Legionnaire Disease Outbreaks in County Prompt Health Alert

An outbreak of Legionnaire’s disease in a West Los Angeles retirement home this summer, along with a string of Legionnaire’s cases over the past year at UCLA Medical Center, has caused the county’s Department of Health Services to alert local physicians to watch for serious pneumonia-like symptoms in patients who are elderly or whose immune systems are not fully functioning.

The notice, dated July 29, is in effect through the end of September, according to a letter written by Dr. Steve Waterman, chief of the county’s acute communicable disease-control program. The letter, which was not made available to the public, was obtained by The Times this week.

Although at least seven deaths have been attributed to these outbreaks, the notice was mailed out as a routine precautionary measure since there is no evidence of an ongoing problem or a threat to the general public, said Dr. Shirley Fannin, director of the disease control program for the county. Officials at both facilities say the problems seem to have been corrected.

Illness at Two Sites

The outbreak at a 240-unit Westwood Horizons residential facility for the elderly occurred in June and July and resulted in four deaths, Fannin said.

A second apparent outbreak of eight cases of Legionnaire’s disease at UCLA since last fall has resulted in three deaths of patients who were already gravely ill, said Dr. Marcus A. Horwitz, chief of infectious diseases at UCLA.

Investigations at both facilities have been completed and officials say they are reasonably confident that there is no reason for alarm.

“We are definitely not pulling our hair out or worried that the west side of town is more at risk for Legionnaire’s disease than any other part of the city or the country,” said Dr. Laurene Mascola, who works on communicable disease control for the county.

First recognized to cause a disease similar to pneumonia or debilitating flu, Legionella bacteria was so named after 29 infected people died after an American Legion convention in Philadelphia in 1976.

“It is a bacteria that is ubiquitous,” Mascola added. “It is everywhere. . . . Only occasionally do we see clusters that can lead us to an identifiable source.”

According to county officials, the source of the outbreak of Legionella infection at the Westwood retirement home was a new air-conditioning unit. An investigation in July by experts from both the county and the federal Centers for Disease Control resulted in the system’s condensers and ducts being dismantled and replaced with a new system treated with chlorine to destroy any remnants of the bacteria.

The new system will be closely monitored to make certain there is no recurrence of infection, Fannin said.

UCLA has conducted its own investigation of an unusually large number of cases that have developed there, Horwitz said. All eight patients apparently contracted the disease while in the hospital, although in each of the cases the patients were at extremely high risk for infection because their immune systems had been suppressed, in most cases by drugs designed to keep them from rejecting transplanted organs, he said.

Peril in Water System

A investigation turned up detectable levels of Legionella bacteria in the hospital’s hot water system. Horwitz said the university has since cleaned out its water tanks, flushed its pipes and turned up the temperature of the water, which has resulted in the apparent disappearance of the organism.

Despite these efforts, he said, one more case of Legionnaire’s disease has since been reported at the hospital, leading to the continuing bafflement of physicians about the source and transmission of the disease.

Physicians at UCLA and at the county are quick to point out that most people who are exposed to Legionella bacteria do not become ill, even those patients who are at risk for infection. The disease has been thought to be spread through the air, although in many cases the source of infection has been the water supply, which continues to puzzle researchers.

That was the case at Wadsworth Veterans Administration Medical Center in Westwood, when it suffered a lingering epidemic of Legionnaire’s disease in the late 1970s. Between 1977 and 1981, 201 cases were reported there. Dr. Sydney Feingold, chief of staff for research, said “all possible sources” of infection were investigated, including the cooling and heating systems and the soil. Thinking that the bacteria was being blown into the hospital complex, a large barrier was constructed. It was not until three years later, however, that the source of infection was found in the hospital’s drinking water, Feingold said.

Since the beginning of the year, three other cases of Legionnaire’s disease, one on the west side of town and two in other parts of the city, have been reported to the county, Mascola said.

But none of these instances, she said, in any way indicates the actual number of cases of Legionnaire’s disease in the area, since physicians are required to report only those cases that appear in large enough clusters to suggest the possibility of epidemic.