In Alabama alone there were 41 cases of Legionnaires’ disease reported in 2013, and 18 more so far this year (Source: article in AL.com)
Legionnaires By The Numbers
It is important to note that not all instances of the disease result in death. Less than 20 percent of cases result in death. OSHA estimates that there are over 25,000 cases of the illness each year. And of those 4,000 result in death.
The challenge with determining the actual rate and frequency of Legionnaires’ disease is difficult because it is often difficult to distinguish from other forms of pneumonia. As a result, many cases go unreported.
Exposure Doesn’t Always Lead to Sickness
Another factor to consider is the the likelihood of a a particular individual in contracting Legionnaires’ disease, which will depend on the level of contamination in the water source, the relative health and susceptibility of the person exposed, as well as the intensity of exposure. Generally speaking only 5% of those exposed to the legionella bacteria contract Legionnaires’ disease. And just because a person tests positive for the disease does not necessarily mean they will get sick. Some people that test positive are asymptomatic.
Weak Immune Systems and Elderly Are More Susceptible to the Disease
With the cases reported in Alabama, it is no surprise the frequency of the disease is higher among the elderly, living in nursing homes, where outbreaks can occur. Of the 41 confirmed cases in Alabama in 2013, 15 were from an outbreak at a nursing home (one person died). This year there has been 18 cases so far. Nine of those resulting from the recent outbreak at University of Alabama Birmingham, with two deaths.
The bottom line is Legionnaires’ disease is more prevalent than we realize. But fortunately most cases will not result in death. And for people with healthy immune systems, they will not likely get sick from legionella exposure.