According to the hospital as reported in a newspaper article, the outbreak of Legionnaires’ disease at Miami Valley Hospital, which sickened 11 people between February and March 2011, was primarily caused by inadequate hot water temperatures. Officials at MVH claim that the hospital originally planned to heat the water in the new patient tower to 140 degrees Fahrenheit, a temperature at which legionella bacteria may reasonably be expected to die. Construction management officials, however, (again, according to the hospital) allegedly instructed the hospital to lower its hot water temperatures to 120 degrees Fahrenheit in order to comply with the Ohio Plumbing Code, which supposedly caps hot water temperatures at 120 degrees due to a potential risk of scalding. Since the outbreak, Miami Valley Hospital has raised its hot water temperature to 140 degrees and has adopted temperature control measures that lower the water temperature at faucets and fixtures by mixing hot and cold water. The hospital has decided not to release either its report on the outbreak or a white paper discussing lessons it has learned.
The hospital seems to be eschewing blame by citing state regulations on water temperatures. Although thermal disinfection is one method for legionella control, it is not sufficient as the sole component of a legionella management plan, which the hospital should have had in place prior to the construction of the new patient tower. Legionella is commonly associated with building construction and renovation, when water flow is shut off, water sits stagnant, and biofilm, a shelter for bacteria from chemical treatment, develops. It is unclear what happened during construction to foster conditions ideal for the growth of legionella; regardless, Miami Valley Hospital should have been aware of the possibility for a surge in legionella levels and prepared to handle them. While it is true that the hospital implemented a hyperchlorination program in response to the outbreak, it is also true that they waited three weeks after the first confirmed case of Legionnaires’ disease to do so. Had the hospital acted more quickly, it could possibly have contained the outbreak and minimized the number of cases.