Toxoplasmosis is a common infection that usually occurs by eating infected meat or by exposure to the faeces (poo) of infected cats. It is usually harmless but can cause serious problems if you are pregnant or have a weak immune system.
- Toxoplasmosis is a disease caused by infection with the Toxoplasma gondii parasite, one of the world's most common parasites.
- It can cause serious problems for babies born to infected mothers and people with a weakened immune system.
- Toxoplasmosis may cause flu-like symptoms but most people affected do not develop any symptoms so don’t realise they have it.
- Toxoplasmosis infection can be detected by a blood test.
- If you are diagnosed with toxoplasmosis and you are pregnant or have lowered immunity you will be prescribed medicine.
Who is most at risk of toxoplasmosis?
Toxoplasmosis is normally harmless but in rare cases it can cause serious problems. Your risk is increased if:
- you get infected when you are pregnant – toxoplasmosis can cause miscarriage. If it spreads to your baby it can cause serious complications, especially if you catch it early in pregnancy. Read more about toxoplasmosis in pregnancy.
- your immune system is weakened – for example, if you have HIV, have recently had an organ transplant or you are having chemotherapy.
How do I know if I have toxoplasmosis?
Toxoplasmosis doesn’t normally cause symptoms and most people won’t know they have had it. Some people get flu-like symptoms, which normally get better on their own within about 6 days. Symptoms are more common and more severe in people with weakened immune systems. In these cases, symptoms may include confusion, seizures, poor coordination, blurred vision and lung pain.
If you have a weakened immune system, or are pregnant, and think you may be infected by toxoplasmosis, see your doctor. Toxoplasmosis can be diagnosed through a blood test. Your doctor can prescribe medicines to treat the infection if necessary.
Once you have had toxoplasmosis you are normally immune for the rest of your life.
How is toxoplasmosis treated?
If you think you may have been exposed to toxoplasmosis infection and you are pregnant or have a weakened immune system, see your doctor. They will take a blood test to check for infection. If the laboratory results confirm infection, your doctor will usually recommend treatment with one or more medications.
Read more about treating toxoplasmosis in pregnancy.
How can I prevent getting toxoplasmosis?
The parasite that causes toxoplasmosis is found in infected meat and in the faeces (poo) of infected cats. It can also be present in soil contaminated by infected cat poo.
Image credit: Canva
If you are pregnant or have a weakened immune system:
- don’t eat raw or undercooked meat, or cured meats, such as salami or ham
- don’t have unpasteurised milk or any products made from it
- wear gloves while emptying cat litter trays and empty them every day (the Toxoplasma parasite does not become infectious until 1 to 5 days after it is shed in a cat’s poo).
- wear gloves while gardening
- wash your hands before preparing food and eating
- wash hands, knives and chopping boards thoroughly after preparing raw meat
- wash fruit and vegetables thoroughly to get rid of any traces of soil
- cover children’s sandboxes.
Toxoplasmosis in pregnancy Health Navigator, NZ, 2018
Toxoplasmosis NHS Choices, UK, 2017
- Toxoplasmosis Mayo Clinic, US
- Toxoplasmosis Centers for Disease Control and Prevention, US, 2017
||Dr Jeremy Tuohy is an Obstetrician and Gynaecologist with a special interest in Maternal and Fetal Medicine. Jeremy has been a lecturer at the University of Otago, Clinical leader of Ultrasound and Maternal and Fetal Medicine at Capital and Coast DHB, and has practiced as a private obstetrician. He is currently completing his PhD in Obstetric Medicine at the Liggins Institute, University of Auckland.
Toxoplasmosis and pregnancy
Toxoplasmosis infection during pregnancy can be very serious. Care must be taken to avoid exposure to the parasite that causes it.
- Toxoplasmosis is an infection caused by a common parasite called Toxoplasma gondii.
- If you are pregnant and get toxoplasmosis, you can pass the infection on to your developing baby.
- Infected babies commonly develop serious complications, including visual and learning problems.
- You can get toxoplasmosis by eating raw or undercooked meat or by contact with infected cat faeces (poo).
- There are some simple precautions that you can follow to reduce your chances of becoming infected.
How do I know if I have toxoplasmosis?
Toxoplasmosis is not routinely tested for during pregnancy in New Zealand. You may request a blood test from your GP if you feel you may have put yourself at risk or you are concerned about symptoms.
Blood tests for toxoplasmosis can be done at any stage before or during pregnancy.
How do I know if my baby has been infected?
If your blood test results come back positive for toxoplasmosis, further tests can be carried out to find out if your baby has been infected. Your doctor will discuss the risks and benefits of conducting these tests. The most common test is amniocentesis. This is a technique where amniotic fluid is removed by a fine needle from the amniotic sac – the fluid-filled sac around the baby. This procedure carries a 0.5–1% chance of causing miscarriage.
How likely is it that I will pass toxoplasmosis on to my baby?
The risk and severity of the baby’s infection depend upon when in pregnancy the infection occurs.
- You are more likely to pass the infection on to your baby if you become infected later in your pregnancy. Studies suggest that when mothers are infected in the first trimester, about 15% of fetuses become infected, as compared to about 30% in the second trimester and about 60% in the third.
- However, the earlier in pregnancy the infection occurs, the more serious the baby’s symptoms tend to be.
Once you have had toxoplasmosis you are normally immune for the rest of your life. If you have been infected with Toxoplasma before becoming pregnant your unborn child will most likely be protected by your immunity.
How does toxoplasmosis affect a newborn?
Most newborn infected with toxoplasmosis during pregnancy do not show any symptoms. However, 1 in 10 babies will be born with signs of infection, such as eye infection, enlarged liver or spleen, jaundice or pneumonia. Some die within a few days of birth. Others develop impaired eyesight, mental retardation, hearing loss and other problems. Without treatment, up to 85% of babies born with toxoplasmosis infection will go on to develop problems months to years later. Toxoplasmosis can also cause stillbirth or pre-term delivery.
How is toxoplasmosis in pregnancy treated?
If you think you may have been exposed to toxoplasmosis infection and you are pregnant see your doctor. They will take a blood test to check for infection. If the laboratory results confirm infection, your doctor will usually recommend treatment with one or more medications.
- If you are in your first or early in your second trimester of pregnancy you may be treated with an antibiotic called Spiramycin. Some studies suggest that Spiramycin can reduce the likelihood of the fetus becoming infected by about 60%.
- If you are 18 weeks or more pregnant, your doctor may recommend an amniocentesis to see if the fetus is infected. If your doctor thinks the fetus is infected, she or he will treat the mother with the drugs Pyrimethamine and Sulfadiazine. Pyrimethamine is not recommended before 18 weeks of pregnancy because it may increase the risk of birth defects. These medications appear to reduce the number and severity of the newborn’s symptoms.
How can I avoid catching toxoplasmosis?
Follow these helpful tips to reduce your risk of exposure to Toxoplasma.
When eating or preparing food:
- only eat meat that has been thoroughly cooked (i.e., with no trace of blood or pinkness)
- avoid raw meat and cured meat, such as salami or ham
- wash your hands, kitchen utensils and chopping board thoroughly after preparing raw meat
- wash all fruit and vegetables thoroughly before cooking/eating to remove all traces of soil
- avoid unpasteurised milk and dairy products made from it.
If you have a cat:
- avoid changing cat litter if possible – if no one else can perform the task, wear disposable gloves and wash your hands with soap and water afterwards
- ensure that the cat litter box is changed daily – the Toxoplasma parasite does not become infectious until 1 to 5 days after it is shed in a cat’s poo
- feed your cat commercial dry or canned food, not raw or undercooked meats
- keep cats indoors, so they cannot eat infected rodent, birds or other small animals
- avoid stray cats, especially kittens and do not get a new cat while you are pregnant
- keep outdoor sandboxes covered.
- wear gloves during contact with soil or sand because it might be contaminated with cat poo that contains Toxoplasma
- wash your hands with soap and water after gardening or contact with soil or sand.