Legionnaires’ disease in nursing homes is caused by a type of bacteria that can get into the water supply. In nursing homes, the bacteria can proliferate in cooling towers, hot water tanks, large plumbing systems, or decorative fountains. There are many species of Legionella, but the most common is Legionella pneumophila serogroup 1. In warm, stagnant waters Legionella can multiply and cause pneumonia when residents inhale it during showering or while drinking water.
In an analysis of cases of Legionnaires’ that occurred in 2015, about 550 of the cases happened in a healthcare facility, including nursing homes. Of those cases, nearly 70 patients died from the disease that year. Legionnaires’ disease in nursing homes is particularly dangerous, because older adults are more susceptible to this type of illness due to age, compromised immune systems, or comorbid illnesses.