The bacteria that causes Legionnaires' disease was found in the water systems of a Towson office building where hundreds of state and county employees work, but the organism is probably no longer there, building managers and Baltimore County health officials said yesterday.
Testers from Clayton Environmental Consultants of Novi, Mich., took water samples in the 13-story Investment Building, off York Road in central Towson. The building's water systems were disinfected earlier this month, after an unidentified woman who works there was diagnosed with the disease.
Ten of 35 sites tested showed "low levels of legionella bacteria" in the roof cooling tower, the hot-water tank and one faucet, building officials announced yesterday.
It is unclear whether the worker, a county Health Department staffer, contracted the disease from the Investment Building.
"The preliminary laboratory report also indicates that the strain of bacteria present was not the same as the one that caused the [worker's] infection," read a letter distributed to building tenants yesterday.
Legionnaires' disease is contracted by breathing tiny water droplets contaminated with the legionella bacteria. The elderly and people with weak immune systems are most susceptible.
The disease can cause pneumonia, fever, chills and a cough. Between 5 percent and 15 percent of the 15,000 annual cases are fatal. Baltimore County has reported four cases this year.
Before the test results were available, the building was treated as if it were the source of an outbreak. Since Oct. 6, the cooling tower has been cleaned and treated with chlorine twice, the hot water system was pasteurized -- heated to kill harmful bacteria, and the cold water system was treated with chlorine to the level of a swimming pool.
"The important thing is, we have done all of the cleanup in the building that any public agency or private consultants have asked us to do," said Lee Baylin, a spokesman for building owners A.G.M. Realty Partners of New York.
"There have been no new reported cases of Legionnaires' disease in the building," Baylin said. "We've done everything that we can do to make it as safe as we can."
Baylin said the water systems would be retested next week for bacteria, along with further tests to determine whether the infected worker contracted the disease in the building.
"The fact that there hasn't been more cases is encouraging," said Clayton Environmental's Patrick Rafferty.
Dr. Michelle A. Leverett, the county health officer, said the chlorine treatment should ease concerns of employees.
No cases of Legionnaires' disease have ever been reported when the Centers for Disease Control protocol for cleaning buildings has been followed, she said. That protocol was followed in this case, she said.
"Based on past experience, we feel comfortable the building is safe," Leverett said.
The 700 workers in the building generally felt the same yesterday. While some acknowledged concern and wondered if they were being told the full story, others said they were comfortable that managers had acted properly.
"I'm glad they are doing what they are doing," said Pat Douglas, owner of the Kard Korner sundry shop on the ground floor. "They seem pretty thorough. The building is in better shape now than it's ever been in."