News You Can Use: E. Coli Safety Facts

Oct. 9, 2006 — -- The recent cases of E. coli contamination have made consumers wary of everything from their salad greens to fast-food tacos.

In the case of October's spinach contamination, the source was traced to water used in irrigation systems in California's Salinas Valley. One company voluntary recalled its lettuce that might have been irrigated with contaminated water.

Shortly afterwards, the Salinas-based Nunes Co. ordered a recall of lettuce after learning of the possible existence of E. coli contamination.

Most recently, Taco Bell's offerings have fallen under suspicion. With more than four dozen people sick in at least three states, Taco Bell has ordered the removal of green onions from its 5,800 restaurants nationwide Wednesday after testing by an independent lab suggested the bacteria may have come from scallions.

But if these incidents have scared you off from greens, what veggies are safe for you and your family to eat? What do you do if you believe you have E. coli? How is the bacteria spread?

We set out to answer your five most burning questions on eating healthy and safely, getting answers from medical experts experienced in food production, E. coli and microbiology.

What Vegetables and Foods Are Considered Unsafe?

While raw spinach and lettuce should be avoided, other vegetables, especially when cooked, are safe.

"Eat very well cooked vegetables," said Vanessa Sperandio, and microbiologist at the University of Texas Southwestern Medical Center. "That's what I've been doing with my children. If you cook it very well, you're going to kill it -- this is not a very heat-resistant bacteria."

"Cooking will eliminate the risk," said Dr. Pascal James Imperato, professor and chairman at SUNY Downstate Medical Center, and former New York City Health commissioner. "Well-done burgers [beef] are safe."

Surface E. coli, which often breeds in the humid petri-dish environment of plastic bags, is something to watch out for, Imperato said.

"Food and vegetables in plastic bags, can be part of the problem," he said. "There were surface organisms found on the bags of some of the contaminated spinach."

"E. coli can be present in other foods like unpasteurized milk, raw beef," said Dr. Roshini Rajapaksa, gastroenterologist and assistant professor of medicine at New York University School of Medicine. "But raw spinach and raw lettuce are the only things that are potentially contaminated in this outbreak."

"E. coli is an organism that's found normally in the intestinal tract of cows and sheep, but the main source in the U.S. is cows, and anything that can be contaminated with that, can affect humans," Imperato said.

The advice for making sure the meat you eat is safe is the same as it is for dealing with vegetables.

"E. coli is primarily found on the surface of beef. Cooking it will eliminate the risk. But ground beef, when it's ground, it gets inside, the organism can be inside and viable," according to Imperato. "The best thing to do is eat hamburgers that are well done."

How Can You Reduce the Risk of E. Coli?

There have been some reports that the E. coli strain found in the contaminated spinach was "incorporated into the DNA" of the spinach, but E. coli experts insisted that this isn't possible.

The strain of E. coli can be taken up in water through the roots of the plant and exist within the spinach, but it cannot become part of the leafy greens' genetics.

"It would not be inside of the cell of the plants, and it certainly has no exchange of DNA with the plants," Sperandino said.

But because there's a chance that it still exists inside the plant, "washing cannot get rid of it," said Ben Miller, and E. coli expert at the University of Rochester.

"Cooking can kill it if the material is cooked thoroughly," Miller said.

Frozen food is also safe, because "most of the frozen spinach that was out there was cooked before freezing, and canned vegetables of any kind are fine because of processing," said Miller.

What Are the Symptoms of E. Coli?

The symptoms of E. coli are relatively straightforward, but usually more intense than a normal stomach bug.

"The main symptom is diarrhea, usually with blood," Rajapaksa said. "Weakness, low-grade fever, abdominal pain or cramps and just generally feeling tired."

If it is E. coli, patients should remain vigilant even after they've recovered and received treatment for kidney disorders, Sperandio said.

"Hemolytic hermetic syndrome, kidney complications, happens after the diarrhea," Sperandio said. "Between five to seven days afterwards ... if you have fatigue, fever, blood in urine, pain after the diarrhea resolves, immediately go see a doctor. It's normally seen in young children, but in this outbreak, it seems to go all the way up to 18-year-olds."

What Are the First Steps to Take If You Think You Have E. Coli?

Early treatment is the best bet for a quick and complete recovery from E. coli, the experts said.

"If there's concern, you shouldn't wait at all," according to Miller. "What you'd want to do first is contact your family doctor, and the family doctor can then refer you to more intensive treatment if needed."

"You might need IV hydration," Rajapaksa said. "Take steps to not spread it to other people in your household -- washing your hands, don't prepare food and no sharing of utensils."

What Is the Government Doing to Assure Public Safety?

So far, the Centers for Disease Control and Prevention and the FDA have been aggressive in finding the source of the E. coli outbreak in the contaminated spinach case.

"Since 1997, E. coli has been a reportable disease," Sperandio said. "The CDC has been tracking this with the FDA, and I know they're trying to see exactly what the source is. They've been on the case since the beginning.

"As soon as they find the source, it's less of a moving target because then they can tackle that," she said.

"I think that investigations are going on to test the water that these vegetables are exposed to," Rajapaksa said. "Food handlers and people that work in the plants are being checked to see if they're carrying this bacteria."

But the real story was in the voluntary recall of the lettuce, before an E. coli outbreak even took place, Imperato said.

"[It] reflects the fact that they didn't wait till people began to become ill. They're not even sure if that contaminated water was used on that crop of lettuce," he said. "It shows that the industry is becoming much more proactive at eliminating and preventing outbreak in humans."

ABC News' Rachel Konrad contributed to this report.