Cat parasite: Symptoms and causes of toxoplasmosis - Insider

• Toxoplasmosis is a parasitic disease that you can get from cats, contaminated food, and more.
• It causes symptoms similar to the flu, such as chills, fever, body aches, fatigue, and headaches.
• The parasite is especially dangerous for pregnant people, since it can be passed on to the fetus. 

Pets can be loving companions, but they can also pose some risks to humans, including the risk of spreading disease. Cats in particular can carry a parasite known as Toxoplasma gondii. 

This is one of the most common parasites in the world and more than 40 million Americans are estimated to carry it. One way humans can come into contact with this parasite is through cat feces that contain it, but that isn't the only way. You may also come into contact with Toxoplasma gondii by eating undercooked meat or drinking contaminated water.

The infection can develop into a disease that can be dangerous for certain groups, particularly for pregnant people and those with weakened immune systems.

Here's what you need to know about treating and preventing an infection. 

What is toxoplasmosis? 

Toxoplasmosis is a parasitic disease caused by the parasite Toxoplasma gondii (T. gondii). 

In healthy people with strong immune systems, a T. gondii infection may produce mild or no symptoms at all, says Dr. John Mourani, medical director of infectious disease at Pomona Valley Hospital Medical Center.

Those who do experience mild symptoms may mistake them for the flu or another viral infection since they typically include:

• Fever
• Chills
• Body aches
• Sore Throat
• Headaches
• Fatigue
• Enlarged lymph nodes 

For healthy individuals, these symptoms typically resolve on their own in about two to four weeks. However, for some groups, toxoplasmosis can cause more severe symptoms.

Who is most at risk for toxoplasmosis?

Anyone can become infected with toxoplasmosis, but pregnant people and those with weakened immune systems are most at risk for developing complications from toxoplasmosis, Mourani says. 

People who have recently received an organ transplant, are receiving chemotherapy, or have HIV/AIDS are considered immunocompromised and at an increased risk of more dangerous toxoplasmosis symptoms, including:

• Eye infections, which can lead to blindness if left untreated
• Seizures
• A life-threatening brain infection, known as encephalitis, which can be fatal

For pregnant people, toxoplasmosis can increase the risk of miscarriage or stillbirth, Mourani says. The pregnant person may also pass the infection on to the fetus, which can result in complications for the baby, including:

• Seizures
• An enlarged liver or spleen
• Jaundice, or yellowing of the skin and whites of eyes
• Eye infections 
• Hearing loss
• Mental disabilities

Signs of toxoplasmosis in infants may not be apparent at birth but develop later in life, sometimes not until their teenage years. 

Toxoplasmosis in cats

The T. gondii parasite doesn't discriminate: It will infect cats both wild and domestic. But toxoplasmosis rarely causes actual disease in these animals, says Dr. Jamie Whittenburg, lead veterinarian at Cat World and Director of Kingsgate Animal Hospital. 

Similar to humans, a cat infected with T. gondii typically shows no signs of disease, Whittenburg says. But if the cat has an underlying health issue, like cancer or feline leukemia, the immune system may fail to suppress the parasite, resulting in clinical signs of toxoplasmosis.

Mild symptoms of toxoplasmosis in cats include:

• Fever
• Loss of appetite
• Lethargy

Symptoms of more severe toxoplasmosis in cats include:

• Inflammation of the eye
• Jaundice
• Seizures
• Neurological symptoms, such as abnormal behavior
• Pneumonia

How do you get toxoplasmosis?

Toxoplasmosis is typically affiliated with cats since they are an essential part of the T.gondii life cycle, Mourani says. But there are actually a few different ways a human can get infected with the parasite and develop toxoplasmosis. These include:

• Contact with cat feces that contain the parasite. Cats can acquire toxoplasmosis by eating infected prey or raw meat. Once infected, cats then shed the parasite in their feces. You may accidentally ingest the parasite if you touch your mouth after cleaning a cat's litter box without washing your hands. The only way you can become infected from a cat with the parasite is by coming into contact with their feces. Petting an infected cat or letting them lick you will not result in an infection. 

• Contaminated meat or dairy. You can become infected by T. gondii by eating raw or undercooked meat, particularly lamb, pork, or venison as they are especially likely to be infected with the parasite. You may also expose yourself to the parasite if you use a contaminated cutting board, knife, or other utensils that have come into contact with the raw meat. Occasionally unpasteurized dairy products, like goat milk, may also contain the parasite, Mourani says. 
• Unwashed fruits and vegetables. Produce from the grocery store may also contain T. gondii and you can become infected by eating these foods without washing them first. To reduce your risk, thoroughly wash fruits and vegetables before eating them. 
• Contaminated soil. You may also come into contact with T. gondii by accidentally ingesting infected soil, says Dr. Nima Majlesi, director of toxicology at Staten Island University Hospital. This is most likely to occur if you don't wash your hands after gardening or you eat unwashed food from a garden. 
• Organ transplant or blood transfusion. Toxoplasmosis can be transmitted through an organ transplant or blood transfusion, though this is rare, Mourani says. 
• Parent-to-child (congenital) transmission. If a pregnant person gets infected during or just before pregnancy, they can pass it on to the fetus.

Treatment and prevention of toxoplasmosis

Treatment is typically not necessary for mild cases of toxoplasmosis as the immune system will fight off the infection and eradicate it from your system. 

If, however, you do experience symptoms, over-the-counter pain relievers and rest can help you feel better.  

For those with more severe cases, Majelsi says that a doctor will often suggest prescription medications including:

• Pyrimethamine, an anti-malaria drug considered to be the most effective in treating toxoplasmosis. 
• Sulfadiazine, an antibiotic used in combination with pyrimethamine.
• Clindamycin, an alternative antibiotic that may be used if the patient is sensitive to sulfa drugs.
• Leucovorin, a folic acid that protects the bone marrow from the toxic effects of pyrimethamine.

There are also steps you can take to minimize your risk of contracting toxoplasmosis. These include:

• Thoroughly cook meat before eating it. Poultry should reach a temperature of 165° F, while ground meat should reach a temperature of 160° F. Whole cuts of lamb, pork, venison, or beef should reach a temperature of 145° F..
• Wash hands, kitchen utensils, and cutting boards with soap and warm water, especially after contact with raw meat, produce from the grocery store, or fruits and vegetables from a garden.
• Wear gloves and wash hands after contact with cat litter. If you are pregnant or immunocompromised and at an increased risk of developing severe toxoplasmosis, try to have someone else clean the litter box. If someone else isn't able to clean the litter box for you, wear gloves and wash your hands thoroughly afterward.
• Feed your cat dry or canned food. Cats become infected with toxoplasmosis by eating contaminated raw meat, so if you feed your cat dry or canned food, you can minimize this risk.
• Keep your cat indoors. You can also reduce the risk of your cat eating an infected animal by keeping them indoors and away from stray cats or other animals. 

Insider's takeaway

Toxoplasmosis is a parasitic disease caused by the parasite Toxoplasma gondii (T. gondii). The disease often does not cause symptoms in healthy people, and if it does the symptoms are usually mild and resolve on their own.

Toxoplasmosis poses a risk of more severe complications for immunocompromised and pregnant people. These complications can include seizures and eye infections. For pregnant people, toxoplasmosis can increase the risk of miscarriage or stillbirth and potentially cause adverse outcomes for the baby, including mental disabilities and hearing loss.

Cats often carry the parasite and shed it in their feces, so you can become infected by touching your mouth after cleaning a cat's litter box. Eating raw or undercooked meat and unwashed produce can also result in an infection. 

To minimize your risk, wear gloves and wash your hands after cleaning a cat's litter box, thoroughly cook meat before eating, wash hands after gardening, and wash produce before eating. 

Erin Heger