What are the symptoms of toxoplasmosis?

People often do not notice that they have toxoplasmosis. This is because a Toxoplasma infection almost never causes symptoms. It can sometimes cause mild symptoms, such as tiredness, listlessness or fever. Because these symptoms are so general, people do not realise that they could indicate toxoplasmosis.

Sometimes patients can become seriously ill. This mainly happens in people who have a weakened immune system. They could have serious eye infections, pneumonia and meningitis.

There is also a form of toxoplasmosis that looks a lot like mononucleosis. This form can cause swollen lymph nodes and muscle pain. The spleen and liver can also become enlarged. This will go away on its own. This form is less common.

Who can become very ill from toxoplasmosis? 

Serious illness resulting from toxoplasmosis is mainly a risk for people who have a weakened immune system. This includes people with HIV.

Is it dangerous to get toxoplasmosis during pregnancy?

Most pregnant people with a Toxoplasma infection have never had toxoplasmosis before. People usually have their first exposure between the ages of 25 and 44 years. Until then, their body has not yet produced any antibodies against the parasite. They do not have any immunity to the parasite, which means that an infection is particularly dangerous during pregnancy.

If you have toxoplasmosis during pregnancy, you could pass the infection on to your baby. An infection early in your pregnancy could lead to a miscarriage or stillbirth. This risk is lower if you have toxoplasmosis later in pregnancy – but even then, the infection could cause birth defects in the eyes or nerves.

In some cases, if the infection is severe, the baby could die before, during or shortly after birth.

Avoid contact with potentially contaminated food or soil as much as possible during pregnancy. For more information, go to the RIVM page on pregnancy and infectious diseases.

How does toxoplasmosis spread?

Toxoplasmosis is caused by a parasite that lives in the intestinal tract of cats. Young cats are more likely to carry this parasite. The parasite’s eggs are transferred to soil, vegetables or water through cat faeces. These immature eggs can survive for a very long time, and are contagious after 48 hours. Humans and animals can be exposed through:

• contact with soil or cat faeces, for example when gardening or cleaning the litterbox.
• eating unwashed fruit or vegetables, for example grown in your own garden.
• eating raw or undercooked meat from infected animals.

In rare cases, you could also be infected by drinking raw milk from infected animals.

The time between exposure and illness (the incubation period) is usually 5 to 23 days.

Can animals also get toxoplasmosis?

Toxoplasma gondii is a parasite that is found in all animals. Cats and other felines are the only animals that spread the parasite’s eggs. When other animals carry the parasite, no eggs are developed. However, they can infect other animals by being eaten. An infected mouse does not have eggs – but a cat that eats that mouse will also be infected. The cat can then spread the parasite’s eggs.

Most animals do not become ill from a Toxoplasma infection. This also applies to cats. Young cats can sometimes have diarrhoea or develop encephalitis, pneumonia or a liver infection. In farm animals, such as sheep, toxoplasmosis can cause a miscarriage.

How can I prevent toxoplasmosis?

There are various things you can do to prevent toxoplasmosis:

• Always cook meat thoroughly before eating it.
• Do not let cats have access to areas where children play. For example, put a lid on the sandbox.
• Always wash fruit and vegetables thoroughly, especially if you grow them yourself.
• Wear gloves when gardening.
• Clean the litterbox every day.
• Are you pregnant? Then have someone else clean the litterbox.
• Always wash your hands thoroughly after contact with soil, sand, dirt or straw.
• Do you work or live on a farm? Practice good hygiene when calves, lambs or kids are born, or after a miscarriage. Wear protective clothing and do not touch your face with your hands. Have visitors keep their distance.

Is there any treatment for toxoplasmosis?

Treatment is not usually needed. Healthy people with a strong immune system often recover on their own. In some cases, treatment may be needed, for example in people with a weakened immune system (such as people with HIV) or severe symptoms, such as an eye infection. A doctor can prescribe antibiotics to fight off the parasite.

How common is toxoplasmosis in the Netherlands?

The parasite Toxoplasma gondii is found all over the world. The exact levels of Toxoplasma vary in different regions. In the Netherlands, about 40% of the population have Toxoplasma antibodies in their blood. This means that they have had toxoplasmosis before – often without noticing it.

There is no information on how many people were exposed through meat and how many through cat faeces (found in contaminated soil or on vegetables). Toxoplasma antibodies are not found in the blood of all people who have a cat living in their home.