#16,622
Long-time readers with particularly good memories may recall a curious report from nearly 12 years ago (June, 2010) on suspected cases of Legionnaires' Disease in the UK, thought to have been contracted due to using plain water as a windshield wiper fluid (see Study: Wiper Fluid And Legionella).
Legionella bacteria thrives in warm water, such as is commonly found in air-conditioning cooling towers, hot tubs, and even ornamental water fountains. When water is sprayed into the air the bacteria can become aerosolized and inhaled.
According to the 2010 study, published in the European Journal of Epidemiology, ". . . professional drivers are five times more commonly represented among community acquired sporadic cases in England and Wales than expected."
These researchers conducted a case-control study on sporadic cases reported in England and Wales between 2008 and 2010, and reported:
Their working theory was putting plain water in the wiper reservoir - which is kept warm and dark under the hood near the engine - is likely conducive to the growth of Legionella. It can then become aerosolized when you clean your windshield, and subsequently inhaled by the driver or passengers.The results were analysed using logistic regression. 75 cases and 67 controls were included in the study. Multivariable analysis identified two exposures linked to vehicle use associated with an increased risk of Legionnaires' disease: Driving through industrial areas (OR 7.2, 95%CI 1.5-33.7) and driving or being a passenger in a vehicle with windscreen wiper fluid not containing added screenwash (OR 47.2, 95%CI 3.7-603.6).
Not adding screenwash to windscreen wiper fluid is a previously unidentified risk factor and appears to be strongly associated with community acquired sporadic cases of Legionnaires' disease. We estimated that around 20% of community acquired sporadic cases could be attributed to this exposure. A simple recommendation to use screenwash may mitigate transmission of Legionella bacteria to drivers and passengers.
The CDC estimates that between 8,000 and 18,000 Americans are hospitalized with Legionnaire's Disease each year. Those most susceptible to serious illness are often older, smokers, or immunocompromised.
Most cases are sporadic, and the cause is never identified. Large outbreaks, however, spark major public health investigations to isolate, and eliminate the source.
All of which brings us to a new dispatch, published this week in the CDC's EID Journal, that finds further evidence of plain water wiper fluid serving as a potential source for Legionnaires’ Disease in commercial truck drivers.
I've only reproduced the link, abstract, and some excerpts. Follow the link to read the full report.
Vehicle Windshield Wiper Fluid as Potential Source of Sporadic Legionnaires’ Disease in Commercial Truck Drivers
Julieta Politi, Andreu Queralt, Natalia Valero, Maria T. Martín-Gómez, Raquel González Durán, Elena Parra, Sara Sabaté Camps, Ingrid Avellanés, Anna Hernández-Pineda, Eva Masdeu, Cristina Rius, and Dolores Álamo-Junquera
Abstract
Sporadic Legionnaires’ disease is frequently detected in commercial truck drivers. We report 2 sporadic cases of this disease in Barcelona, Spain, that occurred during December 2019 and September 2020. Laboratory findings were consistent with windshield wiper fluid without added screen wash as a possible source of infection for both cases.
(SNIP)
Conclusions
We report 2 sporadic cases of Legionnaires’ disease in commercial truck drivers in which the laboratory findings were consistent with, but not exclusive to, the windshield wiper fluid as the source of infection. The etiologic agent was presumed to be L. pneumophila serogroup 1 (Lp1) because both patients were given a diagnosis by UAT, which detects only Lp1. DNA of L. pneumophila (unknown serogroup) was found in the windshield wiper fluid for the first case, and Legionella spp. was cultured from the fluid for the second case. Although the presence of Lp1 was not confirmed in the windshield wiper fluid for either case, laboratory findings indicated that the flid was a potential source for both cases.
Previous studies have identified windshield wiper fluid without screen wash as a potential risk factor for Legionnaires’ disease (4). Furthermore, 2 previous studies have identified Legionella spp. in windshield wiper fluid (8,9), confirming that the bacteria can survive in this medium and the fluid as a possible source of infection. These results are consistent with our observations for the windshield wiper fluid for the second case described. Despite these observations, transmission from this source has not been epidemiologically confirmed. Our findings strengthen the epidemiologic connection between windshield wiper fluid as a source of infection for truck drivers.
Several vehicle-related sources have been described as confirmed or potential sources of Legionnaires’ disease, although these sources were infrequently considered and difficult to investigate (3,10,11). Kanatani et al. identified L. pneumophila in road puddles (12) and hypothesized that bacteria reach the windshield wiper fluid tank through road splashes. Alternatively, Legionella spp. could reach the tank after a car wash at a contaminated installation or through a contaminated water source used to fill the tank. Warm temperatures or heat radiated from the motor of the vehicle to the water tank, along with lower or absent methanol levels in screen wash fluid, and water stagnation could favor bacterial proliferation in the windshield wiper fluid tank.
Beyond routinely investigating this source, especially in commercial truck drivers, a simple measure of adding screen wash to the fluid can be recommended. This action has the potential benefit of decreasing the risk for infection by inhibiting growth of Legionella spp. growth through a bactericidal effect of screen wash components, such as propanol/methanol (9).
In summary, our results indicate that windshield wiper fluid is a potential source of sporadic Legionnaires’ disease, especially in commercial truck drivers, and should be routinely investigated. A simple recommendation of adding screen wash to windshield wiper fluid or emptying the tank when the vehicle is unused for several months is a preventive measure likely to be effective and should be adopted by drivers.
Dr. Politi is a preventive medicine and public health physician at Parc de Salut Mar, Barcelona, Spain. Her primary research interests are surveillance, prevention, and control of infectious diseases.
Even though I remember the initial study well - and even made a point of using washer fluid for several years - I've been guilty of using plain water in my wiper reservoir for the past couple of years.
Since I'm at a vulnerable age (67) for acquiring Legionella, I guess I'm putting it back on the shopping list.