Toxoplasmosis is a parasitic disease caused by gondii toxoplasma, a representative of protozoa. It is most dangerous for pregnant women, as it can lead to fetal malformations and even death.

T. gondii is a microscopic parasite, the main host of which is a cat. It can also be found in the soil.

In most healthy people, this infection does not cause any symptoms or occurs in the form of mild flu-like diseases. In a fetus infected by the mother, or in a person with a weakened immune system, T. gondii can lead to severe complications.

T. gondii is very common. It is found all over the world, and in some countries up to 95% of the population is infected. According to WHO, about 23% of people over the age of 12 suffer from toxoplasmosis. Infection occurs when eating contaminated food (especially poorly cooked meat) or water, as well as when cleaning cat droppings, when transmitting infection from mother to child, and in rare cases during organ transplantation or blood transfusion.

The final owners for T. gondii are wild and domestic cats. After cats become infected by eating infected birds, rodents, or raw meat, T. gondii undergo a sexual development cycle that leads to the formation of eggs encased in a protective shell (oocyst). During the activity of the pathogen, millions of microscopic oocysts can be released in a few weeks in a cat with feces. They become contagious within two days and can remain viable for several months. In all other hosts, including humans, i.e. Gondii go through only a limited part of their life cycle, and then form inactive cysts in the muscles, brain, and eyes. The host's immune system protects the human body from further infection. The latent period can last for the entire life of the host until the immune system decreases.

Primary or repeated infection with T. gondii leads to pronounced symptoms of the disease in people with weakened immune systems, for example, in HIV/AIDS patients undergoing chemotherapy, patients after organ transplantation or taking immunosuppressants. The eyes and nervous system can be affected, which causes headaches, seizures, confusion, fever, encephalitis, loss of coordination and blurred vision.

When a pregnant woman becomes infected, the probability that the infection will be transmitted to the unborn child is 30-40%. Moreover, if infection occurs early in pregnancy, it can cause miscarriages, stillbirths, or lead to serious complications in newborns, including mental retardation, seizures, blindness, and enlargement of the liver or spleen. Many infected children, especially those who become infected closer to birth, are born healthy, but after a few years they develop severe eye infections, hearing loss, and mental retardation.

When a person comes into contact with T. gondii, their immune system reacts by producing antibodies against the parasite. Two types of antibodies to toxoplasma can be detected in the blood: IgM and IgG.

IgG antibodies are produced by the body a few weeks after initial infection to provide long-term protection. IgG levels increase during infection activity, and then stabilize as soon as the disease passes and the parasite becomes inactive. Once confronted with T. gondii, a person will have some measurable amounts of IgG antibodies in their blood throughout their life.

An IgM test will help confirm the presence of acute or past infection with toxoplasma.