TOXOPLASMOSIS is one of the most common parasitic diseases worldwide. Although estimated that one third of the world's population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic). On the other hand, recent findings indicated that latent TOXOPLASMOSIS is not only unsafe for human, but also may play various roles in the etiology of different mental disorders. This paper reviews new findings about importance of latent TOXOPLASMOSIS (except in immunocompromised patients) in alterations of behavioral parameters and also its role in the etiology of schizophrenia and depressive disorders, obsessive–compulsive disorder, Alzheimer's diseases and Parkinson's disease, epilepsy, headache and or migraine, mental retardation and intelligence quotients, suicide attempt, risk of traffic accidents, sex ratio and some possible mechanisms of T. gondii that could contribute in the etiology of these alterations.

TOXOPLASMOSIS is an important congenital disease, which may have dangerous consequences for the fetus, following the affliction of mother during pregnancy. The affliction risk of the fetus is usually about 50%, which is closely related to the trimester when the mother is contaminated. The risk amount of contamination increases with the term of pregnancy, but at the same time, the intensity and severity of contamination is reduced. Fetus contamination varies from syndrom-free infection to very severe neurologic pathologies. Moreover, abortion may occur during the first trimester of pregnancy. In this study, 2761 samples of the blood from umblical cords (1651 samples on programmed basis and 1110 samples on random basis) of the newborns at the time of birth, as well as the blood of all the children were sampled and tested at periodic intervals, according to the research program. The mothers blood was tested using IFAT method, while IgM/ISAGA method was used to test the blood of umblical cords of the newborns, and finally IgM/ISAGA, IgM/IFA and TOTAL/IFA methods were used to test the toxoplasmic children. The results show that from 18 cases of pregnancy contaminated with the parasite, one case ended to abortion, and eight cases caused fetus contamination. From the samples of umblical cords which were collected randomly, four cases were reported to be positive from the viewpoint of TOXOPLASMOSIS antibody. one infant died and the other three were contaminated. The Newborns contamination varies from subclinical congenital TOXOPLASMOSIS to cases with complications such as retinochoroidities, purpura, convulsions, diplopia, mental retardation, etc.

Introduction: Neuroretinitis (NR) is considered to be an inflammatory condition which is characterized by optic disc edema and, as a result, formation of a macular star figure. NR is an atypical presentation of TOXOPLASMOSIS infection, and such cases are quite rare.Case Presentation: A 13-year-old girl presented with painless subacute visual loss in her right eye for a week at Khatam-Al-Anbia eye hospital in Mashhad, Iran. Following comprehensive evaluation, a diagnosis of toxoplasmic NR was made. The NR favorably responded to classic anti-TOXOPLASMOSIS treatment. A juxtapapillary retinochoroidal scar appeared after disc swelling resolution.Conclusions: Although TOXOPLASMOSIS NR is rare, it should be considered in the differential diagnoses of NR.

TOXOPLASMOSIS is one of the essential zoonotic parasitic diseases caused by Toxoplasma gondii. TOXOPLASMOSIS may be asymptomatic or cause subclinical manifestations in immunocompetent people, but it is life-threatening in immunodeficient patients and causes serious problems, especially in the central nervous system. Furthermore, congenital toxoplasma is harmful to the fetus and may lead to abortion. Due to the above, knowing the parasite biology, the interaction between the parasite and the host immune system, and diagnostic methods is crucial to preventing harmful damage and finding better treatment. In this article, the taxonomy and morphology of T. gondii are reviewed, and the immunological characteristics of T. gondii are summarized. Due to the importance of an appropriate diagnosis, we summed up some of the diagnostic methods.