Ocular manifestations of systemic disease: toxoplasmosis

To provide an overview of ocular toxoplasmosis, the leading cause of infectious posterior uveitis, focusing on recent trends of disease epidemiology, pathogenesis, diagnosis, therapy and prevention.

Novel aspects of epidemiology, including growing importance of water transmission are discussed. The historical controversy of congenital versus postnatally acquired toxoplasmosis is revisited. Recent insights into pathogenesis of ocular toxoplasmosis are also reviewed, tipping the delicate balance between parasite virulence and host immunity. Diagnosis of ocular toxoplasmosis is also discussed in the light of serological, molecular and imaging tools. Finally, a critical analysis of current and emerging therapies for ocular toxoplasmosis is made. Preventive aspects are also commented upon.

Waterborne toxoplasmosis is increasingly recognized in outbreaks and in endemic areas. The importance of postnatally acquired toxoplasmosis is now well established, but should not lead to underestimation of congenital disease. Genetic determination of parasite virulence/individual susceptibility might correlate with disease outcomes. Serological, molecular and imaging tools may improve the diagnosis and follow-up of individuals with ocular toxoplasmosis. Despite emergence of alternative therapeutic regimens, including intravitreal antibiotics, classical therapy with sulfadiazine/pyrimethamine is still standard for toxoplasmic retinochoroiditis. Adequate prophylaxis is expected to have an effect in ocular burden of toxoplasmosis.