Listeria food poisoning, better known as ‘listeriosis’, is an uncommon illness caused by consuming food contaminated with the bacterium ‘Listeria Monocytogenes’. In the body, it leads to many other serious diseases, such as meningitis and brain infection. In this article we present the causes, symptoms, and treatment of listeriosis.
Listeria monocytogenes, also known as Listeria, is a food-borne bacteria that causes illness. It normally invades the body through the gastrointestinal tract, and then travels throughout the body. It is mostly found inside the cell walls, and contains toxins that can damage the cells. It mainly targets the central nervous system, and the mortality rate is 30% in immunodeficient or pregnant hosts.
Listeria mainly leads to listeriosis, encephalitis (brain infection), and meningitis or septicaemia (blood infection). It is transmitted from mother to fetus, and causes spontaneous abortion or stillbirth. Among infants, listeriosis is caused by the placenta of the infected mother or during the childbirth process. Listeria is often sporadic in cattle, fowl, and sheep, and also in fruits, vegetables, and dairy products. The risk of the disease is decided based on the amount and the virulence. Though the causes in humans are occasional and treatable, listeria still remains as an important threat to public health.
Causes of Listeria Infection
As we already know, listeriosis is caused by consuming contaminated edibles. Some food products, like canned seafood such as mussels or smoked fish, premixed vegetables such as coleslaw, canned meat items such as deli meat, pate, cooked chicken, soft serve ice creams, soft cheese like Ricotta, Camembert and Brie, unpasteurized milk and its byproducts, etc., are at a higher risk of being infected. Listeria monocytogenes is a remarkably tough bacteria and it resists salts, nitrites, heat, and acidity much better than many other organisms. Listeria can survive on cold surfaces and multiplies slowly even at 24° F. This surviving ability defeats one traditional food safety defense, i. e., refrigeration.
Symptoms of Listeria
Ingestion of only about a thousand cells of the bacteria can cause illness. After ingestion, the incubation period ranges between one to eight weeks, with an average of 31 days. Three weeks after the ingestion, listeria invades all body parts, including the central nervous system, the eyes, and the heart. Early symptoms include muscle aches, fever, tiredness, loss of energy, pain in body organs, etc. If the infection spreads to the central nervous system, the host can experience strong headaches, loss of balance, decreased consciousness, convulsions, or confusion. If the infection spreads to the brain, then it may mimic a stroke.
Infected pregnant women may experience only mild flu or flu-like illness, but it can lead to the infection in the newborn, premature birth, miscarriage, or even stillbirth. Pregnant women are 20% more vulnerable than other healthy adults. The statistics for listeriosis in newborns is 8.6 cases per 100,000 childbirths. The perinatal (stillbirth) and neonatal (early infant) mortality rate from listeriosis is 80%. Other people at high risk are people affected by cancer, diabetes, HIV/AIDS, and kidney or liver disease, because their immune system is already compromised.
Treatment and Detection
If there are lasting symptoms of the disease then a spinal fluid test is a must. During pregnancy, a blood test is the best way to find out if you are suffering from listeriosis. So, if you are in the high-risk group and are showing the above symptoms, then get a medical checkup done as a precautionary measure. There are a few antibiotics that treat listeriosis. All the infected hosts, ranging from babies to adults, are treated with the same antibiotics, though the combinations are different.
There are certain general recommendations to prevent this bacteria from invading your body, which include:
- Wash and clean your hands, and all kitchen appliances such as knives, containers, counters, and cutting boards before and after cooking food.
- Wash all raw material that is required to prepare the food, such as vegetables, fruits, meat, fish, and poultry products.
- Keep uncooked meat, fish, and poultry products separate from vegetables, cooked food, and ready-to-eat foods.
- Avoid unpasteurized milk, and products prepared from it.
- Instead of soft cheese, use hard cheese, like cheddar, during pregnancy. Cook soft cheese until it boils and then consume, if you must.
- Consume only thoroughly-cooked food, especially meat, seafood, and poultry products.
- Consume ready-to-eat food products as early as possible.
- Pregnant women and people from the high-risk group should avoid hot-dogs, meat spreads, deli meats, smoked seafood, and luncheon meat, unless they are cooked and reheated thoroughly.
- Cover food before preserving, and clean countertops, utensils, and the insides of the fridge on a regular basis.
The symptoms of listeriosis may not appear for as many as seventy days after the actual infection. Hence, a little precaution every time you eat can always help in avoiding this gruesome condition.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.