CDC Starts Difficult Task of Recording Hurricane's Effects

Data, if Available, Are Scattered Wide

NEW ORLEANS -- The full health consequences of Hurricane Katrina probably never will be known.

The frantic effort to rescue and treat thousands of stranded survivors left little in the way of records describing their illnesses and injuries. The long-term health effects of the storm and flooding on the scattered evacuees will be chronicled in a hundred places and will be hard to document and analyze.

At best, epidemiologists may be able to sketch a picture of who suffers from what from now on, as a major American city is brought back from a near-death experience.

Teams from the Centers for Disease Control and Prevention fanned out across this damaged city last week, trying to find out what information was available and laying the groundwork to capture as much more as possible.

Despite the gaps in the record, what seems almost certain is that this city's epochal disaster will not be followed by plague and pestilence.

"We do not generally see massive outbreaks after these events," said Ali Khan, the physician and epidemiologist who is the CDC's team leader in Orleans Parish.

This is true even of natural disasters in the developing world. Khan helped head up the World Health Organization's response to last winter's tsunami in Indonesia. The populations of dozens of villages and towns were instantly reduced to primitive living conditions, living in hand-built shelters, defecating on the ground and drawing water from streams.

"That was hundreds of thousands of deaths and damage over multiple countries," he said. "We had a handful of cases here and there of measles, a handful of cases of dysentery that were quickly taken care of. So there was not these large outbreaks that people fear."

There are many reasons for this, the most important being the robustness of the human body and its immune system. Although the floodwater covering much of New Orleans is highly polluted, few if any people are drinking it, and mere contact is not enough to cause disease, except in rare cases.

One of the ailments floodwater might cause is infection with Vibrio vulnificus , a bacterium that resides in warm coastal waters. It can infect wounds or cause illness in people who eat raw seafood. People with weak immune systems or alcoholics are the most vulnerable. Wound infections with V. vulnificus are fatal 20 percent of the time; food-borne cases more often.

So far, the CDC has heard of fewer than a dozen cases in the hurricane zone, with several fatalities. Late last week, Thomas A. Clark, 35, a medical epidemiologist from the federal public health agency, was looking for more.

"Have you had any cases of Vibrio vulnificus ?" he asked Wanda Eppling, a supervisor in the microbiology lab at Ochsner Foundation Hospital on the northern border of New Orleans.