scholarly journals Correlation between specific IgM levels and percentage IgG-class antibody avidity to Toxoplasma gondii

2008 ◽  
Vol 50 (4) ◽  
pp. 237-242 ◽  
Author(s):  
Marcel Leite ◽  
Sonia Siciliano ◽  
Lucia Silvieri A. Rocha ◽  
Teresa R. Justa ◽  
Katia Regina César ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Acute Phase ◽  
Turnaround Time ◽  
Antibody Avidity ◽  
Igg Avidity ◽  
Avidity Test ◽  
Evaluation Test ◽  
Fetal Malformations ◽  
Two Parameters ◽  
Class Antibody

Toxoplasmosis is an usually asymptomatic worldwide disseminated infection. In its congenital presentation it may lead to abortion or fetal malformations. Antenatal evaluation is considered of paramount importance to identify seronegative women and allow for prophylaxis. Recent improvements in sensitivity of IgM tests has made IgM detection an extremely protracted acute phase marker, and IgG avidity evaluation test became necessary. Observation has shown that a correlation can be established between IgM levels and avidity percentages, suggesting that frequently the avidity test may not be necessary. In this study we analyzed Toxoplasma gondii IgM levels of 202 samples and their IgG avidity percentages, in order to define specific levels whose IgM quantification could by itself define serodiagnosis and therefore make the avidity evaluation unnecessary. We showed that for IgM levels bellow 2.0 and above 6.0 serodiagnosis of toxoplasmosis could be established without need of IgG avidity test. IgM levels between these two parameters are associated with varying avidity indexes highlighting the importance of its evaluation as a means to confirm toxoplasmosis. Following this demonstration it was possible to avoid the avidity test for 75% of the cases, to reduce the turnaround time and to reduce costs.

scholarly journals Toxoplasmosis and pregnancy: Perinatal results and association of the IgG avidity test with congenital infection in pregnant women with positive anti-Toxoplasma gondii IgM [Abstract in English]

2010 ◽  
Vol 20 (1) ◽  
pp. 45
Author(s):  
Virgílio Gonçalves de Souza-Júnior ◽  
Ernesto Antonio Figueiró-Filho ◽  
Danilo De Cerqueira Borges ◽  
Vanessa Marcon Oliveira ◽  
Lílian Rezende Coelho
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Predictive Value ◽  
Congenital Infection ◽  
Neonatal Infection ◽  
High Avidity ◽  
Igg Avidity ◽  
Risk Pregnancy ◽  
Avidity Test ◽  
Acute Toxoplasmosis

AIMS: To verify the perinatal outcomes in pregnant women with acute toxoplasmosis, and to determine if there was association between the results of Toxoplasma gondii-specific IgG avidity test and the presence or absence of fetal/neonatal infection. METHODS: A cross-sectional study included pregnant women with serological diagnosis of acute toxoplasmosis (presenting a positive Toxoplasma gondii-specific IgM test) attended at the outpatient unit for high-risk pregnancy of the Faculty of Medicine, Federal University of Mato Grosso do Sul, Brazil, in the period from November 2002 to November 2007. Test results demonstrating IgG avidity index above 30% were considered high avidity, while values below 30% were considered low avidity. Fetal and/or neonatal infection was defined by positive result for the polymerase chain reaction in amniotic fluid, or by a positive Toxoplasma gondii-specific IgM test in the newborn's serum. RESULTS: Considering all pregnant women referred to the outpatient unit for high-risk pregnancy in the period of study, frequency of pregnant women with positive Toxoplasma gondii-specific IgM was 10.8% (176/1.634). The rate of congenital infection in these patients was 4% (7/176). The IgG avidity test was performed in 162 patients (92% of the 176 pregnant women with positive IgM), and the avidity was high in 144 (88.9%). There was an association (p=0.003) between high avidity and no fetal/neonatal toxoplasmosis in our sample, with a prevalence ratio of 13.4 (confidence interval [CI] 95% 2.2-86.6). The positive predictive value of the avidity test (probability of congenital infection with a low avidity) was 22% (95% 6%-47%), while the negative predictive value (probability of absence of congenital infection with a high avidity) was 98% (95% CI 94% -99%). CONCLUSIONS: In this study the rate of congenital infection in pregnant women diagnosed with acute toxoplasmosis was 4%. In pregnant women with positive Toxoplasma gondii-specific IgM, results of Toxoplasma gondii-specific IgG avidity test were associated with the presence or absence of congenital infection, with a high negative predictive value (no fetal/neonatal infection when avidity was high).

scholarly journals Evaluation of Toxoplasma gondii Seropositivity and the Results of IgG Avidity Test of Patients with Suspected Toxoplasmosis

2018 ◽  
Author(s):  
Salih Maçin ◽  
Duygu Fındık ◽  
Aslıhan Demircan ◽  
Uğur Arslan ◽  
Hatice Türk Dağı
Keyword(s):  
Toxoplasma Gondii ◽  
Igg Avidity ◽  
Avidity Test

scholarly journals Toxoplasma gondii seroprevalence among pregnant women in Rabat, Morocco

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Majda Laboudi ◽  
Zoubida Taghy ◽  
Oussama Duieb ◽  
François Peyron ◽  
Abderrahim Sadak
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Congenital Toxoplasmosis ◽  
Immunoglobulin M ◽  
Bivariate Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Seroprevalence Rate ◽  
Recent Infection ◽  
Igg Avidity ◽  
Avidity Test

Abstract Background Toxoplasmosis is an infectious disease caused by a protozoan parasite named Toxoplasma gondii (T.gondii). Pregnant women are considered one of the risk groups. The objective of this retrospective study is to provide an updated estimate of the seroprevalence of anti-T. gondii antibodies among a group of Moroccan pregnant women monitored at the Parasitology Laboratory of the National Institute of Hygiene in Rabat in Morocco. Methods Serum samples were tested for the presence of specific anti-T. gondii immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies using indirect enzyme-linked immunosorbent assay (ELISA). Anti-Toxoplasma IgM- and IgG-positive cases were also evaluated with the anti-Toxoplasma IgG avidity test. All cases were evaluated according to the age, parity, and historical of abortion. Results Among 677 pregnant women, 94.1% (637/677) were serologically screened for the first time and therefore had no knowledge of their serological status, and only 5.9% (40/677) were screened for the second or third time. The overall anti-T. gondii IgG and IgM seropositivity among the 637 pregnant women included in the study analysis was 43% (274/637) and 3.9% (25/637), respectively. The use of the IgG avidity test allowed excluding recent infection among 83% of cases with IgG and IgM positive sera. The mean age was 29.4 ± 6.3 years. The result of the bivariate analysis revealed that the age influenced significantly the seroprevalence rate, while the parity and the existence of previous spontaneous abortion did not have any significant statistical correlation with seropositivity to T. gondii. Conclusion This study shows that 43% of pregnant women were positive and 57% of them had no antibody against the T. gondii infection. However, the pregnancy follow-up and the counseling of pregnant women remain essential for the prevention of congenital toxoplasmosis.

EVALUATION OF Toxoplasma gondii SEROPREVALENCE AND IGG AVIDITY TEST RESULTS AMONG CHILDBEARING-AGE WOMEN IN KARABUK PROVINCE

2021 ◽  
Vol 6 (12) ◽  
pp. 98-103
Author(s):  
Meryem COLAK ◽  
Nergis ASGIN
Keyword(s):  
Toxoplasma Gondii ◽  
Congenital Toxoplasmosis ◽  
Epidemiological Data ◽  
Test Results ◽  
Childbearing Age ◽  
Igg Antibody ◽  
Seropositivity Rate ◽  
Igg Avidity ◽  
Avidity Test ◽  
Childbearing Age Women

Toxoplasmosis is a zoonotic infectious disease that is common worldwide and caused by the Toxoplasma gondii. Congenital toxoplasmosis is one of the major complications of this infection. The present study aimed to investigate T.gondii seroprevalence and evaluate the IgG avidity test results among childbearing- age women retrospectively. A total of 9401 samples obtained from childbearing -age (15-49 years of age) women who attended Karabuk University Training and Research Hospital between February 2016- January 2020, over the four-year, were included in the study.The Toxoplasma-IgM, Toxoplasma-IgG antibody, and Toxoplasma IgG avidity tests were analyzed chemiluminescent method by using ARCHITECT I 2000 SR immunoassay device (Abbott Laboratories, USA). Toxoplasma-IgM and Toxoplasma-IgG seropositivity were detected as 0.7% (67/9401) and 15.7% (1415/9005) respectively. A high percentage of Toxoplasma-IgM and Toxoplasma-IgG seropositivity were detected among 31-35 years of age group. The Toxoplasma seropositivity increased by age, but no statistically difference was found (P >0.05).The Toxoplasma IgG avidity was high in 45 patients (69.4%), low avidity was detected in 16 patients (22.6%) and from the remaining 6 patients were borderline (8%). The Toxoplasma IgM and IgG seropositivity rate decreased 2016 to 2020. The highest Toxoplasma IgM and IgG seropositivity were in 2016 with 1.2% and 16.8%, respectively. The T. gondi seropositivity rate was decreased from 2016 to 2020; it is probably a result of increasing awareness of the disease among patients. We think our results will contribute to the epidemiological data in our province and country and raise awareness.

scholarly journals Detection of acute Toxoplasma gondii infection in early pregnancy by IgG avidity and PCR analysis

2007 ◽  
Vol 56 (11) ◽  
pp. 1495-1499 ◽  
Author(s):  
Jamshaid Iqbal ◽  
Nabila Khalid
Keyword(s):  
Toxoplasma Gondii ◽  
Early Pregnancy ◽  
Therapeutic Intervention ◽  
First Trimester ◽  
Pcr Analysis ◽  
High Avidity ◽  
Past Infection ◽  
Igm Antibodies ◽  
Igg Avidity ◽  
Avidity Test

Acute Toxoplasma gondii infection in early pregnancy carries the risk of transmitting the infection to the fetus with serious sequelae. However, serological testing for IgG/IgM anti-Toxoplasma antibodies may fail to differentiate between a recent and past infection. Two hundred and twenty-four Kuwaiti women in their first trimester were screened for IgG/IgM antibodies by the Vitek Immuno Diagnostic Assay System (VIDAS) and VIDAS IgG-avidity tests. On serological screening, 119 (53.1 %) women were positive for IgG antibodies and 31 (13.8 %) for IgM antibodies. Nine of the IgM-positive and 7 IgM-negative women had low-avidity antibodies. However, the IgG-avidity test detected low-avidity antibodies only in 9 (29 %) of the 31 IgM-positive women, suggesting a recent infection; 19 (61.3 %) women had high-avidity antibodies, indicating that the infection was acquired in the distant past. Based on IgM serology alone, at least 31 IgM-positive women may have been wrongly labelled as having acute Toxoplasma infection thus warranting appropriate therapeutic intervention. All the 19 IgM-positive women with high-avidity antibodies were confirmed negative for Toxoplasma DNA on PCR analysis. Compared with PCR analysis, the VIDAS avidity test was a helpful tool for the diagnosis of recent Toxoplasma infection in IgM-negative women with low-avidity antibodies and IgM-positive women with high-avidity antibodies; the specificity was >85 –100 %. It is concluded that the VIDAS avidity test when used in combination with VIDAS IgG/IgM tests is a valuable assay for the exclusion of ongoing or recently acquired T. gondii infection in pregnant women in their first trimester and that it decreases significantly the necessity for follow-up testing and unnecessary therapeutic intervention.

scholarly journals Detection of Acute and Chronic Toxoplasma gondii Infection among Women with History of Abortion in the Southwest of Iran

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Jasem Saki ◽  
Maryam Zamanpour ◽  
Mahin Najafian ◽  
Niloofar Mohammadpour ◽  
Masoud Foroutan
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Umbilical Cord ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Avidity ◽  
Normal Delivery ◽  
Blood Samples ◽  
Igg Avidity ◽  
Avidity Test ◽  
History Of

Background. Toxoplasma gondii (T. gondii) is one of the most common intracellular protozoan parasites, which can infect humans and a wide range of mammals and birds. The current study is aimed at investigating the occurrence of T. gondii infection in women with a history of abortion in Khuzestan, Iran. Materials and Methods. A total of 480 women with an abortion history, as well as 200 pregnant women with a normal delivery, were examined in this study. The blood, placenta, and umbilical cord blood samples were assessed by the enzyme-linked immunosorbent assay (ELISA) and nested-polymerase chain reaction (PCR) assay. Results. Based on the results of ELISA assay, the prevalence of toxoplasmosis was 30.83% in women with a history of abortion (25.62% with T. gondii IgG and 5.20% with T. gondii IgM). According to the IgG avidity test, 60.16% of IgG-positive samples showed high avidity, while 27.64% showed low avidity. On the other hand, the prevalence of toxoplasmosis in women with a normal delivery was 23% (21.5% with T. gondii IgG and 1.5% with T. gondii IgM). According to the IgG avidity test, 81.39% of these women showed high avidity, while only 4.65% showed low avidity. Based on the nested-PCR method, T. gondii DNA was detected in 14.18% of blood samples, 4.69% of placental samples, and 1.34% of umbilical cord samples, collected from 148 seropositive women with a history of abortion. Besides, using this method, the parasite DNA was identified in 4.34% of blood samples, collected from 46 seropositive women with a normal delivery, but not in any of the umbilical cord or placenta samples. Conclusion. The present results showed that T. gondii infection contributes to abortion in Khuzestan Province, Iran. Therefore, it is essential to investigate toxoplasmosis in pregnant women, especially in those who are seronegative, using molecular and serological methods and inform them about their disease and the associated risks.

scholarly journals Toxoplasma gondii specific IgG avidity assay: Role and implication in the confirmatory diagnosis of acute toxoplasmosis in seropositive pregnant women

2016 ◽  
Vol 9 (2) ◽  
pp. 96
Author(s):  
Chowdhury Rafia Naheen ◽  
Shirin Tarafder ◽  
Humayun Sattar ◽  
Shafinaz Khan
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Acute Infection ◽  
High Avidity ◽  
Past Infection ◽  
Congenital Transmission ◽  
Avidity Assay ◽  
Igg Avidity ◽  
Avidity Test ◽  
Specific Igg

<p>This study was undertaken to apply<em> Toxoplasma gondii</em> specific IgG avidity test in seropositive pregnant women to differentiate acute and past infection. <em>T. gondii</em> specific IgG avidity test was conducted in 39 seropositive pregnant women and their pregnancy outcomes were observed later on. Out of 39 <em>T. gondii</em> seropositive pregnant women 33 (84%) were only IgG positive and 6 (15.4%) were both IgG-IgM positive. All the IgG positive cases (100%) and 2(33.3%) IgG-IgM positive cases had high avidity antibodies and they gave birth to healthy babies. Rest of the 4 (66.7%) IgG-IgM positive women had low avidity and 50% of them had abortion and 50% gave birth to unhealthy babies. This reveals that the seropositive mothers having high IgG avidity had past infection and no risk of congenital transmission. Seropositive mothers having low IgG avidity had acute infection and so congenital transmission occurred. Presence of<em> T. gondii</em> specific IgG and IgM antibody does not indicate acute infection always. IgG-IgM positive pregnant women should be further evaluated by IgG avidity assay to confirm acute infection.</p><p> </p>

scholarly journals IMPORTÂNCIA DO RASTREAMENTO SOROLÓGICO DA TOXOPLASMOSE EM GESTANTES ATENDIDAS EM AMBULATÓRIO DE PRÉ-NATAL DE ALTO RISCO

2011 ◽  
Vol 36 (1) ◽  
pp. 29
Author(s):  
Sandra Trevisan Beck ◽  
Cristine Kolling Konopka ◽  
Felipe Polgati Diehl ◽  
Alexandre Kieslich da Silva
Keyword(s):  
Retrospective Study ◽  
High Risk ◽  
Toxoplasma Gondii ◽  
Prenatal Care ◽  
Pregnant Women ◽  
Serological Test ◽  
Serological Screening ◽  
Igg Avidity ◽  
Avidity Test ◽  
Acute Toxoplasmosis

Estudo transversal, retrospectivo, de 408 gestantes imunocompetentes, atendidas em Ambulatório de Pré-Natal de Alto Risco, entre janeiro de 2005 a dezembro de 2006 para verificar a relevância da triagem sorológica da infecção por Toxoplasma gondii, nesta população. Foram analisados os perfis sorológicos, para pesquisa de anticorpos específicos IgM, IgG e avidez de IgG, através de métodos imunológicos ELFA® e MEIA®. Foram identificadas, 271 (66,42) imunes, 121 (29,6%) suscetíveis, seis (1,47%) com provável doença aguda e 10 (2,45%) casos com teste da avidez de IgG foi realizado após o quarto mês de gestação, além do tempo estabelecido como ideal para pesquisa deste parâmetro laboratorial. A realização do teste de avidez de IgG, em tempo adequado, permitiu definir um maior número de casos passiveis de tratamento. O encontro de 29,6% de gestantes suscetíveis à infecção por T. gondii mostrou a importância da triagem sorológica na prevenção de casos de toxoplasmose aguda .Palavras-chave: toxoplasmose; gestantes; IgG; IgM; cuidado pré-natal Transversal retrospective study of serological test to T. gondii infection for 408 immunocompetent pregnant women attended in The High Risk Prenatal Ambulatory, among January, 2005 to December, 2006 to determinate the importance of screening for Toxoplasma gondii (T. gondii) infection in this population. Serological profile for specific IgM, IgG and IgG avidity done by ELFA® e MEIA® methodology were analyzed. There were found 271(66,42%) out of 408 pregnant women immune to T.gondii infection, 41 (29,3%) susceptible, six (1,47%) with probable acute disease and ten (2,45%) with avidity test realized after the adequate period established like optimal for research. The accomplishment of the IgG avidity test during the correct time allows the detection of a higher number of acute diseases. The data for 29,6% of pregnant women susceptible to infection by T. gondii shows the importance of serological screening for toxoplasmosis in order to prevent cases of acute toxoplasmosis in the population studied.Keywords: Toxoplasmosis, Pregnant, IgG, IgM, Prenatal Care. 

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