Questions and Answers on Hepatitis A Outbreaks Associated With Eating Raw or Undercooked Green Onions (Scallions)
November 15, 2003
Q1: What did FDA announce today?
A1: FDA advised consumers that three recent hepatitis A outbreaks have been associated with eating raw or undercooked green onions (scallions).
Q2: Does this announcement apply to all products containing green onions?
A2: No. It only applies to raw or undercooked green onions or products containing them. Commercially prepared products, such as salsa in jars, have received a treatment that eliminates the hepatitis A virus.
Q3: What can consumers do to decrease their risk of infection from hepatitis A caused by contaminated green onions?
A3: Consumers can cook all raw green onions thoroughly before eating them. This minimizes the risk of illness by reducing or eliminating the virus. Consumers can also avoid eating raw or lightly cooked green onions. Consumers who wish to avoid undercooked green onions should also specifically request that raw or lightly cooked green onions not be added to their food prepared in restaurants.
Q4: Should additional precautions be taken by people with chronic liver disease or weakened immune systems such as patients undergoing chemotherapy or AIDS patients?
A4: Persons with chronic liver disease or weakened immune systems are not more likely to acquire hepatitis A. However, persons with these chronic illnesses sometimes have a more severe form of hepatitis A. People with chronic liver disease or weakened immune systems should consider avoiding raw or undercooked green onions until the cause of green onion contamination has been identified and corrected. All persons with chronic liver disease should get hepatitis A vaccination (see below).
Q5: What caused the outbreak of hepatitis A in the Pittsburgh area?
A5: The State of Pennsylvania, the Centers for Disease Control and Prevention (CDC) and FDA are working together to investigate this outbreak. As of November 15, 2003, the investigation is not finished, and it is not yet known what caused this outbreak. Investigators are now trying to determine if the outbreak was caused by a contaminated food such as raw or undercooked green onions.
Q6: Has FDA asked the restaurant industry to do anything in response to these outbreaks?
A6: Yes. FDA has informed the restaurant industry of the association of hepatitis A with raw or undercooked green onions in recent outbreaks so that restaurants can take actions to protect their customers.
Q7: What are the symptoms of hepatitis A?
A7: The average incubation period for hepatitis A is 28 days (range: 15Ð50 days). This means that symptoms of hepatitis A develop within 50 days of exposure. Persons with hepatitis A virus infection may not have any signs or symptoms of the disease. Adults are more likely to have symptoms than children. If symptoms are present, they usually occur abruptly and 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 2 months; a few persons are ill for as long as 6 months. There is no chronic infection with the hepatitis A virus.
Q8: How serious is hepatitis A?
A8: Most persons with hepatitis A make a full recovery and will never get hepatitis A again. However, in rare instances (an average of 3 in every 1000 reported cases), hepatitis A can be fatal.
Q9: What should consumers do if they recently ate food containing raw or lightly cooked green onions?
A9: Consumers who have recently eaten raw or lightly cooked green onions and feel well only need to monitor their health. Consumers who are experiencing symptoms that might be hepatitis A should consult their health care provider.
Q10: Is there a test for hepatitis A?
A10: Yes, there is a blood test for hepatitis A, called an IgM anti-HAV. However, the only people who need this test are those who are showing symptoms of hepatitis A. Persons who feel well should not be tested, even if they recently ate green onions.
Q11: What is immune globulin (often called IG or ISG) and who should receive it?
A11: Immune globulin is a preparation of antibodies that can be given before exposure to provide short-term protection against hepatitis A to reduce the risk of infection among persons who have recently been exposed to hepatitis A. For maximum protection immune globulin must be given within 2 weeks after exposure. Persons who have recently eaten green onions do not need to get immune globulin. If a specific exposure is identified for which immune globulin prophylaxis is indicated, public health officials will provide information indicating who should receive immune globulin.
Q12: Are there treatments for hepatitis A?
A12: There is no medication that treats hepatitis A. Some patients with hepatitis A may need to be hospitalized to treat dehydration or liver complications.
Q13: Is there a vaccine for hepatitis A?
A13: Yes, but it should be given before an exposure to work most effectively. Hepatitis A vaccine has been licensed in the United States for use in persons 2 years of age and older. The vaccine is recommended for persons who are more likely to get hepatitis A virus infection or are more likely to get seriously ill if they do get hepatitis A. More information on vaccination can be found here. CDC does not recommend that persons who have eaten green onions get vaccinated, unless a healthcare professional recommends that they get vaccinated because of other risk factors for hepatitis A.
Q14: Have there been other recent outbreaks of hepatitis A caused by contaminated food in the U.S.? Have these outbreaks been associated with raw green onions?
A14: Yes. Hepatitis A outbreaks associated with raw or undercooked green onions served in restaurants occurred in Tennessee, North Carolina and Georgia in September. The source of the green onions from the Tennessee outbreak appears to be Mexico. The agency has been in consultation with Mexican authorities to obtain their assistance in assessing the situation. In addition, FDA is monitoring certain import entries of green onions for evidence of potential contamination.
For the press release, see "Consumers Advised That Recent Hepatitis A Outbreaks Have Been Associated With Green Onions."
This article was provided by U.S. Food and Drug Administration. Visit the FDA's website to find out more about their activities and publications.