Deadly Listeria Food Poisoning: Who is Most at Risk?
By Dana L. Pitts, MPH, Centers for Disease Control and Prevention
Stephanie strived to take care of herself and her unborn baby. As an ultrasound technologist working with high-risk pregnancies, Stephanie knew more than most what could go wrong during a pregnancy. She knew the risks of Listeria--a germ that can cause food poisoning or worse--after seeing its damaging effects firsthand while working at the hospital. Unfortunately, Stephanie developed listeriosis, an infection caused by eating Listeria-tainted food. Her beautiful son, Michael, delivered brain dead and unable to breathe on his own, died two days later--another casualty of Listeria food poisoning. (Read Stephanie’s entire story.)
Sometimes foods we love and count on for good health are contaminated with germs that cause illness and can be deadly for certain people. A new Vital Signs report on foodborne illness looks at one of the most deadly germs spread by contaminated food—Listeria—and the people it strikes the hardest.
Rare but Deadly
Although Listeria is common in the environment, it rarely causes listeriosis. About 1,600 people in the United States get sick from Listeria each year. While the infection is rare, in 2011, a new source—cantaloupes contaminated with Listeria—caused one of the deadliest foodborne outbreaks in the US.
Most at Risk
Listeria, the third leading cause of death from food poisoning, targets pregnant women and their babies, people with weakened immune systems, and those 65 years or older. Listeria hits these groups the hardest, accounting for at least 90 percent of reported Listeria infections and resulting in higher rates of hospitalization and death than most other foodborne bacteria.
- Pregnant women, fetuses, and newborn infants
Listeria can pass from a pregnant woman to her fetus or newborn. It can cause miscarriage and still birth; in newborns it can cause bloodstream infection, meningitis, or death. The risk for pregnant women is ten times higher than for the general population. For Hispanic pregnant women, the risk is 24 times higher. More consumption of Mexican-style soft cheese, like queso fresco, may explain the higher rates among Hispanics.
Listeria Outbreak: Queso fresco (a type of soft cheese) sickened 142 people, killed 10 newborns and 18 adults, and caused 20 miscarriages.
- People with weakened immune systems
A weak immune system increases the risk of Listeria infection. Many illnesses can weaken the immune system, including different kinds of cancer, HIV/AIDS, kidney and liver disease. In addition, many medicines can weaken the immune system, including steroids, cancer chemotherapy, and drugs to treat rheumatoid arthritis and other autoimmune diseases. Listeria infection occurs more often in this group than in people with strong immune systems.
Listeria Outbreak: Pre-cut celery in chicken salad served at hospitals sickened 10 people who had other serious health problems. Five of them died as a result.
- Adults 65 years or older
Listeria can spread through the bloodstream to cause meningitis and often kills. The risk for those 65 years or older is four times higher than for the general population.
Listeria Outbreak: Contaminated whole cantaloupes sickened 147 people in 28 states and caused one of the deadliest foodborne outbreaks in the US. There were 33 deaths, mostly in adults over 65, reported during the outbreak.
What Can You Do?
We have made some progress against Listeria. However, we can do more to protect those at higher risk for food poisoning and make food safer for everyone. People at higher risk and those who cook for them can reduce the threat of listeriosis by following these food safety tips.
- Learn which foods are risky and do not eat these foods.
- Do not drink raw (unpasteurized) milk or eat soft cheeses made from it.
- Be aware that Mexican-style cheeses made from pasteurized milk, such as queso fresco, likely contaminated during cheese-making, have caused Listeria infections.
- Heat deli meats and hot dogs until steaming hot before eating.
- Avoid refrigerated smoked seafood unless it is in a cooked dish, such as a casserole.
- Use ready-to-eat, refrigerated foods as soon as possible. The longer they are stored in the refrigerator, the more chance Listeria has to grow.
- Refrigerate leftovers within 2 hours in shallow covered containers and use within 3-4 days.
- Be careful to avoid cross-contamination in the refrigerator or other places in the kitchen.
- Use a thermometer to make sure your refrigerator is 40°F or lower and your freezer is 0°F or lower.
CDC wants to thank Stephanie and her family and the STOP organization for providing public awareness about those impacted by food poisoning.
For more information about Listeria, who is most at risk, and tips for preventing food poisoning from Listeria and other foodborne bacteria, visit:
- Listeriosis (CDC)
General information on diagnosis, treatment, prevention, and lessons from outbreaks.
- Vital Signs: Recipe for Food Safety: Protecting people from deadly Listeria food poisoning (CDC)
Recent data and calls to action on Listeria food poisoning and its impact on vulnerable populations.
- Listeria monocytogenes (USDA)
General information plus directives and notices, compliance guidelines, and more.
- Education materials for At Risk People (CDC, FDA, USDA)
- Foodsafety.gov/ Listeria
- Special Handling for Ready-to-Eat, Refrigerated Foods: Reducing the Risks of Foodborne Listeria (FDA)
Dana L. Pitts is the Associate Director of Communications in the Division of Foodborne, Waterborne, and Environmental Diseases at the National Center for Emerging and Zoonotic Infectious Diseases of the CDC.