Combatting Legionella and Carbon Footprints

Legionella bacteria pose a significant public health threat, especially to hospitals and health care settings. The causative agent of Legionnaires’ disease, these bacteria make their way into your lungs through overgrowth in showerheads and sink faucets, cooling towers, decorative fountains, hot water tanks and heaters, large plumbing systems, and even hot tubs that aren’t fully drained after each use. Cases are not limited to those with weakened immune systems or those with lung issues; outbreaks can easily occur in hotels and facilities with poor testing or water management programs. A recent outbreak in an Atlanta hotel is raising concern as 1 person has already died due to this disease that infects between 10,000 and 18,000 people in the United States annually.

Thankfully, the disease isn’t transmitted between people and it can be treated with antibiotics, but there can still be serious complications, such as lung failure or even death. Given the potential for large-scale exposures among vulnerable populations, it’s not surprising that hospitals take Legionella very seriously. A single case of health care-associated Legionella can result in exhausting water-monitoring efforts for months in coordination with local public health departments. Typical health care control methods range from routine sampling to temperature control measures, like keeping cold water below 20°C and hot water at a minimum of 60°C. This has been the tried and true approach to Legionella control since there will always be some small level of the bacteria in water and the ultimate goal is to avoid growth that can cause human disease.

Investigators in the United Kingdom recently published a study assessing a large health care facility’s approach to reducing Legionella risk through use of copper and silver ionization at hot water temperatures that were deliberately reduced to 43°C within a new water system.

The research team collected 1589 water samples between September 2011 and June 2017, looking for not only Legionella bacteria, but also copper and silver ion levels, and total viable counts. To also assess the internal costs and function of this system, investigators collected data on energy consumption and water usage.

Following these changes and their 6 years of sample collection, the research team found that they were able to totally control Legionella by maintaining a hot water temperature of 42°C. Moreover, energy savings and reduction in carbon emissions were cut by roughly 30% when compared with other temperature-controlled systems. By utilizing copper and silver ionization and managing the hot water temperatures, they were able to maintain Legionella control while reducing energy expenditures. The energy use that was assessed within the study is particularly interesting as more hospitals and federal health care agencies are looking at ways to reduce their carbon footprints. Health care is notoriously wasteful and the inclusion of this piece into the study is beneficial in efforts to help facilitate a culture of change. This study should also be seen as an inspiration for future research within the United States, as we work towards not only reducing Legionnaires’ disease outbreaks but also towards making health care more environmentally conscious and cost-effective.