[New trends in ocular toxoplasmosis--the review]

For past ten years some new trends can be observed in the field of ocular toxoplasmosis. In this article on the basis of reviewing scientific articles the author tried to point out important, or new information which may have an impact on clinical researches and clinical practice in the close future. 1. There is evidence that some tissue cysts can be present in untouched retinal tissue, and can produce an inflammatory reaction even many years after primary infection. This concerns both congenital and acquired toxoplasmosis. 2. The coexistence of intraocular inflammatory reaction without focal necrotizing retinochoroiditis in patients with acquired systemic toxoplasmosis was described--but there is no evidence that those inflammations were directly cause by T. gondii parasite themselves. It is too early to include this changes into the classical clinical picture of toxoplasmic retinochoroiditis. 3. For the past ten years there have been published articles showing higher prevalence of acquired ocular toxoplasmosis but this is well documented only in south America. In Europe and USA the frequency of ocular toxoplasmosis cases are low. Despite the different percentage of infected people in these populations, this controversial result can be caused by different distribution of pathogenic and non-pathogenic strains of the parasite as like by differences in human genotypes. 4. There is model of "dynamic equilibrium" existing between host defence and parasite cyst ruptures helpful for understanding reactivation. Level of tissue cyst-specific antigens does not rise in the population of HIV patients or during reactivation of ocular retinochoroiditis--this places the responsibility for reactivation on the side of host immunoresponse. 5. The most specific and reliable laboratory assessment for ocular toxoplasmosis, which is specifically helpful in clinically atypical cases, is combination of IgG, IgA and IgM serology tests made of serum and intraocular fluids. It can proof intraocular production of antibodies. PCR tests have got some value, but they are not as efficient as have been thought previously. 6. There is no efficient treatment diminishing recurrence rate and the time of singular inflammation yet. The combination of pyrimethamine, sulfadiazine and clindamycin, given for 3 to 4 weeks with supplementation of folinic acid for diminishing side effects, can diminish the measure of future scar. Long lasting treatment as it is used in children with congenital disease or in HIV patients can be probably more efficient. Atovaquone is as effective as traditional drugs and gives fewer side effects.