Ocular Involvement Following Postnatally Acquired Toxoplasma gondii Infection in Southern Brazil: A 28-Year Experience.

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.

Ocular Involvement Following an Epidemic of Toxoplasma gondii Infection in Santa Isabel do Ivaí, Brazil.

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 IgM+ individuals (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.

Survey of obstetrician-gynecologists in the United States about Chagas disease.

Chagas disease affects an estimated 300,000 people in the United States, and as many as 300 congenital infections are estimated to occur annually. The level of knowledge about Chagas disease among obstetricians-gynecologists in the United States has not been assessed. The American College of Obstetricians and Gynecologists surveyed a representative sample of 1,000 members about Chagas disease. Among 421 respondents, 68.2% (95% confidence interval [CI] = 63.5-72.6) described their knowledge level about Chagas disease as "very limited." Only 8.8% (95% CI = 6.2-12.0) knew the risk of congenital infection, and 7.4% (95% CI = 5.1-10.4) were aware that both acute and chronic maternal infections can lead to congenital transmission. The majority of respondents (77.9%; 95% CI = 73.5-81.9) reported "never" considering a diagnosis of Chagas disease among their patients from endemic countries. Most of those who did consider the diagnosis did so "rarely." Knowledge of Chagas disease among obstetricians-gynecologists in the United States is limited. Greater awareness may help to detect treatable congenital Chagas cases.

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.

Prevalence of intestinal microsporidiosis in human immunodeficiency virus-infected patients with diarrhea in major United States cities.

To determine the prevalence of intestinal microsporidiosis in HIV-infected patients, we performed a prospective study of HIV-infected patients with diarrheal illnesses in three US hospitals and examined an observational database of HIV-infected patients in 10 US cities. Among 737 specimens from the three hospitals, results were positive for 11 (prevalence 1.5%); seven (64%) acquired HIV through male-to-male sexual contact, two (18%) through male-to-male sexual contact and injection drug use, and one (9%) through heterosexual contact; one (9%) had an undetermined mode of transmission. Median CD4 count within six months of diagnosis of microsporidiosis was 33 cells/microL (range 3 to 319 cells/microL). For the national observational database (n = 24,098), the overall prevalence of microsporidiosis was 0.16%. Prevalence of microsporidiosis among HIV-infected patients with diarrheal disease is low, and microsporidiosis is most often diagnosed in patients with very low CD4+ cell counts. Testing for microsporidia appears to be indicated, especially for patients with very low CD4+ cell counts.

Prevalence of intestinal microsporidiosis in Human Immunodeficiency Virus-infected patients with diarrhea in major United States cities

To determine the prevalence of intestinal microsporidiosis in HIV-infected patients, we performed a prospective study of HIV-infected patients with diarrheal illnesses in three US hospitals and examined an observational database of HIV-infected patients in 10 US cities. Among 737 specimens from the three hospitals, results were positive for 11 (prevalence 1.5 percent); seven (64 percent) acquired HIV through male-to-male sexual contact, two (18 percent) through male-to-male sexual contact and injection drug use, and one (9 percent) through heterosexual contact; one (9 percent) had an undetermined mode of transmission. Median CD4 count within six months of diagnosis of microsporidiosis was 33 cells/µL (range 3 to 319 cells/µL). For the national observational database (n = 24,098), the overall prevalence of microsporidiosis was 0.16 percent. Prevalence of microsporidiosis among HIV-infected patients with diarrheal disease is low, and microsporidiosis is most often diagnosed in patients with very low CD4+ cell counts. Testing for microsporidia appears to be indicated, especially for patients with very low CD4+ cell counts.

Para determinar a prevalência de microsporidiose intestinal em pacientes infectados pelo HIV foi realizado um estudo prospectivo em três hospitais dos Estados Unidos da América do Norte (EUA) e analizada uma base de dados nacional composta de dados coletados de pacientes infectados pelo HIV em 10 cidades dos EUA. De um total de 737 amostras de fezes de pacientes infectados pelo HIV que apresentavam diarréia, amostras de 11 pacientes (prevalência de 1,5 por cento) foram positivas para microsporídios. Todos os positivos eram do sexo masculino e, entre eles, sete (64 por cento) pacientes adquiriram a infecção pelo HIV através de relação homossexual, dois (18 por cento) através de relação sexual e drogas injetáveis e um (9 por cento) através de contato heterosexual, enquanto que em um paciente o modo de transmissão do HIV não foi determinado. A contagem média de linfócitos CD4 realizada até seis meses do diagnóstico de microsporidiose foi de 33 células/microlitro (3 a 319 células/microlitro). A análise da base de dados nacional (n = 24.098) mostrou uma prevalência de microsporidiose de 0,16 por cento. A prevalência de microsporidiose em pacientes HIV-positivos com diarréia é baixa. Entretando, como a microsporidiose é mais frequentemente diagnosticada em pacientes com contagens de CD4 muito baixas, a indicação de pesquisa de microsporídios é justificada, especialmente para estes pacientes.

Recently acquired Toxoplasma gondii infection, Brazil.

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).

Waterborne toxoplasmosis, Brazil, from field to gene.

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.

Toxoplasma gondii infection in rural Guatemalan children.

To determine the prevalence and risk factors for Toxoplasma gondii infection in Guatemalan children, in 1999 and 2003 we surveyed caretakers and serologically tested children in the San Juan Sacatepequez area using Platelia Toxo IgG TMB enzyme immunoassay kits. In 1999, of 532 children six months to two years old, 66 (12.4%) were antibody positive. In 2003, in 500 children 3-10 years old antibody prevalence increased from 24% to 43% at age five years then leveled off. By multivariate analysis, drinking well water (relative risk [RR] = 1.78, 95% confidence limit [CL] = 1.00, 3.17, P = 0.05) and not cleaning up cat feces (RR = 2.06, 95% CL = 1.00, 4.28, P = 0.05) increased the risk of T. gondii seropositivity. Most T. gondii infections in children from these villages occurred by age five, but half were still not infected by adolescence. Therefore, it is important to educate girls entering child-bearing age about the risks of acute T. gondii infection and the local risk factors for infection.

Highly endemic, waterborne toxoplasmosis in north Rio de Janeiro state, Brazil.

In Campos dos Goytacazes, northern Rio de Janeiro state, Brazil, reports of uveitis consistent with toxoplasmosis led to a survey of the prevalence and risk factors for Toxoplasma gondii infection in 1997-1999. The survey population was selected randomly from schools, randomly chosen communities, and an army battalion. Serum samples from 1,436 persons were tested. With results adjusted for age, 84% of the population in the lower socioeconomic group was seropositive, compared with 62% and 23% of the middle and upper socioeconomic groups, respectively (p<0.001). When multivariate analysis was performed, drinking unfiltered water was found to increase the risk of seropositivity for the lower socioeconomic (odds ratio [OR]: 3.0, 95% confidence interval [CI] 1.3 to 6.9) and middle socioeconomic (OR: 1.7, 95% CI 1.2 to 2.3) populations. We also found a high T. gondii seroprevalence in this Brazilian community. Drinking unfiltered water increased the risk of T. gondii seropositivity, indicating the potential importance of oocyst transmission in water in this region.