Legionnaires’ disease is on the rise. The CDC reported over 6,100 cases of Legionnaires’ disease, a severe and often lethal form of pneumonia, in 20161. Its less potent cousin, Pontiac Fever, also affects many people each year. It is widely suspected, however, that both of these diseases are underdiagnosed. Some even speculate that there could be more than 100,000 cases occurring in the US alone.
There is a general public perception that Legionnaires’ disease is rare. In fact, I suspect that if you stopped passersby on the street, the vast majority couldn’t even tell you what it is. This could be due to the fact that Legionnaires’ rarely makes the front page, or even back page news. Only a very small percentage of cases occur as localized outbreaks and are rarely spoken of or written about in a manufactured attempt to save a company’s image.
Cases of Legionnaires’ disease will often go undetected because more specialized testing is required. Such testing is often not requested due to a lack of awareness, both on the part of the patient and the medical professionals. This leads to many cases simply being diagnosed as “pneumonia with no apparent cause”. It sure makes one wonder what percentage of the other almost 20,000 annual pneumococcal deaths could be tied to Legionella bacteria? Or maybe the more frightening question: how many contaminated sources are left undetected and remain a threat?
Taking a closer look at the data provided by the CDC, one can definitely see a correlation between the average temperature of a region and the increased presence of Legionella. For example, data provided by the CDC show that Alaska and Wyoming had a combined total of four – yes four – confirmed cases in 2016, while California and Ohio had nearly 1,100 in the same time period. Warm water and public works are the breeding ground for this undercover killer. So it stands to reason that the more pools, fountains and office cooling towers there are, the higher the likelihood that Legionella will be present in a given area.
This is not to say that everyone should pack up and move to Alaska. Knowledge is power, and an awareness of the fact that Legionella is an ever-present danger in modern society is really a great tool. Not only in mitigation and prevention, but also in diagnosis and treatment.