last month.

New rules would enhance existing testing and reporting requirements for building water systems. They would also include penalties for failure to comply with reporting inspections that include test sampling for Legionella bacteria.

What to know about Legionnaires' disease

Legionnaires' is a severe and potentially deadly form of pneumonia that grows in warm, stagnant water and spreads through mist in the air. It does not spread from person to person. Symptoms include cough, fever, chills, muscle aches and shortness of breath.

Tony Esselstyn, NYC Health's deputy chief medical officer, said it could take up to two weeks for certain people to show symptoms. While most people are at a low risk, Legionella poses a greater threat to smokers and people over 50.

Monday's update follows recent efforts by health and community leaders to educate the public on ways to prevent the bacteria from growing and spreading.

Health leaders hit the streets of Harlem late last week with fliers urging people to take precautions as the number of infections continues to rise.