Toxoplasmosis is an infection caused by a parasite called Toxoplasma gondii. It can be found in cat feces, undercooked meat, and contaminated food and water.
The Centers for Disease Control and Prevention (CDC) estimates that
Of those with the parasite, the people most at risk of serious illness are people with weakened immune systems and babies born to parents with toxoplasmosis.
Keep reading to learn more about toxoplasmosis, how it’s diagnosed and treated, and the steps you can take to avoid getting this parasitic infection.
Most people who’ve contracted T. gondii show no signs or symptoms. When symptoms are present, they may last for
Toxoplasmosis symptoms are often flu-like and may include:
- muscle aches and pains (myalgia)
- sore throat
- swollen lymph nodes, especially in the neck
Toxoplasmosis is especially serious for people who have severely weakened immune systems, potentially leading to complications involving the eyes, brain, lungs, or other organs.
People who are at risk of serious infection include:
- people with HIV
- people who are taking chemotherapy to treat cancer
- organ transplant recipients
Pregnant people with toxoplasmosis can also pass it on to the fetus. This is called congenital toxoplasmosis and can have serious consequences like miscarriage or stillbirth. “Congenital“ refers to conditions acquired in the womb or that exist in a child from birth.
Children born with congenital toxoplasmosis can also develop other health problems later in life.
Toxoplasmosis in babies
However, sometimes toxoplasmosis can be life threatening for the baby soon after birth.
Signs and symptoms of these rare cases include:
- poor feeding
- swollen lymph nodes
- skin rash
- jaundice, a yellowing of the skin and the whites of the eyes
- enlarged liver or spleen
- anemia, which is due to low numbers of red blood cells
- low platelet count, which can cause easy bruising, bleeding, or purple dots on the skin (petechiae)
- eye damage
- crossed eyes
- nystagmus, an involuntary, repetitive movement of the eyes
- low birth weight
- cerebral calcifications, signs that T. gondii has caused damage to the brain
- hydrocephalus, when fluid builds up in the skull
- macrocephaly, a head that’s larger than normal
- microcephaly, a head that’s smaller than normal
Toxoplasmosis in children
Sometimes babies with congenital toxoplasmosis aren’t noticeably ill at birth but develop signs and symptoms as they get older.
Some of these latent symptoms include:
- hearing loss
- vision problems
- learning disorders
- intellectual disability
- developmental delays
The name of the parasite that causes toxoplasmosis is T. gondii. It’s a tiny, single-celled organism.
Aside from congenital toxoplasmosis, which is passed from a pregnant parent to their baby, most people become infected when they ingest the T. gondii parasite. This can happen in several different ways.
In the United States, T. gondii can be found in cat feces. Although the parasite can be in nearly all warm-blooded animals, cats are the only known hosts. This means that the parasite only reproduces in cats. A cat with toxoplasmosis can shed millions of eggs in its feces for
It’s possible to contract T. gondii when you’re exposed to contaminated cat feces. This could happen if you clean out a cat litter box without washing your hands afterward.
If you’re pregnant, you should ask someone else to take care of any cat litter chores. If you absolutely must clean out the litter box yourself, use gloves and empty waste from the box daily. The parasite isn’t infectious until
Overall, it’s very rare for humans to get toxoplasmosis from cats. House cats that aren’t allowed outside have a very low chance of carrying T. gondii. Wild cats or cats that live outside and hunt are more likely to be hosts of the parasite. Cats don’t usually show symptoms of toxoplasmosis.
You can get toxoplasmosis from raw or undercooked meat and shellfish.
- oysters, mussels, or clams
Make sure all meat and shellfish are cooked to a safe internal temperature before eating.
Handwashing is also important. You can get toxoplasmosis by handling raw or undercooked meats or shellfish and then touching your mouth without first washing your hands.
Contaminated food and water
In addition to being present in some meats and shellfish, T. gondii can also contaminate food or water. The parasite can then move to humans who eat or drink the contaminated substance.
Because the parasite can exist in feces, it can also be found on some unwashed produce that has been contaminated with animal feces or manure. Washing your fruits and vegetables can help prevent toxoplasmosis.
Contamination can happen if you use utensils or cooking surfaces that have been in contact with raw meat, shellfish, or produce. To prevent cross contamination it’s important to wash these items thoroughly between uses.
Maintaining proper kitchen hygiene can help keep your surfaces (and you) safe from harmful bacteria and parasites.
A doctor will typically perform a blood test, called a toxoplasma test, to check for antibodies to T. gondii. If you’ve ever been exposed to T. gondii, antibodies to the parasite will be present in your blood. If your antibody test is positive, then you’ve had toxoplasmosis at some point in your life.
However, a positive result doesn’t necessarily mean that you currently have an active infection. If your test comes back positive for antibodies, your doctor might do further testing.
Testing for an active infection can involve looking for specific types of antibodies called IgM and IgG, which reach high levels in the blood in the weeks and months after an infection.
Here’s how it works:
- IgM antibodies will be present earlier in a toxoplasmosis infection (possibly active). IgMs can usually be seen about a week after infection and will continue to rise and then fall.
- Repeat testing is usually done 2 weeks after the first result to confirm the presence of IgM antibodies.
- IgG antibodies appear a couple of weeks or so after a toxoplasmosis infection. These antibodies will likely be present for life.
A molecular test can also be used to detect DNA from T. gondii in a sample of blood or another bodily fluid. While a biopsy can allow a doctor to see the parasite in a tissue sample, this is done less frequently.
If you’re pregnant and have an active infection, your doctor will test your amniotic fluid and the fetus’ blood to see if toxoplasmosis has been transmitted to the fetus. An ultrasound can also help determine whether the fetus has signs of toxoplasmosis.
Toxoplasmosis can lead to serious complications for pregnant people and their babies, as well as for people with weakened immune systems, such as those living with HIV.
Complications for pregnant people
The reason that pregnant people need to take special precautions to avoid toxoplasmosis is that it can be very serious for a fetus to contract toxoplasmosis in the uterus. Toxoplasmosis can lead to a miscarriage, stillbirth, or premature delivery.
When a baby is born with toxoplasmosis, it can have lasting consequences on the body, particularly the eyes and brain. In general, babies who get toxoplasmosis early in a pregnancy have more severe health issues than those who get it later in a pregnancy.
Complications for people with HIV
People with a weakened immune system, especially people with HIV, can experience more serious complications during a toxoplasmosis infection.
These complications can include:
- cerebral toxoplasmosis (toxoplasmic encephalitis), which is when toxoplasmosis affects the brain, causing:
- vision changes
- trouble with movement
- problems with thinking and memory
- pneumonitis, when toxoplasmosis impacts the lungs, leading to fever, cough, and shortness of breath
- ocular toxoplasmosis, an eye infection that causes blurry vision, eye pain, and light sensitivity
In rare cases when toxoplasmosis affects the brain, for people with HIV this infection can be an
Other areas of the body
If you’re in good overall health and are asymptomatic or have mild symptoms, you may not need treatment for toxoplasmosis. This is because the infection resolves on its own in most healthy people.
However, if toxoplasmosis is severe or occurs in a person with a weakened immune system, treatment is required. In rare cases, hospitalization is necessary.
The medications that your doctor will typically prescribe are:
- Pyrimethamine (Daraprim) is an antiparasitic. It is also used to treat malaria.
- Sulfadiazine is an antibiotic. It targets bacteria that cause infections.
Treatment for toxoplasmosis with medication often lasts
Pyrimethamine decreases your levels of folic acid (vitamin B9). Because of this, your doctor may also ask you to take folinic acid (leucovorin) to help prevent folic acid deficiency while in treatment for toxoplasmosis.
If you have a weakened immune system, you’ll likely need to continue your treatment for at least an additional
In people with HIV, treatment continues until levels of CD4 cells, the immune cell impacted by HIV, improve and viral load is suppressed by antiretroviral therapy. This is because it’s possible for toxoplasmosis to reactivate when CD4 counts are low.
Treatment during pregnancy
Treatment during pregnancy is somewhat different. Your course of treatment will depend on the severity of the infection and whether the fetus has contracted it.
If the fetus doesn’t have toxoplasmosis, you’ll be prescribed medications according to how far along you are in your pregnancy to reduce the likelihood of transmission to your baby.
- Spiramycin, an antibiotic and antiparasitic, is usually recommended if the infection is detected
prior to 18 weeks.
- After this, a combination of pyrimethamine, sulfadiazine, and folinic acid is generally used.
Your doctor will talk with you about the best course of treatment for your particular case and may refer you to a specialist.
Treatment of congenital toxoplasmosis
Newborns with signs or symptoms of toxoplasmosis are typically treated with a combination of pyrimethamine, sulfadiazine, and folinic acid for
However, both pyrimethamine and sulfadiazine can have significant side effects like liver toxicity and suppression of the bone marrow that helps produce blood cells. Because of this, these infants will need to have regular monitoring of their blood counts and liver function.
Some babies born to a parent with toxoplasmosis have no symptoms of congenital toxoplasmosis at birth. As they grow, these children will need regular assessments for signs of vision problems, hearing loss, or developmental delays.
Most people recover from toxoplasmosis in days to weeks. Your doctor may not prescribe any treatments if your symptoms are mild and you are otherwise in good overall health.
Pregnant people who get toxoplasmosis will need to work with their doctor to come up with a treatment plan that’s right for them. The effects of congenital toxoplasmosis are typically worse when the infection is transmitted to the fetus earlier in the pregnancy.
Prenatal treatment of toxoplasmosis can help reduce the risk of transmitting the parasite to the fetus. If transmission has already occurred, treatment can lower the baby’s risk of health complications at birth or later in life.
Nevertheless, babies born with toxoplasmosis may receive treatments for up to a year. They may also still develop long-term health problems.
People with a severely weakened immune system may need to be hospitalized for toxoplasmosis treatment to prevent complications. The outlook is improved in these individuals when toxoplasmosis is diagnosed and treated early.
Knowing the risks of contamination and practicing proper hygiene can help prevent this infection.
Key tips for prevention include:
- Wash your hands frequently, especially:
- after scooping cat litter or cleaning the cat litter box
- before, during, and after handling or preparing food
- before eating
- after working or gardening in potentially contaminated soil
- Make sure all meat or shellfish is properly cooked to safe internal temperatures before eating it.
- Don’t drink untreated or “raw“ water.
- Wash all fresh produce before you eat it.
- Clean all utensils and cooking surfaces that are used for raw meat, shellfish, or unwashed produce.
- Keep cats indoors to help prevent them from becoming infected with T. gondii.
Pregnant people should plan to have someone else clean the cat litter box during their pregnancy. If you must clean it yourself, do so daily, be sure to wear gloves, and wash your hands thoroughly afterward.
Toxoplasmosis is a parasitic infection that causes flu-like symptoms. It can be spread by eating raw or undercooked meats or shellfish, consuming contaminated food and water, or through contact with cat feces.
Most people who get toxoplasmosis will have no symptoms or very mild symptoms. However, toxoplasmosis can have potentially serious complications for pregnant people, fetuses, and newborns, as well as for people with a weakened immune system.
You can take simple steps to lower your risk of acquiring toxoplasmosis. These include frequent handwashing, cooking meats and shellfish to safe internal temperatures, and avoiding cleaning or scooping the cat litter box if you’re pregnant.
If you believe you or a loved one has symptoms of this infection, reach out to a doctor.