Toxoplasmosis - Symptoms of toxoplasmosis

In most cases, toxoplasmosis doesn't cause any symptoms and a person is not aware they are infected.

In healthy children and adults, the immune system is usually strong enough to prevent the Toxoplasma gondii (T. gondii) parasite causing serious illness.

After a toxoplasmosis infection, most people are immune to further infection for the rest of their life. This means that if a woman who has previously been infected becomes pregnant, there will be no risk to her baby.

However, a blood test would be needed to check for immunity. You should also still take precautions if you're pregnant, such as wearing gloves while gardening or cleaning out your cat's litter tray.

Flu-like symptoms

In some cases, toxoplasmosis can cause the lymph nodes (glands that are part of your immune system) to swell, particularly in the throat or armpits. This can lead to flu-like symptoms, such as:

a high temperature (fever) of 38°C (100.4°F) or over
aching muscles
tiredness
feeling sick
sore throat

People who are otherwise healthy rarely experience any serious symptoms of toxoplasmosis.

Pregnancy

The risk of getting toxoplasmosis when you're pregnant is low. For example, a 2008 study showed that in non-immune pregnant women (those who haven't had the infection before), about 5 in 1,000 may get a toxoplasmosis infection.

However, if you develop toxoplasmosis when you're pregnant or shortly before conceiving, there's a risk that you'll pass it on to your baby. If a baby gets toxoplasmosis from their mother, it's known as congenital toxoplasmosis.

Although you probably won't experience any symptoms of the infection yourself, an infection that develops during the early stages of pregnancy also increases the risk of:

miscarriage – the loss of a pregnancy during the first 23 weeks
stillbirth – where a baby is born after 24 weeks of pregnancy without any signs of life

Congenital toxoplasmosis

The symptoms of congenital toxoplasmosis vary depending on when the mother becomes infected. The baby's symptoms will usually be more severe if the mother is infected around the time she became pregnant or during the first or second trimester (up to week 27 of the pregnancy).

Symptoms of toxoplasmosis in babies can include:

hydrocephalus – water on the brain
brain damage
epilepsy – a condition that affects the brain and causes repeated seizures (fits)
jaundice – yellowing of the skin and the whites of the eyes
deafness
eye infections and reduced vision
an enlarged liver or spleen (the organ that filters impurities from your blood)
growth problems
cerebral palsy – a brain and nervous system condition that affects a child's movement and co-ordination

If a mother becomes infected during the third trimester of pregnancy (from week 27 to birth) and the infection is passed on to her baby, the baby may not have any symptoms at birth.

However, complications may develop later in life. For example, months or years later a child born with congenital toxoplasmosis may develop reduced vision, hearing loss or learning difficulties.

Read more about the complications of congenital toxoplasmosis.

People with immune deficiencies

Toxoplasmosis can be fatal for someone with a weakened immune system. This is because their body may not be able to fight off the infection.

Your immune system can be weakened if you:

have an illness that affects your immune system, such as HIV and AIDS or cancer
are receiving certain types of medication, such as chemotherapy (powerful cancer-killing medication)
are taking immunosuppressant medication – for example, after having an organ transplant

There's also a risk of permanent eye or brain damage when toxoplasmosis infects someone with a weakened immune system.

If toxoplasmosis begins to affect the brain, it can cause encephalitis. This is sometimes called toxoplasmosis encephalitis (TE) and it can be fatal in people with AIDS.

Signs and symptoms of TE and toxoplasmosis in people with immune deficiency include:

headaches
confusion
poor co-ordination
seizures (fits)
chest pains
coughing up blood
difficulty breathing
a high temperature (fever) of 38°C (100.4°F) or over
vision problems, such as blurred vision and floaters (small pieces of debris that can cloud your vision)
multiple lesions (wounds) in the brain