Cases of Legionnaire’s disease in the United States are way up. In fact they have tripled in the past decade and the Centers for Disease Control and Prevention are baffled as to the reason or reasons why.
One guess is that the increase may be due to a rise in the number of seniors and other people at high risk for infection. Elderly people account for most cases of Legionnaire’s disease, a type of pneumonia caused by bacteria that can be present in the mist from water in hot tubs or showers or air conditioning systems in large buildings.
While older people and those living in the Northeast are most at risk, Legionnaire’s disease occurs in all age groups and regions. Men account for 60% of the cases overall.
The number of cases reported to the CDC Prevention rose from 1,110 in 2000 to 3,522 in 2009. The incidence rate increased from 0.39 to 1.15 per 100,000 people during that time.
Also according to the CDC, Legionnaires’ disease is caused by a type of bacteria called Legionella. The bacteria got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of this disease, a type of pneumonia (lung infection). Although this type of bacteria was around before1976, more illness from Legionnaires’ disease is being detected now. This is because we are now looking for this disease whenever a patient has pneumonia.
Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires’ disease in the U.S. However, many infections are not diagnosed or reported, so this number may be higher. More illness is usually found in the summer and early fall, but it can happen any time of year.
Legionnaires’ disease can have symptoms like many other forms of pneumonia, so it can be hard to diagnose at first. Signs of the disease can include: a high fever, chills, and a cough. Some people may also suffer from muscle aches and headaches. Chest X-rays are needed to find the pneumonia caused by the bacteria, and other tests can be done on sputum (phlegm), as well as blood or urine to find evidence of the bacteria in the body.
Legionnaires’ disease can be very serious and can cause death in up to 5% to 30% of cases. Most cases can be treated successfully with antibiotics (drugs that kill bacteria in the body), and healthy people usually recover from infection.
Most people exposed to the bacteria do not become ill. If you have reason to believe you were exposed to the bacteria, talk to your doctor or local health department. Be sure to mention if you have traveled in the last two weeks.
A person diagnosed with Legionnaires’ disease in the workplace is not a threat to others who share office space or other areas with him or her. However, if you believe that there your workplace was the source of the person’s illness, contact your local health department.
The CDC has said it’s working with state health departments to identify the reasons for the rising number of Legionnaire’s cases. I n January 2011, Legionella was added to the CDC’s Active Bacterial Core surveillance project, a population-based effort for testing clinical specimens for a range of bacterial pathogens.
Written by Sy Kraft