While many foods may be contaminated with nonthreatening amounts of Listeria monocytogenes, the bacteria’s ability to withstand cold conditions can allow small communities to reproduce and form colonies large enough to cause illness or a serious infection, explains Robert Buchanan, PhD, the director of the University of Maryland’s Center for Food Safety and Security Systems in Baltimore. Many foods that are left sitting out for a few hours at room temperatures — especially meats, cut fruit, and dairy foods — are risky. “At room temperature, listeria will double every 20 minutes,” Buchanan says. “In a refrigerator at 40 degrees, they double about once a day.”
Taking that into account, it’s important to eat foods soon after pulling them out of the fridge, and to refrigerate them as soon as possible if you’re not going to eat them, he says. Learn More About How and Why Listeria Makes You Sick
Learn More About Treatment for Listeria Infections
Listeria Infections Can Be Much More Dangerous if You’re Pregnant
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Learn More About Specific Listeria Risks in Pregnant Women
Prevention of Listeria Infection
Always cook or heat meat products before eating them.Promptly refrigerate any foods you’re not going to eat right away.If you handle or prepare raw meat, be sure to wash your hands and any food prep equipment before you work with other foods.
It’s important to pay attention to news of listeria outbreaks in your area. The U.S. Department of Health and Human Services offers info about all food-related recalls and health issues at FoodSafety.gov, and you can sign up for automatic alerts about listeria concerns in your region. Learn More About How to Prevent Listeria Infection
Sepsis (infection of the blood)Meningitis (inflammation of the membranes surrounding the brain and spinal cord)Encephalitis (inflammation of the brain)
As one of the leading health organizations in the United States, the CDC tracks listeriosis outbreaks, offers answers to the most common questions, and outlines a list of the riskiest foods. You can also keep tabs on CDC projects like whole genome sequencing, which aims to prevent foodborne-illness outbreaks like listeriosis. KidsHealth From Nemours KidsHealth.org offers doctor-reviewed advice on hundreds of topics, free lesson plans and programs for educators, and tools like videos and slideshows to help families stay healthy. Check out their informational page on listeria infections, which outlines steps to take if you suspect your child has eaten contaminated food. Mayo Clinic Whatever you want to know about listeria infections, the Mayo Clinic has you covered. This site provides info on risk factors, symptoms, diagnosis, and treatment options, as well as tips to help you prepare for an appointment with your doctor. U.S. Food and Drug Administration Want to know how to keep listeria out of your food? The FDA outlines which foods are no-no’s and offers key food safety tips to reduce the risk of contamination. You’ll also find advice for maintaining your kitchen and refrigerator as clean, sanitary spaces. U.S. National Library of Medicine Have a question about listeria and listeriosis? The U.S. National Library of Medicine will direct you to a number of high-quality government and nongovernment health agencies — like the FDA, CDC, and Mayo Clinic — to help you fill in the blanks. You’ll also find information about clinical trials, journal articles, and high-risk groups. Additional reporting by Lauren Bedosky.