Seroprevalencia de Toxoplasma gondii y su relación con trastornos mentales en adultos / Seroprevalence of Toxoplasma gondii and its Relationship with Mental Disorders in the Adult Population

El Toxoplasma gondii es un parásito que se encuentra, aproximadamente, en el 30 % de la población humana. Durante los últimos años se ha evidenciado que la infección latente puede ser un factor de riesgo para el desarrollo de trastornos mentales; particularmente para la esquizofrenia, ansiedad, trastornos bipolares y trastornos de conducta. La asociación con los trastornos neuropsiquiátricos pueden explicarse por la influencia que tiene el parásito sobre la expresión de múltiples neurotransmisores; entre ellos la dopamina. Se realizó una búsqueda en las bases de datos PubMed y SciELO de 2015 a 2023, se seleccionaron artículos originales y de revisión de revistas científicas internacionales, en idiomas inglés y español con el objetivo de describir la relación entre la seroprevalencia de T. gondii y el desarrollo de trastornos mentales en población adulta. Existe relación entre los trastornos mentales en la población adulta con la infección por Toxoplasma gondii y este aumenta la posibilidad de desarrollar esquizofrenia y depresión en individuos sin historial previo, y que podría exacerbar cuadros psiquiátricos previos con dificultad en el tratamiento. Sin embargo, no todos los datos estadísticos establecen una relación directa, algunos estudios demuestran una asociación, ciertos datos son discordantes, lo que abre una puerta para futuras investigaciones.

Toxoplasma gondii is a parasite that is found in approximately 30 % of the human population. In recent years, it has been shown that latent infection can be a risk factor for the development of mental disorders; particularly schizophrenia, anxiety, bipolar disorders, and conduct disorders. The association with neuropsychiatric disorders can be explained by the influence of the parasite on the expression of multiple neurotransmitters; among them, dopamine has received the most attention. A narrative bibliographic review article was done with the search of original and review articles in international scientific journals, in English and Spanish listing the relationship between the seroprevalence of T. gondii and the development of mental disorders in the adult population. The relationship between mental disorders in the adult population with Toxoplasma gondii infection is present and increases the possibility of developing schizophrenia and depression in individuals with no previous history, including the ability to worsen previous psychiatric conditions, making it difficult for standard management. Not all statistical data establish a direct relationship, some studies show an association and certain data are discordant, which opens a door for future research.

Patogénesis de la infección y Manejo Preconcepcional de la infección por T. gondi

La toxoplasmosis es una infección provocada por el parásito unicelular Toxoplasma gondii. Según las encuestas serológicas de la Tercera Encuesta Nacional de Salud y Nutrición en los Estados Unidos, alrededor del 23% de los adolescentes y adultos tienen signos serológicos de infección por T. gondii, de los cuales el 15% son mujeres en edad fértil. Estas infecciones suelen ser asintomáticas o causar síntomas leves en el adulto (como fiebre, malestar general y linfadenopatía), pero la infección en la mujer embarazada puede provocar graves problemas de salud en el feto si se transmite el parásito (toxoplasmosis congénita) y ocasionar secuelas graves en el bebé como coriorretinits, retraso mental, ceguera, sordera sensorineural y epilepsia. No hay evidencia concluyente de que la prueba y el cuidado preconcepcional reduzcan la infección por Toxoplasma gondii o mejoren el tratamiento de las mujeres infectadas. Por otro lado, si se realiza el asesoramiento preconcepcional, las mujeres que dieron positivo pueden estar tranquilas de que no corren riesgo de infección durante el embarazo y las que dieron negativo pueden recibir consejos sobre cómo prevenir la infección. Las mujeres que se infectan durante el embarazo deben recibir tratamiento. Se deben implementar programas educativos y de detección temprana para las embarazadas que sean rentables para reducir el impacto financiero y emocional de esta enfermedad. (provisto por Infomedic International)

Toxoplasmosis is an infection caused by the single-celled parasite Toxoplasma gondii. According to serologic surveys from the Third National Health and Nutrition Survey in the United States, about 23% of adolescents and adults have serologic signs of T. gondii infection, of which 15% are women of childbearing age. These infections are usually asymptomatic or cause mild symptoms in the adult (such as fever, malaise, and lymphadenopathy), but infection in the pregnant woman can cause serious health problems in the fetus if the parasite is transmitted (congenital toxoplasmosis) and cause severe sequelae in the infant such as chorioretinits, mental retardation, blindness, sensorineural deafness, and epilepsy. There is no conclusive evidence that preconception testing and care reduces Toxoplasma gondii infection or improves treatment of infected women. On the other hand, if preconception counseling is performed, women who tested positive can be reassured that they are not at risk of infection during pregnancy and those who tested negative can receive advice on how to prevent infection. Women who become infected during pregnancy should be treated. Cost-effective educational and early detection programs for pregnant women should be implemented to reduce the financial and emotional impact of this disease. (provided by Infomedic International)

Toxoplasmosis en el embarazo: Características epidemiológicas, clínicas y laboratoriales en un centro de referencia

La toxoplasmosis es una zoonosis causada por el protozoarioToxoplasma gondii (T. gondii), de gran impacto en la salud fetal cuando se adquiere durante el embarazo, debido al riesgo de transmisión vertical. Puede producir manifestaciones clínicas en los recién nacidos: coriorretinitis, hidrocefalia, calcificaciones y retardo psicomotor. La detección precoz y la instauración de una terapéutica adecuada son claves para evitar complicaciones asociadas a la transmisión materno fetal. Objetivo: Describir las características clínicas de gestantes con diagnóstico de toxoplasmosis y de los recién nacidos de éstas, durante los años 2018 al 2021 que acudieron al Servicio de Infectología del Instituto de Previsión Social (IPS). Materiales y métodos: Estudio observacional, descriptivo, de corte trasversal, utilizando un registro de datos de pacientes gestantes que acudieron al IPS durante los años 2018 al 2021. Resultados: Se incluyeron 62 gestantes; mediana de edad de 30 años, (21-44 años); 4 (6%) gestantes, realizaron su primera consulta en el primer trimestre, 39 (63%) en el segundo y 19 (31%) en el tercer trimestre. 9 (15%) pacientes fueron clasificadas como seroconversión, y 53 (85%) con sospecha de infección aguda. 55 pacientes fueron sometidas a amniocentesis; 26 (47%) tuvieron resultado de PCR detectable para Toxoplasma gondii en liquido amniótico, y 29 (53%) no detectable. Sólo 19 recién nacidos contaban con serologías para diagnóstico de toxoplasmosis congénita. Entre las complicaciones fetales se encontraron macrocefalia, e ictericia del RN.

Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii (T. gondii), with a great impact on fetal health when acquired during pregnancy, due to the risk of vertical transmission. It can produce clinical manifestations in newborns: chorioretinitis, hydrocephalus, calcifications and psychomotor retardation. Early detection and the establishment of adequate therapy are key to avoiding complications associated with fetal-maternal transmission. Objective: To describe the clinical characteristics of pregnant women diagnosed with toxoplasmosis and their newborns, during the years 2018 to 2021 who attended the Infectious Diseases Service of the Social Welfare Institute (IPS). Materials and methods: Observational, descriptive, cross-sectional study, using a data registry of pregnant patients who attended the IPS during the years 2018 to 2021. Results: 62 pregnant women were included; median age 30 years, (21-44 years); 4 (6%) pregnant women had their first consultation in the first trimester, 39 (63%) in the second and 19 (31%) in the third trimester. 9 (15%) patients were classified as having seroconversion, and 53 (85%) with suspected acute infection. 55 patients underwent amniocentesis; 26 (47%) had detectable PCR results for Toxoplasma gondii in amniotic fluid, and 29 (53%) undetectable. Only 19 newborns had serology tests for the diagnosis of congenital toxoplasmosis. Among the fetal complications were macrocephaly, and newborn jaundice.

Seroprevalencia y factores de riesgo de Toxoplasma gondii en Personas que Viven con VIH/SIDA (PVVS) en el departamento de Cochabamba, Bolivia

Objetivo: determinar la seroprevalencia y los factores de riesgo de infección crónica por T. gondii en personas que viven con VIH/SIDA (PVVS) en el departamento de Cochabamba. Metodología: estudio observacional-descriptivo de corte transversal. Se emplearon 325 muestras de plasma/suero proveniente de pacientes que asistieron a LABIMED entre Julio y agosto del año 2016. La recopilación de datos se realizó en un formulario sociodemográfico. Se emplearon ensayos serológicos cualitativos de Hemaglutinación Indirecta (HAI) e Inmunoflorecencia Indirecta (IFI), este último para confirmación de casos positivos. Adicionalmente se realizó el recuento de Linfocitos T CD4+ por citómetria de flujo para determinar el estado inmunológico de los pacientes que sirve de guía en el tratamiento clínico. Los datos fueron analizados con el programa/software SPSS versión 20. Resultados: la seroprevalencia global de infección crónica por T. gondii en la población de estudio fue del 40%. El consumo de carne poco cocida (OR: 2,85; 95%IC: 1,56-5,22) y la actividad de agricultura/jardinería (OR: 1,7; IC del 95%: 1,07-2,70) fueron factores de riesgo para adquirir la infección crónica por T. gondii. El 45.6% de las PVVS positivos para toxoplasmosis tiene un recuento de Linfocitos T CD4+ < a 200 células/mm3, equivalente a una inmunodeficiencia severa. Conclusión: El estudio muestra una seroprevalencia significativa de infección crónica por T. gondii, además de presentar una inmunodeficiencia severa en PVVS

Objective: To determine the seroprevalence and risk factors for chronic infection by T. gondii in people living with HIV/AIDS (PLHA) in the department of Cochabamba. Methods: observational-descriptive cross-sectional study. 325 samples (n=325) of plasma/serum from patients who attended LABIMED between the months of July to August of the year 2016 were used. Data (age, gender and risk factors) were collected in the sociodemographic form. Qualitative serological tests of Indirect Hemaglutination (HAI) and Indirect Immunoflorescence (IFI) were used the latter for confirmation of positive cases. Additionally, the count of CD4+ T lymphocytes was performed by flow cytometry to determine the immunological status of the patients that serves as a guide in clinical treatment. The data were analyzed with the program/software SPSS version 20. Results: the global seroprevalence of chronic infection by T. gondii in the study population was 40%. Consumption of undercooked meat (AOR: 2.85; 95% CI: 1,56-5,22) and farming/gardening activity (AOR: 1,7; 95% CI: 1,07-2,70) were risk factors for chronic T. gondii infection. 45,6% of people living with the HIV/AIDS virus who are positive for toxoplasmosis have a CD4+ T lymphocyte count <200 cells/ml, equivalent to severe immunodeficiency. Conclusions: the study shows a significant seroprevalence of chronic infection by T. gondii, as well as presenting a high severe immunodeficiency in patients with the HIV/AIDS virus.

Molecular and serological pattern of Toxoplasma gondii among rural population in four regions of Gabon

Toxoplasma gondii is an obligatory intracellular parasite that causes a zoonotic disease capable of infecting nearly all warm-blooded hosts, including humans. However, reports on the molecular prevalence of T. gondii in humans are rare in Gabon. The present study aimed to evaluate the serological and molecular prevalence of T. gondii among apparently healthy rural populations in four regions of Gabon. This study included six hundred blood samples from the Interdisciplinary Center for Medical Research (CIRMF) bank, including 300 women and 300 men living in 111 villages. Blood samples were screened using enzyme-linked fluorescent assay (ELFA), while buffy coat samples were analyzed using PCR analyses. Of the 600 samples screened, 548 (91.3%) showed IgG antibodies against T. gondii; 11 (2%) had both IgG and IgM. Among the 548 positive samples, 155 (28%) had higher IgG titers (>300 UI/ml), and 49 of them (31.6%) were detected with T. gondii DNA. The present findings on human toxoplasmosis in Gabon suggest that at an older age, reactivation of old infections seems more frequent than new infections, as indicated by the presence of T. gondii using PCR among elevated IgG subjects without IgM. Further studies should be performed to identify the genotypes of T. gondii that infect humans in Gabon.

Bioinformatics analysis of the RNA binding protein DDX39 of Toxoplasma gondii / 中国血吸虫病防治杂志

Objective To analyze the RNA binding protein of Toxoplasma gondii (TgDDX39) using bioinformatics technology, and to evaluate the immunogenicity of TgDDX39, so as to provide insights into development of toxoplasmosis vaccines. Methods The amino acid sequences of TgDDX39 were retrieved from the ToxoDB database, and the physicochemical properties, transmembrane structure domain, signal peptide sites, post-translational modification sites, coils, secondary and tertiary structures, hydrophobicity, and antigenic epitopes of the TgDDX39 protein were predicted using online bioinformatics tools, incluiding ProtParam, TMHMM 2.0, SignalP 5.0, NetPhos 3.1, COILS, SOPMA, Phyre2, ProtScale, ABCpred, SYFPEITHI and DNA-STAR. Results TgDDX39 protein was predicted to be an unstable hydrophilic protein with the molecular formula of C2173H3458N598O661S18, which contained 434 amino acids and had an estimated molecular weight of 49.1 kDa and a theoretical isoelectric point of 5.55. The protein was predicted to have an extremely low possibility of signal peptides, without transmembrane regions, and contain 27 phosphorylation sites. The β turn and random coils accounted for 39.63% of the secondary structure of the TgDDX39 protein, and a coiled helix tended to produce in one site. In addition, the TgDDX39 protein contained multiple B and T cell antigenic epitopes. Conclusions Bioinformatics analyses predict that TgDDX39 protein has high immunogenicity and contains multiple antigenic epitopes. TgDDX39 protein is a potential candidate antigen for vaccine development.

Expression of CD47 and its ligands in pregnant mice infected with Toxoplasma gondii during pregnancy / 中国血吸虫病防治杂志

Objective To investigate the dynamic expression of cluster of differentiation 47 (CD47) and its ligands signaling regulatory protein α (SIRPα) and thrombospondin-1 (TSP-1) in mice infected with Toxoplasma gondii in the second and third trimesters.. Methods C57BL/6J mice (6 to 8 weeks old) were used for modeling T. gondii infection in the first trimester, and the pregnant mice were randomly divided into the normal control and infection groups, of 10 mice in each group. Pregnant mice in the infection group were intraperitoneally injected with 150 T. gondii tachyzoites on gestational day (Gd) 6.5, while pregnant mice in the normal control group were intraperitoneally injected with the same volume of physiological saline at the same time. The uterine and placental specimens were collected from all pregnant mice on Gd12.5 and Gd18.5, and the pregnant outcomes were recorded. The pathological damages of mouse uterine and placental specimens were observed using hematoxylin-eosin (HE) staining on Gd12.5 and Gd18.5. The relative expression of CD47, SIRPα, TSP-1, surface antigen 1 (SAG1), interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4 and IL-13 mRNA was quantified in mouse uterine and placental specimens using real-time fluorescence quantitative PCR (qPCR) assay, and the CD47, SIRPα, TSP-1 expression was determined in mouse uterine and placental specimens using immunohistochemical staining. Results As compared with those in the normal control group, the pregnant mice in the infection group showed back arching, bristling, trembling and listlessness during pregnancy, and several mice presented virginal bleeding and abortion. Pathological examinations showed inflammatory cell infiltration, congestion and necrosis in uterine and placental specimens of pregnant mice in the infection group, a higher abortion rate of pregnant mice was seen in the infection group than in the normal control group on Gd12.5 (χ2 = 20.405, P < 0.001) and Gd18.5 (χ2 = 28.644, P < 0.001). qPCR assay showed significant differences in the expression of CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 genes in mouse placental specimens between the normal control and infection groups on Gd12.5 and Gd18.5 [F′ (F) = 37.511, 29.337, 97.343, 53.755, 67.188, 21.145, 8.658 and 13.930, all P values < 0.001]. Higher CD47, SIRPα and TSP-1 gene expression was quantified in mouse placental specimens in the infection group than in the normal control group on Gd12.5 (all P values < 0.01), and lower CD47, SIRPα and TSP-1 gene expression was quantified in the infection group than in the normal control group on Gd18.5 (all P values < 0.001), while higher SAG1 gene expression was detected in placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01). In addition, higher INF-γ and IL-2 expression and lower IL-4 and IL-13 expression was detected in mouse placental specimens in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001), and there were significant differences in the CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 gene expression in uterine specimens of pregnant mice between the normal control and infection groups on Gd12.5 and Gd18.5 [H(F′ and F) = 14.951, 25.977, 18.711, 48.595, 39.318, 14.248 and 15.468, all P values < 0.01], and higher CD47 and TSP-1 expression was detected in mouse uterine specimens in the infection group than in the control group on Gd12.5 and Gd18.5 (all P values < 0.01); however, no significant difference was found in the SIRPα expression (P > 0.05). Higher SAG1 expression was detected in uterine specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01), and higher INF-γ and IL-2 gene expression and lower IL-4 and IL-13 gene expression was found in the placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001). Spearman correlation analysis showed that the CD47 gene expression correlated positively with IFN-γ (rs = 0.735, P < 0.05) and IL-2 (rs = 0.655, P < 0.05) and negatively with IL-4 (rs = −0.689, P < 0.05) and IL-13 expression (rs = −0.795, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd12.5, and the CD47 gene expression correlated negatively with IFN-γ (rs = −0.745, P < 0.05) and IL-2 expression (rs = −0.816, P < 0.05) and positively with IL-4 (rs = 0.704, P < 0.05) and IL-13 (rs = 0.802, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd18.5. Immunohistochemical staining showed mild CD47, SIRPα and TSP-1 expression in uterine and placental specimens of pregnant mice in the normal control group on Gd12.5 and Gd18.5, strong CD47, SIRPα and TSP-1 expression in the placental specimens of pregnant mice in the infection group on Gd12.5 and strong CD47 and TSP-1 expression in the uterine specimens of pregnant mice in the infection group on Gd12.5. Conclusions T. gondii infection in the first trimester may cause abnormal expression of CD47 and its ligands SIRPα and TSP-1 in the maternal-fetal interface of pregnant mice in the second and third trimesters, which may be associated with the immune escape of T. gondii at the maternal-fetal interface.

Molecular and serological diagnosis of toxoplasmosis: a systematic review and meta-analysis

ABSTRACT Toxoplasmosis is an infection of vast worldwide distribution whose etiologic agent is Toxoplasma gondii. This disease can cause problems ranging from mild symptoms to serious conditions, such as encephalitis, miscarriage and blindness. Therefore, it is of utmost importance to perform a diagnosis with reproducible techniques in order to obtain a good prognosis. The aim of this review was to analyze the efficiency of toxoplasmosis diagnostic techniques based on sensitivity and specificity results. Five research platforms in English language were used (Eric, Elsevier, Google Scholar, PubMed and SciELO), which contained data on the diagnosis of toxoplasmosis. The search and selection were performed for studies published prior to June 2021. The search resulted in the inclusion of 13 articles published from 2005 to 2020. The data revealed the use of different samples in the standardization of techniques such as serum, total blood, colostrum and amniotic fluid. The flow cytometry, lateral flow immunoassay and qPCR techniques showed 100% sensitivity, whereas the ELISA, western blotting, qPCR and RE-LAMP techniques achieved 100% specificity. Significantly, the qPCR and LAMP techniques were more accurate when the likelihood ratio was assessed. The meta-analysis identified that ISAGA and western blotting have low sensitivity values and LIASON, ELFA and ELISA, using a silica bioconjugate, also have low specificity values. It was noted that a wide range of methods have high values of sensitivity and specificity. Therefore, the choice of the method will be based on the conditions and its financial viability.

Infección por Toxoplasma gondii y accidentes de tránsito. Evidencias epidemiológicas de una asociación poco conocida

Recientes pesquisas en las que se utilizó la detección de anticuerpos anti-Toxoplasma gondii como herramienta diagnóstica de toxoplasmosis latente, demostraron asociación entre la infección crónica por el parásito y la disminución de funciones cognitivas, las enfermedades psiquiátricas (esquizofrenia, bipolar, trastornos obsesivo-compulsivos), las enfermedades degenerativas (enfermedad de Alzheimer, múltiples esclerosis, enfermedad de Huntington), y cambios de comportamiento (mayor frecuencia de conductas suicidas y, sobre todo, de accidentes de tránsito). En la literatura revisada, varios estudios demostraron seroprevalencias de anticuerpos anti-T. gondii significativamente mayores en grupos de personas involucradas en accidentes de tránsito que las de sus correspondientes grupos control. La no disponibilidad de fármacos adecuados contra los bradizoítos de T. gondii y de vacunas efectivas contra el parásito, además de no posibilitarse la demostración de una posible relación causal, se obstaculizaba la que podría resultar una vía complementaria para el control de los accidentes de tránsito, un problema de la cotidianidad universal de muy adversas consecuencias humanas y sociales. En perspectivas, la superación de estas limitaciones debe recibir una adecuada atención, tanto de las autoridades sanitarias como de la Academia. En esa dirección, el propósito de este documento es contribuir a ganar conciencia sobre la existencia de esa asociación.

Recent investigations, in which the detection of anti-Toxoplasma gondii antibodies has been used as a diagnostic tool for latent toxoplasmosis, have shown an association between chronic infection by the parasite and decreased cognitive functions, psychiatric illnesses (schizophrenia, bipolar disorder, obsessive - compulsive disorders), degenerative diseases (Alzheimer's disease, multiple sclerosis, Huntington's disease) and behavioral changes (greater frequency of suicidal behaviors and, above all, traffic accidents). In the reviewed literature, several studies demonstrated significantly higher seroprevalence of anti-T. gondii in groups of people involved in traffic accidents than in their corresponding control groups. The unavailability of adequate drugs against T. gondii bradyzoites and effective vaccines against the parasite, in addition to not allowing the demonstration of a possible causal relationship, hinders what could be a complementary way to control traffic accidents, a problem of universal daily life with very adverse human and social consequences. In perspective, overcoming these limitations should receive adequate attention, both from the health authorities and from academia. In this direction, the purpose of this document is to contribute to raising awareness of the existence of this association.

Transmisión vertical de Toxoplasma gondii asociado a la edad gestacional / Vertical transmission of Toxoplasma gondii associated with gestational age

Una de las principales consecuencias de la infección por Toxoplasma gondii en mujeres embarazadas es la transmisión vertical al feto. Aunque es poco frecuente, la toxoplasmosis congénita puede causar enfermedades neurológicas u oculares graves. La infección primaria por T. gondii durante el embarazo puede tener consecuencias peligrosas, como retinocoroiditis, hidrocefalia, calcificaciones cerebrales, encefalitis, esplenomegalia, pérdida de audición, ceguera y muerte. La atención prenatal debe incluir educación sobre la prevención de la toxoplasmosis. Se trata de un estudio observacional, analítico y transversal. Se evaluaron 209 mujeres gestantes e igual número de recién nacidos; 136 de las mujeres embarazadas resultaron con infección aguda positiva a IgM. De estas 51,20% y 64,71% resultaron primoinfectadas según la determinación de IgA e IgG avidez, respectivamente. 20 de los 35 neonatos provenientes de madres primoinfectadas, adquirieron la infección congénita en el tercer trimestre de la gestación. La conciencia sobre la prevención y el control de la toxoplasmosis es baja entre las poblaciones de alto riesgo. Es necesario fortalecer la educación en salud relacionada con la prevención y el control de la toxoplasmosis en las mujeres en edad reproductiva para prevenir la transmisión vertical a sus productos de gestación y evitar los efectos negativos y hasta mortales de la inefcción por el parásito(AU)

One of the main consequences of Toxoplasma gondii infection in pregnant women is vertical transmission to the fetus. Although rare, congenital toxoplasmosis can cause serious neurological or ocular disease. Primary T. gondii infection during pregnancy can have dangerous consequences, including retinochoroiditis, hydrocephalus, cerebral calcifications, encephalitis, splenomegaly, hearing loss, blindness, and death. Prenatal care should include education on the prevention of toxoplasmosis. This is an observational, analytical and cross-sectional study. 209 pregnant women and the same number of newborns were evaluated; 136 of the pregnant women were acutely infected with IgM. Of these, 51.20% and 64.71% were primary infected according to the determination of IgA and IgG avidity, respectively. 20 of the 35 neonates from mothers with primary infection acquired the congenital infection in the third trimester of pregnancy. Awareness of toxoplasmosis prevention and control is low among high-risk populations. It is necessary to strengthen health education related to the prevention and control of toxoplasmosis in women of reproductive age to prevent vertical transmission to their gestational products and avoid the negative and even fatal effects of infection by the parasite(AU)

Congenital ocular toxoplasmosis in consecutive siblings / Toxoplasmose ocular congênita em irmãos consecutivos

ABSTRACT Toxoplasma gondii infection can cause ocular manifestations after acquired and congenital disease. We report two cases of symptomatic congenital toxoplasmosis with ocular involvement in non-twin siblings, with a 2-year interval between pregnancies. Vertical transmission of toxoplasmosis in successive pregnancies, which was once considered impossible, is now found to be plausible even in immunocompetent subjects.

RESUMO A infecção pelo Toxoplasma gondii pode causar manifestações oculares tanto após a sua forma congênita quanto a sua forma adquirida. Reportamos aqui dois casos de toxoplasmose congênita sintomática com envolvimento ocular em irmãos não gêmeos, com intervalo de 2 anos entre gestações. A transmissão vertical da toxoplasmose em gestações sucessivas, outrora considerada impossível, é um evento plausível mesmo em indivíduos imunocompetentes.

Seropositivity of Chlamydia trachomatis & Toxoplasma gondii among male partners of infertile couples in Odisha, India: A facility based exploratory study

Chlamydia trachomatis (CT) is the most common curable sexually transmitted non-viral infection, which can cause urethritis, prostatitis, orchitis and epididymitis among males. Toxoplasma gondii, a protozoan causes toxoplasmosis among humans. These infections may lead to decreased fertility. Hence, this study was aimed to estimate the seropositivity of CT and T. gondii infection among the male partners of infertile couples in Odisha, India. In this facility-based cross-sectional study, first void urine, seminal fluid and blood sample were collected from 153 males attending infertility clinics including 74 healthy controls. Urine and seminal fluid were tested through polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay was used to detect immunoglobulin (Ig) G, IgA and IgM anti-Chlamydia and IgM anti-Toxoplasma antibodies through serum. The prevalence of CT was 1.26 per cent (95% CI: 0.03-6.85) as estimated from semen samples using PCR. We detected anti-Chlamydia antibodies IgM-four per cent [95% confidence interval (CI): 0.83-11.24]; IgA-28.16 per cent (95% CI: 18.13-40.09) and IgG-12.5 per cent (95% CI: 5.87-22.4) among participants. Anti-Toxoplasma antibodies IgM were observed in 27.63 per cent (95% CI: 17.98-39.08) of participants. None of the control samples were found positive. Overall seropositivity of CT and Toxoplasma infections is comparable, which suggests that greater attention is required for screening these infections at clinics, especially among infertile couples.

Alteraciones en la producción de citosinas en respuesta a Toxoplasma gondii aparecen desde las etapas tempranas en pacientes co-infectados con VIH-1 / Alterations in the production of cytokines in response to Toxoplasma gondii appear from early stages in patients co-infected with HIV-1

Resumen Tanto el Virus de Inmunodeficiencia Humana-1 (VIH-1), como el protozoo Toxoplasma gondii son capaces de infectar al ser humano e invadir su sistema nervioso central (SNC). En individuos inmunocompetentes T. gondii causa infecciones crónicas, generalmente asintomáticas; sin embargo, la inmunodeficiencia asociada a etapas avanzadas de la infección por VIH-1, se relaciona con la pérdida del control de la infección parasitaria latente y enfermedades graves a nivel del SNC, como encefalitis toxoplásmica. Este trabajo tuvo como objetivo evaluar la evolución de la respuesta inmunitaria contra T. gondii en pacientes co-infectados con VIH-1, en distintas etapas de la infección viral. La respuesta contra T. gondii se evaluó a través de la producción in vitro de citosinas en respuesta a antígenos parasitarios, en individuos con serología positiva para VIH-1 y negativa para T. gondii (P1), positiva para VIH-1 y T. gondii (P2), negativa para VIH-1 y T. gondii (C1) y negativa para VIH-1 y positiva para T. gondii (C2). Los pacientes (P1 y P2) se agruparon en tempranos/asintomáticos (P1A, P2A) o tardíos/sintomáticos (P1B/C, P2B/C) de acuerdo a su recuento de linfocitos T CD4+ en sangre periférica (>350 o <350 células/μL, respectivamente). La infección por VIH-1, desde etapas tempranas, se asoció con una producción de IL-2, TNF-α e IFN-γ en respuesta a T. gondii significativamente menor. Estos defectos pueden entorpecer la respuesta anti-T. gondii en pacientes co-infectados, aumentando la posibilidad de reactivación de las infecciones latentes, lo que representa un riesgo para la integridad y funcionalidad del SNC.

Abstract Both HIV-1 and Toxoplasma gondii are able to invade central nervous system and affect its functionality. Advanced HIV-1 infection has been associated with defects in immune response to T. gondii, leading to reactivation of latent infections and the appearing of toxoplasmic encephalitis. This study evaluated changes in the immune response to T. gondii in different stages of HIV infection. Immune response to T. gondii was assessed studying cytokine production in response to parasite antigens in HIV-1-infected/T. gondii-noninfected (P1), HIV-1/T. gondii co-infected (P2), HIV-1-non-infected/T. gondiinon-infected (C1) and HIV-1-non-infected/T. gondii-infected (C2) individuals. Patients (P1 and P2) were divided in early/asymptomatic (P1A, P2A) or late/symptomatic (P1B/C, P2B/C) according to peripheral blood CD4+ T lymphocyte counts (>350 or <350/μL, respectively). The HIV-1 infection, from early/asymptomatic stages, was associated with significant lower production of IL-2, TNF-α and IFN-γ in response to T. gondii, when P2 patients were compared with C2 controls. These early defects may impair anti-parasitic response in co-infected patients, allowing to reactivation of parasitic latent infection, enhancing the risk of CNS damage and impairment of neurocognitive functions.

Reactivated Toxoplasmic Encephalitis-A case report with histopathology, ultrastructure and pathogenesis analysis

We report a patient who developed reactivated toxoplasmic encephalitis due to human immunodeficiency (HIV)-associated immune compromise, resulting in a breakdown of the balance between the host immunity and toxoplasma cyst. Through detailed pathological analysis, spilling of tachyzoites from the ruptured wall of toxoplasma cyst can be identified. It was also proved that Toxoplasma gondii would infect endothelial cells of blood vessels, leading to vasculitis and brain ischemic necrosis. By transmission electron microscope (TEM), apical complex of the parasite can be identified, as well as tachyzoites in rapid reproduction through fission. Rhoptry, a club-shaped specialized organelle, which is characteristic of the motile stages of Apicomplexa protozoans, was also identified. The prevention of toxoplasma infection is still an issue to be emphasized in public health. This article is special in its pathophysiology-based description of the morphology. 'Form ever follows function' is a famous quote from the architect Louis Sullivan. In this case report, we make effort to depict a pathophysiology-based or a 'form-function correlation' interpretation of the histopathological findings by light microscope, IHC and ultrastructural examination. We believe such an approach should also be included in the daily pathology resident training program.

Indirect Hemagglutination Test in the Detection of Antibodies against Toxoplasma gondii in Venezuelan Felids / Prueba de hemaglutinación indirecta en la detección de anticuerpos contra Toxoplasma gondii en félidos venezolanos

Abstract Current knowledge of Toxoplasma gondii infection in Venezuelan ecosystems is limited. Mammals and birds are intermediate hosts, and felid species are definitive hosts. In most human-altered habitats, the domestic cat is the predominant definitive host. Cats are important in the epidemiology of T. gondii infection because they are the only hosts that can excrete environmentally resistant oocysts. Other carnivores can be infected consuming tissue cysts when feeding on infected animals and by incidental ingestion of oocysts from environmental contamination. This study aimed to quantify the values of antibodies for T. gondii in blood serum of some felids' species employing the technique of indirect hemagglutination. In the present study, seropositivity of T. gondii was determined in serum of 35 animals (22 stray cats and 13 wild cats) from Venezuela, South America. Antibodies to T. gondii were found in 21 of 22 (95.45 %) stray cats' titers of 1:64 in four, 1:128 in four, 1:256 in one, 1:512 in one, 1:1024 in three, and 1:2048 or higher in eight. In four of six (66.67 %) ocelots' titers of 1:64 in one, 1:256 in one, 1:1024 in one, and one with titers 1:2048. In three of four (75.00 %) jaguars' titers of 1:512 in one, and two with titers 1:2048. The Kruskal-Wallis test showed a statistically significant difference between species (H = 8.413, p = 0 .015).

Resumen El conocimiento actual de la infección por Toxoplasma gondii en los ecosistemas venezolanos es limitado. Los mamíferos y las aves son hospedadores intermedios y los félidos son hospedadores definitivos. En la mayoría de los hábitats alterados por el hombre, el gato doméstico es el hospedador definitivo predominante. Los gatos son importantes en la epidemiología de la infección por T. gondii porque son los únicos hospedadores que pueden excretar los ooquistes resistentes al medio ambiente. Otros carnívoros pueden infectarse por el consumo de quistes tisulares al alimentarse de animales infectados y por la ingestión incidental de ooquistes procedentes de la contaminación ambiental. Este estudio tuvo como objetivo cuantificar los valores de anticuerpos para T. gondii en el suero sanguíneo de algunas especies de félidos mediante la técnica de hemoaglutinación indirecta. En el presente estudio se determinó la seropositividad de T. gondii en el suero de 35 animales (22 gatos callejeros y 13 felinos silvestres) de Venezuela, Sudamérica. Los anticuerpos contra T. gondii se encontraron en 21 de 22 (95,45 %) gatos callejeros con títulos de 1:64 en cuatro, 1:128 en cuatro, 1:256 en uno, 1:512 en uno, 1:1024 en tres y 1:2048 o más en ocho. En cuatro de seis (66,67 %) ocelotes con títulos de 1:64 en uno, 1:256 en uno, 1:1024 en uno, y uno con títulos 1:2048. En 3 de 4 (75,00 %) jaguares con títulos de 1:512 en uno, y dos con títulos 1:2048. La prueba de Kruskal-Wallis mostró una diferencia estadísticamente significativa entre las especies (H = 8,413, p = 0,015).

Toxoplasma gondii Prevalence in Pregnant Women in Jataí - GO: a 10-year profile / Prevalência do Toxoplasma gondii em Gestantes no Município de Jataí ­ GO: um recorte de 10 anos / Prevalencia de Toxoplasma gondii en mujeres embarazadas de la Ciudad de Jataí - GO: un período de 10 años

Background and Objectives: Toxoplasmosis is a cosmopolitan zoonosis caused by the Toxoplasma gondii protozoan, transmitted mainly through contaminated water or food, beyond vertical transmission. In the State of Goiás, there is a lack of data on the prevalence of the disease, hence the relevance of this cross-sectional study to determine the prevalence of toxoplasmosis in pregnant women in the municipality of Jataí. Methods: Data were collected from pregnant women attended by the public health network in the municipality from January 2005 to December 2015. Results: During the analyzed period, 11,350 pregnant women were attended; 75% with IgG antibodies and 0,60% IgM antibodies reactive for T. gondii, with a reduction in the number of cases since 2010. Conclusion: The high seroprevalence found shows that pregnant women are in close contact with factors that trigger the infection and a reduction in the number of cases indicates the efficacy of epidemiological surveillance actions developed for this population group.(AU)

Justificativa e Objetivos: Toxoplasmose é uma zoonose cosmopolita causada pelo protozoário Toxoplasma gondii, transmitido principalmente através de água e alimentos contaminados e pela transmissão vertical. No estado de Goiás existe uma escassez de dados referentes à prevalência da toxoplasmose. Diante dessa realidade, tornou-se relevante esse estudo transversal que determinasse a prevalência da toxoplasmose nas gestantes no município de Jataí. Métodos: Foram coletados dados de grávidas atendidas pela rede pública de saúde no município no período de janeiro de 2005 a dezembro de 2015. Resultados: No período analisado, foram atendidas 11.350 gestantes, sendo 75% delas com anticorpos IgG e 0,60% anticorpos IgM reagentes para T. gondii, com redução no número de casos a partir de 2010. Conclusão: A alta soroprevalência encontrada demonstra que as grávidas estão em íntimo contato com os fatores que desencadeiam a infecção. É necessário investigar os fatores que contribuem para a elevada taxa de infecção.(AU)

Justificacíon y Objetivos: La toxoplasmosis es uma zoonosis cosmopolita causada por el protozoo Toxoplasma gondii, que se transmite principalmente através del agua o alimentos contaminados, además de la transmisión vertical. Em el estado de Goiás, se carece de dados sobre la prevalência de la enfermedad y ante esta realidade, es relevante este estudio transversal para determinar la prevalência de toxoplasmosis em gestantes del município de Jataí. Métodos: Se recolectaron dados de gestantes atendidas por la red de salud pública del município de Enero de 2005 a Diciembre de 2015. Resultados: Entre el período analizado se trató a 11.350 gestantes, 75% de ellas com anticuerpos IgG y 0,60% anticuerpos IgM reactivos para T. gondii, com uma reducción em el número de casos a partir de 2010. Conclusión: La alta soroprevalência encontrada muestra que las mujeres embarazadas están em estrecho contacto com los fatores desencadenantes de la infección y uma reducción em el número de casos apunta a uma eficácia em las acciones de vigilância epidemiológica desarrolladas para este grupo de problación.(AU)

Detección molecular de Toxoplasma gondii en carnes para consumo humano en Ibagué, Colombia / Molecular detection of Toxoplasma gondii in meat for human consumption in Ibague, Colombia

Introducción. Toxoplasma gondii es un parásito con gran potencial zoonótico que puede infectar un amplio rango de huéspedes de sangre caliente, incluidos los animales del sector pecuario, lo que causa pérdidas a la industria. En el humano, es patógeno en personas inmunosuprimidas y afecta el desarrollo del feto en infecciones congénitas. Además, se asocia con diversos trastornos del comportamiento en personas sanas. El humano puede adquirir T. gondii al consumir carnes contaminadas mal cocidas. Objetivo. Determinar la positividad de T. gondii en carnes de consumo humano (res, pollo y cerdo) en Ibagué, Colombia. Materiales y métodos. Se utilizó la PCR convencional anidada y la secuencia del gen B1 de T. gondii como blanco de amplificación. Se tomaron 186 muestras de carne comercializada en la zona urbana de Ibagué (62 de res, 62 de pollo y 62 de cerdo) y se obtuvo el porcentaje de positividad en cada tipo de carne evaluada. Resultados. Se encontró un porcentaje de positividad de 18,8 % en las muestras, siendo la carne de cerdo la del mayor porcentaje (22,5 %; 14/62), seguida por las muestras de carne de res (19,3 %; 12/62) y de pollo (14,5 %; 9/62). Los mejores productos amplificados fueron secuenciados en Macrogen, y alineados con las secuencias del gen B1 depositadas en el GenBank, con lo que se confirmó su identidad. Conclusiones. Este es el primer estudio sobre prevalencia de T. gondii en carnes para consumo humano en Ibagué y el departamento del Tolima. Se demostró que los tres tipos de carne representan un riesgo para la infección en humanos a nivel local.

Introduction: Toxoplasma gondii is a parasite with great zoonotic potential. It can infect a broad range of warm-blooded hosts (including livestock) and causes significant losses in the industry. In humans, it has been described as a pathogen in immunosuppressed people, it affects the fetus development in congenital infections, and is associated with various behavioral disorders in healthy people. Humans can acquire T. gondii by consuming undercooked, contaminated meat. Objective: To determine T. gondii positivity (currently unknown) in meat for human consumption (i.e., beef, chicken, and pork) in the city of Ibague, Colombia. Materials and methods: We used conventional nested PCR and the T. gondii B1 gene sequence as amplification target. We collected samples of meat (N=186) sold in the urban area of Ibagué (62 beef, 62 chicken, and 62 pork samples) and determined the T. gondii positivity percentage for each type of meat. Results: The study found an average of 18.8% positivity for all meat samples, pork having the highest percentage (22.5%; 14/62), followed by beef (19.3%; 12/62) and chicken (14.5%; 9/62). The best-amplified products were sequenced by macrogen and aligned with the B1 gene sequences in GenBank, thereby confirming their identity. Conclusions: This is the first study of T. gondii prevalence in meat for human consumption carried out in the city of Ibagué and the department of Tolima. All three types of meat sampled represent a risk for local human infection.

Masa parotídea de rápido crecimiento, representando un dilema diagnóstico / Rapidly growing parotid gland mass, posing a diagnostic dilemma

La toxoplasmosis es una infección parasitaria con distribución mundial, cuyo huésped definitivo son los felinos. Se presenta con un cuadro clínico sintomático difuso solo en el 20 % de los pacientes inmunocompetentes. Además del malestar general, fiebre y adinamia, el hallazgo más importante lo constituye la presencia de adenopatías a nivel cervical. Describimos un caso poco común de un paciente masculino con masa parotídea izquierda de crecimiento rápido, en quien se practicó parotidectomía, a fin de descartar la enfermedad linfoproliferativa. Se comprobó compromiso por Toxoplasma gondii luego de múltiples análisis.

Toxoplasmosis is a parasitic infection with worldwide distribution, whose definitive host is felines. It is only symptomatic in less than 20% of immunocompetent patients. Symptoms may vary from general malaise, fever, weakness and the presence of cervical lymphadenopathy. A description of an uncommon presentation of this disease in a male patient with progressively growing left-sided parotid mass, in whom a parotidectomy was performed to rule out lymphoproliferative disease. Infection by Toxoplasma gondii was diagnosed after a series of exams

Toxoplasma gondii infection induces cell apoptosis via multiple pathways revealed by transcriptome analysis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients. Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis, but the mechanism of cell apoptosis induced by T. gondii remains obscure. To explore the apoptosis influenced by T. gondii, Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing (RNA-seq). Using high-throughput Illumina sequencing and bioinformatics analysis, we found that pro-apoptosis genes such as DNA damage-inducible transcript 3 (DDIT3), growth arrest and DNA damage-inducible α (GADD45A), caspase-3 (CASP3), and high-temperature requirement protease A2 (HtrA2) were upregulated, and anti-apoptosis genes such as poly(adenosine diphosphate (ADP)-ribose) polymerase family member 3 (PARP3), B-cell lymphoma 2 (Bcl-2), and baculoviral inhibitor of apoptosis protein (IAP) repeat containing 5 (BIRC5) were downregulated. Besides, tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1), TRAF2, TNF receptor superfamily member 10b (TNFRSF10b), disabled homolog 2 (DAB2)‍-interacting protein (DAB2IP), and inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) were enriched in the upstream of TNF, TNF-related apoptosis-inducing ligand (TRAIL), and endoplasmic reticulum (ER) stress pathways, and TRAIL-receptor 2 (TRAIL-R2) was regarded as an important membrane receptor influenced by T. gondii that had not been previously considered. In conclusion, the T. gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells. Our findings improve the understanding of the T. gondii infection process through providing new insights into the related cellular apoptosis mechanisms.

Effects of Toxoplasma gondii infection on mouse and human uterine natural killer cells / 中国血吸虫病防治杂志

Objective To examine the effects of Toxoplasma gondii infection on the proportion, quantity, differentiation and function of mouse and human uterine natural killer cells (uNK cells), so as to explore the role of uNK cells in abortion of early pregnancy caused by T. gondii infection. Methods Pregnant mice were injected intraperitoneally with T. gondii tachyzoites on day 6.5 of pregnancy, and the abortion mouse model caused by T. gondii infections was constructed. Mouse uterine lymphocytes were isolated on day 9.5 of pregnancy. Human uterine lymphocytes were isolated from fresh human decidual specimens after abortion in normal early pregnancy and co-cultured with tachyzoites of the T. gondii RH strain for 48 h at T. gondii/uterine lymphocytes ratios of 0.5:1, 1:1 and 2:1. The phenotypes of mouse uNK cells (CD122, NK1.1, DX5) and human uNK cells (CD3, CD56, CD11b, CD27) and the expression of intracellular cytokines interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were detected by flow cytometry. Mouse and human uNK cells were sorted by magnetic beads, and the cytotoxicity of uNK cells was tested using the lactate dehydrogenase (LDH) release assay at effector/target cell ratios of 1:1, 5:1, 10:1 and 20:1 with mouse or human uNK cells as effector cells and mouse YAC-1 cells or human K562 cells as target cells. Results On day 9.5 of pregnancy, the mouse abortion rate was significantly higher in the infected group than that in the control group (83.02% vs. 3.51%; χ2 = 71.359, P < 0.001). Significantly lower absolute number of uNK cells [(4 547 ± 1 610) cells/mouse vs. (8 978 ± 3 339) cells/mouse; U = 2.000, P < 0.05], lower NK1.1 expression on uNK cell surface [(74.53 ± 8.37)% vs. (93.00 ± 1.11)%; U = 0.000, P < 0.05], higher proportion of NK1.1-DX5-cells [(20.10 ± 8.03)% vs. (5.04 ± 0.68)%; U = 0.000, P < 0.05], lower proportion of NK1.1+ DX5+ cells [(21.70 ± 12.48)% vs. (45.75 ± 2.26)%; U = 0.000, P < 0.05] and higher IFN-γ expression [(16.74 ± 1.36)% vs. (8.13 ± 1.90)%; U = 0.000, P < 0.05] were detected in the infected group than in the control group, while no significant difference was seen in TNF-α expression between the two groups [(67.98 ± 9.20)% vs. (52.93 ± 10.42)%; U = 2.000, P > 0.05]. The mouse uNK cells showed a strong cytotoxicity in the infected group, and the cytotoxicity gradually increased with the effector/target cell ratio. The cytotoxicity of uNK cells against YAC-1 cells was 2.30%, 4.32%, 8.12% and 12.65% in the infected group and 1.21%, 1.63%, 2.51% and 3.22% in the control group at effector/target cell ratios of 1:1, 5:1, 10:1 and 20:1, respectively. Following co-culture of human uterine lymphocytes and tachyzoites of the T. gondii RH strain for 48 h, the proportion [TOX 2:1 group vs. control group: (6.61 ± 1.75)% vs. (17.48 ± 4.81)%; F = 7.307, P < 0.01], and absolute number of human uNK cells in uterine lymphocytes of human uNK cells in uterine lymphocytes [TOX 2:1 group vs. control group: (12 104 ± 5 726) cells/well vs. (65 285 ± 21 810) cells/well; H = 11.540, P < 0.01] were significantly lower in the infected group than in the control group. A lower proportion of CD56brightCD16- NK cells [TOX 2:1 group vs. control group: (25.25 ± 5.90)% vs. (36.03 ± 4.51)%; F = 3.213, P > 0.05] and higher proportion of CD56dimCD16+ NK cells [TOX 2:1 group vs. control group: (11.15 ± 2.15)% vs. (7.09 ± 2.24)%; F = 2.992, P > 0.05] were detected in uNK cells in the infected group than in the control group, and the ratio of CD56brightCD16- cells/CD56dimCD16+ cells was significantly lower in the infected group than in the control group [TOX2:1 group vs. control group: (2.37 ± 0.92) vs. (5.58 ± 2.39); H = 8.228, P < 0.05]. In addition, the proportion of CD11b+CD27- cells in human uNK cells was significantly higher in the infected group than in the control group [TOX 2:1 group vs. control group: (30.28 ± 6.91)% vs. (17.48 ± 4.67)%; H = 6.556, P < 0.05], while no significant differences were found between the two groups in terms of IFN-γ [TOX 2:1 group vs. control group: (14.13 ± 1.28)% vs. (15.19 ± 1.64)%; F = 1.639, P > 0.05] or TNF-α expression [TOX 2:1 group vs. control group: (54.76 ± 10.02)% vs. (50.33 ± 3.67)%; F = 0.415, P > 0.05]. Human uNK cells presented a strong cytotoxicity in the infected group, and the cytotoxicity gradually increased with the effector/target cell ratio. The cytotoxicity of human uNK cells against K562 cells was 11.90%, 28.11%, 49.91% and 73.35% in the infected group and 12.21%, 21.63%, 33.51% and 48.22% in the control group at effector/target cell ratios of 1:1, 5:1, 10:1 and 20:1, respectively. Conclusions T. gondii infection presents diverse effects on the differentiation and secretion ability of mouse and human uNK cells. However, T. gondii infection causes a reduction in the absolute number and enhances the cytotoxicity of both mouse and human uNK cells.