Epidemiologist warns windshield wiper fluid aerosolises bacteria that can cause severe pneumonia, shares prevention tips

Sometimes, infections can crop up from every day items - windshield wiper fluid in this case. Dr Sundermann explains how contamination can get you sick.

You might think infections only come from obvious or exotic sources, but sometimes, everyday items can harbour hidden dangers - even your car. Did you know your windshield wiper fluid can aerosolise harmful bacteria that you could inhale while driving?

You can contract Legionnaire's disease through windshield wiper sprays. (Unsplash)

Dr Alex Sundermann, an epidemiologist with a doctorate in public health and an assistant professor at the University of Pittsburgh’s Faculty of Epidemiology, has revealed a surprising connection between windshield wiper fluid and severe pneumonia cases. In an Instagram video posted on November 5, the epidemiologist explains how windshield wiper fluid in automobiles was found to harbour Legionella bacteria - the pathogen behind Legionnaires’ disease - and offers practical advice on how to prevent it.

Legions of bacteria growing in windshield wiper fluid

Dr Sundermann highlights a research study that examined windshield wiper fluid and discovered bacterial contamination - specifically Legionella, the bacterium responsible for causing Legionnaires’ disease (a severe form of pneumonia), thriving inside it.

He elaborates, “In this one study of school buses, they looked at the windshield wiper fluid school bus tanks and found that 84% of these school buses had Legionella bacteria in them. And it wasn't just a couple of colonies, there was a high concentration of Legionella bacteria growing in them. And yes, they actually tested when you turn on your windshield wipers and the spray comes out, it aerosolises the Legionella bacteria, which is what you need to actually breathe that bacteria in and cause the pneumonia infection.”

The epidemiologist also points to a case report describing two instances of truck drivers who developed Legionnaires’ disease after exposure to contaminated windshield wiper fluid. He explains, “They looked for community sources of acquisition, but they couldn't actually find anything. But they tested the trucks that they drove, the windshield wiper basin, and found Legionella bacteria in it, implicating it as the likely source for these truck drivers’ Legionella pneumonia.”

So what’s the solution?

Dr Sundermann recommends buying windshield wiper fluid which contains methanol, which acts as a disinfectant for the Legionella bacteria. He explains, “In that one study I mentioned, they tested various levels of methanol concentration and found that a higher level of methanol concentration killed more of that Legionella bacteria.”

Methanol is added to windshield wiper fluid as an antifreeze agent, helping to prevent the liquid from freezing in cold temperatures. However, the epidemiologist highlights that not all types work equally well - “Some summer types of windshield wiper fluid don't have high levels of methanol in them. You want that all-season types of windshield wiper fluids that has lots of methanol in it.” He strongly warns against opting for wiper fluids that do not contain any methanol because they can actually promote the growth of Legionella bacteria. Dr Sundermann advises checking product labels carefully to ensure they state ‘contains methanol’.

Ultimately, the doctor highlights the prevalence of infectious disease causing germs in everyday life. He concludes, “So, this is one of those weird examples of an environmental source of infectious disease that we don't always consider. Infectious diseases don't have to come from these exotic, new, weird sources. They can come from everyday types of things that we do, such as turning on your windshield wipers.”

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. It is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.