More New Yorkers are being infected and hospitalized with a deadly lung disease spreading throughout the city, officials have warned. 

As of August 7, around 81 residents of upper Manhattan have contracted Legionnaire’s disease, a form of pneumonia caused by bacteria thriving in warm water.

Legionnaires’ disease is caused by Legionella bacteria, which thrive in warm water and can become airborne when water turns to steam. 

New York City health officials also reported that 24 individuals have been hospitalized with the ailment, which poses the greatest risk to older adults, smokers, and those with chronic lung conditions.

All cases have been detected in five ZIP codes covering the Harlem, East Harlem and Morningside Heights neighborhoods. 

The exact mode of infection has not been identified, but the New York City Department of Health indicated that a cooling tower in the vicinity is the ‘likely source.’ 

In a news release on Thursday, officials clarified: ‘This is not related to any building’s plumbing system. Residents in these ZIP codes can safely drink water, bathe, shower, cook, and use air conditioning.’

Even though building owners ‘must register cooling towers’ and ‘regularly test the water’ for bacteria, inspection rates reportedly dropped to nearly unprecedented lows in the months before the outbreak. 

Cooling towers and air conditioning units are seen in the Harlem neighborhood amid a Legionnaires’ disease outbreak in New York City

Officials told Gothamist, which discovered the decline, that staffing issues were to blame. 

The NYC Department of Health noted in Thursday’s release: ‘Inhaling mist containing Legionella bacteria can lead to illness. Water sources with potential Legionella contamination include cooling towers, showers, and hot tubs.’

‘Window air conditioners do not spread the bacteria that causes Legionnaires’ disease.’ 

No information has been released about those who have died or been hospitalized. 

Infected patients initially suffer from a headache, muscle aches, and fever that may be 104 Fahrenheit (40 Celsius) or higher. 

But within three days, they may experience a cough, shortness of breath, chest pain, nausea, vomiting and diarrhea, and confusion or other mental changes.

In serious cases, patients can develop severe pneumonia, and the bacteria can spread to the heart and blood, causing the potentially fatal complication sepsis.

Patients die from the disease due to lung failure, septic shock, a sudden severe drop in blood flow to vital organs, or acute kidney failure. 

Legionnaires’ affects 8,000 to 10,000 Americans every year and kills about 1,000. 

The five ZIP codes affected in the outbreak are: 10027, 10030, 10035, 10037 and 10039. 

City health officials said while ‘most people who are exposed to the bacteria do not develop Legionnaires’ disease,’ those who are 50 or older, smoke, have a chronic lung disease or a weakened immune system may be at a higher risk. 

The news release cautioned people who experience symptoms to ‘seek medical attention right away.’ 

Doctors treat the disease using antibiotics, but say these are most effective in the early stages before the disease has spread in the body. Patients are often hospitalized.

Dr Asim Cheema, internal medicine and cardiology specialist at Your Doctors Online, told the Daily Mail: ‘August is peak season for Legionnaires’ disease. Hot weather creates perfect breeding conditions, air conditioning systems work overtime, and people spend more time around water features. 

‘This isn’t a condition to take lightly; it can be fatal if not treated promptly, but it’s also completely treatable when caught early.’

In milder cases, patients may also suffer from Pontiac fever, a condition causing fever, chills, headache and muscle aches that occurs when the bacteria do not infect the lungs. 

This condition goes away on its own without treatment and causes no further problems, doctors say.

Air conditioning units are seen in the Harlem neighborhood amid a Legionnaires’ disease outbreak in New York City

The New York City outbreak was first revealed on July 22, when the health department reported eight cases.

All buildings that had units that tested positive for the Legionella bacteria were told to clean their systems within 24 hours.

It follows a previous outbreak in July 2015 in the Bronx, which became the second-largest Legionnaires’ disease outbreak in the US.

Overall, a total of 155 patients were infected and 17 people died due to the disease from July to September that year.

The outbreak was eventually linked back to a cooling tower at the Opera House Hotel in the South Bronx, which had been contaminated with the bacteria and was releasing it in water vapor.

Dr Cheema recommends flushing home water systems after being away for extended periods of time to get rid of lingering bacteria, using distilled water in home humidifiers and medical devices and avoiding breathing mist from public areas.