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Toxoplasma gondii is a protozoan parasite that is widely distributed in the human population and is responsible for corresponding global morbidity. Specifically, T. gondii causes toxoplasmosis, leading to miscarriage, stillbirth, and neural disorders. This parasite attacks different human organs and glands, such as the thyroid gland, and causes various corresponding health issues. Recently, studies have established a link between T. gondii and autoimmune thyroid diseases (AITD), which contributes to preterm delivery, miscarriage, low birth weight, and death. Therefore, the aim of this study was to detect the prevalence of toxoplasmosis and its association with AITD among pregnant women. A total of 180 blood samples were collected from pregnant women and examined using an enzyme-linked immunosorbent assay (ELISA). The patients were within the age range of 15–50 years old, and lived in Duhok City, Iraq; samples and clinical information was collected from August 2021 to February 2022. The corresponding blood samples were tested for anti-Toxoplasma IgG antibody, Toxoplasma IgG avidity, FT3, FT4, and TSH hormones, and TPO, Tg, and TSHR antibodies. Overall, our results showed that out of 180 pregnant women, 110 (61.1%) were seropositive for anti-Toxoplasma IgG antibody; specifically, 25 (22.7%) and 85 (77.3%) had recent and past infections, respectively. Approximately 54.4% (98) of the pregnant women had thyroid disorders; further, 22 (12.2%), 13 (7.2%), and 8 (4.4%) women had TPO, Tg, and TSHR antibodies, respectively. A total of 43 (23.8%) patients screened positive for AITD. Out of the 110 Toxoplasma IgG–positive women, 35 (31.8%) had AITD. The older women, rural residents, restaurant food consumers, and women with cat contact had relatively high infection rates. Toxoplasma seropositive women had more elevated autoantibodies than seronegative ones. In conclusion, this study demonstrated a high rate of toxoplasmosis and a corresponding association with thyroid hormones changes and AITD in pregnant women in Duhok, Iraq. Further, it is necessary to reduce overall infection rates through effective health and educational programs. Therefore, it is essential to measure Toxoplasma antibodies, screen for thyroid hormones and autoantibodies, and encourage gynecologist visits to reduce the risks to mothers and fetuses. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii, an obligate intracellular protozoan parasite, is the causative agent of one of the most prevalent zoonoses worldwide. T. gondii infection is extremely important from a medical point of view, especially for pregnant women, newborns with congenital infections, and immunocompromised individuals. Thus, an accurate and proper diagnosis of this infection is essential. Among the available diagnostic tests, serology is commonly used. However, traditional serological techniques have certain limitations in evaluating the duration of T. gondii infection, which is problematic, especially for pregnant women. Avidity of T. gondii-specific IgG antibodies seems to be a significant tool for discrimination between recent and distant infections. This article describes the problem of diagnosis of T. gondii infection, with regard to IgG avidity tests. The IgG avidity test is a useful serological indicator of toxoplasmosis, which in many cases can confirm or exclude the active form of the disease. IgG antibodies produced in the recent primary T. gondii infection are of low avidity while IgG antibodies with high avidity are detected in the chronic phase of infection. Furthermore, this paper presents important topics of current research that concern the usage of parasite recombinant antigens that may improve the performance of IgG avidity tests. [ABSTRACT FROM AUTHOR]

Objective: Toxoplasmosis acquired in early pregnancy is a potentially severe complication for the fetus. Evaluating the risk of transplacental infection in pregnant women accessing the Tuscany Reference Center for Infectious Diseases in Pregnancy during the last 20 years with suspected or confirmed toxoplasmosis acquired in early pregnancy was the aim of the study.Study Design: We retrospectively enrolled all pregnant women undergoing amniocentesis for toxoplasmosis acquired in the first 16 gestational weeks in the period 1999-2019, comparing patients with certain acute infection (seroconversion occurred in pregnancy, CAIP) with those with suspected acute infection (IgG positive with low/intermediate IgG avidity index, SAIP).Results: 237 patients were enrolled, 187 (78.9%) with SAIP and 50 (21.1%) with CAIP. Specific IgM was detected in 47.5% and 76.7% (p-value 0.001), and the mean IgG avidity index was 22.7% and 7.1% (p-value < 0.001) in the SAIP and in the CAIP group, respectively. The mean delay from diagnosis to antibiotic initiation was 14.6 in SAIP and 11 days in CAIP group. Toxoplasma DNA was detected in the amniotic fluid in one case in a patient with CAIP. Excluding 24 newborns with not available data, prevalence of congenital infection was 0.47% [1/213 (95% CI 0.08%-2.61%)], 0% [0/178 (95% CI 0%-2.11%)] in SAIP and 2.8% [1/35 (95% CI 0.51%-14.53%)] in CAIP group.Conclusions: Toxoplasmosis acquired in early pregnancy has a low risk of fetal infection. Actively discussing case-by-case amniocentesis indication with patients, especially when a recent toxoplasmosis is not properly confirmed, is desirable. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the current study was to assess prevalence of Toxoplasma infection and its associated risk factors in women of childbearing-age in central Iran. Results: Of 400 serum samples assessed for anti-T. gondii antibodies, 81 (20.25%) samples were positive for anti-T. gondii antibodies, including 74 positive samples (91.3%) for anti-T. gondii IgG and seven positive samples (8.7%) for IgG and IgM. Of seven IgG and IgM positive samples, five and two samples were high and low in IgG avidity, respectively. Based on PCR analysis, Toxoplasma infection was detected in one sample with anti-T. gondii IgM and low IgG avidity. The Chi-square test showed significant correlations of T. gondii seropositivity with history of undercooked meat consumption and contacts with cats (p < 0.05). In the present study, 79.75% of the participants were negative for IgG against T. gondii infection. Furthermore, recently acquired Toxoplasma infection was found using IgG avidity and PCR assays among women of childbearing-age in the study area, which would increase the risk of their fetus becoming infected. Educational program and antenatal screening of childbearing-age women for T. gondii infection may be important primary prevention strategies and help reduce the risk of congenital toxoplasmosis in this population. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the current study was to assess prevalence of Toxoplasma infection and its associated risk factors in women of childbearing-age in central Iran. Results: Of 400 serum samples assessed for anti-T. gondii antibodies, 81 (20.25%) samples were positive for anti-T. gondii antibodies, including 74 positive samples (91.3%) for anti-T. gondii IgG and seven positive samples (8.7%) for IgG and IgM. Of seven IgG and IgM positive samples, five and two samples were high and low in IgG avidity, respectively. Based on PCR analysis, Toxoplasma infection was detected in one sample with anti-T. gondii IgM and low IgG avidity. The Chi-square test showed significant correlations of T. gondii seropositivity with history of undercooked meat consumption and contacts with cats (p < 0.05). In the present study, 79.75% of the participants were negative for IgG against T. gondii infection. Furthermore, recently acquired Toxoplasma infection was found using IgG avidity and PCR assays among women of childbearing-age in the study area, which would increase the risk of their fetus becoming infected. Educational program and antenatal screening of childbearing-age women for T. gondii infection may be important primary prevention strategies and help reduce the risk of congenital toxoplasmosis in this population. [ABSTRACT FROM AUTHOR]

Background: We aimed to evaluate the diagnosis of acute toxoplasmosis by IgG avidity test in pregnant women. Methods: In this cross-sectional study, 250 blood samples were collected from pregnant women with the first month of their pregnancy referring to health centers of University in Mashhad during 2016. Samples were centrifuged at 3000 rpm for 5 min for separation of serum and were kept in the -20 until use. To detection of acute and chronic toxoplasmosis, anti-Toxoplasma antibodies (IgG and IgM, and IgG avidity tests were performed using ELISA. Then, data analyzed using SPSS software by Frequency, Pearson Chi-Square, Likelihood Ratio, and Exact tests. And P<0.05 was statistically considered as significant. Results: Total prevalence of IgG and IgM was 23.2% and 7.2%, respectively. A significant correlation was observed between the mean age and IgG level (P<0.05). It was not found any correlation between the history of raw meat consumption, cats keeping, education, and residency site. Moreover, 16 people (6.4%) had IgM antibody, of which, 10 cases (62.5%) with low avidity for IgG and 1 people (6.2%) with moderate avidity and 5 cases (31.3%) with high avidity for IgG. Moreover, 76% of pregnant women were seronegative. Conclusion: More than half of the women (62.5%) with positive IgM antibody in their serum had a low avidity for IgG which revealed an acute infection among pregnant women. Toxoplasma infection should be considered as an important factor that affects the pregnancy and IgG avidity as an important test for screening the women who need the treatment. [ABSTRACT FROM AUTHOR]

Background: Toxoplasma gondii is one of the major causes of abortion in pregnant women. Most cases of abortion occur in the acute phase of infection and early pregnancy. The purpose of this study was to investigate the association between spontaneous abortion and seropositive status of toxoplasmosis in women with first-time spontaneous abortion. Materials and Methods: This research is a case-control study on 240 serum samples from women experiencing spontaneous abortion for the first time as the case group, and 240 serum samples from women who had a normal delivery with no history of abortion as the control group. The level of anti-Toxoplasma gondii IgM and IgG antibodies were assessed in serum samples using ELISA. To separate the acute and chronic infections, all IgM-positive samples in both groups and IgG-positive samples of the case group were examined using IgG avidity. Results: The Toxoplasma IgM antibody was detected in 3.3% (8/240) of the case group and 0.4% (1/240) of the control group, which was a statistically significant difference between the two groups [P=0.019, odds ratio (OR)=10.266]. Of all samples 47.5% and 46.3% of the case and control groups were positive for Toxoplasma IgG antibody, respectively. Seven out of 8 (87.5%) IgM-positive serum samples from the case group had low IgG avidity, indicating acute infections, whereas all IgG-positive sera and 1 IgM-positive serum, which was related to the control group, showed a high IgG avidity, indicating chronic infections. Conclusion: Maternal acute toxoplasmosis during pregnancy is raised as one of the factors that increase the chance of spontaneous abortion. The necessary health training, especially on the parasite transmission ways to women before marriage, as well as the serological test in women before and during pregnancy is recommended. Polymerase chain reaction (PCR) and IgG avidity assays should be performed in the medical diagnostic laboratories for accurate distinguishing of the initial infection of toxoplasmosis in the pregnant women. [ABSTRACT FROM AUTHOR]

Proper diagnosis of toxoplasmosis is very important for proper treatment in manifested cases and to prevent congenital toxoplasmosis in case of pregnancy. Screening of 180 pregnant females by automated immune assay for Toxoplasma IgG and IgM Abs was done first then positive cases and some of negative cases were evaluated for the Toxoplasma IgG avidity test versus Toxoplasma IgM and IgA Abs using ELISA technique for the detection of active toxoplasmosis during gestation using IHA rising titer as reference test. Assessment of Toxoplasma IgM by ELISA compared with rising titer of IHA as a reference test revealed that the sensitivity, specificity, PPV, and NPP of IgM by ELISA were 66.67, 88.73, 42.86, and 95.45%, respectively. Assessment of Toxoplasma IgA Abs by ELISA compared with rising titer IHA as a reference test showed that the sensitivity, specificity, PPV, and NPP of IgA Abs by ELISA were 44.4, 92.96, 44.4, and 92.96%, respectively. Additionally, by assessment of Toxoplasma IgG avidity compared with rising titer of IHA as a reference test, the sensitivity, specificity, PPV, and NPP of Toxoplasma IgG avidity were 100, 98.59, 90%, and 100%, respectively. Detection of specific Toxoplasma IgM by ELISA is not always sufficient in the diagnosis of early and late during pregnancy, because Toxoplasma-specific IgM antibodies may persist as long as 18 months after acute acquired infection. Thus, the specific IgG avidity test should be used as more or less low cost tool to detect acute . [ABSTRACT FROM AUTHOR]

Abstract: The preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis was suspected was higher, at 100% and 95.4%, respectively, than for people with chronic infection, at 88.2% and 70.6%. In this study a different trend in avidity maturation of IgG antibodies for two mixtures of proteins in comparison with native antigen was observed. The results suggest that a new IgG avidity test using the mixtures of recombinant antigens may be useful for the diagnosis of difficult-to-identify phases of toxoplasmosis. For this reason, selected mixtures after the additional tests on groups of sera with well-defined dates of infection could be used as a better alternative to the native antigens of the parasite in the serodiagnosis of human T. gondii infection. [Copyright &y& Elsevier]

Background: Toxoplasma specific IgM antibodies; the common serologic marker in diagnosis of acute toxoplasmosis has its own limitations. Confirmatory testing with other markers, introduced as a complementary tool in distinguish acute and chronic infections is unusual in Iran. In the present study, we investigated the correlation between the results of IgM ELISA, IgA ELISA, and IgG avidity tests in the diagnosis of toxoplasmosis to demonstrate the necessity of confirmatory testing in serodiagnosis of infection in the country. Methods: A total of 107 positive Toxoplasma IgG and IgM sera were obtained from patients referred to private laboratories and stored at -20 °C for futures use. Serologic tests were set up in duplicate to analyze the serum levels of IgG, IgM, IgA, and IgG avidity antibodies using commercial ELISA kits. The results were presented as semi quantitative for IgG, IgM and IgA ELISA, and Relative Avidity Index in percentage for IgG avidity test. Pearson's correlation coefficient (rp) was applied to analyze the data. Results: Of 107 serum samples, T. gondii specific IgM and IgA antibodies were positive in 67.3% and 53.3%, respectively. Besides, 29.9% of the sera displayed low avidity for IgG antibodies. The rp was - 0.572 (P<0.01) between the IgG avidity and IgM ELISA, - 0.364 between the IgG avidity and IgA ELISA (P<0.01), and 0.564 between the IgM and IgA ELISA (P<0.01). Conclusion: The study strongly highlights the necessity of confirmatory testing in differential diagnosis of acute and chronic toxoplasmosis in Iran. [ABSTRACT FROM AUTHOR]

AIM: The diagnosis of acute toxoplasmosis depends on the presence of immunoglobulin M (IgM), but it may persist for a long time in some cases. The objective of this study was to determine the role and accuracy of IgG avidity for the detection of acute Toxoplasmosis in early pregnancy. METHOD: The study included 160 women. Sera were screened for anti-Toxoplasma IgG and IgM and for IgG-avidity using ELIZA. PCR was done for confirmation in selected group of specimens. This study was performed at the College of Medicine, King Faisal University, Saudi Arabia from January 2008 through April 2009. RESULTS: 32 cases of low avidity were negative IgM while 15 cases of high avidity were positive IgM. 16 cases of low avidity were positive IgG. The accuracy of low avidity in relation to positive IgM revealed a sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratio of 77.0%, 51.5%, 64.0%, 66.7% and 1.58 respectively. The accuracy of low IgG avidity in comparison with PCR demonstrated 91%, 45.7%, 60.4% and 84.2% respectively. CONCLUSION: Negative IgM didn't exclude recent Toxoplasma infection and positive IgG may be present with recent infection. IgG avidity testing help in accurate differentiation of recent infections. [ABSTRACT FROM AUTHOR]

Abstract: Sheep are important domestic animals in the Northeast region of Brazil due to their minimal rearing and maintenance costs, and to their production of both meat and milk. In animals, Toxoplasma gondii infection results in significant reproductive and economic losses. The epidemiology of toxoplasmosis in sheep in the Northeast of Brazil has been little studied; particularly in Rio Grande do Norte State. Sera from 102 sheep intended for consumption in Lajes were subjected to the Toxoplasma-ELISA test to detect anti-T. gondii specific IgG confirming a past infection. Of the total tested, 30 (29.41%) sera were positive for IgG with an increasing number of positive animals with advancing age. We used IgG avidity ELISA in 30 positive samples and observed that 6 (20%) had low avidity antibodies and 24 (80%) had high avidity antibodies. Epidemiological studies are required in order to identify sources of infection for these hosts as well as their impact on animal breeding in the region and risk of transmission to humans. [Copyright &y& Elsevier]

PROBLEM: Toxoplasmosis is a major cause of congenitally acquired infections causing high degree of morbidity and mortality in the newborns. METHODS OF STUDY: IgG avidity method was used to distinguish the recent and more than 4 months old infection in a prospective cohort study for the first time in India. One hundred and eighty pregnant women presented in their first 4 months of pregnancy were included in this study. Their sera were tested for anti-Toxoplasma gondii antibodies using direct agglutination test, immunoglobulin (Ig)G and IgM-enzyme-linked immunosorbent assay, IgM-immunosorbent agglutination assay and VIDAS-IgG avidity. RESULTS: Overall IgG seroprevalence rate of toxoplasmosis was 45%. Only seven women (3.3%)were found to have IgM antibodies and only two of these showed low IgG avidity indicating recent infection of ≤4 months duration. One woman aborted spontaneously at her fourth month of gestation. In remaining five women the recent infection could successfully be excluded by IgG avidity testing. All these women had uneventful pregnancy. CONCLUSIONS: This study indicated that all IgM antibody positive pregnant must be tested for IgG avidity to rule out recent primary infection. [ABSTRACT FROM AUTHOR]