Commercial Vehicle Operators and Legionnaires’ Disease

Posted on by Karl Sieber, PhD; Amy Mobley, MEn; Alison Albert, MPH; Shelby Miller, MPH; and Albert Barskey, MPH

A New Concern Among Commercial Vehicle Operators

Legionnaires’ disease is a serious form of pneumonia that almost always requires treatment in the hospital. Studies from the Centers for Disease Control and Prevention (CDC) and elsewhere have found Legionnaires’ disease occurs at twice the rate in transportation workers as in non-transportation workers. Among the transportation workers reporting Legionnaires’ disease, most (77%) were driver/sales workers or truck drivers.[1]

The Problem

If you are a commercial vehicle operator, you may have a higher chance of getting Legionnaires’ disease, a serious form of pneumonia.

 To keep yourself safe:

  • Only use full-strength windshield wiper fluid in your truck’s windshield wiper fluid tank.
  • Do not use water in place of wiper fluid. Adding water to your truck’s windshield wiper fluid tank can increase the growth of the bacteria that cause this illness.

In nature, the bacteria that causes Legionnaires’ disease live in fresh water and rarely cause illness. In human-made environments such as building plumbing systems, cooling towers, or hot tubs, the bacteria can grow in water that is not properly maintained. People can get sick if they breathe in air that has small water droplets (mist) that contain the bacteria.

As discussed in a recent article published in the Emerging Infectious Disease Journal, commercial vehicle operators may be exposed to the bacteria if they add water to their windshield wiper fluid. The bacteria that cause this illness grow better in water than in full-strength wiper fluid. When using a mix of wiper fluid and water, the bacteria can grow in the wiper fluid tank; if this happens, people may breathe in the bacteria when they mist their windshield to clean it.

Young, healthy people can develop Legionnaires’ disease, but it is uncommon. The risk of Legionnaires’ disease is highest among:

  • People who smoke or used to smoke.
  • People with a weak immune system or underlying medical conditions, such as cancer, diabetes, or chronic obstructive pulmonary disease (COPD).
  • People who are 50 years old or older.

The Solution

Commercial vehicle operators can lower their chances of getting Legionnaires’ disease by using only full-strength windshield cleaner fluid in their windshield wiper fluid tank instead of water. This will decrease the risk of growth and spread of the bacteria. Closing the cab windows while cleaning them may also prevent driver exposure to the bacteria.

Learn more about Legionnaire’s Disease and how to prevent it.

For more information from NIOSH on truck driver safety and health see the website.


Karl Sieber, PhD, is a research health scientist in CDC/NIOSH’s Division of Field Studies and Engineering (DFSE).

Amy Mobley, MEn, is a health communications specialist in in CDC/NIOSH’s Division of Field Studies and Engineering (DFSE).

Alison Albert, MPH, is a health communications specialist in CDC’s National Center for Immunization and Respiratory Diseases (NCIRD).

Shelby Miller, MPH, is a health communications specialist in CDC’s National Center for Immunization and Respiratory Diseases (NCIRD).

Albert Barskey, MPH, is an epidemiologist in CDC’s National Center for Immunization and Respiratory Diseases (NCIRD).


[1] Morano LH, Herzig C, Morawski B, Edens C, Barsky A, Luckhaupt S.  Legionnaires’ Disease in Transportation Occupations 39 U.S. Jurisdictions, 2014-2016. 2019 CSTE Conference, Raleigh, North Carolina. June 4, 2019.:

Posted on by Karl Sieber, PhD; Amy Mobley, MEn; Alison Albert, MPH; Shelby Miller, MPH; and Albert Barskey, MPH

3 comments on “Commercial Vehicle Operators and Legionnaires’ Disease”

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    Interesting. Good to know.
    I thought the article was going to be about, people in transport operating their air conditioners on recycle mode in their cab (which i’ve found if left in this setting and the vehicle parked for some time results in a mould smell when the air conditioner is next turned on). My assumption has been that spores are introduced to the system in ‘fresh’ air mode (i guess they’d be introduced in any mode anyway) then the condensate that seems to remain in the system when it’s in recycle mode grows the spores as the system warms up while parked. I assumed that this article was going to identify that also as the source of Legionella forms.

    Professional drivers incur more risk of Legionellosis due to more road exposure to soil Legionella. The more distance one drives the more the road exposure is. Road exposure occurs when soil Legionella bacteria are washed to the road surface during rainfalls or road work on soil and water and then aerosolized by motor vehicle traffic. Please see my research articles on this subject.

    Han XY. Effects of climate changes and road exposure on the rapidly rising legionellosis incidence rates in the United States. PLoS One. 2021 Apr 22;16(4):e0250364. doi:
    10.1371/journal.pone.0250364. eCollection 2021. PMID: 33886659

    Han XY. Solar and Climate Effects Explain the Wide Variation in Legionellosis Incidence Rates in the United States. Appl Environ Microbiol. 2019 Oct 30;85(22):e01776-19. doi: 10.1128/AEM.01776-19. Print 2019 Nov 15. PMID: 31519664

    Nobody is tracking the sporadic cases with auto tech/mechanics.

    My husband was only at home and work during the 2-10 day incubation period. The only source at home was the same water source as the shop. But numerous cars are in and out in the same incubation period.

    Not only washer fluids. Air hoses spay condensation into the air, part washers infrequently changed that contains cheap detergent…the list goes on…

    Such a disservice to these employees.

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Page last reviewed: September 26, 2023
Page last updated: September 26, 2023