Cristina Muccioli

Genetic Divergence of Toxoplasma gondii Strains Associated with Ocular Toxoplasmosis, Brazil

Brazilian strains of T. gondii differ from lineages in North America and Europe; these differences may underlie severe ocular disease.

The progressive outer retinal necrosis syndrome. A variant of necrotizing herpetic retinopathy in patients with AIDS.

BACKGROUND The progressive outer retinal necrosis syndrome is a recently recognized variant of necrotizing herpetic retinopathy. This report characterizes more fully its clinical features and course. METHODS Using standardized clinical criteria, patients with progressive outer retinal necrosis syndrome from four institutions were identified. Patient records were reviewed retrospectively for the following data: medical and demographic characteristics, presenting symptoms, physical findings, course, responses to treatment, and outcomes. RESULTS Thirty-eight patients (65 involved eyes) were studied. All had acquired immune deficiency syndrome. A known history of cutaneous zoster was documented in 22 (67%) of 33 patients. Median CD4 lymphocyte count was 21/mm3 (range, 0-130/mm3). Median follow-up was 12 weeks. The most common presenting symptom was unilateral decreased vision (35 of 65 eyes, 54%); median visual acuity at presentation was 20/30 (range, 20/20 to no light perception [NLP]). Anterior chamber and vitreous inflammatory reactions were absent or minimal in all patients. Typical retinal lesions were multifocal, deep opacities scattered throughout the periphery, although macular lesions also were present in 21 eyes (32%) at diagnosis. Lesions progressed rapidly to confluence. Initial intravenous antiviral therapy appeared to reduce disease activity in 17 (53%) of 32 eyes, but treatment did not alter final visual outcome. Visual acuity was NLP in 42 (67%) of 63 eyes within 4 weeks after diagnosis. Retinal detachment occurred in 43 (70%) of 61 eyes, including 13 (93%) of 14 eyes that received prophylactic laser retinopexy. CONCLUSION The progressive outer retinal necrosis syndrome is characterized by features that distinguish it from cytomegalovirus retinopathy, acute retinal necrosis syndrome, and other necrotizing herpetic retinopathies. Visual prognosis is poor with current therapies.

The effect of Long-term intermittent trimethoprim/sulfamethoxazole treatment on Recurrences of toxoplasmic retinochoroiditis

PURPOSE To determine the effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis. DESIGN Prospective randomized open-labeled interventional clinical trial. METHODS A total of 124 patients with a history of recurrent toxoplasmic retinochoroiditis were randomized to treatment with one tablet of trimethoprim (160 mg)/sulfamethoxazole (800 mg) (Bactrim F; Roche Pharmaceuticals, Rio de Janeiro, Brazil) every 3 days (61 patients) or to observation without treatment (63 patients) and were followed monthly for up to 20 consecutive months for clinical signs of disease recurrence. A recurrence was defined as a new focus of necrotizing retinochoroiditis with active inflammation either adjacent to or remote from preexisting retinochoroidal scars. RESULTS Recurrences developed in four (6.6%) treated patients and in 15 (23.8%) controls (P =.01). Treatment was discontinued prematurely in four patients because of mild drug reactions. CONCLUSION Long-term intermittent treatment with trimethoprim/sulfamethoxazole can reduce the rate of recurrent toxoplasmic retinochoroiditis.

A follow-up study of Toxoplasma gondii infection in southern Brazil ☆

PURPOSE To understand better the natural history of ocular toxoplasmosis by reexamining a well-characterized population in Southern Brazil. METHODS Ophthalmological examination and serologic tests for Toxoplasma gondii infection were performed in 1997 on 383 individuals who had undergone the same evaluation in 1990. RESULTS Of 109 seronegative subjects in 1990, 21 (19.3%) became seropositive by 1997, and 2 (1.5% of previously seronegative patients; 9.5% of those known to have seroconverted) developed ocular toxoplasmosis. Seroconversion occurred more frequently in individuals under 17 years of age (16 of 46 patients, 34.8%) than in those greater than 17 years of age (5 of 63 patients, 7.9%; p = 0.002). Of 131 seropositive individuals who did not have ocular lesions in 1990, 11 (8.3%) had typical toxoplasmic lesions in 1997. Of the 13 individuals with non-specific hyperpigmented small retinal lesions in 1990, 3 (23%) presented with typical lesions in 1997. CONCLUSIONS Acquired T. gondii infection can result in late development of ocular lesions. Small, non-specific hyperpigmented retinal lesions may represent sites of T. gondii infection in seropositive individuals.

Ocular toxoplasmosis: an update and review of the literature

Ocular toxoplasmosis is the most common cause of posterior uveitis worldwide. The infection can be acquired congenitally or postnatally and ocular lesions may present during or years after the acute infection occur. Current treatment controls ocular infection and inflammation, but does not prevent recurrences. We present a review and update on ocular toxoplasmosis and address misconceptions still found in the current medical literature.

Recently acquired Toxoplasma gondii infection, Brazil.

Soil exposure, eating undercooked meat, and having children are risk factors for acute infection and high rate of eye disease.

Identification of an Atypical Strain of Toxoplasma gondii as the Cause of a Waterborne Outbreak of Toxoplasmosis in Santa Isabel do Ivai, Brazil

Multilocus DNA sequencing has identified a nonarchetypal strain of Toxoplasma gondii as the causal agent of a waterborne outbreak in Brazil in 2001. The strain, isolated from a water supply epidemiologically linked to the outbreak, was virulent to mice, and it has previously been identified as BrI. Using a serologic assay that detects strain-specific antibodies, we found that 13 (65%) of 20 individuals who were immunoglobulin (Ig) M positive during the outbreak possessed the same serotype as mice infected with the purported epidemic strain. The remaining 7 individuals, plus additional IgM-negative, IgG-positive individuals, possessed 1 of 4 novel serotypes, the most common of which matched the serotype of mice infected with strains isolated from chickens foraging near the outbreak site. The latter strains likely reflect the genetic diversity of T. gondii circulating in highly endemic regions of Brazil. The serotyping assay proved a useful tool for identification of specific individuals infected with the outbreak agent.

Postoperative wavefront analysis and contrast sensitivity of a multifocal apodized diffractive IOL (ReSTOR) and three monofocal IOLs.

PURPOSE To compare visual acuity, total and high order wavefront aberrations (coma, spherical aberration, and other terms of high order aberration), and contrast sensitivity in 105 eyes implanted with 4 different types of intraocular lenses (IOLs) (1 multifocal apodized diffractive IOL and 3 monofocal IOLs). METHODS A prospective study comparing four types of IOLs (Alcon ReSTOR [50 eyes], Alcon Acrysof MA30AC [20 eyes], Alcon Acrysof SA60AT [20 eyes], and Mediphacos Acqua IOL [15 eyes]) was carried out. All eyes were targeted for emmetropia. Complete ophthalmological examination, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity (Pelli-Robson chart), and wavefront analysis, was performed 2 months postoperatively. RESULTS All eyes in all groups had BSCVA > or = 20/32 postoperatively. Mean total aberration root-mean-square (RMS) values were: 0.72 +/- 0.25 microm (ReSTOR), 0.94 +/- 0.26 microm (MA30), 0.84 +/- 0.23 microm (SA60), and 2.04 +/- 0.77 microm (Acqua). Mean higher order aberration values were: 0.35 +/- 0.15 microm (ReSTOR), 0.41+/- 0.12 microm (MA30), 0.43 +/- 0.13 microm (SA60), and 0.85 +/- 0.50 microm (Acqua). The Acqua IOL showed statistically significant more total and higher order aberrations when compared with the other IOLs (P < .05). The ReSTOR IOL showed statistically significant less induction of spherical aberration when compared to the monofocal IOLs (P < .05). Mean contrast sensitivity values were: 1.64 +/- 0.08 (ReSTOR), 1.72 +/- 0.08 (MA30), 1.70 +/- 0.07 (SA60), and 1.65 +/- 0.11 (Acqua). CONCLUSIONS Different types of IOLs resulted in measurably different postoperative higher order aberration patterns. The multifocal apodized diffractive IOL (ReSTOR) induced significantly less spherical aberration compared to the monofocal IOLs. Contrast sensitivity revealed better values with MA30 and SA60 IOLs when compared to ReSTOR. The integration of wavefront technology in evaluating pseudophakic patients represents a step towards better understanding and analyzing postoperative visual quality.

Toxoplamosis Transmitted to a Newborn From the Mother Infected 20 Years Earlier

PURPOSE To present a case of congenital toxoplasmosis in a newborn whose mother had a 20-year history of a chorioretinal macular scar and positive serology for toxoplasmosis. DESIGN/METHODS Case report. SETTING/RESULTS: A 38-year-old woman who had been treated for ocular toxoplasmosis 20 years earlier delivered a newborn who presented with a focal necrotizing retinochoroiditis characteristic of toxoplasmosis, as well as positive immunoglobulin (Ig) G and M serology for toxoplasmosis. The workup was negative for other entities. CONCLUSION This case suggests that women with old retinal scars due to toxoplasmosis and long-standing IgG antibodies to toxoplasmosis are also at risk of transmitting this disease to the fetus.

Toxoplasma gondii in the peripheral blood of patients with acute and chronic toxoplasmosis.

Background and aims Toxoplasmic retinochoroiditis may recur months or years after the primary infection. Rupture of dormant cysts in the retina is the accepted hypothesis to explain recurrence. Here, the authors present evidence supporting the presence of Toxoplasma gondii in the peripheral blood of immunocompetent patients. Methods Direct observation by light microscopy and by immunofluorescence assay was performed, and results were confirmed by PCR amplification of parasite DNA. Results The authors studied 20 patients from Erechim, Brazil, including acute infected patients, patients with recurrent active toxoplasmic retinochoroiditis, patients with old toxoplasmic retinal scars, and patients with circulating IgG antibodies against T gondii and absence of ocular lesions. Blood samples were analysed, and T gondii was found in the blood of acutely and chronically infected patients regardless of toxoplasmic retinochoroiditis. Conclusions The results indicate that the parasite may circulate in the blood of immunocompetent individuals and that parasitaemia could be associated with the reactivation of the ocular disease.