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The city of Erechim, Brazil, has a 17% prevalence of ocular toxoplasmosis, and type 1 Toxoplasma gondii predominates. To examine risk factors for acute T. gondii infection in this area, we administered a questionnaire to recently infected persons (n = 131) and seronegative controls (n = 110). Eating undercooked meat; having a garden; working in the garden or yard more than once per week; eating rare meat; eating cured, dried, or smoked meat; eating frozen lamb; and being male increased risk for T. gondii infection in univariate analysis. Risk factors independently associated with acute T. gondii infection in multivariate analysis were working in the garden (odds ratio [OR] 2.35, 95% confidence interval [CI] 1.27-4.33) and eating frozen lamb (OR 2.06, 95% CI 1.15-3.67). Among women (n = 86), having had children markedly increased the risk for T. gondii infection (OR 14.94, 95% CI 3.68-60.73). [ABSTRACT FROM AUTHOR]

Water was the suspected vehicle of Toxoplasma gondii dissemination in a toxoplasmosis outbreak in Brazil. A case-control study and geographic mapping of cases were performed. T. gondii was isolated directly from the implicated water and genotyped as SAG 2 type I. [ABSTRACT FROM AUTHOR]

Focuses on a study which explored the prevalence and risk factors for Toxoplasma gondii infection in Rio de Janerio State, Brazil in 1997 to 1999. Information on the study population; Water distribution and treatment in the study area; Predictors of toxoplasma gondii seropositivity; Risk factors for toxoplasma gondii.

PURPOSE: To investigate ocular involvement (prevalence, incidence, lesion characteristics) following postnatally acquired infection with an ''atypical'' genotype of Toxoplasma gondii during a well-characterized 2001 outbreak in Santa Isabel do Ivaí, Brazil, attributed to a contaminated municipal reservoir. DESIGN: Prospective longitudinal cohort study. METHODS: We performed ophthalmic examinations on 290 of 454 individuals with serologic evidence of T gondii infection during the epidemic (positive IgM antibody tests). Prevalence of ophthalmic findings (intraocular inflammatory reactions [including transient, isolated retinal whitening without clinically apparent retinal necrosis] and necrotizing retinochoroiditis) at initial examination (baseline) and incidence of new findings during 10.5 months of follow-up were calculated. Cumulative risks of ophthalmic events were determined (Kaplan-Meier technique). RESULTS: Ocular involvement was present in 33 of 288 IgMDindividuals (11.5%) at baseline, including 17 with focal retinal whitening only and 13 with necrotizing retinochoroiditis. Incidence of new ocular involvement was estimated to be 1.73 events per 100 person-months (PM); cumulative risk at 10.5 months was 30.1%. Incident necrotizing retinochoroiditis was more common among those with focal retinal whitening at baseline (6.7/100 PM) than among those with no ocular involvement at baseline (1.11/100 PM; hazard ratio 6.07 [1.94-19.01]; P<.0001). CONCLUSIONS: Waterborne infection with an atypical genotype of T gondii is associated with substantial risk of ocular involvement. Lesions may continue to develop during the first year after infection. The increased risk of late necrotizing retinochoroiditis associated with isolated focal retinal whitening at presentation suggests the early presence of parasites in the retina, despite initial lack of observable retinal necrosis. [ABSTRACT FROM AUTHOR]

Purpose: To determine the incidence of, and risk factors for, ocular involvement among people known to have postnatally acquired Toxoplasma gondii infection in a region of southern Brazil where there is a high prevalence of endemic disease., Design: Retrospective longitudinal cohort study., Methods: Records of 302 patients with serologic evidence of recent T gondii infection (a positive anti-T gondii IgM antibody test) from Erechim, Rio Grande do Sul state, Brazil (1974-2002) were analyzed. The incidence of ocular involvement was calculated in terms of person-years (PY) of follow-up. Risk factors for ocular involvement were analyzed using log-rank and Fisher exact tests., Results: At initial ocular examination (baseline), 30 patients (9.9%) had intraocular inflammation only (anterior chamber cells and flare, vitreous inflammatory reactions, retinal whitening), without clinically apparent necrotizing retinochoroiditis. At baseline, men were more likely to have ocular involvement (P = .043) and antiparasitic treatment was associated with less ocular involvement (P = .015). Follow-up examinations were performed on 255 patients (median follow-up, 13.7 months [range 0.4-261.9 months]). Among those without ocular involvement at baseline, the incidence of necrotizing retinochoroiditis was 6.4/100 PY. Patients >40 years of age at first IgM test had a greater risk of incident necrotizing retinochoroiditis (hazard ratio = 4.47, 95% CI = 1.67-11.93, P = .003) than younger patients. The incidence of recurrent necrotizing retinochoroiditis was 10.5/100 PY., Conclusion: Isolated intraocular inflammatory reactions can be an initial manifestation of T gondii infection, with necrotizing retinochoroiditis occurring months or years later. Male sex and older age are risk factors for toxoplasmic retinochoroiditis. Antitoxoplasmic treatment may protect against early ocular involvement., (Copyright © 2015 Elsevier Inc. All rights reserved.)

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.