You Can’t Ignore the Cantaloupe Listeria Issue…Especially During Pregnancy

By Sonia Alvarado, CTIS Pregnancy Health Information Line Counselor

Pregnant women who ask their doctor about food recommendations, or who call a pregnancy information service such as ours in California ( are typically told to avoid unpasteurized milk products such as raw milk, unpasteurized cheese and deli meats to avoid exposure to listeria monocytogenes, a mycobacteria. Listeria infection in pregnancy can cause neonatal infection, stillbirth, miscarriage or prematurity. While we recommend that everyone wash fruits and vegetables before eating, we had not been specifically concerned about listeria contaminating fruit and possibly infecting pregnant women; until now.

At the time this is being written, there is a large investigation being conducted by the Centers for Disease Control (CDC), other Federal authorities, along with the support and cooperation of local health departments on an extensive listeria outbreak resulting from contaminated cantaloupes. The contaminated cantaloupes originated from a Colorado producer, Jensen Farms, who distributed to vendors in 25 states, who then trucked the cantaloupes to stores and supermarkets. According to the CDC, at this time there are at least 72 people who have been sickened, including 13 deaths. It is expected that the number of infected people will rise since illness may not occur until 2-3 weeks after infection, and cases would still have to be reported to the appropriate authorities to be counted. The ages of infected individuals so far ranges from 35 to 96 including two pregnant women, according to media reports.

Listeria infection causes listeriosis and this disease is most dangerous to pregnant women, immunocompromised individuals, children and senior citizens. Pregnant women are reported to be 20 times more likely to get listeriosis. The symptoms of listeriosis are different in the various sensitive groups; pregnant women may experience a mild, flu-like illness, seniors may suffer septicemia: infection throughout the body, and meningitis. Pregnant women may not realize what’s happened until after they’ve suffered a pregnancy loss, one of the risks associated with listeria infection in pregnancy.

Most worrisome at this time is that we do not know how the cantaloupes were infected. Was the listeria in the soil or in the water that irrigated the cantaloupes? This critical piece of information is necessary to prevent this outbreak from occurring again.

This outbreak is yet another warning about the importance of having evidence-based and enforced regulations on food handling, production and inspection. However, since no system is perfect, we all need to take steps to reduce the chance that we’ll be infected from listeria or other bacteria and parasites.

The following are recommendations from the CDC in combination with other sources, to reduce your chance of exposure; recognizing that no recommendations are going to be 100% effective.

1. Wash your hands before handling any food (meat, fruits, vegetables, canned, prepared, not prepared, etc). Wash hands for 20 seconds with soapy, warm water.

2. Wash all homegrown produce and store-bought before eating it. You can use water, a 1% vinegar solution, soapy water or a commercial vegetable-cleaning product. Use a vegetable brush if possible.

3. Wash knives, countertops, and cutting boards after handling and preparing uncooked foods.

4. Thoroughly cook raw food from animal sources, such as beef, pork, or poultry to a safe internal temperature. What’s the appropriate temperature? From the USDA (using a food thermometer):

  • All whole cuts of meat (ground beef, veal, lamb, and pork) to 145 °F as measured with a food thermometer placed in the thickest part of the meat (rest time of 3 minutes before eating)
  • Ground meats, (ground beef, veal, lamb, and pork): 160 °F no rest time recommended
  • All poultry products (ground beef, veal, lamb, and pork); 160 °F no rest time recommended

5. Separate uncooked meats and poultry from vegetables

6. Separate uncooked meats from cooked foods and ready-to-eat foods.

7. Do not drink raw (unpasteurized) milk, and do not eat foods that have unpasteurized milk in them.

8. Consume perishable and ready-to-eat foods as soon as possible.

9. Clean dishes with soap water in the hottest temperature that is safe and comfortable for you. The FDA requires restaurants clean dishes with a minimum temperature of 110 degrees F, so if you have a dishwasher, you may be able to get the water to this recommended temperature.

10. When possible, choose irradiated foods. Cleaning foods on the surface may not get to all of the bacteria. For example, cleaning lettuce with water may not get to bugs that get between nooks in the leaves. Irradiation exposes food to a source of electron beams, and destroys bacteria and parasites. Get informed about irradiated foods from the experts!

11. Clean your refrigerator! You won’t get all the listeria out, but most of it and slow its growth.

12. Keep your refrigerator at 40 degrees or below. This temperature slows the growth of listeria in refrigerators.

About the Author

Sonia Alvarado is a bilingual (Spanish/English) Teratogen Information Specialist with the California Teratogen Information Service (CTIS) Pregnancy Health Information Line, a statewide service that aims to educate women about exposures during pregnancy and breastfeeding. Along with answering women’s and health professionals’ questions regarding exposures during pregnancy/lactation via CTIS’ toll-free hotline and email service, she’s provided educational talks regarding pregnancy health in community clinics and high schools over the past decade. In addition, Sonia contributes to the service’s website, develops training materials for new CTIS staff, and is the supervising Teratogen Information Specialist trainer. Sonia attended San Diego State University and has worked in Tuberculosis Control for San Diego County’s Public Health Department. Sonia’s work has also been published through several tuberculosis studies. In her spare time, she loves to volunteer with the March of Dimes as an expert speaker on themes related to pregnancy.

CTIS Pregnancy Health Information Line is part of the Organization of Teratology Information Specialists (OTIS), a non-profit with affiliates across North America. California women with questions or concerns about pregnancy exposures can be directed to (800) 532-3749 or by visiting Outside of California, please call OTIS counselors at (866) 626-OTIS (6847).