“Many people believe that tap water is sterile”

Home medical devices should be used with caution, doctors warn

A significant proportion of the population uses tap water for medical devices at home, according to a new US study. This poses a risk of bacterial contamination.

“We were surprised to find that many parents use tap water for nasal rinsing bulbs,” explains the lead author of the study published in mid-January in the journal Emerging Infectious Diseases, Shanna Miko, of the US government’s Centers for Disease Control and Prevention (CDC). “Data showed that many people mistakenly believe that tap water is sterile. Our data confirms this, but still, we are still surprised. »

A quarter of respondents to the CDC survey use tap water for positive pressure devices to counter sleep apnea, one in seven for nasal rinses and 9% for rinsing contact lenses.

These results, probably similar in Canada, show that there is an urgent need for an information campaign aimed at the public, according to Marie-Astrid Lefebvre, pediatric infectiologist and head of infection prevention and control at the Montreal Hospital for children. “Personally, I have never had a case of infection linked to the use of tap water for nasal rinses, says Dr.^D Lefebvre. But the water passes very close to the brain, so there is a risk of meningitis. We see cases of this kind in the medical literature. »

The D^D Lefebvre, on the other hand, heard directly from colleagues of cases of eye infections linked to the use of tap water to rinse contact lenses. “I have contact lenses and I have trouble imagining using tap water,” says the Montreal specialist. But I know it happens. »

Tap water can be fine if boiled and then cooled, note the Ds.^res Miko and Lefebvre.

Pneumonia

The use of tap water in negative pressure appliances is also problematic, according to the D^D Mike. “Legionnaires’ disease and non-tuberculous mycobacterium cause pneumonia and can be present in tap water. They are responsible for the majority of waterborne infections in the United States. Older people use positive pressure devices more often for their sleep apnea and they are more vulnerable to pneumonia. »

Legionnaire’s disease is aptly linked to a convention of the American Legion, an association of veterans, in Philadelphia in 1966. More than 25 Legion members, elderly men, had died because of a cooling tower of the air conditioning system in the hotel where the convention was taking place. The bacterium Legionella pneumophila was abundant in the cooling tower.

Countryside

The use of tap water for medical devices is more common in cities than in the countryside (16% versus 7%). “It’s probably because people in the city rarely have to worry about their water supply,” says Dr.^D Mike. In rural areas, you have to take care of your well, when there is no power, there is no water. We are more aware that running water is a privilege. Curiously, the proportion of people who drink tap water is higher in the countryside than in the city: 74% against 62%.

There are no systematic data on the impact of waterborne infections in Canada. But based on American studies, the number of deaths could be 100 to 200 per year in Quebec. “Generally, these are cases related to nautical activities, says the D^D Lefebvre. But it is certain that there can be a contribution from the use of tap water in medical devices in the home. Cities also have problems with their water treatment plants every year. A 2017 Canadian study also reports problems in remote Indigenous communities.