The toll from a mysterious outbreak of Legionnaires’ Disease in New York City’s South Bronx continues to rise. WABC is reporting that as of July 31 there have been three deaths and a total of 57 confirmed illnesses. The city’s Health Department is testing cooling towers of buildings in the affected neighborhoods and has found three thus far that are infected with Legionella which is the cause of the respiratory illness.
One of the buildings where the bacteria has been found is Lincoln Hospital. WABC reports that no one at the hospital has become ill. There are cases of Legionnaires’ Disease in the surrounding neighborhoods.
Legionnaires’ Disease was first discovered in 1976 and named after an outbreak of the illness at an American Legion convention in Philadelphia, according to the Centers for Disease Control and Prevention (CDC). Patients can contract the illness in places where contaminated water is converted into mist, such as with hot tubs, cooling towers and water used for bathing or drinking. The CDC estimates that between 8,000 and 18,000 patients contract the illness every year. Most may not seek medical attention.
The Legionella bacteria is found naturally, in warm water. The illness is not transmitted from patient to patient. The CDC reports that the most common result of an infection is pneumonia.
Legionnaires’ Disease can be severe even in healthy patients and most may require hospitalization, according to the CDC. Death may be the result for between five and 30 percent of those that contract the illness. It can be successfully treated with antibiotics but patients with co-morbid conditions such as lung disease are at greater risk for severe illness.
An unusual aspect of the outbreak in the South Bronx is that infection does not appear to be occurring indoors. Patients seem to be contracting Legionnaires’ Disease through exposure to the mist from the cooling towers on nearby buildings.
The outbreak was first reported to the New York City Health Department on July 10. July 30-31 saw the number of confirmed cases of Legionnaires’ Disease rise from 31 to the present 57. It is possible that additional cases will be discovered.
The Environmental Defense Fund describes how cooling towers operate on city buildings. They serve to cool the water used in the building as air conditioning. The heat removed from the building increases the temperature of the cooling tower’s water and its evaporation. Alemco, a tower maintenance company, states:
The mist which can be seen above a cooling tower is regular steam with the same composition as a normal cloud.
In 2013, Milwaukee, city and county, experienced an outbreak of Legionnaires’ Disease similar to the one in the Bronx. Between June 1 and Sept. 30, 58 confirmed cases were reported. Public health authorities tested a large number of potential sites for contamination and several were positive for Legionella. Specimens obtained from patients tested positive for six strains of Legionella, but none of these strains were found to be related to the strains in the environmental samples. The sources of infected for the 58 patients were never definitively determined.