The number of cases reported to the CDC 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. The CDC suggests 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.
What is Legionnaire’s disease? It’s a type of pneumonia caused by bacteria that can be present in the mist from water in hot tubs, showers, or air conditioning systems in large buildings.
While the CDC states that older people and those living in the Northeast are most at risk, Legionnaire’s disease occurs in all age groups and regions. Men seem to be more at risk, accounting for 60% of the cases.
Symptoms of Legionnaire’s disease include fever, chills, and a cough and sometimes muscle aches and headaches. Other types of pneumonia have similar symptoms, of course. You probably need a chest X-ray to diagnose the pneumonia associated with Legionnaire’s. Lab tests can detect the specific bacteria that caused the disease. If you have a cold or infection, get your doctor’s advice about your condition rather than try to self-diagnose.
Legionnaire’s disease is serious and can be life-threatening. Although the increase in cases is cause for concern, the good news is that most people recover with antibiotic treatment. The CDC is working with state health departments to identify the reasons for the rising number of Legionnaire’s cases.
The Canadian Centre for Occupational Health and Safety says that it is not easy to identify those at risk for contracting Legionnaire’s disease. The people most vulnerable are those with occupations that require them to work in sealed buildings, including those workers who maintain water cooling towers in air conditioning systems.
Some outdoor occupations should be considered at risk as well. Soil disturbed by bulldozing and areas where surface or aerosolized water discharge occurs can cause exposure to the microorganism responsible for Legionnaire’s disease.