In a follow-up on a report last week on the Legionnaires’ disease cluster in a section of Lower Washington Heights in Manhattan, city health officials are now reporting 22 cases, up from 14 one week ago.

This image depicts two Legionella pneumophila bacterial colonies (arrowheads), amongst other bacterial colonies grown on BCYE (Buffered Charcoal Yeast Extract) agar/CDC
This image depicts two Legionella pneumophila bacterial colonies (arrowheads), amongst other bacterial colonies grown on BCYE (Buffered Charcoal Yeast Extract) agar/CDC

The Health Department is investigating these cases and testing the water from all cooling tower systems in this section of Washington Heights. The risk to most people is low, health officials note, but if you have flu-like symptoms, please see your medical provider right away.

Legionnaires’ disease is the cause of pneumonia where a non productive cough is typical. In addition, it is typified by headache, fever, body aches and occasionally abdominal pain and diarrhea.

Legionella bacteria are widely distributed, and normally grow best in warm water environments. They have been found in creeks and ponds, water taps (primarily hot water taps), hot water tanks, cooling towers and evaporative condensers, whirlpool spas, and decorative fountains.

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Most people contract the disease by inhaling mist or vapor from a water source contaminated with the bacteria.

People of any age may get Legionnaires’ disease, but the disease most often affects persons older than 50.  The disease is rare in people younger than 20 years of age.  People at high-risk of acquiring the disease include current and former smokers, persons with chronic lung disease like emphysema or COPD, or those with compromised immunity (like patients who receive corticosteroids or have had an organ transplant).  People with underlying illnesses, such as cancer, kidney disease, diabetes, or AIDS are also at higher risk.