Factors of occurrence of ocular toxoplasmosis. A review

Abstract

Diagnosis is usually based on ophthalmological examination and is confirmed by the response to specific treatment, but also by biological assays including local antibody production, PCR and Western Blot (RobertGangneux et al., 2004; Talabani et al., 2009;Villard et al., 2003). The incidence and the prevalence of this com-The incidence and the prevalence of this complication are difficult to establish precisely. In 1993, a survey in a French hospital service of ophthalmology showed that OT was seen in less than one per thousand outpatients (Dupouy-Camet et al., 1995). In another study performed in Germany, Jakob et al. (2009) reported that toxoplasmosis accounted for 4.2 % of all cases of uveitis at their referral centre. Jones et al. (2010) estimated that 4,839 people develop symptomatic OT each year in the United States. Ocular toxoplasmosis is a complication of both acquired acute and reactivated congenital toxoplasmosis (Delair et al., 2008;Holland, 1999; Stanford et al., 2006). Ocular disease severity can be influenced by variation in parasite isolates, parasitic load, route of infection and host-related factors such as immune function, age and pregnancy. FACTORS OF OCCURENCE OF OCULAR TOXOPLASMOSIS (OT)ot complicates not only congenital but also acquired inFections C lassically, retinochoroiditis secondary to acquired toxoplasmosis was considered an exceptional event in immunocompetent individuals, and was usually defined as a periodic reactivation of latent cysts associated with undiagnosed congenital infections. But recent data, based on ophthalmological examination, seem to establish that acquired infection might be responsible for most cases. This fact was particularly demonstrated by outbreaks reported in Canada, Brazil or India. In Canada, amongst 100 individuals infected during a water-borne outbreak, 19 had OT (Bowie et al., 1997). In southern Brazil 17.7 % of 1,042 individuals examined had OT. The prevalence of the lesions was 0.9 % in 1-to 8-year-olds and 21.3 % in all individuals older than 13, suggesting that in this population, the Summary: Acquired and congenital toxoplasmosis are frequently complicated by ocular toxoplasmosis. The diagnosis relies on clinical aspects, response to specific treatment and results of biological assays. The incidence and the prevalence of this complication are difficult to establish precisely and depend on the prevalence of the parasite infection in the general population, and are affected by factors such as type of exposure to the parasite, genetic backgrounds of the parasite and the host, and type of immune response elicited by the parasite.KEY WORDS: toxoplasmosis, Toxoplasma, eye, retinochoroiditis.Article available at http://www.parasite-journal.org or http://dx.doi.org/10.1051/parasite/2010173177 TALABANI H., MERGEY T., YERA H. ET AL. 178 Parasitic zoonoses in EuropeParasite, 2010, 17, 177-182 disease was a sequela of postnatal rather than congenital infection (Glasner et al., 1992). In India, Balasundaram et al. (2010) described ocular involvement due to t...

Phosphodiesterase Inhibitors as a New Generation of Antiprotozoan Drugs: Exploiting the Benefit of Enzymes that are Highly Conserved Between Host and Parasite

“…Here, the infection constitutes a risk for the developing fetus. In addition, the newborn may contract perinatal ocular toxoplasmosis during birth [34]. Early in pregnancy, the macrolide antibiotic spiramycin is often used to minimize the danger of transplacental infection of the fetus.…”

Clinical pattern of ocular toxoplasmosis treated in a referral centre in Serbia

“…2 Formerly considered to result mainly from congenital infection, 3 OT has in the past decades been well established to occur both after congenital and acquired infection. 1,2,[4][5][6][7] Indeed, a greater frequency of acquired than congenital infection in the origin of OT has been reported in several clinical series, both in Europe and in South America. [4][5][6] However, it appears that congenital infections cause a more severe OT.…”

Serologic, Molecular, and Pathologic Survey of Toxoplasma Gondii Infection in Free-Ranging Red Foxes (Vulpes Vulpes) in Central Italy

“…Toxoplasma gondii infection occurs worldwide in both livestock and humans and it is one of the most common zoonotic protozoa in humans, with prevalences ranging from 20-80% (Tenter et al, 2000). Toxoplasmic retinochoroiditis is the most common cause of posterior uveitis worldwide (Talabani et al, 2010). Congenital toxoplasmosis may cause abortion or fetal abnormalities (Montoya and Remington, 2008).…”