Interesting research from Arizona State University found that the bacteria Legionella, commonly found in fresh water, was able to survive in certain automobile windshield washer fluids and can grow in washer fluid reservoirs.  This could potentially lead to people being exposed to the bacteria and maybe developing Legionnaire’s disease or Pontiac Fever.

Windshield washer fluid (Photo credit: Wikipedia)

The Arizona State University research was conducted by Otto Schwake, an Arizona State University student pursuing a doctoral degree in Microbiology under the supervision of Morteza Abbaszadegan, a professor in the School of Sustainable Engineering and the Built Environment. Although windshield washer fluid was not normally associated with spreading disease, this research was begun after a series of epidemiological studies found motor vehicle use to be associated with increased risk for Legionnaires’ disease.  One such study attributed nearly 20% of Legionnaires’ disease cases in the United Kingdom not associated with hospitals or outbreaks to automobile windshield washer fluid.

Based on a recent webinar held by EMLab P&K featuring the Dr. Harriet Burge, Legionella is a gram negative bacterium that is a widely distributed natural inhabitants of water and is common in many environments.  It is heat loving and will proliferate in temperatures between 20 degrees Celsius to 45 degrees Celsius.  Growth is promoted by other micro organisms.  Legionella is the causative agent of Legionellosis (Legionnaires’ disease and Pontiac fever).


The first recognized outbreak of Legionnaires disease occurred in Philadelphia in 1976.  As many as 221 people were treated and 34 deaths occurred.  The source was identified as the Legionella bacterium and found in the cooling tower of the hotel’s air conditioning system.  Over 90% of legionelloses are caused by Legionella pneumophila.

English: A silver stain of Legionella pneumophila , the bacteria that causes Legionellosis. Although I got this image from a commercial website it is clearly labeled as from the CDC. This website routinely uses images from Wikipedia, which is a good thing, so no issue should be taken with using an presumably public domain image from their website. (Photo credit: Wikipedia)

Legionellosis takes two distinct forms:

• Pontiac Fever: respiratory illness without pneumonia, symptoms resemble acute influenza

• Legionnaires’ Disease: symptoms include fever, chills, cough, muscle achees, headache, tiredness, loss of appetite, loss of coordination (ataxia), and occasionally diarrhea & vomiting.

Legionellosis incubates in 2-10 days.  It is one of the top three causes of community-acquired pneumonia. Legionellosis affect 8,000 to 18,000 people in the United States each year. Transmission is not person to person. Legionellosis infection occurs after inhaling droplets that originated from a water source contaminated with Legionella. Environmental sources include freshwater ponds, rivers and creeks.  Typical manmade water sources that can be a source of Legionella include: cooling towers, evaporative coolers, hot water systems, showers, whirlpool spas, architectural fountains, room-air humidifiers, ice-making machines, and misting equipment.  Based on the above research now windshield washer fluid reservoirs, may be added to this list.