A recent study confirms that two patients are likely to have contracted the Legionnaires' disease by inhaling contaminated toilet water after flushing.
According to a recent report published in the Emerging Infectious Diseases journal last week, the two patients were admitted at a hospital in France who likely contracted the disease after inhaling the toilet water that was sprayed with aerosol while flushing. They used the same hospital room, but five months apart.
As reported in Live Science, Legionnaires' disease could spread through flushing the toilet, which releases "plumes" of contaminated water into the air.
French researchers suspected that toilet plumes could spread the Legionnaires' disease. However, this is the first time that genetic analysis has linked patients' infections with contaminated toilet water.
The study's lead author Dr. Jeanne Couturier, a medical biologist at the Saint-Antoine Hospital in Paris, told Live Science that their analysis strongly suggests that "the toilet water is the source of the transmission."
The Centers for Disease Control and Prevention (CDC) described the Legionnaires' disease as a serious lung infection or pneumonia, which is caused by Legionella bacteria that live in watery environments. The bacteria becomes a health issue when it grows and spreads in building water systems like hot tubs, cooling towers, sink faucets, decorative fountains, and showerheads.
Bacteria are not usually transmitted to other humans, but instead, by inhaling airborne water droplets like mists. People who were exposed to Legionella bacteria do not get sick, but older adults and people with weak immune systems or chronic lung disease have higher risks of acquiring the illness. Meanwhile, some people got sick by drinking contaminated water.
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The report discussed the cases of two patients who both had weak immune systems. The first patient was aged 18, who underwent a bone marrow transplant and took immunosuppressive drugs. The patient was admitted in December 2015 for transplant-related complications. After five months, the 51-year-old man patient was admitted to the same room in May 2016. He was being treated for Hodgkin lymphoma, a cancer of the immune system.
After being released, both patients developed Legionnaires' disease either while in the hospital or. Thus, their infections were regarded as health-care-associated, but they both recovered after taking antibiotics.
After a thorough investigation, researchers located Legionella bacteria in the room's toilet bowl water while no other potential sources of infection were identified.
The genetic analysis found that the bacteria strains in the toilet water were either identical or closely related to those discovered in the patients.The contaminated toilet was disinfected daily with bleach, which prevented the Legionella growth over the next year and a half.
Also, Dr. Couturier advised close the lid before flushing. "It seems important to educate patients to close the toilet lid before flushing, particularly immunosuppressed patients or patients with comorbidities, who are more at risk of Legionnaires' disease," the lead researcher said.
The findings also suggest that investigators of Legionnaires' disease cases in health care settings should consider toilet flushing as a possible route of transmission.