State to resume testing for Legionnaires'

By Kevin Woster, Journal Staff Writer | Friday, August 19, 2005

Previous Page

Share

• del.icio.us
• Digg
• NewsVine
• Fark

Print

Email

RAPID CITY — State Health Department officials have resumed their search for the source of a string of Legionnaires' disease cases in Rapid City after the announcement Wednesday that an eighth case had been identified.

The most recent Legionnaires' confirmation — coming more than a month after the last case had been reported — shook the previously stated optimism of state health officials that the small outbreak could well be over. They had hoped it ended with the last of seven cases — one of them fatal — that were confirmed between late May and early July.

This most recent case, which apparently developed during the week ending Aug. 6, indicates that a source of Legionnaires' could still exist somewhere in the city, even if its transmission capabilities are limited, state Health Secretary Doneen Hollingsworth said Thursday.

"This may indicate an ongoing, low level of transmission," she said. "I mean, it hasn't been an explosive kind of deal."

State health workers took samples of water and cooling systems at 50 sites last month without detecting the Legionnaires' source. The team was out again Thursday, testing potential sources that include outdoor fountains, water systems, cooling systems and other potential sources of the disease on public and private property in the community.

"That process is occurring today," Hollingsworth said. "We are taking samples, and we will be submitting them to the CDC laboratory."

Last month, Hollingsworth called in a team from the Centers for Disease Control and Prevention in Atlanta to help state and local officials search for the disease source. They conducted interviews with victims of the disease or their families in an unsuccessful search for common travel patterns within the city. Teams also worked with city officials to identify points in the city where people gathered and could come in contact with aerosolized water that might have been contaminated with Legionella bacteria.

"We did an exhaustive review of those places — things like cooling towers, fountains, places that water could be aerosolized in a public setting," Hollingsworth said.

The team could not identify a common link between victims or a source of the illness, although tests did confirm the presence of the Legionella bacterium, which is common in the environment.

Citing confidentiality laws, Hollingsworth declined to say which areas of town were tested before or which were being tested now. Identifying specific sites might provide enough information to threaten the confidentiality of the patients involved, she said.

Hollingsworth also refused to say which health-care facility in Rapid City detected the most recent Legionnaires case, or when it was detected. She did say that it was reported within the three-day period required under state regulations for Legionnaires' confirmation.

The waiting period became an issue during the first string of Legionnaires' cases, because Rapid City Regional Hospital delayed, through an apparent oversight, by five weeks reporting its first positive test for Legionnaires'.

The family of 55-year-old Merrilyn Burchell of Rapid City, who died July 1 of the third confirmed case of Legionnaires' disease, criticized the hospital for its delayed report and the state's policy of not issuing a public alert for Legionnaires'. Rapid City Regional has reviewed its reporting procedures to guard against reporting problems in the future.

The Health Department issued alerts to Rapid City health providers in July. But because Legionnaires' is not spread person to person and cannot be prevented by individual diligence — such as washing hands or using bug spray to prevent other diseases — Hollingsworth said previously that there was no reason to contact reporters or issue a public news release. But the Health Department did issue such a release Wednesday about the eighth case.

That pleased Merrilyn Burchell's sister-in-law, Becky Kempe of Black Hawk.

"I'm glad to hear that," she said of the news release. "At least people know. And hopefully, nobody else will die."

Dr. Lon Kightlinger, state epidemiologist, did say that the onset of the most recent case was during the week ending Aug. 6. That victim was not hospitalized, Kightlinger said.

Five of the first seven victims of Legionnaires' were hospitalized in Rapid City, Hollingsworth said.

Although Kempe was gratified by the public notice by the Health Department, she remained worried that "the cause is still out there." And she said the state should be more open about where it does its testing.

"I would like to see a compiled list of where they test," she said. "It's our money paying for it. It just seems like a big cover-up."

Improperly maintained cooling towers for air-conditioning systems, whirlpools, outdoor fountains and other water systems are possible points of public contamination because they can allow the bacteria to amplify to dangerous levels, then take an aerosol form that can be inhaled.

Rapid City Regional Hospital confirmed last week that the cooling tower at the hospital was among the 50 sites originally tested. Legionnella was confirmed at the cooling tower there, as it was in a number of other test sites. But it didn't match the Legionella strain identified in one of the first seven victims.

In a few instances, Legionnaires' cases in the United States and overseas have been linked to potting soil. That was a consideration in the testing during the last round of tests, Kightlinger said.

"We've checked for common things that the Rapid City cases have been doing, such as planting or gardening or visiting nurseries or working with soil," he said. "We have no common thread there."

Ros O'Loughlin, a CDC epidemiologist who worked on the case in Rapid City last month, said Thursday that it was likely that the cause of the Legionnaires' cases in Rapid City were tied to a mechanical system of some kind. The most common threats are the bigger systems, however, more than those in individual homes or small businesses, she said.

Window air conditioners and even central air conditioners don't have the kind of cooling systems that allows for contaminated water to be aerosolized, she said.

Finding the actual source can be especially difficult in smaller outbreaks, she said.

"It could be something we haven't sampled, or something we sampled and it just wasn't there on the day we sampled," O'Loughlin said. "We very thoroughly surveyed the city and looked for as many aerosol-generating structures as we could find. We were looking for where people go and might be exposed to aerosolizing devices. We did as thorough an investigation as we could have."

South Dakota officials are continuing that search today with telephone guidance from the CDC, Hollingsworth said. Heightened surveillance at health-care facilities will continue, as will the site testing, she said.

Right now, the gap between the most recent case and the first cluster of cases remains a big part of the puzzle.

"It's something we need to investigate," Hollingsworth said. "Is there a relationship to that first cluster, or is it something new?"

Contact Kevin Woster at 394-8413 or kevin.woster@rapidcityjournal.com