Toxoplasmosis is an infection by a tiny parasite (Toxoplasma gondii) that
can live inside the cells of humans and animals, especially cats and farm animals.
If you have been pregnant, you may already know it's important to avoid toxoplasmosis,
which people can develop by cleaning the litter box of an infected cat or eating undercooked
meat or other contaminated foods.
The Centers for Disease Control and Prevention (CDC) estimates that about 60 million
people in the United States could have toxoplasmosis, but most won't have symptoms
because their immune systems are strong.
How It Spreads
People can catch toxoplasmosis from:
touching or coming into contact with infected cat feces (poop). A cat can become
infected from eating infected rodents, birds, or other small animals.
eating raw or undercooked meat (especially lamb, pork, and venison) from
animals that were infected
eating raw, unwashed fruits or vegetables that have touched manure
being born with it (a woman who gets toxoplasmosis while pregnant may pass the
parasite to her unborn child through the bloodstream)
accidentally ingesting (swallowing) the eggs of the parasite, which can get
on the hands after handling soil without gloves or handling uncooked, unwashed foods
drinking contaminated water
Although infection doesn't normally spread from person to person except through
pregnancy, in rare instances toxoplasmosis can contaminate blood transfusions and
organs donated for transplantation.
Signs and Symptoms
Toxoplasmosis is passed from animals to humans, sometimes without causing any symptoms.
When kids do have symptoms, they vary depending on a child's age and the immune system's
response to the infection. (Both humans and infected cats often don't show any signs
of a toxoplasmosis infection.)
Toxoplasmosis in Kids
In kids, toxoplasmosis infections can be:
congenital (when a child is infected before birth)
milder, affecting otherwise healthy kids (similar to infections in pregnant
in kids with weakened immune systems
When a pregnant woman (even one with no symptoms) catches toxoplasmosis during
pregnancy and it's not treated, there's a chance that she could pass the infection
to her developing fetus. Babies infected during their mother's first trimester tend
to have the most severe symptoms.
A woman who got toxoplasmosis before getting pregnant usually won't pass
the infection to the baby — this is because she (and, therefore, her baby) will
have built up immunity to the infection. Toxoplasmosis can be reactivated, meaning
it can come back, in a pregnant woman who's had a previous toxoplasma infection and
has a weakened immune system. Generally, it's probably a good idea to wait to try
to get pregnant until at least 6 months after a toxoplasmosis infection.
Up to 90% of children born with congenital toxoplasmosis have no symptoms early
in infancy, but a large percentage will show signs of infection months to years later.
Premature newborns and very small newborns show clear signs of infection at birth
or shortly after.
Signs and symptoms, if they happen, can include:
swollen glands (lymph nodes)
skin and eyes caused by high levels of the liver chemical bilirubin)
They're also at high risk for eye damage involving the retina (the light-sensitive
lining at the back of the eye that's responsible for sight), resulting in severe vision
If a child is born with congenital toxoplasmosis and isn't treated during infancy,
there's almost always some sign of the infection (often eye damage) by early childhood
Toxoplasmosis in Otherwise Healthy Kids
A healthy child with toxoplasmosis may have no signs of infection or only a few
swollen glands that:
usually appear in the neck
are sometimes tender to the touch
may become larger and smaller over several months
Most healthy kids with these symptoms won't need medical treatment unless the infection
Toxoplasmosis in Kids With Weakened Immune Systems
Kids whose immune systems are weakened (for example, by AIDS,
cancer, or medicines
taken after organ transplants) are at special risk for severe toxoplasmosis infections.
Especially in children with AIDS, toxoplasmosis can attack the brain and nervous system,
causing toxoplasmic encephalitis
(an inflammation of the brain) with symptoms that include:
psychosis (a type of severe mental illness)
problems with vision, speech, movement, or thinking
Although toxoplasmosis parasites may grow and multiply within a week of entering
a person's body, it may be weeks or months before symptoms of infection appear (if
they appear at all).
Once someone becomes infected with toxoplasmosis, the infection remains in the
body for life, usually in a latent (inactive) form that won't cause side effects or
harm. The infection can be reactivated, however, if the immune system becomes compromised
by an HIV infection or cancer therapy.
In a child with a healthy immune system, mild symptoms of toxoplasmosis (such as
swollen glands) usually pass within a few months, even without medical treatment.
But kids born with severe congenital toxoplasmosis may have permanent vision problems
or mental retardation. And in a child with a weakened immune system, toxoplasmosis
can be fatal.
Doctors can diagnose toxoplasmosis through laboratory tests that check for microscopic
parasites in the blood, spinal fluid, amniotic fluid, placenta, lymph nodes, bone
marrow, or other body tissues.
More often, doctors order blood tests to measure the level of antibodies (substances
that are part of the body's defensive immune reaction) produced to fight the parasites.
Genetic tests can identify the DNA-containing genes of toxoplasmosis parasites
once they've invaded the body. These tests are especially useful for checking the
amniotic fluid for evidence of congenital toxoplasmosis in a fetus. Obstetricians
may use ultrasounds to help diagnose congenital toxoplasmosis. But these tests aren't
100% accurate and can lead to false-positive results, meaning there may not actually
be an infection.
For babies, doctors ask the mother about things like exposure to household cats
or contaminated food or water sources. Tests that might be done for these babies include
eye, ear, and nervous system examinations, spinal fluid analysis, and imaging of the
head to look for changes in the brain.
Unless someone has a weakened immune system or is pregnant, there's often no need
to treat a toxoplasmosis infection — symptoms (such as swollen glands) usually
go away on their own in a few weeks or months. However, kids should always be checked
by a doctor because swollen glands can be a sign of other illnesses.
If a pregnant woman gets infected, her doctor and an infectious disease specialist
work together to create a treatment plan. Research has shown that treating the mother
can help make the infant’s disease less severe, but it won't necessarily prevent
the infant from getting toxoplasmosis.
Children born with congenital toxoplasmosis are treated with different combinations
of anti-toxoplasmosis medications, usually for 1 year after birth. A specialist will
decide which medicines to use and for how long.
In healthy older kids who develop serious toxoplasmosis infections, treatment usually
lasts 4 to 6 weeks (or for at least 2 weeks after symptoms are gone). Kids with weakened
immune systems often need to be hospitalized when they develop toxoplasmosis, and
those with AIDS may need to take anti-toxoplasmosis medication for life.
When to Call the Doctor
Call your doctor right away if your child develops symptoms of toxoplasmosis
and any of the following:
is already being treated for AIDS or cancer
has a condition that affects the immune system
has been taking medicines that weaken the immune system
Also call the doctor if you are concerned that your otherwise healthy child may
be sick with symptoms of toxoplasmosis.
If you're pregnant, call your doctor right away if you notice even one swollen
gland, especially if you've been exposed to cats or have eaten raw or undercooked
If your cat is kept indoors and never fed raw or undercooked meat, then your family's
feline probably has a low risk of catching or spreading toxoplasmosis. Still, you
can also catch it from eating raw meats or uncooked produce that's contaminated.
Freeze meat for a few days before cooking it, which helps to reduce the likelihood
of toxoplasmosis infection, says the CDC.
Never wash raw chicken. Washing raw meat and poultry can spread germs around the
kitchen. Germs are killed during cooking when chicken reaches an internal temperature
of 165°F (74°C). So washing doesn't help.
Thoroughly wash all cutting boards, utensils, and kitchen surfaces (especially
those that come into contact with raw meat) with hot soapy water after each use.
Cook all meats completely (the juices should be clear and there should be no pink
If you're pregnant, have someone else change your cat's litter box daily. And
ask that he or she use detergent and hot water to clean it, then wash his or her hands
after changing the litter. If you are unable to have someone else change the litter
box, wear gloves when you do it and wash your hands thoroughly afterward.
Keep your cat inside at all times to keep your pet from getting toxoplasmosis
from the soil and/or small infected animals it tries to catch or eat.
Keep your child's outdoor sandbox covered, especially overnight, to prevent wandering
cats from using it as a litter box.
Don't feed your cat raw meat.
Steer clear of stray cats.
Don't take in a new cat if you're pregnant.
General and Household Tips
Wear gloves when gardening and wash your hands afterward.
Use window screens to try to keep your home bug-free (cat feces are a favorite
haunt of flies and cockroaches and the bugs can spread the feces, and the toxoplasmosis,
Don't drink untreated water, especially if you're traveling in underdeveloped