Is Legionnaires’ Disease a Fallout of Hurricane?

The question quietly circulating here is whether Legionnaires’ disease is being spread by the battered refuse left by Hurricane Katrina.

Some New Orleans-area doctors say they think the bacterium that causes the disease, a severe form of pneumonia, may be growing in the soggy remains of buildings flooded after the hurricane. But some experts question whether the bacterium can grow in that environment, and state officials insist there is no public health threat.

The doctors said in interviews this week that preliminary tests had confirmed at least seven cases of Legionnaires’ in recent months.

Most patients were homeowners or contractors who had been gutting flooded houses, the doctors said, leading them to suspect that building materials were a source of the bacteria. The doctors think that ripping apart flooded homes creates an “aerosol” effect that can lead to infection.

The doctors said they feared that many other patients were infected but were not receiving treatment. Others, they said, are probably being treated with antibiotics that will be ineffective because their condition has been misdiagnosed -- partly because the disease is difficult to detect and partly because health officials have not warned hospitals or the public to be on the lookout for the disease.

“It’s probably not being diagnosed,” said Dr. William S. LaCorte, an internist and geriatric specialist who sees patients at nursing homes and two hospitals in the area. LaCorte said he had treated two patients with Legionnaires’ disease. “This is a very serious, life-threatening problem,” he said.

State health officials disputed the doctors’ claims Tuesday. Dr. Raoult Ratard, Louisiana’s epidemiologist, said that he had taken the doctors’ concerns seriously and that it appeared at least four patients had contracted Legionnaires’ since Katrina.

He said there was no evidence that the New Orleans area was seeing an unusual number of cases.

“This is very, very few cases,” he said. “It’s the same as before.”

Ratard questioned whether the bacterium, which thrives in water and wet climates, could have taken root in flooded building materials.

“That’s a crazy story,” he said. “People are so adamant about blaming things on Katrina.”

David Daigle, a spokesman for the federal Centers for Disease Control and Prevention in Atlanta, said the agency had not received reports from the state about suspected cases of Legionnaires’.

Dr. Victor L. Yu, a professor of medicine at the University of Pittsburgh and a Legionnaires’ disease expert, said he agreed with health officials that building materials were an unlikely culprit.

But he said it was possible, even likely, that the New Orleans area could see more cases of Legionnaires’ because the flood could have introduced the bacterium into water systems.

“If you’re ever going to have an outbreak of Legionnaires’ disease, you’re going to have it after a major flood event,” he said.

Each year, between 8,000 and 18,000 people in the United States are hospitalized with the disease, the CDC says. Symptoms include high fever, chills, cough, muscle aches and headaches.

The bacterium cannot be spread from person to person.

The disease got its name after more than 200 people attending a 1976 American Legion convention in Philadelphia became ill; 34 of them died. Researchers eventually linked the illness to a bacterium, which they named Legionella.

Most healthy people do not become ill after coming in contact with the bacteria. Those who do become ill can usually be treated successfully with antibiotics.

But the disease can be fatal, particularly for smokers, the elderly, people with chronic lung disease and those with weakened immune systems.

One New Orleans-area patient diagnosed with Legionnaires’ disease died last month, said Dr. Jesse Penico, an infectious-disease specialist at East Jefferson General Hospital in Metairie.

That patient also had chronic leukemia, and it is unclear what led to the patient’s death, Penico said.

The dispute over the severity of the problem -- or whether there is a problem -- stems from a lack of extensive testing.

Preliminary tests have confirmed the presence of antibodies that amass in patients’ blood after exposure to the bacteria, said doctors who think the disease is spreading.

But traces of those antibodies in blood are fairly common, said Ratard, adding that the bacterium is found in many water sources and that people who are exposed to it carry antibodies in their blood forever, typically without experiencing ill effects. Therefore, results of preliminary tests “do not meet the case definition” of Legionnaires’ disease, Ratard said.

Before declaring a public outbreak, most health officials would seek to confirm the presence of additional antibodies in a second round of tests, as well as related antigens -- molecules that help produce immune responses -- in patients’ urine.

The New Orleans area is still a disaster zone, Penico said, and persuading patients who have been treated successfully with antibiotics to return for secondary testing is difficult.

Many do not have time; others are in transition from one home to another.

The doctors would like health officials to issue a public warning. A warning would probably not keep people from becoming infected, but a warning could prompt people with symptoms to seek medical attention sooner.

“The message here is that if you are remodeling a house and you are very short of breath, get your[self] to the ER,” LaCorte said. “And think: Legionnaires’ disease.”