Water Features Linked to Legionnaires Disease
Posted by Pauline Heidemann on Fri, Jan 27, 2012 @ 06:04 AM
The wall of cascading water was designed to bring feelings of peace and tranquility to the hospital reception area. It offered a place of respite from the ringing phones, beeping equipment, and bustling activity associated with a busy, active, medical facility. But it also harbored the deadly bacteria legionella, responsible for Legionnaires disease, and eight people exposed to the airborne bacteria contracted the severe and potentially life-threatening form of pneumonia.
The hospital was located in Wisconsin, and the outbreak occurred in 2010. A study has just been published linking the outbreak to the water wall. None of the people who contracted the disease were patients at the hospital. One person was a delivery man, passing by the water wall on his way to drop off a package. Three others were picking up medication at the hospital pharmacy, three were outpatients, and one was waiting in the lobby to pick up his wife. Of the eight who contracted the disease, three were hospitalized in intensive care and placed on mechanical ventilators. All eight survived.
This is not the first time a water feature was responsible for an outbreak of Legionnaires disease. In 2007, two cancer patients at the National Institutes of Health in Bethesda were diagnosed with the disease after sitting near a contaminated wall-type water fountain while they waited for their radiology treatment. Last February, 200 partygoers at the Playboy Mansion became ill, with a hot tub thought to be the culprit.
Legionnaires disease is a type of pneumonia that has symptoms like many other forms of pneumonia, such as a high fever, chills, a cough, muscle aches, and headaches. It was first identified in 1976 when 221 people became sick and 34 died attending a convention of the American Legion at an upscale hotel in Philadelphia. It was later determined that the bacteria had spread through the air-conditioning system.
The disease is selective in attack, infecting only 2% to 5% of those exposed to the bacteria. Healthy people usually recover from the infection after treatment with antibiotics, however, it causes death in 5%-30% of cases. Those who are most at risk are people aged 50 or older, current or former smokers, those who have emphysema, and people with weak immune systems from diseases like cancer, diabetes, or kidney failure, or who are taking drugs to weaken the immune system following a transplant operation or chemotherapy. The eight people who became sick at the Wisconsin hospital all had underlying medical conditions or other factors that increased their risks of contracting Legionnaires disease.
The disease is contracted by breathing in the legionella bacteria from mist or vapor found in small droplets of water in the air. It cannot be transmitted from person to person. It grows best in warm water, such as the kind found in hot tubs, hot water tanks, or air-conditioning systems. The mist from water features such as water walls and fountains can harbor the bacteria, as can hot tubs, whirlpools, and misters used on produce at supermarkets.
The American Society of Microbiology has reported that 15% to 30 % of patients admitted to intensive care units with pneumonia have Legionnaires disease. The CDC has estimated that 8,000 to 18,000 persons are hospitalized annually in the U.S., but OSHA has estimated that over 25,000 cases occur each year, causing more than 4,000 deaths. Because the disease is difficult to distinguish from other forms of pneumonia, some medical professionals believe the infection rate may be as high as 100,000 per year. Legionella bacteria can only be detected through urine, blood, or sputum tests.
After the water fountain at the Wisconsin hospital was first suspected as the source of the outbreak, the hospital turned the water wall into a planter. Many other health care facilities in Wisconsin shut down or removed their decorative fountains. CDC experts have been working with the American Society for Heating, Refrigerating and Air Conditioning Engineers to come up with a standard practice for building managers and owners to prevent the disease. In the meantime, Jan Patterson, President of the Society for Healthcare Epidemiology of America, suggests that individuals with underlying health conditions should stay as far away as possible from vaporized water, and health care facilities and hospitals should avoid having them in their facilities altogether.
To read the study linking the outbreak of Legionnaires disease to the Wisconsin hotel, click on http://www.jstor.org/stable/10.1086/663711. To read more about Legionnaires disease, visit the CDC’s website at http://www.cdc.gov/legionella/patient_facts.htm.