A person has died and cases of Legionnaire's disease have reached at least 22 people in New York York.

The New York Health Department said it was alerted to an outbreak in Central Harlem last week after three cases were confirmed in the area.

On July 22, city officials confirmed there were eight people who had been infected with no deaths.

However, the health department provided an update on July 30 and noted that cases have nearly tripled within a week.

The patients are located in Harlem with the ZIP codes 10027, 10030, 10035, 10037, and 10039, along with the bordering communities.

No details about the deceased or infected individuals including their names, ages or genders, have been shared by officials.

Health experts say the outbreak is not linked to an issue with any buildings' plumbing system and residents in these ZIP codes can continue to drink tap water, bathe, shower, cook and use their air conditioning units at home.

The disease is spread from various water sources, particularly public sites such as cooling towers and hot tubs.

About one in 10 people who become sick will die from the infection.

The health department said in a statement: 'People who have been in the affected area since late July with flu-like symptoms, fever, cough, or difficulty breathing should seek immediate medical attention.

'People living or working in the area with flu-like symptoms, such as cough, fever, chills, muscle aches, or difficulty breathing should contact a health care provider immediately.

'It is especially important for people at higher risk - including those ages 50 and older, cigarette smokers, and people with chronic lung disease or compromised immune systems - to get care if they have symptoms.'

The infection is caused by a bacterium, known as Legionella that is primarily spread through the inhalation of contaminated water droplets or aerosols.

These contaminated droplets can be released from various water sources, including cooling towers, hot tubs, showers and decorative fountains.

The disease is not spread by drinking or swimming in water or person to person except in the instance of water accidentally getting into the lungs instead of the stomach.

Plumbing systems, especially those associated with warm water, such as hot water tanks and distribution pipes, can also serve as reservoirs for Legionella bacteria to multiply.

From there it can contaminate water in pipes. Stagnant or low-flow areas in pipes also foster Legionella growth.

Previously, Dr Celia Quinn, deputy commissioner of the health department's Division of Disease Control, revealed that 'very hot and humid [weather] can help the bacteria to grow really rapidly'.

Temperatures in the city are expected to reach 84 degrees Fahrenheit this weekend, with humidity levels of about 80 percent.

In the last week, residents in New York have been dealing with sweltering heat as temperatures climbed to nearly 90F, with humidity levels of more than 70 percent.

The Weather Channel predicts that temperatures above 80F will continue to be experienced by the city through most of August.

Early symptoms of the disease include fever, loss of appetite, headache, lethargy, muscle pain and diarrhea.

The severity can range from a mild cough to fatal pneumonia, and treating infection early with antibiotics is key for survival.

Most healthy individuals do not become infected after exposure to Legionella, however, people most at risk include adults over 50, smokers and those with weakened immune systems or chronic lung conditions.

The disease is treated with antibiotics including azithromycin, fluoroquinolones (like levofloxacin or moxifloxacin), and sometimes doxycycline or rifampin.

The infection is caused by a bacterium known as Legionella and spread through water sources

The CDC reports that cases of Legionnaires' disease have been increasing since the early 2000s and hit a peak in 2018 with 9,933 confirmed cases.

Due to reporting discrepancies and various databases, data on the number of legionnaires' cases and deaths is fragmented and varies.

However, according to the CDC's National Notifiable Diseases Surveillance System (NNDS), from 2000 through 2019, a total of 82,352 confirmed Legionnaires’ disease cases were reported from 52 US jurisdictions.

The most reliable way to determine if your water is contaminated with Legionella is to have it tested by a qualified laboratory.

Home testing kits are also available, which involve collecting water samples and sending them to a lab for analysis.

Earlier this week, health officials in Michigan also sounded the alarm over the spread of Legionnaires' disease after two people died of the infection this summer.

Wayne County officials confirmed that both people were living in Allegria Village, a continuing care retirement community in Dearborn, Michigan when they contracted the infection in June and July.

WHAT IS LEGIONNAIRES' DISEASE?

Legionnaires' disease is a severe form of pneumonia that causes lung inflammation.

It is caused by a bacterium, known as Legionella.

Around 500 people in the UK and 6,100 in the US suffer every year.

The condition can cause life-threatening complications, including respiratory failure, kidney failure and septic shock, which occurs when blood flow to the vital organs is blocked.

Most sufferers become ill by inhaling tiny water droplets from infected sources, such as shower heads, hot tubs, swimming pools or ventilation systems in buildings.

Anyone can become infected, however, at-risk people include the elderly, smokers and those with suppressed immune systems, such as chemotherapy patients.

Symptoms usually develop between two and 10 days after exposure to the bacteria.

Early signs include: