SOUTH DAKOTA DEPARTMENT OF HEALTH
FOR IMMEDIATE RELEASE: Tuesday, October 11, 2005
CONTACT: Doneen Hollingsworth, (605) 773-3361

Two additional Legionnaires’ cases reported;
October 26 educational session planned for cooling tower operators

PIERRE, S.D. – The Department of Health today reported two additional cases of Legionnaires’ disease in Rapid City, bringing to 12 the number reported since July. The latest two cases became ill 51 days after the last reported case. Investigation of both cases is underway and their isolates are being tested to determine if they match the same strain of Legionella as the previous cases or any of the environmental samples tested.

Secretary of Health Doneen Hollingsworth said that while the environmental sampling has not matched with the outbreak strain, it has found other strains of Legionella. “From July through the end of September we’ve tested more than 180 samples and found 19 cooling facilities with Legionella,” said Hollingsworth. “We also found operators had a lot of questions about how to properly operate and maintain their facilities to eliminate the bacteria. That’s why we’re bringing in a nationally recognized expert to provide them with some education.”

Hollingsworth said the department will bring Tim Keane, Legionella Risk Management, Inc., to Rapid City October 26 for a specialized training on operating and maintaining cooling towers and other water systems. The training is targeted for operators, chemical suppliers and others involved in water cooling systems. Keane serves on the ASHRAE committee that is updating the national guidelines for minimizing the risk of legionellosis associated with facility water systems. ASHRAE is the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

Keane assisted the department with its investigation on site in Rapid City, in particular the environmental sampling. The sampling focused on potential sources including cooling towers, swamp coolers, ornamental fountains, and process water systems. The systems were identified by aerial survey, driving and walking surveys of the area and also through contacts with local property managers, water treatment companies, industrial HVAC contractors and industrial plumbing contractors. In addition to sampling the facilities, Keane also audited their operations and worked closely with microbiological experts at the CDC and Special Pathogens Lab, a legionella laboratory in Pennsylvania.       

“It’s disappointing that the testing hasn’t pointed us to a specific source but the experts tell us that’s not unusual in community legionella outbreaks,” said Hollingsworth. “And the fact that we have identified legionella other than the outbreak strain tells us that education about ongoing, routine maintenance of cooling towers and evaporative condensers is something we need to focus on.”

Half of the Rapid City cases have been male and half female. The median age is 66 with ages ranging from 55 to 85. Nine of the cases have been hospitalized.

Legionnaires' is caused by bacteria that are widely distributed in the environment. The bacteria is found in creeks and ponds, hot and cold water taps, hot water tanks, water in air conditioning cooling towers and evaporative condensers, and soil at excavation sites. The disease is spread through the air from a water source. It is not spread person to person.

More information about the disease and its transmission can be found at http://www.state.sd.us/doh/Pubs/legion.htm.