Toxoplasmosis is a disease caused by the parasite Toxoplasma gondii that infects all warm-blooded animals, including humans. Human infection of the disease is caused y eating poorly cooked food containing cysts of the parasite, exposure to infected cat feces, and transmission from an infected mother to fetus during pregnancy.

Adults infected with the parasite may show no apparent symptoms. Sometimes, the signs of the infection may appear as flu-like illness such as tender lymph nodes and aching muscles that may go on for a few weeks or months.

Other people may develop eye problems, and in severe cases, the disease may cause symptoms like seizures and poor coordination in people with compromised immune systems. If infected with parasite while pregnant, the parasite may cause a condition known as congenital toxoplasmosis.

Toxoplasmosis affects about half the world’s population. According to the Centers for Disease Control and Prevention, more than 40 million people in the US are carriers of the disease. Also, there are about 200,000 cases of congenital toxoplasmosis that occur annually.

Causes of Toxoplasmosis

Toxoplasmosis is caused by the T. gondii parasite of the genus Toxoplasma. The parasite can be transmitted from contaminated food and water, or from meat that is raw or not thoroughly cooked.

In rare cases, the parasite can be transmitted via blood transfusions or a transplanted organ. T. gondii can also be found in fecal matter. Thus, the parasite can be transmitted through unwashed produced that has been contaminated with manure.

Although the parasite can infect all warm-blooded animals, only cats are its hosts. It is usually found in cat feces in the United States. The parasite’s eggs reproduce sexually and multiply in cats and are ejected through excretion. Cats show no symptoms of the disease despite being the host.

The parasite can lead to an infection in humans only if they ingest it. This could occur if people are exposed to contaminated cat poop while cleaning out a litter box without washing hands afterward.

There is an increased risk of passing the parasite from a mother to her unborn baby in this manner. It is therefore advised that pregnant mothers seek the help of others in cleaning a cat’s litter box.

Rarely do people get the infection directly from cats. Cats restricted indoors and aren’t allowed outside typically don’t carry T. gondii. Cats who hunt outside or wild cats are more likely to be hosts of the parasite.

Signs and Symptoms of Toxoplasmosis

Toxoplasmosis is usually asymptomatic in adults. However, the symptoms of the disease that may manifest are similar to that of influenza.

These include;

These symptoms usually last for a few weeks or more. People with healthy immune systems are less likely to develop symptoms after being infected with the parasite.

However, for those with a weak or compromised immune system, the symptoms include;

  • Poor coordination
  • Headache
  • Lung problems
  • Seizures
  • Confusion
  • Blurred vision caused by inflammation of the retina

Young children, people living with conditions such as HIV/AIDS, people on chemotherapy, and those who have recently undergone organs are at a high risk of developing severe symptoms of toxoplasmosis.

Toxoplasmosis can also affect an unborn child by passing through the placenta. There symptoms of the disease in a fetus may be mild or severe. However, the disease can be fatal to the baby soon after birth.

Toxoplasmosis has been associated with fetal abortion and death. In infants, it could cause neurological deficits. Infants with congenital toxoplasmosis may appear healthy after birth but can develop the symptoms of the disease as they get older.


A blood test would be required to check for the presence of antibodies of T. gondii. Antibodies are proteins the immune system produces when threatened by harmful substances.

These antibodies detect the presence of alien bodies using their surface makers known as antigens. When antibodies develop antigens of a foreign substance, it remains in the body to protect it against future infections of that foreign substance.

A positive test for the antibodies of T. gondii confirms that a person has been infected with the parasite at some point in your life. It may not necessarily mean that there is a current infection.

A pregnant woman with an active infection may be required to have a test taken for the amniotic fluid and the fetus’s blood. An ultrasound can also be used to determine if the fetus has been infected with the parasite.

If the test on the fetus comes out positive, the mother may be referred to a specialist. There may be an option of terminating the pregnancy, depending on how old the fetus is. Other options include prescribing antibiotics to reduce the child’s risk of developing symptoms.


Treatment of toxoplasmosis depends on the severity of the symptoms. An asymptomatic person may not require any treatment. Treatment is only necessary for people with severe conditions such as HIV, where their immune system is compromised.

In severe cases such as those that involve the eyes and internal organs, the following medication can be prescribed;

  • Pyrimethamine, an antimalarial drug
  • Sulfadiazine, an antibiotic used together with pyrimethamine to treat toxoplasmosis
  • Spiramycin, an antibiotic used to treat pregnant women to prevent the infection of their babies
  • Clindamycin

Amniocentesis can be used to determine if a fetus has been infected with toxoplasmosis. Spiramycin can be used in order to avoid transmission of the parasite from the mother to the child.

The mother can be put on pyrimethamine, sulfadiazine, and folinic acid after the first trimester.

Complications of Toxoplasmosis

Toxoplasmosis can have fatal effects on a pregnant woman and the baby. Also, the disease has lifetime effects on the brain, heart, eyes, and lungs of those that survive the disease. They may also recurrent seizures and delay in mental capabilities.

Children born with the disease may have a higher risk of vision and hearing loss. They may be potentially affected by learning disabilities.


Toxoplasmosis can be prevented by;

  • Washing utensils that have been used to handle raw meat
  • Washing fresh produce before eating
  • Frequent washing of hands especially after handling a cat litter box
  • Properly cooking meat
  • Having someone else handle the cat litter box if you are pregnant