Published on 11/25/03

Thoroughly cook veggies, says food safety expert

By Cat Holmes
University of Georgia

Cook those green onions. That's the word from the U.S. Food and Drug Administration and food safety experts following recent hepatitis A virus outbreaks in Georgia, Tennessee, North Carolina and Pennsylvania that have been associated with raw or undercooked green onions.

With Americans eating more produce than ever, it's important to wash it thoroughly and cook it whenever possible.

"There has been a tremendous increase in fresh produce consumption," said Michael Doyle, director of the University of Georgia Center for Food Safety and an international authority on foodborne bacterial pathogens. "It's doubled in the last 20 years."

More people eating more fresh produce, however, has resulted in more cases of illnesses linked to contaminated produce.

In the case of the recent hepatitis A virus outbreak in Tennessee, the green onions were traced to Mexico. But Doyle cautions against singling out Mexican produce.

"You don't want to condemn all produce from Mexico," he said. "There are major U.S. growers with production farms in Mexico and these operations are very controlled. Produce from these fields is as safe as any grown in the United States."

Where it comes from

Hepatitis A virus, like Norovirus, is always the result of contamination by infected humans.

"The only reservoir of HAV is humans," Doyle said. "The virus is found in the stools of infected humans. Feces from carriers of HAV can contaminate food and water."

When large HAV outbreaks occur, it's usually caused by a restaurant food handler with poor hygienic practices, Doyle said, or polluted water contaminating foods.

This highlights the importance of practicing good hygiene and good food-handling practices: Wash your hands, and cook your food.

Get cooking

The easiest way to avoid potential HAV exposure in green onions is to cook them.

"Cooking is the best way to minimize the risk of HAV infection," Doyle said. "Washing won't eliminate foodborne pathogens, but it can bring the level down so that it doesn't cause problems. People who are severely immune-compromised should only eat cooked produce."

Freshly prepared salsa and green salads are often made with green onions. When you are eating out at restaurants, the FDA recommends that you specifically request that raw or lightly cooked green onions not be added to your food.

Since contamination is typically on the surface, Doyle also suggests peeling fruits and vegetables such as bananas, apples, carrots when possible. In the case of iceberg lettuce or cabbage, remove the outer two layers of leaves.

About hepatitis A

Hepatitis A infection takes an average of about a month to appear, which means the symptoms can develop weeks after exposure.

According to the Centers for Disease Control and Prevention, adults are more likely to have symptoms than children.

Symptoms usually occur abruptly. They may include fever, tiredness, loss of appetite, nausea, abdominal discomfort, dark urine and jaundice (yellowing of the skin and eyes). Symptoms usually last less than two months. A few people, though, are ill for as long as six months. There is no chronic infection with HAV.

Vaccines are available for long-term prevention of hepatitis A. They're not recommended for children 2 years old or younger. According to the CDC Web site, the HAV vaccine was more widely used in the late 1990s and the number of cases reached historic lows.

Cat Holmes is a news editor for the University of Georgia College of Agricultural and Environmental Sciences.

Cat Holmes was a science writer with the University of Georgia College of Agricultural and Environmental Sciences.