toxoplasmosis

Toxoplasmosis (pronounced tok-so-plaz-MOH-sis) is an infection caused by a tiny parasite. Many people never know they have it because it often causes no symptoms. When symptoms do appear, they can feel a bit like the flu, with swollen lymph nodes, muscle aches, or general tiredness. It can be more serious for pregnant women and for people with weakened immune systems.

People often connect this infection with cats because the parasite is spread through cat feces, but people can also get it from undercooked meat, unwashed food, or contaminated soil or water. In most healthy people, it stays quiet and does not cause major problems, but it matters more during pregnancy because it can affect an unborn baby.

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. This tiny organism can infect virtually all warm-blooded animals, including humans, and is surprisingly common worldwide. While it often remains dormant with no noticeable symptoms in healthy individuals—estimates suggest over 30 million people in the United States carry the parasite—it can cause flu-like illness, swollen lymph nodes, muscle aches, and even vision problems in some cases.

The most significant concern surrounding toxoplasmosis is its potential impact during pregnancy. If someone gets the infection for the first time during or just before pregnancy, the parasite can be passed to the unborn baby and may cause severe health problems. People with weakened immune systems, such as those undergoing chemotherapy, living with HIV, or recovering from an organ transplant, are also at higher risk of severe illness or a reactivation of a past infection.

The primary ways people become infected include eating undercooked, contaminated meat, accidentally swallowing the parasite after contact with cat feces or contaminated soil, and consuming contaminated food or water. Rarely, it can also spread through organ transplantation, blood transfusion, or from a newly infected mother to an unborn baby.

Researchers have also studied whether this infection may be linked to changes in behavior or reaction time, but the evidence in humans is still unclear. What is clear is that this is a common infection that is often silent but can sometimes affect the eyes, brain, or other organs. So, cook meat well, wash fruit and vegetables, clean your hands after handling raw food or soil, and take extra care around cat litter if you are pregnant or have a weakened immune system.