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Children's Hospital fights new bacteria strain

Increased risk seenfor those suffering from cystic fibrosis

A newly identified strain of bacteria has invaded the lungs of at least 20 patients with cystic fibrosis at Children's Hospital, possibly contributing to the death of one woman and prompting hospital officials to begin isolating patients who carry the bug to prevent its spread.

 

The bacteria, called Burkholderia dolosa, are harmless to most people -- in fact, they can be found on the surface of onions -- and state health officials stressed that other patients at Children's face no risk. But people with cystic fibrosis, a genetic disease that causes mucus to accumulate in their lungs, are highly susceptible to infection. Adding to doctors' concern, Burkholderia dolosa is resistant to many antibiotics, making it more difficult to kill.

In response, Children's Hospital recently sent letters to 450 cystic fibrosis patients explaining that all those who test positive for the bacteria will be isolated from other cystic fibrosis patients and allowed to leave their rooms only when escorted by staff. Doctors concede that the restrictions will be hard on patients who sometimes are hospitalized for weeks at a time, but they say there is no better way to make sure patients don't transmit the bacteria to each other.

"We were alarmed because we had only seen [the bacteria] one time in the past 10 years," explained Dr. Craig Gerard, chief of the respiratory disease division at Children's.

Because of the precautions, he added, "we have no indication that this is going to be a clinical problem even for our cystic fibrosis patients and certainly I'm not worried about anyone outside of CF patients."

People with cystic fibrosis fight a constant, often losing, battle against infections largely because their lungs lack the normal ability to clear mucus, creating a perfect breeding ground for bacteria. Depending on the severity of the case, patients are hospitalized for two to three weeks periodically to clear their lungs through a combination of antibiotics and physical therapy. Nonetheless, a cystic fibrosis patient's life expectancy is just 31 years.

Until recently, labs could not distinguish Burkholderia dolosa from several related bacteria strains, including one blamed for the deaths of several patients in Cleveland more than a decade ago. New genetic analysis techniques reassured Children's officials that their problem bacteria was different from Cleveland's, but lab results showed a steady increase in the number of Burkholderia dolosa carriers from 2000, when the hospital treated only two.

In 2001, a woman with cystic fibrosis died a few days after she tested positive for the bacteria, leading doctors to suspect it played a role in her death. However, another patient has lived with Burkholderia dolosa in his airways since 1992 with no apparent ill effects, Gerard said, leaving doctors uncertain how dangerous the bacteria really is.

The hospital launched aggressive infection control efforts about six weeks ago when the Michigan lab that analyzes samples from cystic fibrosis patients concluded that five Children's patients had newly tested positive for the bacteria, bringing the number of patients who carry it to at least 20.

Since then, Gerard said, the hospital has all but ruled out the possibility that the hospital or its staff is spreading the bacteria, suggesting that it is instead spread between cystic fibrosis patients, perhaps when an infected patient coughs on an uninfected one. As a result, the hospital decided to isolate patients who carry the bacteria to prevent further contamination. Dr. Alfred DeMaria Jr., chief of the state Bureau of Communicable Disease Control, praised Children's for its aggressiveness. "They seem to be doing all the right things," he said.

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