Fact check: You can't catch Legionnaires’ disease by wearing a face mask

Widely shared social media posts warn that people are at risk of contracting Legionnaires’ disease through using face masks. This is false.

The text was reposted by multiple accounts, with some versions picking up hundreds of shares ( here , here , here ). One version is on over 2,500 shares as of August 5, 2020 ( here ).

The text reads: “Mask wearers beware... A caller to a radio talk show recently shared that his wife was hospitalized and told she had COVID and only a couple of days left to live. A doctor friend suggested she be tested for legionnaires disease because she wore the same mask every day all day long. Turns out it WAS legionnaires disease from the moisture and bacteria in her mask. She was given antibiotics and within two days was better. WHAT IF these ‘spikes’ in COVID are really something else due to mask wearing??”

Legionella.org ( legionella.org/about/history/ ), a non-profit organization that provides information about the disease, states on its website: “You cannot contract Legionnaires’ disease from wearing face masks. Legionella bacteria is transmitted by aspirating drinking water or breathing in water droplets. Legionella is not spread from person-to-person in respiratory droplets nor does the bacteria survive on dry surfaces. Your mask would not be a source of transmission for the Legionella bacteria” ( here ).

Professor Hugh Pennington, emeritus professor of bacteriology at the University of Aberdeen, told Reuters: “Legionella bacteria are not carried in the nose/throat, so how would they get onto the mask in the first place? They come from environmental sources and cause problems when warm water sources like industrial cooling towers or jacuzzis or hotel air conditioners ... have been poorly maintained, and contaminated water then sprays into the air. There have been outbreaks on cruise liners. A different Legionella bacterium occurs in compost and has been a particular problem in Australia. Many studies and case reports regarding legionnaires have been published over the years. I am not aware of any that say that mask wearing is a risk factor for developing the disease.”

Reuters has not seen any evidence of the radio station phone call referenced in the post, though unsourced accounts of such a call ( here, here ) have been shared on social media in recent weeks. The disease did feature in a news story connected to COVID-19 in April 2020, when health experts warned that the bacteria that causes Legionnaires’ disease could be present in the pipes of buildings closed because of the pandemic ( here ).

VERDICT

False. Legionnaires’ disease is not transmitted through the use of face masks.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts here .