Number of cases of Legionnaires' climbing, but rate of spread slowing

MILWAUKEE (WITI) -- The number of cases of Legionnaires' Disease in Milwaukee has increased from 14 to 19 confirmed cases -- with the latest onset being July 16th.

"It appears that the rate of new case reporting has gone down slightly, which is good news. A majority of these cases were hospitalized. They were all adults with underlying medical conditions, including a history of smoking," Paul Biedrzycki with the Milwaukee Health Department said.

Biedrzycki says the 19 cases in Milwaukee are among the 27 confirmed cases in Milwaukee County, and there are two suspected cases in the county as well.

The city cases have all been adults, and at least two remain in the hospital.

Legionnaire's Disease is a severe form of pneumonia caused by inhaling contaminated water vapor.

Potential sources for the legionella bacteria include decorative fountains, hot tubs and cooling towers.

The timing of the outbreak -- starting when the hot weather arrived in June pushes cooling towers as a primary suspect.

"These cooling towers became activated. We believe again aerosolization of contaminated water, mist and vapor occurred at multiple locations that created inadvertent exposure to the public," Biedrzycki said.

Biedrzycki says multiple locations, because the cases are now spread out across the city and results from potential sources investigators tested came back negative.

"We also analyzed clinical specimens from sick individuals and found different strains of legionella bacteria -- indicating there wasn't a single common source," Biedrzycki said.

Biedrzycki said with the rate of reported confirmed cases slowing down, the sources may be fixed before the Health Department can identify them.