Samples of the water that Hurricane Katrina sent rampaging through New Orleans contain at least 10 times the acceptable levels of bacterial strains common in sewage. The tests can't detect higher levels.

Infections with Vibrio vulnificus, a bacterium naturally found in salt water, have killed an evacuee in Texas and three people in Mississippi, according to Centers for Disease Control and Prevention (CDC) spokesman Tom Skinner. He said the numbers came from state and local health officials.

Healthy people infected with the bacterium usually suffer nothing worse than diarrhea, but the bug can be lethal to those with weak immune systems. Humans are infected by swallowing infested water, through exposed wounds or by eating infected shellfish. The bug does not spread between people.

'Not Going Away Any Time Soon'

Environmental Protection Agency chief Stephen Johnson said samples of the water that Hurricane Katrina sent rampaging through New Orleans contain at least 10 times the acceptable levels of bacterial strains common in sewage. The tests can't detect higher levels.

The water also contains enough lead, perhaps from paint or pipes, to make it unsafe to drink. The EPA found low levels of roughly 100 other chemicals, including pesticides and solvents.

"Contact ... should be avoided as much as possible," Johnson said.

"This water is still a very important threat," CDC Director Julie Gerberding said. "For the evacuees who haven't left the city yet, you must do so. This water is not going away any time soon."

Gerberding said the germs in sewage can cause a variety of gastrointestinal illnesses, some through skin contact alone.

'Bacterial Soup'

CDC spokesman Skinner said an outbreak of norvovirus, a type of virus that causes stomach symptoms such as vomiting and that has erupted on cruise ships, has struck evacuees living in Houston's Astrodome. The virus is usually not life-threatening.

Johnson and Gerberding emphasized that water sampling is far from complete. The results made public Wednesday are based on water samples from less than two dozen sites. Most of the samples were from flooded residential neighborhoods, and many were taken close to the breached levees.

The EPA also found slightly elevated levels of eight pesticides and toxic metals in the water. The levels did not violate health standards. Testing by the state confirmed the EPA results, finding a "bacterial soup" in the floodwaters but no high levels of chemicals, said Darin Mann of the Louisiana Department of Environmental Quality.