CDC report calls Legionella the leader in waterborne disease outbreaks

With New York City’s Legionnaires’ disease already in the headlines, media are likely to take increased interest in a U.S. Centers for Disease Control and Prevention report released yesterday. CDC released its bi-annual "Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water — United States, 2011–2012," and as with outbreak summaries for 2007–2008 and 2009–2010, the most frequent disease associated with potable water has been legionellosis. The report states, "Legionella was implicated in 21 (66 percent) outbreaks, 111 (26 percent) cases, 91 (89 percent) hospitalizations, and all 14 deaths."  

The most commonly identified deficiency leading to 66 percent of drinking water–associated outbreaks was Legionella in building plumbing systems. Among 21 Legionella outbreaks in community water systems, 14 (67 percent) occurred in hospitals or health care facilities. With 12 of 14 deaths associated with Legionella in health care settings, CDC has called for "improved Legionella control and mitigation are needed, especially in health care settings." CDC also emphasized the need for the "maintaining sufficient residual disinfectant in plumbing systems."  

The outbreak in New York City will add to the above statistics and shows the continued need for vigilance in maintaining water quality in premise plumbing by building owners and operators. The EPA is developing a guide for treatment options for buildings planning to install treatment to prevent Legionnaires’ disease; the agency’s current schedule has the guide’s release slated for later this year.