Legionnaires’ Outbreak in New York City: Some Basics for Nurses

By Betsy Todd, MPH, RN, CIC, AJN clinical editor

11148_loresIn the largest U.S. outbreak of Legionella infection since 1976, when there were 221 cases and 34 related deaths in an outbreak at a Philadelphia American Legion convention, more than 113 cases of the disease have been diagnosed in New York City since mid-July. Twelve people have died.

Legionnaires’ disease is neither rare nor exotic; it is a type of community-acquired pneumonia (it can also be hospital acquired). Symptoms include fever, cough, and progressive respiratory distress. Legionella can also cause a milder, flulike illness known as Pontiac fever that generally resolves without treatment. Because many cases of Legionnaires’ disease are never actually diagnosed, mortality rates are difficult to determine, but the rate currently is estimated at 5% to 30%.

The CDC estimates that 8,000 to 18,000 people are hospitalized with Legionnaires’ disease each year in the U.S., yet only about 3,000 cases are diagnosed and reported. Most cases of Legionnaires’ disease are sporadic, unlinked to any outbreak. The infections often are not recognized as Legionnaires’ disease, for several reasons.