New York, August 19: At least five people have died and more than 100 have fallen ill in New York City’s Harlem neighbourhood following an outbreak of Legionnaires’ disease, a severe lung infection linked to contaminated cooling towers. The illness, which is not spread from person to person, has put several others in the hospital and sparked urgent investigations by health officials. With the sudden spike in cases, many are now asking, What is Legionnaires’ disease?

The outbreak has put a spotlight back on this rare but dangerous infection that often thrives in large water systems like air conditioners, hot tubs, and fountains. With symptoms ranging from high fever to life-threatening lung complications, the disease poses a greater risk to older adults, smokers, and those with weak immune systems. With its history dating back to a 1976 outbreak in Philadelphia, it remains a global health concern. Let’s know all about Legionnaires’ Disease. Measles Outbreak in Texas: Measles Cases Rise to 597 Since January 2025, US State on High Alert.

What is Legionnaires’ Disease?

According to the Mayo Clinic, Legionnaires’ disease is a severe form of pneumonia caused by Legionella bacteria. The infection typically spreads when people inhale contaminated water droplets from sources like showers, cooling towers, or hot tubs. While it is not contagious person-to-person, it can be life-threatening if left untreated. Older adults, smokers, and people with weakened immune systems are at higher risk. The infection primarily affects the lungs, though it can spread to other organs in serious cases. A milder version, called Pontiac fever, causes flu-like symptoms and often resolves without treatment. Measles in US: Person With Confirmed Case of Measles Visited ‘Five Guys’ Outlet in Washington DC, Probe Launched Amid Outbreak Fears.

Causes

Legionnaires’ disease is caused by the bacterium Legionella pneumophila. While the bacteria naturally occur in soil and water, infections typically happen when they multiply in man-made water systems. Outbreaks are often linked to cooling towers, hot water tanks, fountains, and whirlpools. Infection spreads when people breathe in tiny contaminated droplets or mist. Rarely, it can occur through aspiration—when water accidentally enters the lungs while drinking.

Symptoms

The illness usually develops two to ten days after exposure. Early signs include headache, fever, chills, and muscle aches. As the infection worsens, symptoms can progress to coughing (sometimes with mucus or blood), chest pain, shortness of breath, and gastrointestinal issues like nausea, diarrhoea, or vomiting. In some cases, patients may also experience confusion or mental changes.

Treatment

Legionnaires’ disease requires immediate medical attention. Doctors typically prescribe antibiotics, which are effective when started early. While most patients recover promptly, some may experience lingering health problems. In severe cases, untreated infections can cause lung failure, septic shock, or kidney failure, making urgent treatment critical.

Prevention

Proper monitoring and cleaning of water systems is the best way to prevent Legionnaires’ disease. Regular disinfection of cooling towers, hot tubs, and plumbing networks helps limit bacterial growth. Health experts also recommend caution for high-risk groups, such as older adults and smokers, who should seek medical care promptly if symptoms appear.

Legionnaires’ disease remains a serious public health concern, particularly during large outbreaks like the recent one in New York. While it is not contagious from person to person, its ability to spread through contaminated water systems makes vigilance essential. Early detection, timely treatment, and proper maintenance of water sources are key to reducing risks.

(The above story first appeared on LatestLY on Aug 19, 2025 02:46 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).