Which are the causes of Toxoplasmosis?

Toxoplasmosis is an infectious disease caused by the parasite Toxoplasma gondii. This parasite is found worldwide and can infect humans as well as a wide range of warm-blooded animals, including birds and mammals. Toxoplasmosis is considered one of the most common parasitic infections globally, affecting millions of people each year.

T. gondii has a complex life cycle involving both intermediate and definitive hosts. The primary modes of transmission to humans include:

1. Ingestion of contaminated food or water: The most common route of infection is through the consumption of undercooked or raw meat, particularly pork, lamb, and venison, that contains tissue cysts of the parasite. Additionally, consuming unwashed fruits and vegetables contaminated with oocysts shed in cat feces can also lead to infection.



2. Direct contact with cat feces: Cats are the definitive hosts of T. gondii, meaning they are the only animals in which the parasite can complete its sexual cycle. Handling cat litter or soil contaminated with infected cat feces, or even accidentally ingesting oocysts after touching contaminated surfaces and then touching the mouth, can result in infection.



3. Transplacental transmission: Pregnant women who are infected with T. gondii can transmit the parasite to their unborn child through the placenta. This is known as congenital toxoplasmosis and can lead to severe complications in the developing fetus.



4. Organ transplantation or blood transfusion: Although rare, transmission of T. gondii can occur through organ transplantation or blood transfusion from an infected donor.

It is important to note that T. gondii can also be transmitted through other routes, such as laboratory accidents, consumption of contaminated unpasteurized milk, or through contaminated soil. However, these modes of transmission are relatively uncommon compared to the ones mentioned above.

Several factors can influence the risk of acquiring toxoplasmosis. These include:

• Geographical location: The prevalence of T. gondii infection varies across different regions of the world. Factors such as climate, cultural practices, and food habits can contribute to the differences in infection rates.



• Food habits: Individuals who consume raw or undercooked meat, particularly from animals that have been infected with T. gondii, are at a higher risk of acquiring the infection. Similarly, eating unwashed fruits and vegetables can also increase the chances of contamination.



• Exposure to cats: People who have close contact with cats, especially those that have access to the outdoors and hunt, are more likely to come into contact with T. gondii oocysts shed in their feces.



• Immune status: Individuals with weakened immune systems, such as those with HIV/AIDS, undergoing chemotherapy, or organ transplant recipients, are more susceptible to severe forms of toxoplasmosis due to their compromised ability to fight off the infection.

It is worth mentioning that T. gondii can also infect animals that are part of the food chain, such as livestock and poultry. This highlights the importance of proper food handling, cooking, and hygiene practices to reduce the risk of infection.

In conclusion, the causes of toxoplasmosis primarily revolve around the ingestion of T. gondii through contaminated food or water, direct contact with cat feces, transplacental transmission, and, although rare, through organ transplantation or blood transfusion. Various factors, including geographical location, food habits, exposure to cats, and immune status, can influence the risk of acquiring the infection. By understanding these causes and taking appropriate preventive measures, individuals can reduce their chances of contracting toxoplasmosis.