Clinical Features/Signs and Symptoms
Listeriosis Linked to Frozen Vegetables (Final Update)
This outbreak investigation is over. However, people could continue to get sick because recalled products may still be in freezers and people who don’t know about the recalls could eat them. Retailers should not sell and consumers should not eat recalled products. Read the Recall and Advice to Consumers and Retailers.
Listeriosis is a life-threatening infection caused by eating food contaminated with the bacterium (germ) Listeria monocytogenes. The disease primarily affects pregnant women and their newborns, adults older than 65, and people with immune systems weakened by cancer, cancer treatments, or other serious conditions (like diabetes, kidney failure, liver disease, and HIV). Rarely, people without these risk factors are affected.
A person with listeriosis usually has fever and muscle aches, sometimes preceded by diarrhea or other gastrointestinal symptoms. Almost everyone who is diagnosed with listeriosis has invasive infection, meaning the bacteria spread from their intestines to the blood, causing bloodstream infection, or to the central nervous system, causing meningitis. Although people can sometimes develop listeriosis up to 2 months after eating contaminated food, symptoms usually start within several days. Listeriosis is treated with antibiotics.
The symptoms vary with the infected person:
- Adults older than 65 and people with weakened immune systems: Symptoms can include fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions.
- Pregnant women: Pregnant women typically experience only fever and other non-specific symptoms like chills and headache. However, infection during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.
- Healthy people. Healthy people rarely develop invasive listeriosis. However, people exposed to a very large dose of Listeria bacteria can develop a non-invasive illness (meaning the bacteria do not spread into their bloodstream or other sites) with diarrhea and fever.