Wednesday, July 29, 2015

NYC DOH: Investigating A South Bronx Legionella Outbreak


Legionella Bacteria - Photo Credit CDC PHIL




The New York City Department issued a press release today regarding an extended outbreak of Legionella among residents of the South Bronx, which has thus far infected 31 people, killing 2. The source of this outbreak has yet to be be determined.  The Health Department advises:


New Yorkers with respiratory symptoms, such as fever, cough, chills and muscle aches, are advised to promptly seek medical attention.


First, the press release, then some background on the disease.


Press Release # 030-15
Wednesday, July 29, 2015

Health Department Investigating Outbreak of Legionnaires' Disease in the South Bronx

31 cases of Legionnaires' disease have been reported since July 10 New Yorkers with respiratory symptoms, such as fever, cough, chills and muscle aches, are advised to promptly seek medical attention

The Health Department is currently investigating an outbreak of Legionnaires' disease in the South Bronx. Thirty-one cases have been reported since July 10. There have also been two deaths reported in patients with Legionnaires' disease in these neighborhoods. The Health Department is actively investigating these deaths and their relationship to the outbreak. The Health Department is testing water from cooling towers and other potential sources in the area to determine the source of the outbreak. New Yorkers with respiratory symptoms, such as fever, cough, chills and muscle aches, are advised to promptly seek medical attention.

“We are concerned about this unusual increase in Legionnaires’ disease cases in the South Bronx,” said Health Commissioner Dr. Mary Bassett. “We are conducting a swift investigation to determine the source of the outbreak and prevent future cases. I urge anyone with symptoms to seek medical attention right away.”

Legionnaires' disease is caused by the bacteria Legionella. Additional symptoms include: headache, fatigue, loss of appetite, confusion and diarrhea. Symptoms usually appear two to 10 days after significant exposure to Legionella bacteria. Most cases of Legionnaires’ disease can be traced to plumbing systems where conditions are favorable for Legionella growth, such as whirlpool spas, hot tubs, humidifiers, hot water tanks, cooling towers, and evaporative condensers of large air-conditioning systems.

Legionnaires' disease cannot be spread from person to person. Groups at high risk for Legionnaire’s disease include people who are middle-aged or older – especially cigarette smokers – people with chronic lung disease or weakened immune systems and people who take medicines that weaken their immune systems (immunosuppressive drugs). Those with symptoms should call their doctor and ask about testing for Legionnaire’s disease.

For more information about Legionnaires’ disease, please visit the Health Department website.



Nearly 40 years ago, iIn July of 1976, while many of us in the healthcare field were waiting for the expected arrival of a swine flu pandemic (see Deja Flu, All Over Again), another medical crisis was brewing  at the Bellevue Stratford Hotel in Philadelphia.


This was the scene of the gathering of hundreds of veterans belonging to the American Legion, celebrating this country’s bicentennial.  Within a couple of days of their arrival, scores fell ill with a serious flu-like illness.


At first, many believed this was the first arrival of the expected flu pandemic, but soon it became evident that this was something else entirely.  But exactly what it was would take months to determine.


During this outbreak, 221 people were treated and 34 died.


But it wouldn’t be until early in 1977 that a definitive cause would be isolated by the CDC a Gram negative, aerobic bacteria found growing in the hotel’s air-conditioning cooling tower – that provoked a serious form of pneumonia.


Dubbed `Legionnaire's Disease’ by the press, this bacterium was named Legionella, and the pneumonia it produces Legionellosis.


While `discovered’ in 1976 and identified the following year, Legionella had been with us, and causing serious illness, for a long time. It had caused earlier outbreaks, including one in Austin, Minnesota in 1957 (Osterholm et al., 1983) and at Saint Elizabeth’s Hospital in Washington, D.C. in 1965.  


The cause of these outbreaks wasn’t identified, however, until retrospective studies were conducted after the Philadelphia outbreak.


We now know Legionella to be a major cause of infectious pneumonia, and that it sometimes sparks large outbreaks of illness.  According to the CDC between 8,000 and 18,000 Americans are hospitalized with Legionnaire's Disease each year, although the actual number of infected is likely higher.


The bacteria thrives in warm water, such as is often found in air-conditioning cooling towers, hot tubs, and even ornamental water fountains. Improper maintenance or poor design can lead to the bacteria blooming. 


When water is sprayed into the air the bacteria can become airborne, and if inhaled by a susceptible host, can cause a serious (and sometimes fatal) form of pneumonia.


In one of the oddest examples, in 2010 we saw a study (see Wiper Fluid And Legionella) that linked the use of plain water in windshield wiper reservoirs to an increased risk of infection.


The idea being that plain water, kept warm and dark under the hood near the engine, is apparently conducive to the growth of Legionella, and can become aerosolized when you clean your windshield, and subsequently inhaled.


While large outbreaks of Legionella are often traced to specific causes, quite often the source of the infection for sporadic cases remains a mystery.  


For more information on the disease, the CDC maintains a fact sheet at Patient Facts: Learn More about Legionnaires' disease.

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