Toxoplasmosis: new challenges for an old disease

Abstract

More than a century after the identification of Toxoplasma gondii, major issues need to be addressed for the optimal management of ocular disease. Toxoplasmic retinochoroiditis is the main cause of posterior uveitis in several geographical areas. The parasite establishes a love-hate relationship with the eye, manipulating the immune response and inducing variable initial lesions and further relapses. It is now well established that most cases are acquired after birth and not congenital. The severity of the disease is mainly due to the parasite genotype and the host immune status. Diagnosis is based on clinical features, but may be confirmed by biological tools applied to ocular fluids. Combining several techniques improves the diagnostic yield in equivocal cases. Therapeutic management is the most important challenge. Even though evidencebased data on the efficacy of anti-parasitic drugs are still missing, new strategies with a good safety profile are available and may be proposed earlier during the course of the disease, but also in selected cases, to reduce sight-threatening relapses. Revisiting the therapeutic options and indications may be an important step towards long-term maintenance of the visual function and avoidance of major complications.

Ocular Toxoplasmosis: A Case Report

“…These then are transmitted to the fetus through the placenta. If the disease is acquired during the first quarter of pregnancy, severe manifestations such as hydrocephalus, microcephaly, cranial calcifications and mental retardation and even spontaneous abortion may occur [3,4]. Significant visual impairment occurs in many of the congenital cases [2].…”

“…Approximately 75% of cases are do not show any obvious clinical signs at birth [5], and are only detected during the first few months of life. However, if the mother became infected prior to becoming pregnant, toxoplasma gondii is not transmitted to the fetus [1][2][3]6]. Congenital infection has an incidence between 1 in 10,000 live births in USA; 1 in 1000 in Europe to 1 in 770 in Brazil [2].…”

“…Toxoplasma gondii is a protozoa parasite, which utilises cat as the final host, but also other animals such as mice, cows, sheep and pigs as well as humans, like intermediate hosts [2,3]. The three main forms of the parasite are: oocyst (spore form that is excreted in cat feces), tachyzoite (actively proliferating) and bradyzoite (inactive form that becomes encysted in the tissues) [1][2][3].…”

“…The three main forms of the parasite are: oocyst (spore form that is excreted in cat feces), tachyzoite (actively proliferating) and bradyzoite (inactive form that becomes encysted in the tissues) [1][2][3].…”

“…Toxoplasmosis can be congenital or acquired [1], with a higher impact in terms of public health and similar ocular morbidity [2,3]. This report summarizes the most relevant aspects of this relatively rare disease related to optometric and primary care provider practice, and describes the (non-expected) findings in a routine follow-up visit of a contact lens (CL) patient.…”