Search

Toxoplasma gondii (T. gondii) affects around 30% of humans worldwide. Recently, it has emerged as a significant opportunistic pathogen to immunocompromised patients. Data available is still lacking about toxoplasmosis in cancer patients in Egypt. This study aimed to reveal the current trend of T. gondii in cancer patients in Sohag, Egypt. Sera from 50 cancer patients and 50 healthy controls were screened for Toxoplasma IgG and IgM. Further, buffy coats from both groups were used for detection of T. gondii B1 and RE genes via conventional and nested PCR, respectively. The overall seroprevalence of T. gondii IgG was high (58%). IgG and IgM were detected in 30% and 9% cancer patients, respectively. Patients with solid cancers exhibited a greater IgG seropositivity compared to those with hematologic tumors (77.27% and 46.43%, respectively) (P = 0.03). Concerning the molecular results, only 4 (9%) were positive regarding both PCR assays. In conclusion, T. gondii is highly prevalent in cancer patients in Sohag, Egypt. PCR is strongly recommended to complement serology to diagnose acute or reactivated toxoplasmosis in cancer patients. B1 PCR was found to be equivalent to RE PCR. Nevertheless, thorough large-scale research must be implemented., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Consent to participate: The participants/ their legal guardians gave informed consents for participation in the current study. Consent for publication: All authors agreed to the publication of the manuscript., (© 2025. The Author(s).)

Background: Toxoplasma gondii (T. gondii) is the most successful obligate protozoan that can infect warm-blooded vertebrate hosts. Some researchers suggest that the presence of Toxoplasma cysts in the brain can lead to mental disorders. Bipolar disorder (BD) is one of the serious neuropsychiatric disorders. Several studies have shown a high seroprevalence of T. gondii in bipolar patients. Therefore, this study aims to determine the prevalence of this infection in patients with BD., Methods: In this case-control study, anti-Toxoplasma immunoglobulin (Ig) G and IgM antibodies were measured in serum samples from 115 patients with BD and 115 subjects without this disorder from the general population using commercially available enzyme-linked immunosorbent assay. Demographic characteristics of the patient and control groups, information about T. gondii infection and BD, and their potential risk factors were analyzed. We utilized the Mann-Whitney U test for continuous variables, the chi-square test for categorical data, and multivariate logistic regression to assess T. gondii infection and BD, with significance set at P < 0.05., Results: Twenty-eight (24.34%) of 115 patients with BD and 10 (8.7%) of 115 controls had anti-T. gondii IgG antibodies. IgM antibodies against T. gondii were not reported to be positive in any participants. Furthermore, there was a statistically significant difference in the results [odds ratio (OR) = 2.89: 95% confidence interval (CI) = 1.08-7.73. P = 0.03]. Within the study population, various factors were identified as significant risk factors for BD: sex (OR 8.10, 95% CI 3.16-20.75), age 20-50 (OR 5.11, 95% CI 1.81-14.45), age over 50 (OR 19.54, 95% CI 4.02-94.89), education level (OR 0.24, 95% CI 0.09-0.60), working status (non-employment, OR 4.12, 95% CI 1.65-10.30), and income (middle, OR 0.29, 95% CI 0.10-0.89; high, OR 0.12, 95% CI 0.01-0.77), all with P-values less than 0.05. In addition, in the group of patients, there was no statistically significant relationship between T. gondii infection with the type of bipolar disease (P = 0.93), the severity of the disease (P = 0.61), and the history of suicide attempts (P = 0.63)., Conclusion: This study showed that toxoplasmosis is a risk factor for BD and increases the chance of developing BD. However, more studies with a larger sample size are recommended to clarify the development pathways of this disorder and provide new strategies for the prevention and treatment of this disease., Clinical Trial: Not applicable., Competing Interests: Declarations. Ethics approval and consent to participate: The study protocol received approval from Birjand University of Medical Sciences, under the ethical code number IR.BUMS.REC.1399.385. All participants in our study provided informed consent prior to their inclusion. We adhered to all relevant guidelines and regulations throughout the study. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Introduction: The objective of this study was twofold: first, to evaluate the method of sample collection that would enable the measurement of anti-Toxoplasma antibodies in forensic samples, and second, to report the prevalence of antibodies in deceased individuals due to traffic accidents, homicides, and suicides who are brought to the National Institute of Legal Medicine and Forensic Sciences, Western Regional Office (INMLCF) in Armenia, Manizales and Pereira, cities located in the center andes region of Colombia., Methods: Initially, we assessed the feasibility of measuring antibodies on filter paper or in Vacutainer tubes. Serum samples from 15 voluntary individuals were collected as controls, and the measurement of antibodies on filter paper was compared with the same samples collected in Vacutainer tubes after two days at room temperature. Subsequently, 42 blood samples were collected from forensic cases involving various causes of death in Manizales, Armenia, and Pereira. Measurement of anti-Toxoplasma IgG and IgM antibodies was performed using the VIDAS II kit from Biomerieux®., Results: The volunteer samples consistently tested negative when using filter paper, whereas their positivity was preserved when collected in Vacutainer tubes and before 48 h after death. Therefore, the forensic samples were collected using Vacutainer tubes. Out of the 42 forensic blood samples, 19 (45.2 %) tested positive for IgG anti-Toxoplasma antibodies. All samples tested negative for IgM anti-Toxoplasma antibodies. A significant association was observed between antibody positivity and the city of origin, while deaths due to traffic accidents showed a negative association with toxoplasmosis., Conclusions: We found that filter paper was unsuitable for collecting samples for post-mortem serological studies. The positivity of antibodies varied significantly depending on the city, and in Manizales, deaths resulting from traffic accidents were not associated with toxoplasmosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Toxoplasmosis is a zoonotic disease caused by the obligate intracellular protozoan Toxoplasma gondii. The current study assessed the seroepidemiological status and risk factors of T. gondii in the West Bank, Palestine. We conducted a retrospective study among 1,475 patients referred for serological examination for toxoplasmosis between 2017 and 2021 at the Central Public Health Laboratory. The overall prevalences of anti-T. gondii IgG and IgM antibodies were 1.0% [18.9-23.0%] and 1.0% [0.5-1.6%], respectively. Multifactorial analysis showed that age and sex were significantly associated with the presence of IgG antibodies. The prevalence of IgG antibodies was highest in 2018 and decreased significantly each year until 2021. Routine serological screening in women of childbearing age and pregnant women is recommended.

Background and Aim: Immunity alterations have been observed in bipolar disorder (BD). However, whether serum positivity of antibodies to Toxoplasma gondii (T gondii), rubella, and cytomegalovirus (CMV) shared clinical relevance with BD, remains controversial. This study aimed to investigate this association., Methods: Antibody seropositivity of IgM and IgG to T gondii, rubella virus, and CMV of females with BD and controls was extracted based on medical records from January 2018 to January 2023. Family history, type of BD, onset age, and psychotic symptom history were also collected., Results: 585 individuals with BD and 800 healthy controls were involved. Individuals with BD revealed a lower positive rate of T gondii IgG in the 10-20 aged group (OR = 0.10), and a higher positive rate of rubella IgG in the 10-20 (OR = 5.44) and 20-30 aged group (OR = 3.15). BD with family history preferred a higher positive rate of T gondii IgG (OR = 24.00). Type-I BD owned a decreased positive rate of rubella IgG (OR = 0.37) and an elevated positive rate of CMV IgG (OR = 2.12) compared to type-II BD, while BD with early onset showed contrast results compared to BD without early onset (Rubella IgG, OR = 2.54; CMV IgG, OR = 0.26). BD with psychotic symptom history displayed a lower positive rate of rubella IgG (OR = 0.50)., Limitations: Absence of male evidence and control of socioeconomic status and environmental exposure., Conclusions: Differential antibody seropositive rates of T gondii, rubella, and cytomegalovirus in BD were observed., Competing Interests: Declaration of competing interest The authors have no competing interests to declare that are relevant to the content of this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: To evaluate the ability of the estimated plasma expression levels of genes of microRNA (MiR-) 146a and 155 to differentiate between samples of pregnant women suspected to be infected by T. gondii. 50 newly pregnant women who had at least one of the criteria of high risk for toxoplasma infection and 50 newly primigravida women free of these criteria gave blood samples for qualitative determination of serum toxoplasma antibodies and estimation of plasma expression levels of MiR-146a and 155 using the qRT-PCR. During the pregnancy course, the incidence of pregnancy complications was recorded., Results: Twenty-six women were IgM - /IgG - , 17 women were IgM + /IgG - and 7 women were IgM + /IgG + . Thirty-two women had pregnancy complications with significantly lower incidence in IgM - /IgG - women. Plasma expression levels of MiR-146a and 155 were significantly higher in total patients compared to control levels and were significantly higher in samples of IgM + /IgG + patients than in other samples. Statistical analyses defined a high plasma level of MiR-155 as the highly significant predictor for oncoming pregnancy complications and high levels of both microRNAs as predictors for the presence of toxoplasmosis despite seronegativity. Kaplan-Meier regression analysis defined increasing cumulative risk of having toxoplasmosis despite seronegativity with plasma levels of MiR-146a and MiR-155 of 1.2 and 3, respectively., Conclusion: The incidence of pregnancy complications is high, irrespective of the seronegativity of women at high risk of toxoplasmosis. Estimated plasma levels of MiR-155 might identify women liable to develop complications and differentiate seronegative women vulnerable to having T. gondii infection., Trial Registration: The study protocol was approved preliminarily by the Local Ethical Committee at Benha Faculty of Medicine. Before enrollment, the study protocol was discussed in detail with the study participants, and those accepted to participate in the study signed written fully informed consents. The final approval of the study protocol was obtained after the end of case collection and registered by RC: 5-11-2022., (© 2024. The Author(s).)

Toxoplasma gondii is a neurotropic protozoan parasite that affects neuronal processing in the brain. This study aimed to investigate the prevalence of T. gondii infection in psychiatric disorder patients. We also investigated the potential association between sociodemographic, clinical manifestation, and behavior of Toxoplasma-seropositive patients with psychiatric disorders. Commercial ELISAs (IgG, IgM, and IgG avidity) using serum and PCR using buffy coat were performed on samples from 54 individuals in each of the following groups: patients diagnosed with depressive disorder, bipolar disorder, and schizophrenia, as well as psychiatrically healthy subjects (control group). They were recruited from the Hospital Universiti Sains Malaysia in Kelantan, Malaysia. Of 54 patients with depressive disorder, 24/54 (44.4 %) were seropositive for IgG, and four (16.7 %) were IgG+/IgM+. Among the latter, a high avidity index indicating a past infection was observed in half of the samples (50.0 %), and the other half (50.0 %) showed a low avidity index, indicating a possible recent infection. Meanwhile, 30/54 (55.6 %) patients with bipolar disorder were seropositive for IgG+, five (16.7 %) were IgG+/IgM+, and four of them had a high avidity index, and one had a low avidity index. Patients with schizophrenia showed 29/54 (53.7 %) seropositive for IgG, two of them (6.9 %) were IgG+/IgM+; one of latter had a high avidity index, and one had a low avidity index. Of 54 people in the control group, 37.0 % (20/54) were seropositive for T. gondii IgG antibodies. However, no significant difference was observed in seroprevalence between the control group and each patient group. No PCR-positive results were documented. A Chi-Square and multiple logistic regression showed that age (p = 0.031), close contact with cats/pets (p = 0.033) and contact with soil (p = 0.012) were significantly associated with Toxoplasma seropositivity in patients with psychiatric disorders. Additional research is needed to elucidate the causal relationships and underlying mechanisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Toxoplasmosis is a zoonotic parasitic disease caused by Toxoplasma gondii (T. gondii) . It has a wide host range and is capable of vertical transmission in pregnant women, which may lead to undesirable pregnancy outcomes such as congenital malformations, miscarriage, premature birth and stillbirth. This study investigated the seroprevalence of T. gondii infection among pregnant women attending the antenatal clinic at Namwala District Hospital in Southern Zambia., Methods: This was a cross-sectional study where blood was collected, and the serum was tested for Toxoplasma IgG and IgM. A questionnaire was administered to participants on demographic characteristics and risk factors. Data were entered in Microsoft Excel and exported to STATA version 14 for analysis., Results: A total of 401 women were enrolled in the study from 3 March to 5 August 2021. The seroprevalence of Toxoplasma IgG was 4.2% (n=17), while the seroprevalence of Toxoplasma IgM was 0.7% (n=3). The median age was 27 (IQR: 24-30) years, and a larger proportion had primary-level education (n=223, 55.6%). The majority (81.6%) of the women were married. None of the risk factors investigated in this study were significant for T. gondii infection., Conclusion: There was a low seroprevalence of T. gondii infection among pregnant women in the Namwala district of Southern Province, Zambia, and regular screening may not be warranted in this population. Continued research on toxoplasmosis is recommended to understand its epidemiology across Zambia., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

We aimed to assess salivary and seroprevalence of Toxoplasma immunoglobulins in risky populations and evaluate drug docking targeting TgERP. A cross-sectional study was conducted in Alexandria University hospitals' outpatient clinics. 192 participants were enrolled from September 2022 to November 2023. Anti-Toxoplasma IgG and IgM were determined in serum and saliva by ELISA. An in-Silico study examined TgERP's protein-protein interactions (PPIs) with pro-inflammatory cytokine receptors, anti-inflammatory cytokine, cell cycle progression regulatory proteins, a proliferation marker, and nuclear envelope integrity-related protein Lamin B1. Our findings revealed that anti-T. gondii IgG were detected in serum (66.1%) and saliva (54.7%), with 2.1% of both samples were positive for IgM. Salivary IgG had 75.59% sensitivity, 86.15% specificity, 91.40% PPV, 64.40% NPP, 79.17% accuracy and fair agreement with serum IgG. On the other hand, the sensitivity, specificity, PPV, NPV, and accuracy in detecting salivary IgM were 75.0%, 99.47%, 75.0%, 99.47%, and 98.96%. AUC 0.859 indicates good discriminatory power. Examined synthetic drugs and natural products can target specific amino acids residues of TgERP that lie at the same binding interface with LB1 and Ki67, subsequently, hindering their interaction. Hence, salivary samples can be a promising diagnostic approach. The studied drugs can counteract the pro-inflammatory action of TgERP., (© 2024. The Author(s).)

Background: An immunochromatography technology (ICT) rapid diagnostic test, the Toxoplasma ICT IgG-IgM ® , was recently developed. Our aim was to study its contribution to establish accurately the Toxoplasma immune status in Tunisian pregnant women using Western blot (WB) Toxo II IgG ® as a reference technique., Methods: Thirty-nine sera were selected for the study from among 2,615 which were already tested by IgG and IgM ELISA. They displayed equivocal IgG titres (4.4-9 IU/ml) in absence of IgM (19 sera) or IgM anti-Toxoplasma antibodies in absence of IgG (titre <4.4 IU/ml) (20 sera). All these sera were additionally tested by WB Toxo II IgG ® ., Results: Immunochromatography technology Sensitivity in the detection either of low IgG titres in absence of IgM or of specific anti-Toxoplasma IgM was 100%. Only one serum with equivocal IgG titre by ELISA and negative with Toxo II IgG ® test revealed positive in ICT. However, this serum showed a P30 band in WB analysis. On the other hand, three sera positive in ELISA IgM and negative in ELISA IgG revealed positive in ICT and negative in WB Toxo II IgG ® , the reference test., Conclusion: Results confirm the high sensitivity of Toxoplasma ICT IgG-IgM ® in detecting both specific anti-Toxoplasma IgG and IgM, and highlight the usefulness of this rapid test as a first or second-line Toxoplasma serological test in pregnant women., (© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

The seroepidemiology of infection with Toxoplasma gondii (T. gondii) in alcohol consumers is largely undeveloped. In light of this, we sought to determine the seroprevalence of T. gondii infection in alcohol consumers in Durango, Mexico, and the association of T. gondii seroprevalence with characteristics of the population studied. Anti-T. gondii IgG and IgM antibodies were searched in sera of participants using commercially available enzyme immunoassays. Bivariate and logistic regression analyses were then used to determine the association between T. gondii infection and the characteristics of the population studied. Of the 1544 people studied (mean age: 39.4±14.0 years), 173 (11.2%) tested positive for anti-T. gondii IgG antibodies. We were able to test 167 of the 173 anti-T. gondii IgG positive sera for anti-T. gondii IgM antibodies. Fifty-five (32.9%) of these 167 serum samples were positive for anti-T. gondii IgM antibodies. Bivariate analysis showed that visual impairment, history of surgery, and hepatitis were negatively associated with T. gondii IgG seropositivity (P<0.05). In women, seropositivity to T. gondii was positively associated with a history of pregnancy (P<0.05). Logistic regression analysis showed that T. gondii seropositivity was associated with the variables consumption of armadillo meat (OR = 2.33; 95% CI: 1.04-5.22; P = 0.03), and the use of latrines for elimination of excretes (OR = 2.27; 95% CI: 1.07-4.80; P = 0.03); and high (>150 IU/ml) anti-T. gondii IgG antibodies were associated with consumption of both armadillo meat (OR = 2.25; 95% CI: 1.01-5.02; P = 0.04) and crowding at home (OR = 1.63; 95% CI: 1.02-2.61; P = 0.03). We found a distinct T. gondii seroprevalence in people with alcohol consumption from those previously found in population groups in the region. This is the first study that illustrates the association between high anti-T. gondii antibodies and crowding in Mexico, and the second study on the association between T. gondii infection and consumption of armadillo meat and the use of latrines in this country. We conclude that epidemiology of T. gondii infection in people with alcohol consumption deserves further investigation., Competing Interests: The authors have declared that no competing interests exist.

Glycosylphosphatidylinositol anchored proteins (GPI-APs) are natural conjugates in the plasma membrane of eukaryotic cells that result from the attachment of a glycolipid to the C-terminus of many proteins. GPI-APs play a crucial role in cell signaling and adhesion and have implications in health and diseases. GPI-APs and GPIs without protein (free GPIs) are found in abundance on the surface of the protozoan parasite Toxoplasma gondii. The detection of anti-GPI IgG and IgM antibodies allows differentiation between toxoplasmosis patients and healthy individuals using serological assays. However, these methods are limited by their poor efficiency, cross-reactivity and need for sophisticated laboratory equipment and qualified personnel. Here, we established a label-free electrochemical glycobiosensor for the detection of anti-GPI IgG and IgM antibodies in serum from toxoplasmosis seropositive patients. This biosensor uses a synthetic GPI phosphoglycan bioreceptor immobilized on screen-printed gold electrodes through a linear alkane thiol phosphodiester. The antigen-antibody interaction was detected and quantified by electrochemical impedance spectroscopy (EIS). The resultant device showed a linear dynamic range of anti-GPI antibodies in serum ranging from 1.0 to 10.0 IU mL -1 , with a limit of detection of 0.31 IU mL -1 . This method also holds great potential for the detection of IgG antibodies related to other multiple medical conditions characterized by overexpression of antibodies., Competing Interests: Declaration of competing interest The authors declare there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This study compared the performance of the LIAISON®XL system of immunoglobulin (Ig) G and IgM immunoassays for the diagnosis of Toxoplasma gondii, cytomegalovirus (CMV), and rubella virus infections with that of the ARCHITECT system. Patient serum samples, previously screened and clinically diagnosed with T. gondii, CMV or rubella, were used to compare LIAISON®XL and ARCHITECT IgG and IgM immunoassays. LIAISON®XL Toxo and CMV IgG avidity assays were also compared with equivalent ARCHITECT assays and reference methods. Overall agreement between the LIAISON®XL and ARCHITECT assays was 99% and 92% for the Toxo IgG and IgM assays, respectively, 98% and 96% for the CMV IgG and IgM assays, respectively, and 93% and 98% for the rubella virus IgG and IgM assays, respectively. LIAISON®XL IgG Toxo and CMV avidity assays showed high concordance with the VIDAS® Toxo IgG avidity assay and an in-house CMV avidity assay (reference methods), and faster IgG avidity maturation in a larger number of samples collected months after the primary infection compared with equivalent ARCHITECT assays. LIAISON®XL assays for detection of anti-T. gondii, CMV and rubella virus IgG and IgM are at least equal to the competitor assays on the ARCHITECT platform.

Background: Toxoplasmosis is one of the most important cosmopolitan life-threatening diseases in immune-compromised patients. It is caused by an intracellular protozoon: Toxoplasma gondii (T. gondii). The parasite can cause pneumonia, encephalitis or disseminated disease in immune-deficient patients and dangerous congenital anomalies in infants born to mothers infected during early pregnancies. The present study aims to evaluate the prevalence of toxoplasmosis in Egyptian cancer patients and to correlate the prevalence with type of malignancy and the different cancer treatment modalities. Materials and Methods: Blood samples from 150 cancer patients and 50 control subjects have been examined for presence of anti-toxoplasma antibodies using a lateral flow chromatographic immunoassay. Results: Among cancer patients included in this study, the prevalence of anti- T.gondii antibodies was 20% for IgG and 4% for IgM, while in the control group it was 8% and 2% in the same order. This difference was statistically significant for IgG (P =0.003) but not for IgM (P = 0.44). Patients with solid organ tumors treated with chemotherapy had the highest prevalence rate of toxoplasmosis (28%). It was also found higher in males (26%) than females (10%) and higher among urban (18%) than rural dwellers (16%). Conclusion: Cancer patients showed a significantly higher rate of infection with T. gondii than their cross-matched control. For that reason, we recommend the inclusion of a screening test for toxoplasmosis in their routine workup., (Creative Commons Attribution License)

The present study investigated: (a) the presence of antiphospholipid antibodies and (b) the obstetric outcome in healthy pregnant women showing false-positive TORCH-Toxoplasmosis, Other: syphilis, varicella-zoster, Rubella, Cytomegalovirus (CMV), and Herpes infections-results. Data from 23 singleton healthy pregnancies with false-positive TORCH results were collected. Each woman was systematically screened for TORCH IgG and IgM during the pre-conception assessment and/or at the beginning of pregnancy. In the presence of IgM positivity, when indicated (CMV, toxoplasmosis, rubella, herpes simplex virus), IgG avidity was evaluated and, if possible, polymerase chain reaction was performed on an amniotic fluid sample in order to distinguish between primary infection or false positivity. The antiphospholipid antibodies tests were: lupus anticoagulant, anticardiolipin antibodies IgG, IgM, and anti-β2glicoprotein I IgG, IgM. The antiphospholipid antibodies tests, if positive, were repeated after 12 weeks to confirm the results. In pregnant women with false-positive TORCH, the overall prevalence of positive antiphospholipid antibodies for one or more tests was 52.2%. To clarify the correlation of false-positive TORCH results with clinical practice, obstetric outcome was analyzed in terms of live births, week of delivery, neonatal birth weight, and neonatal birth weight percentile. A statistically significant lower neonatal birth weight and neonatal birth weight percentile were observed in women with false-positive TORCH associated with antiphospholipid antibodies positivity (Group A) in comparison with those in women with false-positive TORCH without antiphospholipid antibodies positivity (Group B). No statistically significant difference was found for the week of delivery between the two groups. It is hoped that future studies will verify the life-long persistence of antiphospholipid antibodies positivity by follow-up of these women and identify who will develop a classical antiphospholipid syndrome or other autoimmune disorders.

Background: Toxoplasmosis is a widely distributed zoonotic disease, caused by the protozoan parasite Toxoplasma gondii. T. Infections can result in stillbirths, abortions or congenital defects during pregnancy, as well as toxoplasmic encephalitis in HIV/AIDS patients. This study aimed to determine the seroprevalence and risk factors for T. gondii infection in women seeking antenatal and medical care in the locality of Njinikom, North West of Cameroon., Methods: We conducted a cross-sectional study from August to December 2014 consecutively enrolling 178 consenting women aged 15 to 49 years attending antenatal care or medical check-ups at the hospital. A questionnaire survey was administered to study participants and potential risk factors for Toxoplasma exposure sought. Venous blood was collected and serum from each participant analysed for T. gondii infection as evidenced by the presence of anti-T. gondii IgG and IgM antibodies detected using the indirect enzyme-linked immunosorbent assay (ELISA) technique. The proportion of anti-T. gondii antibody positivity calculated as the percentage of antibody seropositivity to T. gondii antigens. Predictors of T. gondii infection were analysed by univariate and multivariate regression and association with T. gondii seropositivity assessed. Epi-Info 3.5.4 was used for statistical analyses. A p < 0.05 was considered significant for all analyses., Results: The seroprevalence of anti-T. gondii antibodies (IgM or IgG) were 54.5 % (97/178). Among seropositive women, 88.7 % (86/97), 30.9 % (30/97), and 19.6 % (19/97) were respectively seropositive for IgG antibody, IgM antibody and both IgM and IgG antibodies. Among the risk factors evaluated, only the consumption of raw or undercooked meat (p = 0.02) was observed to be an independent risk factor of T. gondii infection. The consumption of unwashed vegetables and fruits was significant (p = 0.01) only with simple logistic regression analysis., Conclusions: Our findings suggest recent T. gondii exposure is high in our study population, and may constitute a significant risk factor for stillbirths, abortions or congenital defects during pregnancy in women attending antenatal care, or toxoplasmic encephalitis in those who are immunosuppressed such as in HIV/AIDS. Education and screening of HIV-positive individuals and pregnant women for T. gondii infection may be important primary prevention strategies in this population.

Congenital toxoplasmosis is associated with important morbidity and mortality. Since vertical transmission of Toxoplasma gondii can occur in acute cases, antenatal screening for recent infections is vital. Accurate determination of acute toxoplasmosis requires a combination of immunoassays, usually not routinely applied for screening purposes. This study evaluated the anti-T. gondii (IgG+IgM)/IgM prenatal screening procedure by IgG avidity assay. The routine prenatal screening for (IgG+IgM) anti-T. gondii by indirect hemagglutination (IHA) in serum samples was done of 2247 pregnant women who attended two hospitals between 2011 and 2013 revealed 487 (21.7%) positive samples. Examination of IHA-positive sera by IgM and IgG/IgG-avidity concurrent ELISA tests revealed 7 positive and 3 border-line IgM-ELISA titers during the initial check-up of 10 women, who were then followed up at 3-4 week-intervals. Among these, 4 (40%) showed simultaneous high avidity IgG antibodies, indicating distant infection by the parasite, and no anti-T. gondii specific IgG could be detected in follow-up sera of two cases (20%), indicating false IgM initial positive results. Only 4 (40%) women showed simultaneous IgM and low avidity IgG antibodies indicating active infections. Avoidance of an over-diagnosis of acute toxoplasmosis Anti-T. gondii (IgG+IgM)/IgM prenatal screening must be supplemented by a discriminative test like IgG avidity ELISA.

Toxoplasma gondii (T. gondii) is a protozoan parasite that can cause toxoplasmosis in humans. However, there is no current data regarding Toxoplasma infection among individuals who were referred to medical laboratories in Mazandaran province (northern Iran). Therefore, we performed a population-based study of Toxoplasma seroprevalence in this region. A total of 1832 sera samples (from 654 men and 1178 women) were collected from people who were referred to medical laboratories in different cities throughout Mazandaran province between March and July 2012. The serum titers of anti-T. gondii IgG and IgM were measured using enzyme-linked immunosorbent assays. The seroprevalence of anti-Toxoplasma IgG was 55.5%; and 14.4% of the positive samples were seropositive for anti-Toxoplasma IgM. The highest seroprevalence was observed among people who were >50 years old (90.6%), and the lowest seroprevalence was observed among children who were 0-9 years old (9.4%; P<0.001). There was no significant difference in the seroprevalences for each sex in the study population. However, a regional sex-specific difference in seroprevalence was observed between men (54.1%) and women (70.6%; P=0.003) in the western cities of Mazandaran. As the seroprevalence of T. gondii in western and eastern Mazandaran was higher than that in the central cities, there is a need to evaluate the nature of the infection chain in these areas., (Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)

This prospective cross-sectional study was aimed to evaluate the prevalence of IgM and IgG anti-T. gondii antibodies and the associated risk factors among healthy blood donors in Kerman province, south-eastern Iran. Structured questionnaires (before the donors gave blood) were used to obtain information on risk factors for infection. Totally, 500 serum samples from healthy blood donors of Kerman Blood Transfusion Organization (KBTO) at Kerman, Iran, were screened for IgG and IgM anti-T. gondii antibodies by enzyme-linked immunosorbent assay (ELISA) and Roche Elecsys Toxo IgM assay. Real-time PCR was used to detect DNA of T. gondii in the IgM-positive samples. Seroprevalence of IgG and IgM anti-T. gondii antibodies was 28.8% and 3.2%, respectively. In the multiple logistic regression, it could be observed that living in rural regions, having B blood type, being in contact with cats, consuming raw vegetables and raw milk/egg and doing agricultural activities were independent risk factors for Toxoplasma seropositivity. T. gondii DNA was also found in one (9.0%) of IgM-positive samples. In this study, it was found that T. gondii infection was present among healthy blood donors in south-east of Iran. Therefore, it is suggested to design screening programmes for preventing transfusion-transmitted toxoplasmosis., (© 2015 John Wiley & Sons Ltd.)

Objective: In this study, the serological results of the patients who applied with the suspicion of toxoplasmosis in Kâtip Çelebi University Atatürk Training and Research Hospital in 2012 were evaluated to contribute to the toxoplasmosis sero-prevalence in our city, İzmir., Methods: The results of Anti-T. gondii IgG in 2942 serum samples and Anti-T. gondii IgM in 3899 serum samples that were sent by various clinics to our laboratory between January 1, 2012 and December 31, 2012, for the researching of the the presence of anti-T. gondii IgM and IgG antibodies were retrospectively investigated. The avidity value were searched in the serums in which Anti-T. gondii IgM antibodies were determined., Results: In 106 serum samples (2.7%) Anti-T. gondii IgM antibodies, in 954 serum samples (32.4) anti T. gondii IgG antibodies were found. The avidity value was low in the eight (7.5%) and the avidity value was high in eighty-eight (83%) in the serum samples which were studied with the Anti-T. gondii IgG avidity test., Conclusion: In this study in which we evaluated the anti-T. gondii tests of the year 2012 retrospectively, the prevalence of anti-T. gondii IgM and IgG antibodies were fond in order of 2.7-32.4%.

Background: The prevalence of toxoplasma gondii (T.g) infection in blood donors has been poorly studied. The aim of this study was to assess the prevalence of acute and chronic toxoplasmosis in blood products., Methods: A total of 223 blood products (101 fresh frozen plasma (FFP) and 122 packed cells (PC)) in Imam Reza hospital blood bank, Tehran, Iran were tested for specific T.g antibodies (IgG and IgM) by ELISA method. Positive IgG anti-T.g samples were further tested for IgM anti-T.g. A positive IgG test with the negative and positive IgM test was interpreted as a chronic and acute toxoplasmosis respectively., Results: Of 223 samples 38.6% and 0.45% were positive for IgG anti-T.g and IgM anti-T.g levels respectively. Therefore, one and 85 samples were involved acute and chronic toxoplasmosis respectively. Twenty-six of fresh frozen plasma samples were positive for IgG anti-T.g and one of them was positive for IgM anti-T.g. Sixty packed cell samples were positive for IgG anti-T.g., Conclusions: Our study showed that there were chronic and acute toxoplasmosis in blood products and the prevalence of toxoplasmosis especially chronic form was high. Therefore screening of blood for T.g antibodies may be considered., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objective: In this study, we aimed to investigate Toxoplasma gondii seroprevalence and risk factors in pregnant women., Methods: A total of 196 patients, admitted to the clinic in the first trimester and with ongoing pregnancy follow-up of between May 2012 and January 2013, were included in the study. Toxoplasma IgG and IgM antibodies were detected by ELISA test in blood samples obtained from patients during routine screening. SPSS statistical software, version 19.0 was used to analyze the data. Descriptive statistics were used to present the data, percentage, mean, and standard deviation. Chi-square test was used for categorical variables. p-value for statistical significance was defined as p<0.05., Results: The mean age was 29.07±5.3 years in our study group. Anti-Toxoplasma IgG and IgM antibodies were found in 28.8% and 2.7%, respectively; 58.9% of pregnant women in the study reported that they had done at least one risky behavior during their pregnancy. However, there was no significant association between T. gondii IgG antibody positivity and risk factors, such as pregnancy, feeding animals in the past years, and consumption of raw food products (p>0.05)., Conclusion: We found that Toxoplasma IgG antibody seropositivity (28.8%) was similar to that found in the other studies from western Turkey.

The aim of the study was to evaluate the performance of the ImmunoComb® Toxo IgG and ImmunoComb® Toxo IgMassays (rapid diagnostic test) in the laboratory diagnosis of toxoplasmosis in pregnant women in Cotonou. We interviewed 266 pregnant women, who first answered an epidemiological questionnaire, and collected blood samples for measurement of IgG and IgM anti T. gondii antibodies with the ImmunoComb toxo assays and with the ARCHITECT CIMA method. The sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were calculated to determine the performance of the rapid test. The seroprevalences of IgG against T. gondii by CIMA technique and rapid test were respectively 48.9% and 48.5%. The prevalence increased with age. Performances for IgG were: sensitivity 97%, specificity 100%, PPV 100%, NPV = 97.10%. For IgM, Sensitivity: 33.3% Specificity: 100%, PPV 100%, NPV = 99.2%. Seroprevalence obtained shows that about half of the study population is not immune against T. gondii and requires regular serological monitoring until delivery. According to these results, and given the needs of toxoplasmosis diagnosis on the field characterized by an important decrease of immunized women, this test may be recommended in the laboratory diagnosis of toxoplasmosis in peripheral levels of the health pyramid.

Objective: The aim of this study is to investigate the distribution of anti-Toxoplasma gondii IgG and IgM antibodies in patients with suspected toxoplasmosis referred to the Uludağ University Medical School, Department of Medical Microbiology Enzyme-Linked Immunosorbent Assay (ELISA) laboratory over a 72-month period (March 2002-December 2008)., Methods: The samples were analyzed using VIDAS (BioMérieux, France) IgG-avidity tests and the fluorescent enzyme-linked assay (ELFA) technique., Results: Results showed that the prevalence of anti-T. gondii IgG and IgM among women (29.2% and 2.02%, respectively) was higher than that of men (21.2% and 1.7%, respectively). The seroprevalence of anti-T. gondii IgG was 30.7% in childbearing-aged women, with rates ranging from 35.8% and 27.4% over the years. Avidity was found to be high, borderline, and lower (81.9%, 10.2%, and 7.9%, respectively) in the fertile age group of 166 women receiving the IgG avidity test., Conclusion: Although the study data may not reflect our entire province, it virtually turns out that the risk of toxoplasmosis must be seriously taken into account, particularly when approaching some risk groups, such as seronegative women of fertile age, pregnant women, and immunocompromised patients.

The performance values of available techniques used in serodiagnosis of toxoplasmosis are satisfactory but they raise problems of equivocal and discordant results for very low IgG titers. Recently marketed, LDBio-Toxo II IgG Western blot (IB) showed an excellent correlation with the dye test. We estimated the proportion of equivocal and discordant results between the enzyme immunoassay Platelia Toxo IgG (EIA-IgG) and fluorescent antibody test (FAT) and assessed the usefulness of the IB as a confirmatory test. Out of 2,136 sera collected from pregnant women, 1,644 (77.0%) tested unequivocally positive and 407 (19.0%) were negative in both EIA-IgG and FAT. The remaining 85 (4%) sera showed equivocal or discordant results. Among them, 73 (85.9%) were positive and 12 (14.1%) were negative in IB. Forty-one (89.1%) equivocal sera in EIA-IgG and 46 (86.8%) equivocal sera in FAT were positive in IB. Reducing the cut-off values of both screening techniques improved significantly their sensitivity in detecting very low IgG titers at the expense of their specificity. In conclusion, equivocal results in routine-used techniques and their discordance in determination of the immune status in pregnancy women were not uncommon. IB test appeard to be highly useful in these situations as a confirmatory technique.

Background: Toxoplasma gondii is an obligate intracellular zoonotic parasite of the phylum Apicomplexa which infects a wide range of warm-blooded animals, including humans. In this study in-vivo induced antigens of this parasite was investigated using in-vivo induced antigen technology (IVIAT) and pooled sera from patients with serological evidence of acute infection., Methods: The pooled sera was first pre-absorbed against three different preparations of antigens from in-vitro-grown cells of each T. gondii and E. coli XL1-Blue MRF', subsequently it was used to screen T. gondii cDNA phage expression library. Positive clones from each group were subjected to quantitative real-time PCR expression analysis on mRNA of in-vivo and in-vitro grown parasites., Results: A total of 29 reactive clones from each IgM and IgG immunoscreenings were found to have high homology to T. gondii genes. Quantitative real-time PCR expression analysis showed that 20 IgM-detected genes and 11 IgG-detected genes were up-regulated in-vivo relative to their expression levels in-vitro. These included genes encoding micronemes, sterol-regulatory element binding protein site, SRS34A, MIC2-associated protein M2AP, nucleoredoxin, protein phosphatase 2C and several hypothetical proteins. A hypothetical protein (GenBank accession no. 7899266) detected by IgG had the highest in-vivo over in-vitro fold change of 499.86; while another up-regulated hypothetical protein (GenBank accession no. 7898829) recognized by IgM showed high sensitivity (90%) and moderate specificity (70%) in detecting T. gondii antibodies when tested with 20 individual serum samples., Conclusion: The highly up-regulated genes and the corresponding proteins, in particular the hypothetical proteins, may be useful in further studies on understanding the disease pathogenesis and as potential vaccine candidates.

Purpose: To ascertain the seroprevalence of human immunodeficiency virus (HIV), hepatitis B (HBV), toxoplasmosis and rubella infections in pregnant women in northwestern Paraná., Methods: We conducted a retrospective study based on the results of serological screening during prenatal care of 1,534 patients during the first half of 2010. We included only results from the first prenatal exam and with a simultaneous search for IgG and IgM antibodies to rubella and toxoplasmosis. Serology was performed by microparticle enzyme immunoassay (MEIA). Data were analyzed statistically by the χ² test, with the level of significance set at 5%., Results: HIV positivity was 0.3%, positivity of HBV serology (HbsAg) was 0.5%, reactivity to IgM antibodies to Toxoplasma gondii was 1.1%, and reactivity to IgG antibodies was 59.0%. For rubella, no patient was positive for IgM, and IgG reactivity was 99.6%. Data analysis showed no statistical association between seroprevalence and patient age, except for the frequency of anti-T. gondii IgG, which was higher in the 30 to 44 year age group., Conclusion: The prevalence of these infectious diseases in pregnant women from northwestern Paraná is comparable to that observed in other regions of Brazil.

In the present study we evaluated the performance of a flow cytometry-based algorithm as a new serological approach to detect antibodies to T. gondii and specific IgG avidity to diagnose acute toxoplasmosis. The results showed that using FC-AFTA-IgM assay, all serum samples from patients with acute toxoplasmosis demonstrated seropositivity, whereas 90% of patients with chronic infection and 100% of non-infected individuals presented negative results. Thus, only 10% of patients with chronic toxoplasmosis showed residual IgM, in contrast with other methodologies used to diagnosis acute toxoplasmosis. On the order hand, FC-AFTA-IgG assay as well as FC-AFTA-IgG subclasses is unlikely to discriminate acute from chronic toxoplasmosis. We have also evaluated the performance of FC-AFTA-IgG avidity as a tool to exclude chronic toxoplasmosis in patients with positive FC-AFTA-IgM. Our data showed an excellent performance of FC-AFTA-IgG avidity employing the cut-off of 60% for Avidity Index (AI) with sensitivity and specificity of 100%. All serum samples from patients presenting acute toxoplasmosis showed low avidity index (AI≤60%), whereas all chronic patients showed high avidity index (AI>60%). The outstanding performance indexes of this novel flow cytometry-based algorithm support its use as a non-conventional alternative serological approach to diagnose human acute toxoplasmosis., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The epidemiology of Toxoplasma gondii infection is known to depend on a number of behavioral factors, including contact with animals and eating habits. The epidemiology in specific populations (i.e., in indigenous ethnic groups) is not well studied. We therefore investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 156 Tepehuanos, an indigenous ethnic group in Durango State in northern Mexico, using ELISAs. Of the 156 Tepehuanos (mean age 31.03±16.71 years), 35 (22.4%) had anti-Toxoplasma IgG antibodies. IgG levels of 14-99, 100-150, and >150 IU/mL were found in 15 (42.9%), 1 (2.8%), and 19 (54.3%) anti-Toxoplasma IgG-positive Tepehuanos, respectively. Also, 15 (9.6%) subjects had anti-Toxoplasma IgM antibodies. Male Tepehuanos aged 31-50 years showed a significantly higher frequency of exposure to T. gondii than female Tepehuanos of the same age. Seroprevalence of anti-T. gondii IgM antibodies was significantly higher in Tepehuanos without education than those with 7-12 years of education. Tepehuanos suffering from frequent headaches had significantly higher seroprevalences of anti-T. gondii IgG and IgM antibodies than those without this clinical feature. In addition, Tepehuanos suffering from hearing impairment had significantly higher seroprevalence of anti-T. gondii IgM antibodies than those without this clinical feature. Logistic regression analysis did not show an association of T. gondii exposure with any behavioral characteristics, including contact with cats or eating habits. The seroprevalence of T. gondii exposure in Tepehuanos is comparable to that reported in other populations in North America; however, seroprevalence in the largely rural Tepehuanos is higher than that reported in a nearby urban center. Toxoplasma may be impacting the health of Tepehuanos. This is the first report of T. gondii infection in Tepehuanos, and the results should prove useful for the design of preventive measures.

A cross-sectional study was developed to determine anti-Toxoplasma gondii immunoglobulin G (IgG) and IgM antibodies from 80 persons aged 18-21 years without a history of previous contact with cats. Individuals who consented to take part in the survey were served with a questionnaire to obtain response on their eating habits. Blood samples were taken and specific IgM and IgG antibodies against T. gondii were measured by indirect enzyme-linked immunoassay. Seropositivity was found in 29 (37%) and 20 (25%) of 80 persons for IgM and IgG, respectively. Of the cases, 14 (18%) of 80 were positive to both IgM and IgG T. gondii antibodies. A significant association of IgM seropositivity was found in people consuming pork (p-value = 0.04) and wildlife meat (odds ratio = 4.5; confidence intervals = 1.47-14.25; p-value = 0.009). The presence of specific IgG and IgM antibodies in the studied population indicate previous contact and/or recent infections with T. gondii despite avoiding direct contact with cats. Ingestion of pork and meat from wild animals appears to be playing a key role in transmitting the parasite.

Roche Diagnostics has developed two new rapid and fully automated assays for the detection of Anti-Toxo-IgG and Toxo-IgM antibodies from human sera and plasma. The performance evaluation of the Elecsys Toxo IgG resulted in a sensitivity of 100% and a specificity of 99.91% showing that this assay allows a very sensitive and specific detection of Toxo IgG antibodies with an excellent discrimination of positive and negative results. The performance evaluation of the Elecsys Toxo IgM assay revealed a sensitivity of 100% and a specificity of 99.11% after resolution. Less reactivity towards persistent Toxo IgM antibodies in samples from Toxoplasma infections > 3 months was found with Elecsys Toxo IgM. The performance evaluation data demonstrate that the Elecsys Toxo IgG and Elecsys Toxo IgM assays are reliable tools in routine diagnostics of Toxoplasma infections with the additional advantage of a high throughput on fully automated analyzers MODULAR ANALYTICS Serum Work Area.

In this study, we evaluated a new immunoassay for the automated detection of anti-toxoplasma IgG and IgM with Immulite 2000 (DPC-Siemens, La Garenne-Colombes, France). We tested 280 sera from 112 patients with past infection (PI), 40 PI with residual IgM, 75 seronegatives, 16 infants (31 sera) monitored for neonatal screening of congenital toxoplasmosis, and 13 patients with recent seroconversion (SC) (22 sequential sera). Detection sensitivity and specificity for IgG were 99 and 100%, respectively. IgG titers obtained with Immulite 2000 were higher than with Vidas (BioMérieux, Marcy I'Etoile, France) and Access (Beckman-Coulter, Villepinte, France) (paired Wilcoxon test z=4.44 and z=3.67, respectively, P<0.001). IgM specificity was 100%. Detection sensitivity for IgM was 100% in the SC group, 86% in congenitally infected infants, and 75% in PI with persistent IgM. IgM detection seemed less prolonged in time than with the IgM Access and ISAGA IgM techniques.

A dipstick dye immunoassay (DDIA) was developed to detect immunoglobulin G (IgG) or IgM antibodies of toxoplasmosis infection in humans. The assays employ a blue colloidal dye particles (D-1) conjugated to sheep anti-human IgG and rabbit anti-human IgM as the visualizing agents and a soluble antigen of tachyzoites of Toxoplasma gondii strain RH (TSA) as the detective antigen. The mixture of dye-labeled anti-human antibody-special human antibody was captured by TSA onto a nitrocellulose membrane dipstick by means of immunochromatography. The assays are rapid (the whole test can be completed within 15 min), simple, and cheap, and they don't require any equipment. They are sensitive and specific for the detection of anti-Toxoplasma IgG or IgM antibodies and generally agree closely with the results from the enzyme-linked immunosorbent assay. The assays are especially suitable for field applications.

Aim: Severe congenital infection is a consequence of primary Toxoplasma gondii infection in early pregnancy. Antenatal screening is problematic because IgM antibody to Toxoplasma persists for months to years and thus may falsely indicate a recent infection. Serological screening for T. gondii infection is not currently included in routine antenatal testing in New Zealand. The aim of this study was to determine the prevalence of IgG and IgM antibody to T. gondii in pregnant Auckland women., Methods: Five hundred serum samples submitted for routine antenatal blood tests were tested anonymously for IgG and IgM antibodies to T. gondii. One hundred consecutive serum samples were tested from five age groups: <20, 21-25, 26-30, 31-35, >36 years. The number of positive IgM results that would have occurred if there were routine screening for toxoplasmosis was estimated for the year 2000 by multiplying the number of women giving birth in the respective age groups by the proportion with positive IgM results in these samples., Results: One hundred and sixty three (33%) women had IgG antibody to T. gondii and 12 (2.4%) also had IgM antibody. For the year 2000, if there had been routine screening for toxoplasmosis, 296 of 14 530 (2.03%, 95% CI: 1.8-2.2%) pregnant Auckland women would have had a positive IgM result., Conclusions: Screening would detect IgM antibodies in up to 2.2% of pregnant women. Significant and invasive further investigations would be required to identify the subset of pregnancies with fetal infection. Serological tests that are specific for recent primary infection are needed before routine screening could be considered for New Zealand. In the meantime, advice on how to avoid infection is necessary given that two thirds of pregnant Auckland women are susceptible to T. gondii.

Clinical non-relevant (CNR) IgM specific for Toxoplasma gondii is responsible for false-positive results in commercially available IgM assays. Using IgM immunoblotting, it is possible to distinguish between IgM in sera of acutely infected (AI) patients and CNR IgM. Especially the combination of staining of a 55 and 30 kD antigen in T.gondii lysate proved useful in this respect. The 55 kD antigen was identified as Rop1, while the 30 kD antigen was confirmed to be Sag1. However, the use of recombinant antigens instead of lysates for diagnostic assays would improve reproducibility. IgM recognized recombinant Rop1, but most CNR sera also had low anti-Rop1 titers. Although purified native Sag1 separated AI and CNR sera very well on immunoblot, IgM did not recognize recombinant Sag1 at all. Clearly, it is difficult to produce a recombinant Sag1 that can be recognized by IgM. Recombinant Rop1 might be suitable as one of the recombinant antigens in an IgM immunoblot assay, but has to be combined with at least one other immunogenic antigen.

IgM antibodies are indicative for a recent infection, thus the detection of this isotype is of essential significance particularly in the diagnosis of infections with Toxoplasma gondii during pregnancy (primary infection, seroconversion). Numerous serological tests and test kits (e.g. indirect immunofluorescent assay/IFAT, enzyme-linked immunosorbent assay/ELISA, Immunosorbent agglutination assay/ISAGA, Westernblot/WB) using different antigens and antigen preparations are provided by numerous companies. The sensitivities of such tests, however, variy considerably: The serological test results of four pregnant women with seroconversions and of three newborns from mothers with seroconversions are presented: VIDAS M and ISAGA M from one company yielded false negative results in three pregnant women whereas ISAGA M from another company could detect specific IgM. However, examination of the cord blood of the three newborns unanimously revealed IgM-negative results. Thus, our diagnostic strategy for pregnant women includes IIFT (or SFT) as basic test and ISAGA M (Toxotool I from Innogenetics) as well as IgG avidity test as additional tests; the serological diagnosis of suspected congenital infection comprises IFAT (or SFT), ISAGA M (from Innogenetics) and IgM/IgG Westernblot.

The detection of specific IgM is an important element in the diagnosis of seroconversion. In this study, we compared the new test Access Toxo IgM (II) versus the previous test Access Toxo IgM (I). This comparative study was done with 507 random sera and 89 selected sera (seroconversion, residual IgM, non specific IgM). The sensitivity and the specificity are higher with the new test (100% & 100% versus 97% & 98,6% respectively). Then, the high sensitivity of Access Toxo IgM (II) is more convenient for the earlier diagnosis of primary Toxoplasma infection. Moreover, the Access Toxo IgM (II) test was evaluated with our first results in routine laboratory (11,000 serology results between June 2000 and June 2001). With these results, we can confirm the specificity of the new test, and also determine the relevance of anti-toxoplasmic IgM. Moreover, an increase of sensitivity leads to an increase of residual IgM detection: 64% (37/58) of positive IgM is residual (> 4 months) as compared to 35% (27/78) with the previous test. In these case, the initiation of other tests such as the avidity test is necessary to validate or invalidate a seroconversion during pregnancy.

A major problem in anti-toxoplasma IgM serology is the occurrence of clinically non-relevant (CNR) IgM in sera of latently infected (LI) individuals. The susceptibility for CNR IgM of the Toxo ISAGA IgM, Platelia Toxo IgM and Vidas Toxo IgM assays was determined using sera of LI individuals with an IgM titer in the Abbott IMx Toxo IgM assay. The specificity of CNR-IgM and IgM antibodies in sera of acutely infected (AI) individuals was compared by immunoblotting.Seven/19 samples with CNR IgM antibodies were found positive in the ISAGA IgM, compared with 16/19 and 17/19 with the Vidas and Platelia Toxo IgM assays, respectively. In contrast, immunoblotting allowed a distinction between CNR IgM and AI IgM antibodies of the 30 sera studied.Clearly, IgM assays are susceptible to CNR IgM antibodies. In cases of doubt, immunoblotting is of value as confirmation method. Because CNR IgM antibodies are specific for toxoplasma, it will be difficult to improve IgM ELISAs in such a way that CNR IgM antibodies will not interfere with the analysis.

A Toxoplasma gondii immunoglobulin G (IgG) avidity enzyme-linked immunosorbent assay (ELISA) was developed that combines the accuracy of assays based on end point titers and the relative ease of assays based on optical density values. Like published procedures, the new assay's avidity index (AI) was based on differential T. gondii-specific IgG reactivity in serum-treated wells washed with urea buffer versus that in wells washed with control buffer; unlike previous assays, however, the IgG reactivity was measured quantitatively using a standard curve. The assay was evaluated using 24 IgG-positive and IgM-positive sera collected within 5 months of the onset of symptoms (recent-infection group) and 25 IgG-positive and IgM-negative sera (past-infection group). All sera in the recent-infection group exhibited AI values of <0.18, whereas all sera in the past-infection group exhibited AI values of >0.27. The AI values of the recent-infection group showed significant correlation with the number of days after the onset of symptoms. A subset of 16 sera (8 recent and 8 past) was tested using a commercially available T. gondii IgG avidity ELISA based on end point titration; the results of the two assays showed highly significant correlation (R(2) = 0.9125). In addition, we confirmed and extended the findings of other investigators, showing that AI values calculated using optical density values, but not AI values calculated using quantitative IgG values, varied significantly depending on the serum dilution used. This new assay should facilitate the accurate measurement of T. gondii IgG avidity in a reference laboratory setting.

Four hundred and ninety five human sera with clinical and biological data were tested for the evaluation of Immulite 2000 Toxoplasma Quantitative IgG and Immulite 2000 Toxoplasma IgM produced by Diagnostic Products Corporation (Los Angeles, USA) for the diagnosis of human toxoplasmosis. The results of these kits were compared to those of the University Hospital of Nancy where the reference assays were Enzygnost Toxoplasmosis IgG and Enzygnost Toxoplasmosis IgM (Berhing-Dade, Germany), Toxoscreen (bioMérieux, France), ISAgA Plus (IgM et IgA) (bioMérieux, France). The sensitivity and the specificity of IgG detection by Immulite 2000 Toxoplasma Quantitative IgG were 98% and 100%, respectively. The high sensitivity of IgM detection by Immulite 2000 Toxoplasma IgM was adapted to the early diagnosis of toxoplasmic primo-infection and to the pediatric diagnosis or follow-up of congenital toxoplasmosis but could reveal IgM a long time after primary infection.

Early diagnosis of toxoplasmosis in pregnant women can be of great help in early intervention and prevention of congenital disorders that usually lead to fetal death. The purpose of the present study was to evaluate nested PCR amplification of the B1 gene of Toxoplasma gondii before and after treatment and in comparison to serological follow-up during treatment. The efficiency of treatment on the bases of PCR detection of T. gondii DNA was statistically significant, while it was insignificant when anti-toxoplasma specific IgM and IgG antibodies were used. PCR detection of T. gondii DNA when performed on whole blood is a rapid, sensitive and specific diagnostic procedure and is a valuable tool for establishing the diagnosis of T. gondii infection in women before or during pregnancy.

Background: To study the usefulness of IgG and IgM titration, and avidity of IgG to date IgM anti-Toxoplasma gondii., Methods: VIDAS Toxo IgG, VIDAS Toxo IgM and VIDAS Toxo IgG Avidity tests were used. 64 sera containing both IgM and IgG T. gondii antibodies were analyzed, 32 from 12 individuals infected 40 weeks previously (group I), and the remainder from 17 individuals with an infection of more than 40 weeks (group II)., Results: An IgM index < 1.05 was associated with an infection > 12 weeks. An avidity index > 0.164 excluded 100% infections of < or = 12 weeks. Avidity indexes > 0.26 and 0.45 excluded infections of < or = 20 and < or = 40 weeks, respectively., Conclusions: The serology methods used in this study can adequately identify residual IgM anti-T. gondii, often avoiding the need of a new blood extraction to analyze IgG kinetics in pregnant women.

We have evaluated the diagnostic utility of eleven Toxoplasma gondii recombinant antigens (P22 [SAG2], P24 [GRA1], P25, P28 [GRA2], P29 [GRA7], P30 [SAG1], P35, P41 [GRA4], P54 [ROP2], P66 [ROP1], and P68) in immunoglobulin G (IgG) and IgM recombinant enzyme-linked immunosorbent assays (Rec-ELISAs). Following an initial evaluation, six recombinant antigens (P29, P30, P35, P54, P66, and P68) were tested in the IgG and IgM Rec-ELISAs with four groups of samples which span the toxoplasmosis disease spectrum (negative, chronic infection, acute infection, and recent seroconversion). Our results suggest that the combination of P29, P30, and P35 in an IgG Rec-ELISA and the combination of P29, P35, and P66 in an IgM Rec-ELISA can replace the tachyzoite antigen in IgG and IgM serologic tests, respectively. The relative sensitivity, specificity, and agreement for the IgG P29-P30-P35 Rec-ELISA were 98.4, 95.7, and 97.2%, respectively. The resolved sensitivity, specificity, and agreement for the IgM P29-P35-P66 Rec-ELISA were 93.1, 95.0, and 94. 5%, respectively. Relative to the tachyzoite-based immunocapture IgM assay, the IgM P29-P35-P66 Rec-ELISA detects fewer samples that contain IgG antibodies with elevated avidity from individuals with an acute toxoplasmosis.

Cell-mediated immunity that results in IL-12/IFN-gamma production is essential to control infections by intracellular organisms. Studies in animal models revealed contrasting results in regard to the importance of CD40-CD40 ligand (CD40L) signaling for induction of a type 1 cytokine response against these pathogens. We demonstrate that CD40-CD40L interaction in humans is critical for generation of the IL-12/IFN-gamma immune response against Toxoplasma gondii. Infection of monocytes with T. gondii resulted in up-regulation of CD40. CD40-CD40L signaling was required for optimal T cell production of IFN-gamma in response to T. gondii. Moreover, patients with hyper IgM (HIGM) syndrome exhibited a defect in IFN-gamma secretion in response to the parasite and evidence compatible with impaired in vivo T cell priming after T. gondii infection. Not only was IL-12 production in response to T. gondii dependent on CD40-CD40L signaling, but also, patients with HIGM syndrome exhibited deficient in vitro secretion of this cytokine in response to the parasite. Finally, in vitro incubation with agonistic soluble CD40L trimer enhanced T. gondii-triggered production of IFN-gamma and, through induction of IL-12 secretion, corrected the defect in IFN-gamma production observed in HIGM patients. Our results are likely to explain the susceptibility of patients with HIGM syndrome to infections by opportunistic pathogens.

Toxoplasma gondii IgG and IgM antibodies of Thai and Austrian pregnant women were studied, in the same laboratory unit, by using the Sabin-Feldman dye test and ISAGA-IgM. In Thai pregnant women, IgG antibody was found in 21.7%, mostly the IgG titers were low and all were negative for IgM antibody. Conversely in Austrian pregnant women, IgG antibody was found in 30.0% with high titer, and there were 19 (6.3%) cases positive for IgM antibody. The seropositivity of T. gondii IgG antibody in Austrian pregnant women was significantly higher than in Thai (p = 0.02) and the titers were much higher. Two possibilities are postulated to explain the data: it may be because Thai women were infected at a younger age than Austrian women, so they were in the chronic infection stage corresponding with their negativity of IgM antibody or it may be due to the difference of strain virulence of T. gondii from the different parts of the world.

The development of specific antibodies following primary Toxoplasma gondii infection during pregnancy was assessed by six different antibody assays: dye test, Platelia Toxo-IgG, Toxo-Screen DA IgG, Platelia Toxo-IgM, Toxo-ISAGA IgM, and Platelia Toxo-IgA. A total of 126 sera from 27 pregnant women, for whom the time of acquisition of infection could be estimated fairly accurately, were included. All tests showed great individual variation in the peak amounts of antibodies detected. The times elapsed after infection until the peak was reached also varied greatly from individual to individual: the ranges were 2 to 21 weeks for the dye test, 4 to 36 weeks for Platelia Toxo-IgG, 4 to 30 weeks for Toxo-Screen DA IgG, 2 to 18 weeks for Platelia Toxo-IgM, 1 to 6 weeks for Toxo-ISAGA IgM, and 2 to 21 weeks for Platelia Toxo-IgA. In the early phase of the infection the dye test and the specific-IgM tests were the most sensitive. Toxo-Screen DA IgG was more sensitive than Platelia Toxo-IgG in the acute phase, while Platelia Toxo-IgA was clearly the least sensitive assay. Of the sera collected 21 to 52 weeks after infection, all were positive by the dye test, all except one (which was negative by Platelia Toxo-IgG) were positive by the specific-IgG tests, approximately 80% were positive by the IgM tests, and 45% were positive by the IgA test. Due to the great individual variation it seems impossible to estimate when the infection occurred based on results obtained from a single serum, and it may even be difficult to assess when a titer increase in paired sera is detectable unless the first sample is only marginally positive. As a diagnostic criterion a dye test titer of >/=300 IU/ml has a low sensitivity for recent primary infection.

Although tests for detection of immunoglobulin M (IgM) toxoplasma antibodies have been reported to have a high degree of accuracy, it is well recognized by investigators in the United States and Europe that false-positive results may occur with many of these tests, at times to an alarming degree. Unfortunately, this information is not well documented in the literature. Studies on various toxoplasma IgM test kits are frequently flawed. The investigators often use reference tests which have not previously been carefully evaluated as well as sera that were not appropriate to answer the question of how often false-positive results might occur. We recently had the unique opportunity to evaluate the accuracy of the Platelia Toxo IgM test in 575 serum samples obtained during an outbreak of toxoplasmosis which occurred in 1995 in the Capital Regional District of British Columbia, Canada. When compared with results obtained in a reference IgM enzyme-linked immunosorbent assay (ELISA), the Platelia Toxo IgM test had a sensitivity of 99.4%, specificity of 49.2%, positive predictive value of 51.9%, negative predictive value of 99.3%, and an overall agreement of 67.0%. In an attempt to resolve discrepancies between these two tests, a serological profile (Sabin-Feldman dye test, IgA and IgE antibody tests, differential agglutination [AC/HS] test, and IgG avidity method) was performed. Of 153 serum samples that were positive in the Platelia Toxo IgM test and negative in the IgM ELISA, 71 (46.4%) were negative in the Sabin-Feldman dye test. Of the serum samples that were positive in the dye test, 77 (93.9%) had a serological profile most compatible with an infection acquired in the distant past. These results reveal high numbers of false-positive results in the Platelia Toxo IgM test and highlight the importance of appropriate evaluation of commercial tests that are currently being marked. Our results also emphasize the importance of confirmatory testing to determine whether the results of an IgM antibody test reflect the likelihood of a recently acquired infection.

We compared the Abbott Toxo immunoglobulin G (IgG) and IgM IMx assays with the Sabin-Feldman dye test and an IgM enzyme-linked immunosorbent assay (ELISA) in 398 serum samples previously tested in our laboratory (retrospective group) and 1,000 consecutive serum samples, tested as they were received in our laboratory in 1995 (prospective group). In the retrospective group, the IgG IMx had a sensitivity of 100%, specificity of 99.0%, positive predictive value of 99.0%, negative predictive value of 100%, and overall agreement of 99.5%. The percentages for the IgM IMx were 97.8, 99.0, 98.9, 98, and 98.4%, respectively. In the prospective group, the IgG IMx had a sensitivity of 97.8%, specificity of 98.7%, positive predictive value of 97.8%, negative predictive value of 98.7%, and overall agreement of 98.4%. The percentages for the IgM IMx were 88.3, 95.9, 74.7, 98.3, and 95%. A serological profile (IgA and IgE antibodies and the differential agglutination [AC/HS] test) was performed in an attempt to resolve discrepancies. Of 21 serum samples that were positive in the IgM IMx and negative in the IgM ELISA, 19 had serological profiles which were most compatible with an infection acquired in the distant past. Of 8 serum samples which were positive in the IgM ELISA and negative in the IgM IMx, 5 had serological profiles which were most compatible with an infection acquired in the distant past. Of the 55 serum samples that were positive in both IgM tests, 21 were from patients who had serological profiles which were most compatible with an infection acquired in the distal past. In conclusion, our data highlight the importance of confirmatory testing for the diagnosis of recently acquired infection with Toxoplasma gondii. When compared with the dye test and IgM ELISA, the Toxo IgG and IgM IMx assays, respectively, revealed high overall agreement in the retrospective and prospective study.