Toxoplasmosis - one of the world´s most widespread parasitic diseases
August 8 is International Cat Day. On this occasion, SAS scientists looked closely at a disease often associated with these animals. Toxoplasmosis is caused by Toxoplasma gondii, a microscopic parasite. It is reported that 10% - 60% of people worldwide are infected, depending on hygiene and dietary habits. According to surveys conducted by SAS parasitologists, an average of 21% of adults in Slovakia are infected.
"The infection usually does not manifest itself in humans at all or takes the form of a mild, flu-like illness. It can cause problems if a woman becomes infected during pregnancy, when the foetus can be damaged, or she may even have a miscarriage. Another risk group is people with weakened immunity, who can develop a serious, sometimes even fatal disease," says parasitologist Daniela Antolová from the Institute of Parasitology SAS.
Humans can contract toxoplasmosis by eating food, drinking water or accidentally ingesting soil that has been contaminated with cat faeces. The same is true when consuming raw or insufficiently heat-treated meat from animals that have been infected with Toxoplasma gondii. However, scientists emphasize that healthy immunocompetent people and pregnant women who have been exposeto infection in the past and have positive antibodies against Toxoplasma gondii cannot become infected again.
"The cat is the definitive host of the parasite which lives in its intestine. During the acute phase of infection, it excretes a huge amount of oocysts (eggs) in the faeces into the environment, which are infectious for humans, cats, and all kinds of warm-blooded animals. This phase of excreting oocysts lasts an average of two weeks. After this period, toxoplasma migrates to the cat's muscles and organs, where it encapsulates itself, and the cat ceases to be dangerous to humans. Therefore, there is no reason to panic," explains the parasitologist.
A study conducted in Switzerland showed that less than 1% of cats excrete oocysts into the environment. This is also confirmed by the results of SAS parasitologists - out of 750 cats examined in 2022, T. gondii oocysts were confirmed in only six animals.
"Cats that are kept exclusively indoors and are not fed raw meat pose virtually no risk to humans. It is unlikely that you will become infected by touching an infected cat because the oocysts are not usually found on the cat's fur and take at least 2 to 4 days after leaving the body in the faeces to become infectious," adds the scientist.
As a prevention, parasitologists recommend washing fruits and vegetables that could be contaminated with soil and thus potentially with cat faeces. During heat treatment, the temperature inside the meat should reach a minimum of 70 °C for 3 minutes. Toxoplasma can also be destroyed by freezing to -20 °C for at least 3 days.