What is Toxoplasmosis?

Toxoplasmosis is a disease that occurs as a result of infection by a single-celled parasite called Toxoplasma gondii. One of the most widespread parasites in the world, it is most commonly found in contaminated, undercookes food or water and cat feces. It can also be transferred from a mother to her baby or by receiving an infected organ or infected blood through a transplant or transfusion.

Pregnant women, babies born to newly infected mothers, and patients with severely compromised immune systems are among those most likely to contract the parasite. Once infected, a person cannot be infected again but may experience symptoms if the infection is reactivated.

What are the Symptoms of Toxoplasmosis?

Most people who become infected never show any signs of having the parasite. When symptoms do occur, they often mimic the flu and may last for a few days or several weeks.

Symptoms include:

  • Muscle pain
  • Headache
  • Fever
  • Fatigue
  • Enlarged lymph nodes in the neck

Acute toxoplasmosis can result in damage to the brain or other organs, as well as:

  • Confusion
  • Seizures
  • Poor coordination
  • Lung problems resembling tuberculosis
  • Encephalitis

Ocular toxoplasmosis affects the eyes and may cause blurred or reduced vision, pain, tearing, inflammation of the retina, and redness. Babies who are infected early before birth are often stillborn or miscarried.

The ones who survive are likely to encounter serious problems such as an enlarged spleen and liver, seizures, hearing loss, mental disability, jaundice, and severe eye infections.

Toxoplasmosis Causes

Toxoplasmosis is caused by a single-cell organism called toxoplasma gondii (T. gondii). It reproduces only in cats, which means that it is usually contracted by humans when they come into contact with the feces of an infected cat.

In most healthy people, the organism is controlled by the immune system. However, if the immune system is weakened in any way, toxoplasmosis can have a harmful effect on the body. Sometimes, the parasite will remain inactive in the body when the immune system is working well and become reactivate when the immune systems is weakened at a later point.

People with HIV or AIDS have weakened immune systems and are therefore very vulnerable to the infection. Individuals going through chemotherapy are also susceptible because their bodies struggle to fight off infections. Finally, steroids or immunosuppressant drugs can cause someone infected with the parasite to develop complications.

Pregnant women are also particularly vulnerable to toxoplasmosis and can risk passing the infection onto their unborn baby if they contract it while pregnant or just before becoming pregnant.

How is Toxoplasmosis Treated?

Patients who are typically healthy are unlikely to need any treatment if they become infected with toxoplasmosis, since normal immune systems are strong enough to prevent the parasite from causing any illness.

However, those with weakened immune systems need to monitor the condition for any signs of complications. Doctors may prescribe antibiotics or anti-parasitic drugs, and patients with HIV or AIDS might have to take the medications for life.

Toxoplasmosis Prevention

To prevent toxoplasmosis you should practice a range of good hygiene habits. Pregnant women and people with a weakened immune system should be particularly careful about avoiding contact with the infection.

It is particularly important to wash hands very thoroughly after changing cat litter boxes or coming into contact with cat feces. Cat feces can often by found in soil in the garden, so washing hands after gardening is also very important.

Lamb, venison and pork are often infected with T. gondii, so if there is any risk that meat is contaminated it should be cooked thoroughly before consumption. Similarly, kitchen utensils which have come into contact with raw meat should be thoroughly cleaned in hot, soapy water. Fruits and vegetables should be washed thoroughly or peeled before being eaten raw, particularly if they have come from a garden which is accessible to cats.

Last Reviewed:
October 11, 2016
Last Updated:
April 03, 2018