Frequently Asked Questions?
How great is the risk for
listeriosis?
How does Listeris
get into food?
How do you get
listeriosis?
How do you
know if you have listeriosis?
Can listeriosis be
prevented?
How
can you reduce your risk for literiosis?
Can listeriosis be
treated?
What is the government doing
about listeriosis?
Listeriosis, a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes, has recently been recognized as an important public health problem in the United States. The disease affects primarily pregnant women, newborns, and adults with weakened immune systems. It can be avoided by following a few simple recommendations.
How
great is the risk for listeriosis?
In the United States, an estimated 1,100 persons become seriously ill with listeriosis
each year. Of these, 250 die. At increased risk are:
Healthy adults and children occasionally get infected with Listeria, but they rarely become seriously ill.
How does
Listeria get into food?
Listeria monocytogenes is found in soil and water. Vegetables can become
contaminated from the soil or from manure used as fertilizer.
Animals can carry the bacterium without appearing ill and can contaminate foods of animal
origin such as meats and dairy products. The bacterium has been found in a variety of raw
foods, such as uncooked meats and vegetables, as well as in processed foods that become
contaminated after processing, such as soft cheeses and cold cuts at the deli counter.
Unpasteurized (raw) milk or foods made from unpasteurized milk may contain the bacterium.
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 after processing.
How do you get
listeriosis?
You get listeriosis by eating food contaminated with Listeria. Babies can be born with
listeriosis if their mothers eat contaminated food during pregnancy. Although healthy
persons may consume contaminated foods without becoming ill, those at increased risk for
infection can probably get listeriosis after eating food contaminated with even a few
bacteria. Persons at risk can prevent Listeria infection by avoiding certain high-risk
foods and by handling food properly.
How
do you know if you have listeriosis?
A person with listeriosis usually has fever, muscle aches, and sometimes gastrointestinal
symptoms such as nausea or diarrhea. If infection spreads to the nervous system, symptoms
such as headache, stiff neck, confusion, loss of balance, or convulsions can occur.
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 for susceptibility to listeriosis during pregnancy, as
there is for rubella and some other congenital infections. If you have symptoms such as
fever or stiff neck, consult your doctor. A blood or spinal fluid test (to cultivate the
bacteria) will show if you have listeriosis. During pregnancy, a blood test is the most
reliable way to find out if your symptoms are due to listeriosis.
Can
listeriosis be prevented?
The general guidelines recommended for the prevention of listeriosis are similar to those
used to help prevent other foodborne illnesses, such as salmonellosis.
How
can you reduce your risk for listeriosis?
General recommendations:
Recommendations for persons at high risk, such as pregnant women and persons with weakened immune systems, in addition to the recommendations listed above:
Can listeriosis
be treated?
When infection occurs during pregnancy, antibiotics given promptly to the pregnant woman
can often prevent infection of the fetus or newborn.
Babies with listeriosis receive the same antibiotics as adults, although a combination of
antibiotics is often used until physicians are certain of the diagnosis. Even with prompt
treatment, some infections result in death. This is particularly likely in the elderly and
in persons with other serious medical problems.
What is
the government doing about listeriosis?
Government agencies and the food industry have taken steps to reduce contamination of food
by the Listeria bacterium. The Food and Drug
Administration and the U. S. Department of Agriculture
monitor food regularly. When a processed food is found to be contaminated, food monitoring
and plant inspection are intensified, and if necessary, the implicated food is recalled.
The National Center for Infectious Diseases (NCID)
is studying listeriosis in several states to help measure the impact of prevention
activities and recognize trends in disease occurrence. NCID also assists local health
departments in investigating outbreaks. Early detection and reporting of outbreaks of
listeriosis to local and state health departments can help identify sources of infection
and prevent more cases of the disease.
Centers for Disease Control and
Prevention
National Center for Infectious Diseases | Division of Bacterial & Mycotic Diseases
1600 Clifton Rd, NE
MS C-09
Atlanta, GA 30333
updated 22 January 1999