Listeria Outbreak 2024 Symptoms And Prevention. In many cases, listeria, which can take one day to 10 weeks to develop symptoms, is so mild people don't know they are infected, according to the mayo clinic. Epidemiologic, laboratory, and traceback data showed that meats sliced at delis, including boar's head brand liverwurst, were contaminated with listeria.

Listeria bacteria can cause an infection called listeriosa, per the centers for disease control and prevention (cdc). It may have serious effects on pregnant people, fetuses, newborn babies, people 65 or older and people who have.