METAIRIE, La. -- The question quietly circulating here is whether Legionnaires' disease is spreading in the battered refuse left by Hurricane Katrina.
Some New Orleans-area doctors are saying the bacterium that can lead to the disease, a severe and stubborn form of pneumonia, might 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 that there is no public health threat.
The doctors said in interviews this week that preliminary tests have 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 focus on building materials as a suspected source of the bacterium. The doctors believe that ripping apart flooded homes can create an "aerosol" effect that can lead to infection.
The doctors said they fear that many other patients have become infected but are not receiving medical treatment. Others, they said, are probably being treated with antibiotics that will have no effect because their cases have been misdiagnosed - partly because the disease is difficult to detect and partly, the doctors said, because health officials have not warned hospitals or the public to guard against the disease.
"It's probably not being diagnosed," said Dr. William LaCorte, an internist and geriatric specialist who sees patients at nursing homes and two hospitals in the area. LaCorte said he has treated two patients who contracted Legionnaires' disease. "This is a very serious, life-threatening problem."
State health officials disputed the doctors' claims yesterday. Dr. Raoult Ratard, Louisiana's state epidemiologist, said he has taken the doctors' concerns seriously and said it appears that at least four patients have contracted Legionnaires' disease since Katrina. But he said there is no evidence that the New Orleans area is seeing an unusual rash of cases.
"This is very, very few cases," he said. "It's the same as before."
Ratard questioned whether the bacterium, typically drawn to water and wet climates, could have taken root in flooded building materials. He said it is just as likely that "Gila monsters" are living there.
"That's a crazy story," he said. "People are so adamant about blaming things on Katrina."
Dave Daigle, a spokesman for the Centers for Disease Control and Prevention in Atlanta, said the federal agency has not received reports from the state about suspected cases of Legionnaires' disease.
Dr. Victor L. Yu, a professor of medicine at the University of Pittsburgh who has studied Legionnaires' disease extensively, said he agreed with health officials that it is unlikely that the source of the bacterium is the building materials.
But he said it is entirely possible, even likely, that the New Orleans area could see cases of Legionnaires' disease because of the flood, which 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 in the United States, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease, the CDC said. Symptoms can include high fever, chills, cough, muscle aches and headaches. The disease cannot be passed from person to person.
The disease is named after the outbreak that led to its discovery. In 1976, more than 200 people attending a convention of the American Legion in Philadelphia fell ill; 34 people died. Doctors were confounded, but researchers eventually linked the illness to a bacterium they named Legionella pneumophila.
Most healthy people do not become ill after coming in contact with the bacterium. Those who do become ill can typically be treated with antibiotics and most recover fully. But the disease can be fatal, particularly among smokers, the elderly, people who have chronic lung disease or people whose immune systems are otherwise compromised.
Some doctors in the area would like health officials to issue a public warning. A warning would probably not keep people from becoming infected; there is little that can be done to avoid it. But a warning could prompt people to seek medical attention sooner if they began to feel ill.
"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."
Scott Gold writes for the Los Angeles Times.