by EBSCO Medical Review Board


Toxoplasmosis is an infection caused by a tiny parasite. Most people do not have problems from it. Others may only have mild problems. People who have a weakened immune system or those who are pregnant may have more severe problems.


The infection is caused by a tiny parasite called a protozoan. It is common in cats, but people and other animals can also get it.

The infection is passed from animals to humans. People can get it by:

  • Touching infected cat feces or something that has touched cat feces, such as soil or insects
  • Eating undercooked, infected meat, or by touching one's mouth after touching the meat
  • Getting a blood transfusion or an organ transplant from an infected person (rare)

A pregnant woman who gets the infection for the first time may also pass it to her fetus.

Risk Factors

This problem is more common in tropical places, such as Latin America and Africa. Other things that may raise the risk are:

  • Eating or drinking contaminated food or water
  • Coming in contact with feces from infected cats
  • Getting an organ transplant from an infected person (rare)
  • Having a weakened immune system due to:
    • HIV/AIDS
    • Taking medicines that suppress the immune system
    • An organ transplant
    • A stem cell transplant


Most people do not have problems. Those who do may have:

  • Lack of energy
  • Headache
  • Muscle pain
  • Fever
  • Swollen glands in the neck

People who have weakened immune systems may also have severe problems, such as:

  • Confusion
  • Blurry eyesight
  • Problems with balance and coordination
  • Seizures
  • Breathing problems
The Immune System
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The infection can cause a pregnant mother to have a miscarriage or stillbirth.

Babies who are born with the infection may not have problems for months or years. Problems may be:

  • Fever
  • Rash
  • Swollen glands
  • Swelling of the belly
  • Yellowing of the skin and eyes
  • Eyesight problems
  • Hearing loss
  • Slowed development
  • Learning problems
  • Seizures


The doctor will ask about your symptoms and health history. A physical exam will be done. You may be asked about any contact with cats or contaminated water or food.

Blood tests will be done to look for antibodies linked to the infection. Other lab tests may also be done to look for signs of the parasite.


People who are healthy and not pregnant do not need treatment for mild problems. They will get better in a few weeks or months.

People with weakened immune systems are treated with anti-parasitic medicine for several months.

People who are less than five months pregnant are treated with antibiotics. This can lower the risk of infection in the fetus.

People who are more than five months pregnant are treated with these medicines:

  • An antibiotic
  • Anti-parasitic medicine
  • Folinic acid


The risk of this problem may be lowered by:

  • Drinking and using safe water
  • Washing fruits and veggies
  • Washing hands after touching raw meat, a cat, or exposure to soil
  • Cooking meat and seafood well
  • Not eating unpasteurized goat's milk
  • Wearing gloves when gardening or touching soil

Cat owners can lower their risk by feeding their cats canned or dried store-bought food or well-cooked table food. The cat's litter box should also be changed every two days by someone who is healthy and not pregnant.


Centers for Disease Control and Prevention 

Kids Health—Nemours Foundation 


Health Canada 

Women's Health Matters 


Parasites—toxoplasmosis (toxoplasma infection). Centers for Disease Control and Prevention website. Available at: Accessed March 3, 2021.

Saadatnia G, Golkar M. A review on human toxoplasmosis. Scand J Infect Dis. 2012 Nov;44(11):805-814.

Toxoplasmosis. EBSCO DynaMed website. Available at: Accessed March 3, 2021.

Toxoplasmosis. Kids Health—Nemours Foundation website. Available at: Accessed March 3, 2021.

Revision Information

  • Reviewer: EBSCO Medical Review Board Kari Kassir, MD
  • Review Date: 12/2020
  • Update Date: 03/03/2021