Alliance recommends comprehensive investigation of Legionnaires’ outbreak in Orange County, CA to determine all possible sources tracing back to incoming water

The Alliance to Prevent Legionnaires’ Disease expresses its concern over the recent Legionnaires’ disease outbreak in Orange County, including unfortunately a death associated with the disease. The presence of Legionella bacteria in two cooling towers suggests that the bacteria was present in the supply water feeding the cooling towers and other water fixtures in the park, which could also serve as transmission modes.

We strongly urge the Orange County Health Department to continue the investigation of this case to determine what steps can be taken to monitor and reduce Legionella bacteria entering plumbing devices and equipment from the water distribution system. A thorough investigation requires testing of all potable and non-potable water sources for the bacteria to identify the bacteria’s source so it can be treated to minimize its growth. The Alliance encourages maintenance of water devices consistent with industry-best practices in ASHRAE Standard 188 and the “Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings” guidelines provided by the CDC.