Listeriosis
Listeriosis is a serious food-borne illness caused by the bacterium Listeria monocytogenes, which can lead to severe complications, particularly in vulnerable populations such as pregnant women, newborns, and individuals with weakened immune systems. The disease is known to have a high fatality rate, making it the third-leading cause of death from food-related illnesses in the United States. Approximately 1,600 cases occur annually, with around 260 resulting in death. Symptoms of listeriosis can include nausea, vomiting, diarrhea, and fever, though healthy individuals may experience mild or no symptoms at all. In pregnant women, the infection poses risks to the fetus, potentially resulting in miscarriage or severe health issues for newborns, such as meningitis or bacteremia.
Listeria is resilient and can thrive in refrigerated environments, often contaminating meats, soft cheeses, and unpasteurized dairy products. Prevention strategies emphasize proper food handling, cooking, and hygiene practices. Recent outbreaks, notably linked to deli meats, have highlighted ongoing public health concerns, with extensive measures like whole genome sequencing being employed to trace sources of infection. Awareness of the risks and symptoms is crucial for those most vulnerable to ensure timely diagnosis and treatment, typically involving antibiotics.
Listeriosis
- ANATOMY OR SYSTEM AFFECTED: Blood, brain, central nervous system
Definition
Listeriosis is a food-borne illness that can lead to death in newborns and persons with compromised immune systems. Infants born to women infected with listeriosis may have meningitis (brain infection) or bacteremia (bacterial blood infection). Infected infants who survive may suffer neurological damage and developmental delays. Listeriosis can cause the death of a fetus of an infected pregnant woman.
Listeriosis is the third-leading cause of death from food-borne illness in the United States, with a fatality rate of around 20 percent. About 1,600 people become ill with listeriosis per year in the United States, and 260 die. The number of infected may be greater, but such cases have not been identified, likely because symptoms were mild.
Causes
Listeriosis is caused by the bacterium Listeria monocytogenes, a pathogen that lives in water and soil. It is resistant to refrigeration and is found in ill-prepared or subsequently contaminated meats and vegetables, particularly in luncheon meats, hot dogs, soft cheeses, coleslaw, and unpasteurized milk.
Risk Factors
Pregnant women have twenty times the risk of developing listeriosis as others, according to the Centers for Disease Control and Prevention, and an estimated one-third of listeriosis cases occur during pregnancy. Other persons at risk are those with compromised immune systems, such as persons with the acquired immune deficiency syndrome (AIDS), who have a three hundred times greater risk for listeriosis compared with healthy persons. In addition, others who are at risk include persons with cancer, kidney disease, or diabetes; persons who have had an organ transplant and who take immunosuppressant drugs; persons taking glucocorticosteroids; and persons aged sixty years and older.
Symptoms
Infected persons may present with nausea, vomiting, diarrhea, and fever. Newborn infants may have jaundice, pneumonia, skin rash, lethargy, and vomiting. Symptoms may occur anywhere from two to seventy days after the contaminated food was consumed. Healthy people may have mild symptoms or no symptoms. Pregnant women may have mild symptoms, but their fetus remains at risk for infection.
Screening and Diagnosis
If listeriosis is suspected, blood, urine, or feces are screened for L. monocytogenes. A spinal fluid test and the amniotic fluid of a pregnant woman may also be used for screening.
Treatment and Therapy
Treatment is with antibiotics such as ampicillin. Infected newborns are also treated with antibiotics.
Prevention and Outcomes
Active measures can help to avoid infection. Meats should be thoroughly cooked, vegetables should be washed, and unpasteurized milk products should be avoided. Uncooked meats should be separated from vegetables and other foods during food preparation.
As soon as possible after food preparation, the preparer should wash their hands and any cutting boards and knives used to prepare uncooked foods.
Persons at high risk for listeriosis should avoid soft cheese unless the label on the product indicates the cheese was made with pasteurized milk. Pregnant women should avoid deli meat, cold salad, soft cheese, and pâté.
In 2024, listeriosis became a significant public health issue when a large outbreak connected to deli meats resulted in nine deaths and over fifty hospitalizations. This outbreak was the largest since 2011 in the United States and was linked to numerous health violations at deli meat plants. To trace the source of this listeriosis outbreak, scientists used whole genome sequencing, which allowed them to connect those who were becoming ill with the origin of the bacteria.
Bibliography
"About Listeria Infection." CDC, 2 Aug. 2024, www.cdc.gov/listeria/about/index.html. Accessed 27 Sept. 2024.
Bortolussi, Robert. "Listeriosis: A Primer." CMAJ: Canadian Medical Association Journalk, vol. 179, 2008, pp. 795-797.
Cheung, Vincent Y., and Wilma L. Sirkin. "Listeriosis Complicating Pregnancy." CMAJ: Canadian Medical Association Journal, vol. 181, 2009, pp. 821-822.
"Investigation Update: Listeria Outbreak, Meats Sliced at Delis." CDC, 25 Sept. 2024, www.cdc.gov/listeria/outbreaks/details-delimeats-7-24.html. Accessed 27 Sept. 2024.
Khare, Manjiri. "Infectious Disease in Pregnancy." Current Obstetrics and Gynaecology, vol. 15, 2005, pp. 149-156.
"Listeriosis." MedlinePlus, 26 Aug. 2023, medlineplus.gov/ency/article/001380.htm. Accessed 27 Sept. 2024.