Congenital toxoplasmosis is a parasitic disease caused by the transmission of the protozoan during pregnancy that can potentially cause severe consequences for the fetus or neonates. The disease disproportionately impacts the global population and is generally correlated with the Human Development Index. Despite its prevalence, there are knowledge gaps among pregnant women and healthcare providers regarding the prevention, diagnosis, and treatment of this condition.
View Article and Find Full Text PDFStudies indicate that neuroscience-informed digital cognitive training can remediate cognitive impairments in schizophrenia, but the factors contributing to these deficits and response to treatment remain unclear. Toxoplasma gondii is a neuroinvasive parasite linked to cognitive decline that also presents a higher prevalence in schizophrenia. Here, we compared the cognition and symptom severity of IgG seropositive (TOXO+; n = 25) and seronegative (TOXO-; n = 35) patients who participated in a randomized controlled trial of digital cognitive training.
View Article and Find Full Text PDFFood Waterborne Parasitol
June 2019
The aim of this study was to contribute to the better understanding of the relative epidemiological importance of different modes of infection with respect to horizontal transmission of Toxoplasma gondii in endemic settings. We investigated the prevalence of salivary IgA against a sporozoite-specific embryogenesis-related protein (TgERP) in a highly endemic area for toxoplasmosis in Brazil in order to pinpoint parasite transmission via oocysts. Prevalence calculated by salivary IgA specific to TgERP was compared to the prevalence calculated by serum IgG against both TgERP and tachyzoites (in conventional serological tests).
View Article and Find Full Text PDFJ Immunol Methods
January 2016
This study intended to apply the flow cytometric analysis of IgA and IgG reactivity and intracytoplasmic cytokine analysis to understand and decode the clinical aspects of infants with ocular congenital toxoplasmosis. The Toxoplasma gondii-infected infants (TOXO) were subdivided according to their clinical aspects based on the absence (NRL), presence of active (ARL), active/cicatricial (ACRL) or cicatricial retinochoroidal lesions (CRL) and compared to non-infected controls (NI). The reactivity of anti-T.
View Article and Find Full Text PDFWe present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondii oocyst testing and for collecting blood from free-range chickens and humans for anti-T.
View Article and Find Full Text PDFJ Immunol Methods
February 2015
In the present study we evaluated the anti-Toxoplasma gondii immunoglobulin profiles of a group of 118 individuals living in an endemic area. The aim of the study was to select biomarkers to support the ophthalmological diagnosis of retinal/retinochoroidal scars presumably caused by T. gondii infection.
View Article and Find Full Text PDFMem Inst Oswaldo Cruz
February 2014
The association of single nucleotide polymorphisms (SNPs) in the interferon (IFN)-γ gene ( IFNG ) with different types of retinal scar lesions presumably caused by toxoplasmosis were investigated in a cross-sectional population-based genetic study. Ten SNPs were investigated and after Bonferroni correction, only the associations between SNPs rs2069718 and rs3181035 with retinal/retinochoroidal scar lesions type A (most severe scar lesions) and C (least severe scar lesions), respectively, remained significant. The associations of two different IFNG SNPs with two different types of retinal lesions attributable to toxoplasmosis support the hypothesis that different inflammatory mechanisms underlie the development of these lesions.
View Article and Find Full Text PDFRetinochoroiditis manifests in patients infected with Toxoplasma gondii. Here, we assessed 30 sibships and 89 parent/case trios of presumed ocular toxoplasmosis (POT) to evaluate associations with polymorphisms in the NOD2 gene. Three haplotype-tagging single-nucleotide polymorphisms (tag-SNPs) within the NOD2 gene were genotyped.
View Article and Find Full Text PDFCongenital Toxoplasma gondii infection can result in intracranial calcification, hydrocephalus and retinochoroiditis. Acquired infection is commonly associated with ocular disease. Pathology is characterized by strong proinflammatory responses.
View Article and Find Full Text PDFToxoplasma gondii infection is an important mediator of ocular disease in Brazil more frequently than reported from elsewhere. Infection and pathology are characterized by a strong proinflammatory response which in mice is triggered by interaction of the parasite with the toll-like receptor (TLR)/MyD88 pathway. A powerful way to identify the role of TLRs in humans is to determine whether polymorphisms at these loci influence susceptibility to T.
View Article and Find Full Text PDFMem Inst Oswaldo Cruz
March 2009
Toxoplasmosis and ascaridiasis evoke polar Th-1 and Th-2 host immune responses, respectively. A study to investigate the specific cytokine profile production by in vitro cultures of peripheral blood mononuclear cells from individuals living under precarious sanitary conditions in a highly endemic area for the parasites Toxoplasma gondii and Ascaris lumbricoides was conducted. High levels of both IFN-gamma (Th-1) and IL-13 (Th-2) were observed in groups of co-infected individuals presenting toxoplasmic ocular lesions.
View Article and Find Full Text PDFUntil recently, Toxoplasma gondii was considered clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T.
View Article and Find Full Text PDFBackground: Toxoplasmic retinochoroiditis appears to be more severe in Brazil, where it is a leading cause of blindness, than in Europe, but direct comparisons are lacking. Evidence is accumulating that more virulent genotypes of Toxoplasma gondii predominate in South America.
Methods: We compared prospective cohorts of children with congenital toxoplasmosis identified by universal neonatal screening in Brazil and neonatal or prenatal screening in Europe between 1992 and 2003, using the same protocol in both continents.
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.
View Article and Find Full Text PDFChemokines and chemokine receptors (CKRs) control the migration of leukocytes during the inflammatory process and are important immunological markers of type 1 (CCR5 and CXCR3) and type 2 (CCR3 and CCR4) responses. The coexpression of CKRs (CCR2, CCR3, CCR5, CXCR3, and CXCR4) and intracellular cytokines (interleukin-10 [IL-10], IL-4, tumor necrosis factor alpha [TNF-alpha], and gamma interferon [IFN-gamma]) on T CD4+ and CD8+ peripheral cells from individuals with indeterminate (IND) or cardiac (CARD) clinical forms of Chagas' disease after in vitro stimulation with Trypanosoma cruzi antigens, were evaluated in this study. The percentage of T CD4+ and CD8+ cells coexpressing CCR5 and IFN-gamma, CXCR3 and IFN-gamma, and CXCR3 and TNF-alpha were higher in CARD than in IND individuals; on the other hand, the percentage of T CD4+ or CD8+ cells coexpressing CCR3 and IL-10 or coexpressing CCR3 and IL-4 were lower in CARD individuals than in IND individuals.
View Article and Find Full Text PDFPrevious studies of Toxoplasma gondii, based on samples dominated by clinical isolates, have concluded that its population structure is clonal, despite the sexual reproduction that occurs in cats. To determine whether this applies to non-clinical isolates, we compared patterns of linkage disequilibrium (LD) among seven loci in samples of T. gondii from Brazil and the US.
View Article and Find Full Text PDFMost isolates of Toxoplasma gondii can be grouped into 3 genetic lineages. In the present study, 67 isolates of T. gondii were obtained by bioassay in mice inoculated with brains and hearts of 96 asymptomatic chickens from an area highly endemic to human infection in Rio de Janeiro, Brazil.
View Article and Find Full Text PDFThe prevalence of Toxoplasma gondii in free-range chickens from Campos dos Goytacazes, Rio de Janeiro State, Brazil, was examined to evaluate environmental contamination by oocysts. Antibodies against T. gondii were assayed by the modified agglutination test (MAT) in sera of chickens.
View Article and Find Full Text PDFThe role of interleukin 10 (IL-10) and gamma interferon (IFN-gamma) on the development of pathology in human Chagas' disease was investigated. Two categories of patients, low and high producers of IFN-gamma, were identified based on the levels of secretion of this cytokine in the supernatant of peripheral blood mononuclear cell (PBMC) cultures. Eighty-three percent of the patients presenting with cardiac disease (CARD) of different degrees and 59% of the patients with the indeterminate form of disease (IND) were identified as high IFN-gamma producers.
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFWe recently evaluated the in vitro proliferative response and interferon (IFN)-gamma production of peripheral blood mononuclear cells from a group of 25 people who were treated for Chagas' disease during the acute phase of Trypanosoma cruzi infection and followed up for a period of 14-30 years. On the basis of the parasitological and serological tests, the individuals were classified as cured (C), dissociated, or not cured (NC). Members of group C (the group without cardiac alterations) presented significantly stronger proliferative response against the parasite antigens, with secretion of high levels of IFN-gamma in comparison with the NC group, raising a question about the role of this cytokine in the curing of human T.
View Article and Find Full Text PDF