Toxoplasmosis is an infection caused by a parasite. If a pregnant woman contracts
toxoplasmosis, there is a 40% chance that her unborn child will also become infected.
However, such infections are not common in the United Sates. One to 2 per 1000 babies that
are born each year have toxoplasmosis. The toxoplasmosis parasite may be found in cat
feces, soils, and in undercooked infected meat. Cats may contract toxoplasmosis after
eating infected birds or rodents, and the infection can spread to persons only through
direct contact with the cats feces or soils in contact with the feces. Unborn
children infected in early pregnancy are most likely to suffer severe health effects,
which may include blindness, deafness, seizures, and mental retardation. Often, infected
infants appear normal at birth, but develop symptoms months or years later. Toxoplasmosis
is easily prevented by taking some simple precautions such as having someone else clean
cat litter boxes, keeping cats indoors, thoroughly cooking meats and washing fruits and
vegetables before eating, wearing gloves while gardening, and washing hands after handling
raw meats. If toxoplasmosis is suspected in a pregnant woman, tests can be done to
determine if the unborn child is also infected. Medications can prevent or reduce severity
of health effects in unborn children.
According to the Organization of Teratology Information Services (OTIS, 2002 ),
"Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. You
can get it by eating undercooked, infected meat, or handling soil or cat feces that
contain the parasite. Swelling of the lymph nodes or a mononucleosis-type (fever, fatigue,
and sore throat) illness may be seen. Most adults have no symptoms. In most cases, once
you have gotten toxoplasmosis, you cannot get it again."
The March of Dimes (http://www.marchofdimes.com/medicalresources_toxoplasmosis.html)
has stated that, "Cats often become infected when they eat an infected rodent or
bird. The parasite reproduces in the cat's intestine, and a form of the parasite ends up
in the cat's litter box, sand or soil. This form of the parasite becomes infectious within
days, and is resistant to most disinfectants. Under certain temperature and humidity
conditions, the parasite may live in soil for more than a year. Infected cats usually
If a woman contracts toxoplasmosis during pregnancy, there is a possibility that her
unborn child will be infected. Unborn children of women who have contracted toxoplasmosis
prior to pregnancy are usually not at risk. According to OTIS (OTIS, 2002 ),
"Congenital toxoplasmosis only occurs when the mother has an active infection during
pregnancy. In general, there is no increased risk to the fetus when toxoplasmosis occurs
more than 6 months prior to conception. If you had toxoplasmosis in the past, you are
usually immune, and the fetus is not at risk."
The Organization of Teratology Information Services (OTIS, 2002 ) has stated,
"In about 40 percent of the cases in which a pregnant woman has toxoplasmosis, the
baby is also infected. Infants who become infected during pregnancy are said to have
'congenital toxoplasmosis' infection. In the United Sates, 1 to 2 per 1000 babies that are
born each year have toxoplasmosis." According to the March of Dimes (MOD 2001),
About one in 10 infected babies has a severe Toxoplasma infection evident at birth. These
newborns often have eye infections, an enlarged liver and spleen, jaundice (yellowing of
the skin and eyes), and pneumonia. Some die within a few days of birth. Those who survive
can have mental retardation, severely impaired eyesight, cerebral palsy, seizures and
other problems. Although up to 90 percent of infected babies appear normal at birth,
between 55 and 85 percent of them develop problems months to years later, including eye
infections that may affect sight, hearing loss and learning disabilities. Toxoplasmosis
during pregnancy also can result in miscarriage or stillbirth.
To prevent toxoplasmosis, the March of Dimes (MOD 2001) suggests that
pregnant woman take the following precautions:
- Don't empty the cat's litter box. Have someone else do this.
- Don't feed the cat raw or undercooked meats.
- Keep the cat indoors to prevent it from hunting birds or rodents.
- Don't eat raw or undercooked meat, especially lamb or pork. Meat should be cooked to an
internal temperature of 160º F throughout.
- If you handle raw meat, wash your hands immediately with soap. Never touch your eyes,
nose or mouth with potentially contaminated hands.
- Wash all raw fruits and vegetables before you eat them.
- Wear gloves when gardening, since outdoor soil may contain the parasite from cats. Keep
your hands away from your mouth and eyes, and wash your hands thoroughly when finished.
Keep gloves away from food products.
- Avoid children's sandboxes. Cats may use them as a litter box.
According to the March of Dimes (MOD 2001), "If a health care provider suspects that a pregnant woman has an active Toxoplamsa
infection, he or she may recommend one or more of several available blood tests. These
tests require expert interpretation and, therefore, the Centers for Disease Control and
Prevention recommends that all positive test results be confirmed by a Toxoplasma
reference laboratory (one with special expertise in diagnosing this disorder)".
If the reference laboratory confirms that a pregnant woman has an active
infection, the next step is to determine whether the fetus is infected. Prenatal tests
including amniocentesis and ultrasound may help to determine whether the fetus is
infected. Fetuses suspected of being infected are treated by giving the mother
pyrimethamine and sulfadiazine. This approach appears to reduce the frequency and severity
of the newborn's symptoms. Time is of the essence and the earlier the treatment of the
mother, the less likely her baby is to have symptoms.
If tests show that the fetus is not yet infected, the mother may be given an antibiotic
called spiramycin. Some studies suggest that spiramycin can reduce by about 50 percent the
likelihood of the fetus becoming infected. Although spiramycin has not yet been approved
for use in this country by the Food and Drug Administration (FDA), and is therefore
considered an experimental drug, it can be obtained from the FDA. Physicians who are
interested in obtaining the drug can contact the FDA at 301/827-2335.
Further information on toxoplasmosis can be found on
the Center for Disease Control's
website at:http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4902a5.htm or
Additional information can be obtained from:
March of Dimes Resource Center
Your source of information on pregnancy and birth defects.
OTIS Information/Pregnancy Riskline
Salt Lake City, Utah 84114-4270
Telephone: (801) 328-BABY, Fax: (801) 538-6510.