Signs You May Have Contracted Listeria

If you've ever gotten sick after eating something that didn't agree with you, you may have eaten food contaminated with listeria. Listeria is a relatively common bacteria and a frequent culprit of foodborne illness (via Everyday Health). Found primarily in water, dust, and soil, listeria can cause serious illness depending on how much bacteria is present in the food you eat. Unlike other pathogens, listeria can still grow at colder temperatures. 

However, the bacteria replicate at a much slower pace when food is refrigerated versus stored in an environment above 40 degrees. Additionally, you would need to consume millions of listeria organisms to feel sick after eating contaminated food, according to Everyday Health. Thus, foods that have been left out for a while carry the highest risk of being contaminated with enough bacteria to cause food poisoning. Some high-risk foods include unpasteurized dairy products, smoked meats, and soft cheeses. 

If ingested, listeria can result in an infection known as listeriosis. Treatment will depend on the severity of the illness and the infected person's overall health (via Healthline). Some people with listeriosis may not experience any symptoms, while others may have a more adverse reaction. Generally speaking, most cases of listeriosis are pretty mild and tend to resolve on their own.

Common symptoms of listeriosis include nausea, fever, muscle aches, and diarrhea, which can occur within one to three days after consuming food contaminated with listeria, according to Healthline. Symptoms usually last until the infection has run its course. More vulnerable groups like older adults, pregnant women, and those with compromised immune systems may experience worse complications. If listeriosis spreads outside of the intestines, it can lead to a more severe infection known as invasive listeriosis, which can cause seizures, confusion, stiff neck, and difficulty walking.