Toxoplasmosis: Symptoms, Transmission & Treatment

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. It can be picked up from cat feces, contaminated water, or undercooked meat (such as pork or lamb) that contains the parasite.

Toxoplasmosis is most often spread by swallowing food or water contaminated with parasite cysts or by accidentally ingesting the parasite after contact with feces from infected cats. It can also be passed from mother to baby during pregnancy if the infection is not diagnosed or treatment is not done correctly.

Most people have no symptoms, but symptoms can appear in people with weakened immune systems. Even without symptoms, it is important to diagnose and treat toxoplasmosis as directed by a doctor to help prevent complications such as blindness, seizures, and, in severe cases, death.

Main symptoms

The main symptoms of toxoplasmosis are:

• Swollen lymph nodes, especially in the neck area;

• Fever;

• Muscle or joint pain;

• Fatigue;

• Headache and sore throat;

• Red spots or rash on the body;

• Trouble seeing.

In most cases, toxoplasmosis causes no symptoms. However, when a person’s immune system is weakened, symptoms may develop. This is more likely in people undergoing chemotherapy for cancer, recent transplant recipients, those living with HIV, or pregnant individuals.

In more severe cases, toxoplasmosis can interfere with how organs like the lungs, heart, liver, and brain work. This can cause shortness of breath, cough, severe headache, dizziness, extreme tiredness, sleepiness, delirium, and reduced strength and movement in the body.

Confirming a diagnosis

Toxoplasmosis is diagnosed by a primary care provider or an infectious disease specialist, who assesses your symptoms and orders a blood test to check for antibodies your body produces in response to the parasite that causes the infection. According to the Centers for Disease Control and Prevention (CDC), diagnosis is usually made by detecting Toxoplasma-specific antibodies in blood, such as IgG and IgM.

For pregnant women who test positive for toxoplasmosis antibodies, the obstetrician may recommend amniocentesis after 15 weeks of pregnancy to determine whether the infection has passed from mother to baby. Although ultrasound cannot confirm a diagnosis of toxoplasmosis in the fetus, it may still be ordered to look for possible signs of the infection, such as hydrocephalus.

How it's transmitted

The main ways to get toxoplasmosis are:

• Drinking contaminated water;

• Eating raw, poorly washed, or undercooked foods, such as pork, beef, lamb, or venison contaminated with T. gondii;

• Eating smoked meats or cured/processed meats made from animals contaminated with the parasite that were not prepared under appropriate hygiene conditions;

• During pregnancy, if the parasite crosses the placenta.

According to the CDC, people most commonly get toxoplasmosis by eating undercooked meat or consuming food or water contaminated with cat feces, and infection can also be passed from mother to fetus during pregnancy

Contact with an infected cat alone is not enough to transmit toxoplasmosis. A person must come into contact with cat feces, which can happen through accidental ingestion of the parasite present in feces. For this reason, when cleaning a litter box, it is important to take protective measures such as wearing gloves and a mask, and washing hands thoroughly afterward.

Different types

Toxoplasma gondii can be classified into types based on the organ affected by the parasite. The main types are:

1. Ocular toxoplasmosis

Ocular toxoplasmosis happens when the parasite affects the eye and damages the retina, causing inflammation. If it is not treated in time, it can lead to blindness. It can affect both eyes, and vision problems may be different in each eye, including decreased vision, eye redness, or eye pain.

This complication is more likely in babies as a result of infection during pregnancy, especially if the fetus is infected early in pregnancy. It can also occur in people with more compromised immune systems, although it is less common.

2. Congenital toxoplasmosis

Toxoplasmosis during pregnancy can lead to congenital toxoplasmosis, which is when the baby is infected while still in the womb. Toxoplasmosis during pregnancy can lead to serious complications, including fetal malformations, low birth weight, premature birth, miscarriage, or stillbirth.

Consequences for the baby vary based on the stage of pregnancy when the infection occurs, with a higher risk of complications when infection happens closer to the end of pregnancy.

Complications can include eye inflammation, severe jaundice, enlarged liver, anemia, heart changes, seizures, and breathing problems. In addition, neurological changes may occur, such as developmental delay, hearing loss, and microcephaly or macrocephaly.

3. Cerebral toxoplasmosis (meningoencephalitic form)

This type of toxoplasmosis is more common in people diagnosed with AIDS and is usually linked to reactivation of T. gondii cysts in people with a latent infection. This means the person was diagnosed and treated, but the parasite was not eliminated from the body, allowing it to reach the nervous system.

The main symptoms of this type of toxoplasmosis are headache, fever, loss of muscle coordination, confusion, seizures, and extreme fatigue. If it is not identified and treated, the infection can lead to coma and become life-threatening.

Treatment options

Most healthy people do not need treatment for toxoplasmosis, because the body can fight the parasite naturally. However, when symptoms are present, treatment should be done with medications prescribed by a doctor, such as pyrimethamine, sulfadiazine, and folic acid, used together as directed.

In pregnant women, depending on the stage of pregnancy, treatment may be done with the antibiotic spiramycin or with pyrimethamine, sulfadiazine, and folic acid, as directed by the obstetrician.

Does toxoplasmosis have a cure?

Toxoplasmosis is a curable infection that often resolves without specific treatment. However, it is important to see a doctor, especially for pregnant individuals and those with weakened immune systems, so the most appropriate treatment can be recommended to control the infection and ensure full recovery.

Prevention measures

To help prevent toxoplasmosis, taking the following precautions is important:

• Drink safe water (filtered or bottled);

• Cook meats thoroughly and avoid eating undercooked meat at restaurants;

• Wash kitchen utensils well with hot water and soap, such as cutting boards and knives, after seasoning or cutting raw meat to avoid contaminating other foods;

• Wash fruits and vegetables well with water and soap, or use a solution made with 1 liter of water and 1 tablespoon of baking soda or household bleach, and soak for about 15 minutes;

• Wear gloves when gardening or caring for plants;

• Avoid contact with cat feces and wear gloves and a mask when cleaning the litter box or picking up feces;

• Cover children’s sandboxes to prevent cats from using them as a litter area.

People who have pets should take them to a veterinarian for testing to identify the toxoplasmosis parasite and to treat the animal if needed, helping prevent possible transmission of toxoplasmosis and other diseases.