CDC estimates that approximately 1600 illnesses and 260 deaths due to listeriosis occur annually in the United States Over the last few years the cases of listeria have been declining in the United States The largest listeriosis outbreak in U.S. history occurred in 2011, when 147 illnesses, 33 deaths, and 1 miscarriage occurred among residents of 28 states; the outbreak was associated with consumption of cantaloupe from a single farm .
The Rate of listeriosis cases in the European has been going up.One scientist suggested that this was because of the differences in diet between Europe and the United States.
In the European Union food is recalled if there is more than 100 listeria bacteria in a gram of food. At that rate most people's immune system can handle it. In the US food is recalled when there is any listeria bacteria in the food sample. There are some food companies that have stopped shipping to the US because of the stricter standards.
Listeria is killed by pasteurization and cooking; however, in some ready-to-eat foods, such as hot dogs and deli meats, contamination may occur after factory cooking but before packaging. Unlike most bacteria, Listeria can grow and multiply in some foods in the refrigerator.
If Listeria gets into the bloodstream it is extremely dangerous. It has the ability to go through the membranes that protect the brain and fetus to protect them from most bacteria.
There are four distinct clinical syndromes:
Infection in pregnancy: Listeria can grow without symptoms in the vagina and uterus. If the mother becomes symptomatic, it is usually in the third trimester. Symptoms include fever, myalgias, arthralgias and headache. Miscarriage, stillbirth and preterm labor are complications of this infection. Symptoms last 7–10 days.
After birth infection: There are two forms. One, an early-onset sepsis, with Listeria acquired in utero, results in premature birth. Listeria can be isolated in the placenta, blood, meconium, nose, ears, and throat. Another, late-onset meningitis is acquired through vaginal transmission, although it also has been reported with caesarean deliveries.
Gastroenteritis: L. monocytogenes can produce food-borne diarrheal disease, which typically is noninvasive. The median incubation period is 21 days, with diarrhea lasting anywhere from 1–3 days. Patients present with fever, muscle aches, gastrointestinal nausea or diarrhea, headache, stiff neck, confusion, loss of balance, or convulsions.
Listeria has also been reported to colonize the hearts of some patients. The overall incidence of cardiac infections caused by Listeria is relatively low, with 7-10% of case reports indicating some form of heart involvement. There is some evidence that small subpopulations that are more capable of colonizing the heart throughout the course of infection, but cardiac manifestations are usually sporadic and may rely on a combination of bacterial factors and host predispositions.
Bacteremia should be treated for 2 weeks, meningitis for 3 weeks, and brain abscess for at least 6 weeks. Ampicillin generally is considered antibiotic of choice; gentamicin is added frequently for its synergistic effects. Overall death rate is 20–30%; of all pregnancy-related cases, 22% resulted in fetal loss or neonatal death, but mothers usually survive
Listeria is found in food, soil, plants, sewage and other places in nature. Animals and humans can carry Listeria in their intestines without knowing it.
People can get listeriosis by eating meat, fish, dairy products, plants or vegetables contaminated with Listeria. Listeria can get on your food from the soil, water, manure-based fertilizers, and even farm animals that look healthy. You can also transfer Listeria from one food to another by not handling it properly.
Foods that are contaminated with Listeria look, smell and taste normal. Unlike most bacteria, Listeria can survive and sometimes grow on foods being stored in the refrigerator. The good news is Listeria can be killed by cooking food properly.
These steps will help you reduce your risk of getting listeriosis and other foodborne illnesses:
Check your fridge temperature. Check the temperature in your refrigerator using a thermometer to make sure it is at 4ºC (40ºF) or below. As the storage temperature increases, so does the growth of Listeria in foods. The higher the number of bacteria in foods, the greater the risk of getting sick.
Clean your fridge often. Wash and disinfect your refrigerator regularly. The more often it is cleaned, the less chance that Listeria will be transferred from contaminated food and surfaces to non-contaminated foods.
Use leftovers safely. Keep leftovers for a maximum of four days, preferably only 2-3 days, and reheat them to an internal temperature of 74ºC (165ºF) before eating them.
Pay attention to "Best before" dates. "Best before" dates do not guarantee product safety, but they indicate how long the unopened products will retain their freshness and high quality. Once a package is opened, the "best before" date no longer applies. In general, after opening, refrigerated ready-to-eat (RTE) foods should not be stored in the refrigerator for longer than 4 days, and preferably only 2-3 days.
Serve and store food quickly. Serve food right away, and refrigerate or freeze perishable food, prepared food and leftovers within two hours. Avoid letting foods sit at temperatures between 4ºC (40ºF) and 60ºC (140ºF).
Cook thoroughly. Cook food completely, using a clean thermometer to measure the temperature. Follow package directions. Read and follow all package labels and instructions about food preparation and storage.
Separate meat from produce. Keep raw meats, poultry and seafood separate from produce and RTE foods in your shopping cart and fridge. Use a separate cutting boards for raw meats, poultry and seafood and one for washed fruits/vegetables and RTE foods.
Wash your hands. Wash your hands with soap and water for at least 20 seconds before, during and after handling food, using the bathroom, changing diapers or handling pets.
Wash produce. Wash fruits and vegetables well before you eat them.
Defrost safely. Never defrost food at room temperature. Defrost in the refrigerator, in the microwave, or in cold water (replaced every 30 minutes).
Clean before re-using. To avoid cross-contamination, clean all knives, cutting boards, thermometers and utensils that touched raw food before using them again. Change dishcloths daily, and avoid using sponges since they are hard to keep clean.
Sanitize. After handling foods in the kitchen, especially raw foods like meat and fish, thoroughly clean and sanitize all surfaces used for preparing food. Use a kitchen sanitizer (following the directions on the container) or a bleach solution (5 ml household bleach to 750ml of water), and rinse with water.
On top of these tips, high-risk people should avoid eating the following foods:
hot dogs, unless reheated until steaming hot
deli meats, unless dried and salted or heated until steaming hot
raw or unpasteurized dairy products, including soft and semi-soft cheese, such as Brie, Camembert and blue-veined cheese.
pâté and meat spreads, unless frozen, canned or shelf-stable
refrigerated smoked seafood and fish. Frozen smoked seafood and fish are of lower risk, with fully cooked, canned or shelf-stable being the safest alternatives.
raw or undercooked meat, poultry and fish
Pregnant women should not change kitty litter.
