Listeriosis

Listeriosis, a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes. Listeria monocytogenes can be found in soil, mud and water. Food such as vegetables can easily be contaminated with the bacterium if contaminated soil or fertilizer is used. Cooked food, especially precooked items or items served cold, can also be contaminated if the cooked food comes into contact with uncooked contaminated foods or in contact with items such as cutting boards or knives that were used for uncooked contaminated foods.

Symptoms of listeriosis may include fever and muscle aches. Some gastrointestinal symptoms may also occur such as nausea or diarrhea. Symptoms such as headache, stiff neck, confusion, loss of balance or convulsions can also occur if the infection spreads to the nervous system. The infection is serious for pregnant women. Though the expecting mother may only experience a mild flu-like illness, the infection can lead to miscarriage, stillbirth, premature delivery or severe infection of the newborn. The fatality rate for newborns ranges from 30 to 50 percent.

People considered at high risk of listeriosis include pregnant women, newborns, the elderly, people with underlying health conditions such as heart or kidney disease and individuals with a weakened or suppressed immune system such as people undergoing treatment for cancer, people taking certain medications or people with AIDS. Healthy adults and children occasionally get infected with Listeria but they rarely become seriously ill.

Infection with Listeria monocytogenes is an ongoing problem in Houston although the number of cases per year is not large. The number of cases per year during the last five years ranges from as low as four in 2002 to as high as 10 in 1999. To date there have been only three cases in 2004.

In Houston during the previous 5 years, 2/3 of the cases have been in females (24/36). Children less than 1 year combined with adults over 65 years make up over half of all case in Houston.