Legionnaires' disease has always been around, infectious disease expert says

Even as New York faces the largest outbreak of Legionnaires' disease in the city's history, John A. Sellick, Jr., DO, University at Buffalo associate professor of medicine, does not believe there is an epidemic.

"Legionella is everywhere," said Sellick, an infectious disease expert in UB's School of Medicine and Biomedical Sciences. "It tends to thrive in pipes and water handling systems, especially those that are more complex or older. It can be in the glass when you turn your water on at home. There is always some question if we are really seeing more of it now, or if we are doing a better job looking for it and finding it."

Sellick is a hospital epidemiologist at Veterans Affairs Western New York Healthcare System. In the past, he said, people would be admitted to the hospital and died from "non-specific" pneumonia. But now, we are better at culturing and have better testing for Legionnaires' disease, he said.

Also, he said, there tends to be more cases in warm and humid weather, when surface water gets warmer and provides more ideal conditions for Legionella bacteria to grow.

"There may be a true increase in cases, but I wouldn't look at this as an epidemic," Sellick said. "There have always been cases around, it just depends on how hard you look for them."

As of Tuesday, New York City Mayor Bill de Blasio said that the total number of cases had risen to 86 and that seven people have died. The victims were older adults with other medical problems, which is not surprising, Sellick said.

"Most people who get serious Legionella infections are not immunologically or physiologically normal," he said. "The majority of cases we see are in transplant or other very immunosuppressed patients, those with chronic lung disease, or smokers. Assuming you are a normal healthy person, your risk is much lower. Of the last dozen cases of Legionnaires' I have been involved with, not one has been a healthy young person."