As of February 6, 2024, a total of 26 people infected with the outbreak strain of Listeria have been reported from 11 states: Arizona 4, California 8, Colorado 4, Florida 1, Georgia 1, Nevada 1, North Carolina 1, Oregon 1, Tennessee 2, Texas 2, Washington 1. Two deaths have been reported, one from California and one from Texas.
Illnesses started on dates ranging from June 15, 2014, to December 10, 2023. Of 26 people with information available, 23 have been hospitalized.
Among people who are pregnant, Listeria can cause pregnancy loss, premature birth, or a life-threatening infection in their newborn. In this outbreak, two people got sick during their pregnancy and one person had a pregnancy loss. There are also two newborns in the case count for this outbreak because Listeria can be passed to newborns during pregnancy.
State and local public health officials are interviewing people about the foods they ate in the month before they got sick. Of the 22 people interviewed, 16 (73%) reported eating queso fresco, cotija, or other similar cheeses. Among people who remembered specific brands, three people who got sick between 2014 and 2022 reported Don Francisco brand queso fresco or cotija. Don Francisco is one of the brands of recalled cheeses.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS).
WGS showed that bacteria from sick people’s samples from 2014 to present are closely related genetically. This suggests that people in this outbreak got sick from the same food.
In January 2024, the Hawaii State Department of Health’s Food and Drug Branch collected a sample of aged cotija cheese product made by Rizo-López Foods during routine sampling. Testing identified the outbreak strain of Listeria in the product.
FDA conducted inspections at the Rizo-López Foods facility and collected food and environmental samples for testing. FDA found the outbreak strain of Listeria on a container where cheeses are kept before they are packaged.
What is Listeria?
Listeria is a bacterium that causes a serious infection called listeriosis. Around 300 deaths in the United States are caused by Listeria infection each year, according to estimates from a 2011 CDC report.
Listeria bacteria are most found in raw foods. Vegetables can be contaminated by soil and water carrying bacteria. Listeria is also found in raw animal products, such as meat and cheese.
Babies can be born with Listeria if the mother eats contaminated food during pregnancy. The death rate among newborns with Listeria is 25 to 50 percent.
Who is most likely to get seriously ill from Listeria bacteria?
Healthy adults and children hardly ever become seriously ill from Listeria. However, people at increased risk of illness from Listeria bacteria include:
- Pregnant women – Pregnant women are 20 times more likely to get listeriosis than the average healthy adult
- People with weak immune systems
- People with cancer, diabetes, or kidney disease
- People with AIDS – People with AIDS are 300 times more likely to get sick from Listeria than people with normal immune systems
- People who take gluticocorticosteroids, such as cortisone
- Elderly people
Symptoms of Listeria
Listeria symptoms appear anywhere between 3 and 70 days after infection, but usually around 21 days later. Typical symptoms include:
- Muscle aches
- Nausea or diarrhea (less common)
If infection spreads to the central nervous system, symptoms can include:
- Stiff neck
- Loss of balance
Symptoms for those with Weakened Immune Systems
If a patient has a weak immune system, Listeria bacteria can invade the central nervous system and cause meningitis or a brain infection.
Symptoms for Pregnant Women and Newborns
Infected pregnant woman experience mild, flu-like symptoms. However, infection during pregnancy can lead to miscarriage, infection of the newborn, or stillbirth. Symptoms usually appear in newborns in the first week of life but can also occur later on. A newborn’s Listeria symptoms are often subtle, and include irritability, fever, and poor feeding.
Diagnosis of Listeria
Doctors can determine whether patients have listeriosis by taking a blood or spinal fluid sample.
Treatment of Listeria
Patients who present with symptoms of listeriosis can be treated with antibiotics.
How to Prevent Listeria
- Thoroughly cook raw food from animal sources, such as beef, pork, or poultry
- Wash raw vegetables before eating them
- Keep uncooked meats separate from vegetables and cooked foods
- Avoid products made with unpasteurized milk
- Wash hands and cooking utensils after handling uncooked foods
- Consume perishable and read-to-eat foods as soon as possible
Foods to Avoid
- Do not eat hot dogs or lunch meats unless they are heated to a temperature sufficient to kill Listeria bacteria
- Avoid getting liquid from hot dog packages on other food
- Wash hands after handling hot dogs and lunch and deli meats
- Do not eat soft cheeses (e.g., feta, Brie, Camembert, blue cheese, and queso blanco) unless the label clearly states that they are pasteurized
- Do not eat refrigerated pâté or meat spread, only canned or shelf-stable ones
- Do not eat refrigerated smoked seafood, sometimes labeled as “nova-style,” “lox,” “kippered,” or “jerky.” Canned or shelf-stable smoked seafood is ok
Marler Clark, The Food Safety Law Firm, is the nation’s leading law firm representing victims of Listeria outbreaks. The Listeria lawyers of Marler Clark have represented thousands of victims of Listeria and other foodborne illness outbreaks and have recovered over $850 million for clients. Marler Clark is the only law firm in the nation with a practice focused exclusively on foodborne illness litigation. Our Listeria lawyers have litigated Listeria cases stemming from outbreaks traced to a variety of foods, such as lettuce, polony, deli meat, cantaloupe, cheese, celery and milk.
If you or a family member became ill with a Listeria infection after consuming food and you’re interested in pursuing a legal claim, contact the Marler Clark Listeria attorneys for a free case evaluation.