Listeria Food Poisoning
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. It contains toxins that can damage the cells. It mainly targets the central nervous system and the mortality rate is 30% in those of 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 stillbirths. Among the infants, listeriosis is caused by the placenta of infected mother or during the childbirth process. Listeria is often sporadic in cattle, fowl, and sheep, also in fruits, vegetables and dairy products. The risk of the disease is decided upon the amount and the virulence. Though the human causes of the listeria food poisoning are mostly 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 at high risk are - 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. It can also contaminate the processed ready-to-eat food or even heated milk and food products of milk if the procedure is wrong. This is a remarkable 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 240F. This surviving ability defeats one traditional food safety defense i. e. refrigeration.
Symptoms of Listeria
Ingestion of only about a thousand cells of the Listeria bacteria can cause illness. After the ingestion, the incubation period ranges between one to eight weeks, with the average of 31 days. Three weeks after the ingestion, listeria invades all the body parts including the central nervous system, eyes and heart. Early symptoms include muscle aches, fever, tiredness, loss of energy, pains in body organs etc. If the infection is spread to the central nervous system the host can experience strong headaches, loss of balance, decreased consciousness, convulsions or confusion. If the infection spreads to 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 of the newborn, premature births, miscarriage or even stillbirths. Pregnant women are 20% more vulnerable than the other healthy adults. The statistics for listeriosis in newborns is 8.6 cases per 100,000 childbirths. The perinatal (stillbirths) and neonatal (early infant) mortality rate from listeriosis is 80%. Other people who are at high risk are the people affected be cancer, diabetes, HIV/AIDS, kidney disease or liver disease, because their immune system is weakened by those diseases.
Treatment and Detection
If there are lasting symptoms of the disease then the spinal fluid test is a must. During pregnancy, a blood test is the best way to find the causes of the symptoms. So, if you are in the high-risk group and are showing the symptoms within two months of consuming the contaminated food, 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 although the combinations are different. But all this happens only when the physician is certain about the diagnosis.
Preventive Measures
There are certain general recommendations to prevent this bacteria from invading your body which includes:
- Wash and clean the hands, kitchen apparatus such as knives, containers, counters and cutting boards, before and after cooking the food.
- Wash the raw material that is required to prepare the food such as - vegetables, fruits, meat, fish and poultry products.
- Keep uncooked meats, fish and poultry products separate from the vegetables, cooked food and the ready-to-eat foods.
- Avoid unpasteurized milk and products prepared using it.
- Instead of soft cheese use hard cheese like cheddar cheese during pregnancy. Cook soft cheese until it boils and then consume if you must.
- Consume only thoroughly cooked food especially, meats, seafood and poultry products.
- Eat ready-to-eat food products as early as possible.
- Pregnant women and people from high-risk group, should avoid hotdogs, meat spreads, deli meats, smoked seafood or luncheon meats, unless they are cooked and reheated thoroughly.
- Cover the food before preserving, clean countertops, utensils and the insides of the fridge on regular basis.
