Listeria and Food poisoning.

 Listeria is a bacteria primarily found in soil and water. According to the CDC, vegetables can become contaminated from soil or from manure used as fertilizer. Animals carrying the bacterium can also contaminate food. Listeria has been found in many types of uncooked foods, such as meats and vegetables, as well as in processed foods that become contaminated after processing, such as soft cheeses (like feta and crumbled blue cheese) and cold cuts.

Unpasteurized milk or foods made from unpasteurized milk may also be sources of listeria infection. Listeria is killed by pasteurization, and heating procedures used to prepare ready-to-eat processed meats should be sufficient to kill the bacterium. However, unless good manufacturing practices are followed, contamination can occur even after processing.
 The CDC estimates 1,600 illnesses and 260 deaths from listeria infection each year. The CDC reports that those at increased risk for developing listeriosis include: pregnant women, people with weakened immune systems, people with cancer, diabetes, or kidney disease, people with AIDS, people, such as those with asthma, who take steroid medications, and the elderly.

Symptoms of a listeria infection can include: fever, muscle aches, nausea, and diarrhea. If listeria infection spreads to the nervous system (brain and spinal cord), the following symptoms can occur: headache, stiff neck, confusion, loss of balance, convulsions, infected pregnant women may experience only a mild, flu-like illness; however, infection during pregnancy can lead to premature delivery, infection of the newborn, or even stillbirth.

There is no routine screening test to find out if you are likely to contract listeria infection during pregnancy. If you have symptoms of listeriosis, consult your doctor immediately.

                      DIAGNOSIS AND TREATMENT OF LISTERIA

Listeria infection is often diagnosed by a medical history and confirmed by blood or spinal fluid tests.

Antibiotic treatment will usually cure the infection, and when given promptly to an infected pregnant woman, may prevent infection of her foetus.

Even with prompt treatment, some infections result in death. In the elderly and people with other serious medical problems, these infections are more likely to be fatal.

SOURCE:
WebMD