protozoan

Toxoplasma gondii (T. gondii) is a protozoan parasitizing all warm-blooded mammals, including humans. The main source of infection is contact with the feces of infected animals, particularly housecats the definitive hosts, in which T. gondii completes its life cycle. Alternative sources of infection are contact with and consumption of contaminated meat (particularly pork), transmission from mother to fetus, and infection by oocytes present in the soil or in polluted water. T. gondii is geographically ubiquitous; its level of seroprevalence is estimated to range from about 3% in South Korea to 76% in Costa Rica. Despite great efforts and considerable progress, toxoplasmosis remains a serious health threat worldwide. There is currently no available vaccine, and anti-toxoplasmosis drugs have substantial side effects and are not very effective. Furthermore, studies show that the parasite is able to develop resistance to them. Many recent studies have focused on how T. gondii is linked to psychiatric diseases and neurocognitive processes. Research has shown a correlation between T. gondii infection and schizophrenia.