• An unwashed face mask will not cause legionnaires disease, but experts still recommend washing masks after each use.
• Legionnaires' disease is a serious form of pneumonia caused by Legionella bacteria.
Image: BRIAN OTIENO
Wearing the same face mask repeatedly without washing it can cause Legionnaires' disease, according to a Facebook post and a WhatsApp message Africa Check received in early August 2020.
The message claims a man called a radio talk show to say his wife had been hospitalised with severe Covid-19 symptoms after she had worn the same face 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,” the message says.
“She thinks, WHAT IF these ‘spikes’ in Covid are really something else due to improper mask-wearing?”
Covid-19 is a respiratory illness spread from one person to the other by virus-carrying droplets released by infected individuals when they speak, cough or sneeze.
Health officials have advised people to wear facial coverings to slow the spread of the disease, and some countries have passed laws requiring everyone to wear masks in public spaces.
The message gives no details about the man, the radio station or the location and origin of the story. Anonymous information lacking an original source is often unreliable.
But could unwashed face masks cause Legionnaires' disease?
Legionnaires bacteria won’t survive on masks. Legionnaires' disease is a serious form of pneumonia caused by Legionella bacteria.
The bacteria are found naturally in freshwater sources such as lakes and rivers and can also be found in indoor water sources, jacuzzis and decorative fountains.
The disease is spread when a person breathes in infected water droplets or when they drink water containing the bacteria.
According to experts on Legionella.org, a person can’t get the disease from wearing a face mask. Unlike Covid-19, Legionnaires' disease “is not spread from person to person in respiratory droplets nor does the bacteria survive on dry surfaces,” the experts say.
“Your mask would not be a source of transmission for the Legionella bacteria.”
Experts recommend washing masks between use
An unwashed face mask will not cause Legionnaires' disease, but experts still recommend washing masks after each use as they can be contaminated by the coronavirus that causes Covid-19 and other bacteria.
The World Health Organization advises washing cloth masks once a day or between each use.
Cloth masks should be washed with hot water and laundry detergent and be completely dry before they are worn again.
But not washing your mask regularly will not cause Legionnaires' disease.