Scope of Legionnaire's investigation narrows

Published Aug. 11, 2010
By 127th Public Affairs

Selfridge Air National Guard Base, Mich. -- The multi-disciplinary team investigating the source of legionnella bacteria which has left six government employees here with confirmed cases of Legionnaire's disease, says it has significantly narrowed the scope of the investigation. No new confirmations of the disease have been reported since early last week.

"We have narrowed down the focus of our investigation to an area of Selfridge that has a possibility to provide us a likely exposure source," reported Mr. John Ambrose, U.S. Army Public Health Command epidemiologist and lead on the team investigating at Selfridge. He also stated, "Most often outbreaks are caused by a number of factors and not just one element. In the past couple of days, we have been putting all those pieces together in order to identify our source."

The ongoing investigation has attempted to identify and interview all individuals with a disease caused by legionnella bacteria in an area at Selfridge suspected as the cause of the outbreak. Employees were interviewed, common exposures were noted, and differences in how employees who worked in the same areas have and have not been sick were tracked. Also, environmental samples, such as water and air, from places thought to be the source of the legionnella were collected. Conclusive laboratory test results have not yet been received but are expected in the near future.

The public health team is confident they are doing the right things and are getting closer to identifying the source of the Legionnaires' disease. The team is also assisting the 127th Wing with creating a preventative maintenance plan to limit the chance for legionnella bacteria returning to facilities at the base.

"We are fully committed to devising a long-term plan in preventing legionnella recurrence," said Lt. Col. Mac Crawford, 127th Mission Support Group commander, who oversees the civil engineers that maintain property and provide maintenance of facilities at Selfridge.

The 127th Wing, the host unit at Selfridge, is now focusing on contracting with an experienced legionnaire's cleaning firm who can provide routine cleaning, chemical additives and regular testing of specific water sources on base, an effort to deter growth of legionnella bacteria. The contract will be examined by CDC personnel currently working on the Selfridge legionnella investigation for their endorsement and recommendations in order to ensure the strongest prevention methods are established and followed.

In mid-July, TACOM leadership noticed a spike in employees reporting illness in two specific buildings at Selfridge. As more information was gathered through Army command channels, Maj. Gen. Kurt Stein, TACOM commander, and his staff immediately began to coordinate with the 127th Wing to address the various issues surrounding these reports. They made the decision to relocate employees of the facilities to other areas, and contracted to thoroughly sanitize both facilities, including a complete disinfection of a cooling tower at building 325.

The U.S. Army Public Health Command was called in to assist the local staff of both commands. The CDC was also invited to augment the multi-disciplinary team investigating the outbreak, which included representatives from the 127th Medical Group at Selfridge, Military Medical Readiness and Occupational Health Center- Detroit Arsenal, and the Michigan Community Health Department. The team has been lead by Ambrose.

The CDC estimates that between 8,000 and 18,000 people are hospitalized with Legionnaire's disease in the United States each year. Only about one in 20 cases of the disease reported to the CDC are associated with outbreaks, or occurrences of more than two for any one area. The other 95% of cases are individual cases that occur in communities through America which are not linked to specific sources. Legionnaire's disease can be indistinguishable from other kinds of pneumonia unless specific tests are done to confirm that it is Legionnaire's disease.