What is Listeria?
Listeria is a type of bacteria found everywhere in soil and
ground water and on plants. Animals and people can carry Listeria
in their bodies without becoming sick. Despite being so widespread,
most infections in humans result from eating contaminated foods.
Most people are not at increased risk for listeriosis. However, there
are some people who are considered at risk because they are more susceptible
to listeriosis. In addition to pregnant women and their unborn babies
and newborns, other at-risk groups include older adults and people with
weakened immune systems caused by cancer treatments, AIDS, diabetes,
kidney disease, etc. By carefully following food safety precautions,
persons at risk for listeriosis can substantially reduce their chances
of becoming ill.
Why is listeriosis especially dangerous for me and my child?
Hormonal changes during pregnancy have an effect on the mother s immune
system that lead to an increased susceptibility to listeriosis in the
mother. According to the CDC, pregnant women are about 20 times more
likely than other healthy adults to get listeriosis. In fact, about
one-third of listeriosis cases happen during pregnancy. Listeriosis
can be transmitted to the fetus through the placenta even if the mother
is not showing signs of illness. This can lead to premature delivery,
miscarriage, stillbirth, or serious health problems for her newborn.
Is Listeria transmitted from the mother to
the baby through breast milk?
While there is a theoretical possibility that Listeria monocytogenes
could be transmitted via mother's milk, this has never been proven.
How will I know if I have listeriosis?
Because the symptoms of listeriosis can take a few days or even weeks
to appear and can be mild, you may not even know you have it. This is
why it's very important to take appropriate food safety precautions
In pregnant women, listeriosis may cause flu-like symptoms with the
sudden onset of fever, chills, muscle aches, and sometimes diarrhea
or upset stomach. The severity of the symptoms may vary. If the infection
spreads to the nervous system, the symptoms may include headache, stiff
neck, confusion, loss of balance, or convulsions. Consult your doctor
or healthcare provider if you have these symptoms. A blood test can
be performed to find out if your symptoms are caused by listeriosis.
What is the treatment for listeriosis?
During pregnancy, antibiotics are given to treat listeriosis in the
mother. In most cases, the antibiotics also prevent infection of the
fetus or newborn. Antibiotics are also given to babies who are born
What steps can I take to prevent listeriosis?
USDA's Food Safety and Inspection Service (FSIS) and the U. S. Food
and Drug Administration (FDA) provide the following advice for pregnant
women and all at-risk consumers: :
- Do not eat hot dogs, luncheon meats, or deli meats unless
they are reheated until steaming hot.
- Do not eat soft cheeses such as feta, Brie, Camembert, blue-veined
cheeses, and Mexican-style cheeses such as "queso blanco fresco."
Hard cheeses, semi-soft cheeses such as mozzarella, pasteurized processed
cheese slices and spreads, cream cheese, and cottage cheese can be
- Do not eat refrigerated pâté or meat spreads. Canned or
shelf-stable pâté and meat spreads can be eaten.
- Do not eat refrigerated smoked seafood unless it
is an ingredient in a cooked dish such as a casserole. Examples
of refrigerated smoked seafood include salmon, trout, whitefish, cod,
tuna, and mackerel which are most often labeled as "nova-style,"
"lox," "kippered," "smoked," or "jerky."
This fish is found in the refrigerated section or sold at deli counters
of grocery stores and delicatessens. Canned fish such as salmon and
tuna or shelf-stable smoked seafood may be safely eaten.
- Do not drink raw (unpasteurized) milk or eat foods
that contain unpasteurized milk.
What can all consumers do to prevent listeriosis and keep their
Because Listeria can grow at refrigeration temperatures of
40 ºF or below, FSIS and FDA advise all consumers to:
- Use all perishable items that are precooked or ready-to-eat as soon
- Clean their refrigerators regularly.
- Use a refrigerator thermometer to make sure that the refrigerator
always stays at 40 º F or below.
What should I do if I've eaten a food that has been recalled because
of Listeria contamination?
If you have eaten a contaminated product and do not have any symptoms,
most experts believe you don t need any tests or treatment, even if
you are pregnant. However, you should inform your physician or healthcare
provider if you are pregnant and have eaten the contaminated product,
and within 2 months experience flu-like symptoms.
It's important to learn how to protect yourself and your unborn baby
from foodborne illnesses. Getting in the habit of eating a safe and
nutritious diet not only benefits your baby, but will also give you
peace of mind.