Ocular toxoplasmosis
The parasite that causes toxoplasmosis can lie dormant (inactive) in the back of the eye (retina) for many years. If it becomes active again – for example, if you receive treatment that weakens your immune system – it can cause inflammation and scarring in the eye. This is known as ocular toxoplasmosis.
Ocular toxoplasmosis can affect one or both eyes and can cause:
blurred vision
floaters (small shapes floating in your field of vision)
reduced vision or loss of vision
Medications are usually given to treat the infection, and steroids are often used to reduce any swelling in your eye. The scarring caused by toxoplasmosis will not clear up, but treatment may prevent it getting worse.
Congenital toxoplasmosis
If a woman becomes infected with toxoplasmosis for the first time during pregnancy or a few weeks before conceiving, there's a risk the infection could spread to her unborn baby. This is known as congenital toxoplasmosis.
Congenital toxoplasmosis can cause a range of problems that are either noticeable from birth or develop months or years later. The severity of the condition varies depending on when the mother became infected.
The baby's symptoms will usually be more severe if the mother is infected early on in the pregnancy, and less severe if they're infected later on.
Problems caused by congenital toxoplasmosis can include:
hydrocephalus (fluid on the baby's brain)
brain damage
epilepsy – a condition that causes repeated seizures (fits)
ocular toxoplasmosis
jaundice – yellowing of the skin and the whites of the eyes
an enlarged liver or spleen
cerebral palsy – a condition that affects a child's movement and co-ordination
Early treatment of congenital toxoplasmosis may help reduce the risk of serious or long-term problems, although it cannot reverse damage that has already occurred.
Cerebral toxoplasmosis
If you have a weakened immune system and you become infected with toxoplasmosis, the infection can spread to organs such as your eyes and brain because your immune system may not be able to fight off the infection.
If toxoplasmosis begins to affect the brain, it can cause a serious and life-threatening infection called cerebral toxoplasmosis.
Signs and symptoms of toxoplasmosis encephalitis and toxoplasmosis infections in people with immune deficiency can include:
confusion
poor co-ordination
seizures (fits)
a high temperature (fever) of 38C (100.4F) or over
slurred speech
ocular toxoplasmosis
Medication can be used to treat the infection and reduce swelling in the brain, although it may not be able to cure the condition completely.
Toxoplasmosis can be serious if a woman becomes infected while she's pregnant or a few weeks before conceiving. This is because there's a chance the infection could be passed to her baby.
However, the risk of getting toxoplasmosis during pregnancy is very low. In the UK, it's estimated that less than 5 in every 1,000 pregnant women will become infected for the first time.
A woman won't usually have any symptoms if she becomes infected during pregnancy, but if the infection spreads to her baby, it can cause:
congenital toxoplasmosis – where the baby develops toxoplasmosis while they're developing in the womb
Congenital toxoplasmosis can cause serious problems that are either noticeable from birth or develop several months or years later, such as brain damage, hearing loss and vision problems.
Problems in people with weak immune systems
Toxoplasmosis can cause serious problems and be life-threatening for someone with a weakened immune system as their body may not be able to fight off the infection.
Your immune system may be weakened if you:
have an illness that affects your immune system, such as HIV and AIDS or some types of cancer
are having chemotherapy
are taking immunosuppressant medication – for example, after having an organ transplant
If your immune system is weak, the infection could spread to organs such as the eyes, heart, lungs and brain. This can cause problems such as headaches, confusion, poor co-ordination, seizures (fits), difficulty breathing and vision problems.
Source Gov.UK- NHS Choices
It does not appear the CDC is conducting or supporting studies on ticks in the USA for the presence of toxoplasmosis; however, researchers in Poland are studying the parasite and ticks harboring toxoplasma, therefore greatly contributing to our knowledge.
What isn't described on the CDC's list below is that ticks have been found to harbor the parasite that causes toxoplasmosis.
A Toxoplasma infection occurs by:
Eating undercooked, contaminated meat (especially pork, lamb, and venison).
Accidental ingestion of undercooked, contaminated meat after handling it and not washing hands thoroughly (Toxoplasma cannot be absorbed through intact skin).
Eating food that was contaminated by knives, utensils, cutting boards and other foods that have had contact with raw, contaminated meat.
Drinking water contaminated with Toxoplasma gondii.
Accidentally swallowing the parasite through contact with cat feces that contain Toxoplasma. This might happen by
cleaning a cat's litter box when the cat has shed Toxoplasma in its feces
touching or ingesting anything that has come into contact with cat feces that contain Toxoplasma
accidentally ingesting contaminated soil (e.g., not washing hands after gardening or eating unwashed fruits or vegetables from a garden)
Mother-to-child (congenital) transmission.
Receiving an infected organ transplant or infected blood via transfusion, though this is rare.