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Franco PS, Scussel ACMO, Silva RJ, Araújo TE, Gonzaga HT, Marcon CF, Brito-de-Sousa JP, Diniz ALD, Paschoini MC, Barbosa BF, Martins-Filho OA, Mineo JR, Ferro EAV, Gomes AO. Systematic Review and Meta-Analysis of Congenital Toxoplasmosis Diagnosis: Advances and Challenges. J Trop Med 2024; 2024:1514178. [PMID: 38419946 PMCID: PMC10901580 DOI: 10.1155/2024/1514178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 10/21/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Objective To understand how congenital toxoplasmosis (CT) diagnosis has evolved over the years, we performed a systematic review and meta-analysis to summarize the kind of analysis that has been employed for CT diagnosis. Methods PubMed and Lilacs databases were used in order to access the kind of analysis that has been employed for CT diagnosis in several samples. Our search combined the following combining terms: "congenital toxoplasmosis" or "gestational toxoplasmosis" and "diagnosis" and "blood," "serum," "amniotic fluid," "placenta," or "colostrum." We extracted data on true positive, true negative, false positive, and false negative to generate pooled sensitivity, specificity, and diagnostic odds ratio (DOR). Random-effects models using MetaDTA were used for analysis. Results Sixty-five articles were included in the study aiming for comparisons (75.4%), diagnosis performance (52.3%), diagnosis improvement (32.3%), or to distinguish acute/chronic infection phases (36.9%). Amniotic fluid (AF) and placenta were used in 36.9% and 10.8% of articles, respectively, targeting parasites and/or T. gondii DNA. Blood was used in 86% of articles for enzymatic assays. Colostrum was used in one article to search for antibodies. In meta-analysis, PCR in AF showed the best performance for CT diagnosis based on the highest summary sensitivity (85.1%) and specificity (99.7%) added to lower magnitude heterogeneity. Conclusion Most of the assays being researched to diagnose CT are basically the same traditional approaches available for clinical purposes. The range in diagnostic performance and the challenges imposed by CT diagnosis indicate the need to better explore pregnancy samples in search of new possibilities for diagnostic tools. Exploring immunological markers and using bioinformatics tools and T. gondii recombinant antigens should address the research needed for a new generation of diagnostic tools to face these challenges.
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Affiliation(s)
- Priscila Silva Franco
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | | | - Rafaela José Silva
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | - Thadia Evelyn Araújo
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
- Instituto René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima, 1715, Barro Preto 30190-002, Belo Horizonte, MG, Brazil
| | - Henrique Tomaz Gonzaga
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | - Camila Ferreira Marcon
- Universidade Federal do Triângulo Mineiro, Rua Frei Paulino, 30, Nossa Sra. da Abadia 38025-180, Uberaba, MG, Brazil
| | - Joaquim Pedro Brito-de-Sousa
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
- Instituto René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima, 1715, Barro Preto 30190-002, Belo Horizonte, MG, Brazil
| | - Angélica Lemos Debs Diniz
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | - Marina Carvalho Paschoini
- Universidade Federal do Triângulo Mineiro, Rua Frei Paulino, 30, Nossa Sra. da Abadia 38025-180, Uberaba, MG, Brazil
| | - Bellisa Freitas Barbosa
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | - Olindo Assis Martins-Filho
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
- Instituto René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima, 1715, Barro Preto 30190-002, Belo Horizonte, MG, Brazil
| | - José Roberto Mineo
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | - Eloisa Amália Vieira Ferro
- Universidade Federal de Uberlândia, Avenida João Naves de Ávila 2121, Uberlândia, Santa Mônica 38408-100, MG, Brazil
| | - Angelica Oliveira Gomes
- Universidade Federal do Triângulo Mineiro, Rua Frei Paulino, 30, Nossa Sra. da Abadia 38025-180, Uberaba, MG, Brazil
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Recombinant AMA1 Virus-like Particle Antigen for Serodiagnosis of Toxoplasma gondii Infection. Biomedicines 2022; 10:biomedicines10112812. [PMID: 36359332 PMCID: PMC9687185 DOI: 10.3390/biomedicines10112812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/27/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022] Open
Abstract
Toxoplasmosis diagnosis predominantly relies on serology testing via enzyme-linked immunosorbent assay (ELISA), but these results are highly variable. Consequently, various antigens are being evaluated to improve the sensitivity and specificity of toxoplasmosis serological diagnosis. Here, we generated Toxoplasma gondii virus-like particles displaying AMA1 of T. gondii and evaluated their diagnostic potential. We found that AMA1 VLPs were highly sensitive and reacted with the sera acquired from mice infected with either T. gondii ME49 or RH strains. The overall IgG and IgM antibody responses elicited by AMA1 VLPs were substantially higher than those induced by the conventionally used T. gondii lysate antigen (TLA). Importantly, AMA1 VLPs were capable of detecting parasitic infection with T. gondii RH and ME49 as early as 1 week post-infection, even when mice were exposed to low infectious doses (5 × 103 and 10 cysts, respectively). AMA1 VLPs also did not cross-react with the immune sera acquired from Plasmodium berghei-infected mice. Compared to TLA, stronger antibody responses were induced by AMA1 VLPs when tested using T. gondii-infected human sera. The sensitivities and specificities of the two antigens were substantially different, with AMA1 VLPs demonstrating over 90% sensitivity and specificity, whereas these values were in the 70% range for the TLA. These results indicated that AMA1 VLPs can detect infections of both T. gondii ME49 and RH at an early stage of infection caused by very low infection doses in mice, and these could be used for serological diagnosis of human toxoplasmosis.
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Diagnosis of Congenital Toxoplasmosis: Performance of Four IgG and IgM Automated Assays at Birth in a Tricentric Evaluation. J Clin Microbiol 2022; 60:e0011522. [DOI: 10.1128/jcm.00115-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For postnatal diagnosis of congenital toxoplasmosis (CT), the gold standard for the detection of anti-
Toxoplasma
IgM in newborns relies on the immunosorbent agglutination assay (ISAGA), which is manufactured from whole
Toxoplasma
parasites that become difficult to maintain. For IgG, only the Platelia assay provides a validated assay for cord blood according to the manufacturer, allowing its use in this context.
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4
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Jean-Pierre V, Miozzo J, Fricker-Hidalgo H, Garnaud C, Robert MG, Pelloux H, Brenier-Pinchart MP. Serological diagnosis of toxoplasmosis: evaluation of the commercial test recomLine Toxoplasma IgG immunoblot (Mikrogen) based on recombinant antigens. Parasite 2022; 29:52. [PMCID: PMC9645231 DOI: 10.1051/parasite/2022050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/06/2022] [Indexed: 11/11/2022] Open
Abstract
Background: IgG detection to determine immune status to Toxoplasma gondii infection and seroconversion mainly relies on ELISA techniques and, if necessary, on a confirmatory test, Western blot. This study evaluated the performance of the recomLine Toxoplasma IgG immunoblot (IB-recomLine) (Mikrogen) as a confirmatory test on a large number of sera. A total of 171 sera were selected (113 patients) and had previously been analyzed by two ELISA tests, ARCHITECT (Abbott) and VIDAS (bioMérieux) ± LDBIO-Toxo II IgG Western blot (WB-LDBIO) (LDBio). The sera were classified into three groups: group 1 included 50 sera without difficulty in interpreting the IgG results (patients with documented past infection or uninfected); group 2 included 47 sera with difficulty in interpreting the ELISA results; and group 3 included 74 sequential sera from 25 pregnant women with seroconversion. Results: In group 1, overall IgG agreements were 94% and 90% with ARCHITECT and VIDAS, respectively. In group 2, low agreement was observed between IB-recomLine and WB-LDBIO, with eight false-positive and 13 false-negative results. In group 3, 4/13 seroconversions were detected earlier with IB-recomLine compared to other tests. Conclusions: IB-recomLine allowed for earlier diagnosis of toxoplasmic seroconversion compared to both ELISA tests and WB-LDBIO but led to insufficient performance to confirm the immune status when ELISA results were discordant or equivocal.
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Affiliation(s)
- Vincent Jean-Pierre
- Parasitology-Mycology, Grenoble Alpes University Hospital 38000 Grenoble France
- Corresponding author:
| | - Julien Miozzo
- Parasitology-Mycology, Grenoble Alpes University Hospital 38000 Grenoble France
| | | | - Cécile Garnaud
- Parasitology-Mycology, Grenoble Alpes University Hospital 38000 Grenoble France
- TIMC, CNRS, Université Grenoble Alpes 38000 Grenoble France
| | - Marie Gladys Robert
- Parasitology-Mycology, Grenoble Alpes University Hospital 38000 Grenoble France
| | - Hervé Pelloux
- Parasitology-Mycology, Grenoble Alpes University Hospital 38000 Grenoble France
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Flores C, Villalobos-Cerrud D, Borace J, Fábrega L, Norero X, Sáez-Llorens X, Moreno MT, Restrepo CM, Llanes A, Quijada R. M, Ladrón De Guevara M, Guzmán G, de la Guardia V, García A, Lucero MF, Wong D, Mcleod R, Soberon M, Caballero E. Z. Epidemiological Aspects of Maternal and Congenital Toxoplasmosis in Panama. Pathogens 2021; 10:764. [PMID: 34204401 PMCID: PMC8234371 DOI: 10.3390/pathogens10060764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 02/06/2023] Open
Abstract
In Panama, epidemiological data on congenital toxoplasmosis are limited, making it difficult to understand the scope of clinical manifestations in the population and factors that may increase the risk of infection. This study provides insight into the epidemiological situation of maternal and congenital toxoplasmosis in Panama and contributing information on the burden of this disease in Central America. Blood samples were collected from 2326 pregnant women and used for the detection of anti-T. gondii antibodies. A high seroprevalence (44.41%) was observed for T. gondii infection in pregnant women from different regions of Panama, with an estimated incidence rate of congenital toxoplasmosis of 3.8 cases per 1000 live births. The main risk factors associated with T. gondii infection using bivariate statistical analysis were an elementary level education and maternal age range of 34-45 years. Multivariate statistical analyses revealed that in some regions (San Miguelito, North and West regions), the number of positive cases correlated with the presence of pets, stray dogs and the consumption of poultry. In other regions (East and Metropolitan regions), the absence of pets was considered a protective factor associated with negative cases, while the presence of stray cats and the age range of 25-34 years did not represent any risk in these regions.
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Affiliation(s)
- Carlos Flores
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
- Laboratorio Clínico, Hospital Santo Tomás, Panama City 0816-00383, Panama;
| | - Delba Villalobos-Cerrud
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
- Departamento de Microbiología y Parasitología, Escuela de Biología, Facultad de Ciencias Naturales Exactas y Tecnología, Universidad de Panamá, Panama 4, Panama City 3366, Panama
| | - Jovanna Borace
- Laboratorio Clínico, Hospital Santo Tomás, Panama City 0816-00383, Panama;
| | - Lorena Fábrega
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
| | - Ximena Norero
- Departamento de Infectología, Hospital del Niño Dr. José Renán Esquivel, Panama City 0816-00383, Panama; (X.N.); (X.S.-L.); (M.T.M.)
| | - X. Sáez-Llorens
- Departamento de Infectología, Hospital del Niño Dr. José Renán Esquivel, Panama City 0816-00383, Panama; (X.N.); (X.S.-L.); (M.T.M.)
- Sistema Nacional de Investigación-Secretaría Nacional de Ciencia, Tecnología e Innovasión (SNI-SENACYT), Panama City 0816-02852, Panama
| | - María Teresa Moreno
- Departamento de Infectología, Hospital del Niño Dr. José Renán Esquivel, Panama City 0816-00383, Panama; (X.N.); (X.S.-L.); (M.T.M.)
| | - Carlos M. Restrepo
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
- Sistema Nacional de Investigación-Secretaría Nacional de Ciencia, Tecnología e Innovasión (SNI-SENACYT), Panama City 0816-02852, Panama
| | - Alejandro Llanes
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
| | - Mario Quijada R.
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
| | | | - German Guzmán
- Facultad de Medicina, Universidad de Panamá, Panama 4, Panama City 3366, Panama; (G.G.); (M.F.L.)
| | - Valli de la Guardia
- Maternidad del Hospital Santo Tomás, Panama City 0816-00383, Panama; (M.L.D.G.); (V.d.l.G.)
| | - Anabel García
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
| | - María F. Lucero
- Facultad de Medicina, Universidad de Panamá, Panama 4, Panama City 3366, Panama; (G.G.); (M.F.L.)
| | - Digna Wong
- Centros de Investigaciones Clínicas y Medicina Traslacional, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama;
| | - Rima Mcleod
- Toxoplasmosis Center, University of Chicago Medicine, Chicago, IL 60637, USA;
| | - Mariangela Soberon
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
| | - Zuleima Caballero E.
- Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Asociación de Interés Público (INDICASAT-AIP), Panama City 0843-01103, Panama; (C.F.); (D.V.-C.); (L.F.); (C.M.R.); (A.L.); (M.Q.R.); (A.G.); (M.S.)
- Sistema Nacional de Investigación-Secretaría Nacional de Ciencia, Tecnología e Innovasión (SNI-SENACYT), Panama City 0816-02852, Panama
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Robert-Gangneux F, Guegan H. Anti-Toxoplasma IgG assays: What performances for what purpose? A systematic review. ACTA ACUST UNITED AC 2021; 28:39. [PMID: 33904818 PMCID: PMC8078101 DOI: 10.1051/parasite/2021035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/31/2021] [Indexed: 12/27/2022]
Abstract
Chronic infection with Toxoplasma gondii is attested by the detection of specific anti-Toxoplasma IgG. A wide panel of serologic methods is currently marketed, and the most suitable method should be chosen according to the laboratory resources and the screened population. This systematic review of evaluation studies aimed at establishing an overview of the performances, i.e. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of marketed anti-Toxoplasma IgG assays, and discussing their technical characteristics to guide further choice for routine diagnostic use. According to PRISMA guidelines, the search performed in PubMed and Web of Science databases recovered 826 studies, of which 17 were ultimately included. Twenty commercial anti-Toxoplasma IgG assays were evaluated, in comparison with an accepted reference method. Most of them were enzyme-immunoassays (EIAs, n = 12), followed by agglutination tests (n = 4), immunochromatographic tests (n = 3), and a Western-Blot assay (WB, n = 1). The mean sensitivity of IgG assays ranged from 89.7% to 100% for standard titers and from 13.4% to 99.2% for low IgG titers. A few studies pointed out the ability of some methods, especially WB to detect IgG early after primary infection. The specificity of IgG assays was generally high, ranging from 91.3% to 100%; and higher than 99% for most EIA assays. The PPV was not a discriminant indicator among methods, whereas significant disparities (87.5%–100%) were reported among NPVs, a key-parameter assessing the ability to definitively rule out a Toxoplasma infection in patients at-risk for opportunistic infections.
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Affiliation(s)
- Florence Robert-Gangneux
- Université de Rennes, CHU Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé Environnement Travail), UMR_S 1085, 35000 Rennes, France
| | - Hélène Guegan
- Université de Rennes, CHU Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé Environnement Travail), UMR_S 1085, 35000 Rennes, France
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Rosuvastatin revert memory impairment and anxiogenic-like effect in mice infected with the chronic ME-49 strain of Toxoplasma gondii. PLoS One 2021; 16:e0250079. [PMID: 33857221 PMCID: PMC8049280 DOI: 10.1371/journal.pone.0250079] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/30/2021] [Indexed: 11/19/2022] Open
Abstract
The aim of this study was to investigate the effect of rosuvastatin treatment on memory impairment, and anxiogenic-like effects in mice chronically infected with Toxoplasma gondii. For this, Balb/c mice were infected orally with chronic ME-49 strain of Toxoplasma gondii. Oral treatment with rosuvastatin (40mg/kg/day) started on the 51st day post-infection and was performed daily for 21 days. After completion of treatment, anxiety-like effects and locomotion were investigated in the open field (OF) test, whereas novel object recognition (NOR) test was used for evaluation of short- and long-term memory. At the end of the experiments, the brain was collected for Toxoplasma gondii DNA quantification and histopathological analysis. Infection with ME-49 strain decreased the time spent in the center of OF, indicating an anxiogenic effect, without affecting total and peripheral locomotion. Rosuvastatin treatment inhibited the change in the center time. Besides, pharmacological treatment increased total and central locomotion in both non-infected and infected animals. Infection also impaired both short- and long-term memory in the NOR test, and these effects were reverted by rosuvastatin treatment. In addition to effects in behavioral changes, rosuvastatin also reduced parasite load in the brain and attenuated signs of brain inflammation such as perivascular cuffs, inflammatory cell infiltration and tissue damage. These findings indicate for the first time the efficacy of rosuvastatin in treatment of memory impairment and anxiogenic effect evoked by infection with Toxoplasma gondii. These effects might be mediated by reduced cyst load, which in turn decrease inflammation and damage in the brain.
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Role of Toxoplasma gondii IgG Avidity Testing in Discriminating between Acute and Chronic Toxoplasmosis in Pregnancy. J Clin Microbiol 2020; 58:JCM.00505-20. [PMID: 32321784 DOI: 10.1128/jcm.00505-20] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Risk of mother-to-child transmission of Toxoplasma gondii during pregnancy is much greater in women who are exposed to primary T. gondii infection (toxoplasmosis) after conception compared to those who were exposed to the infection before conception. Therefore, laboratory tests that help classify recent primary toxoplasmosis are important tools for the management of pregnant women suspected to have T. gondii exposure. Detection of Toxoplasma IgM (Toxo IgM) is a sensitive indicator of primary toxoplasmosis, but the indicator specificity is low because sometimes natural IgM antibodies react with Toxoplasma antigens in the absence of the infection. Furthermore, Toxo IgM sometimes persists in blood serum for several months or years following the primary infection. In recent decades, Toxo IgG avidity assay has been used as a standard diagnostic technique for a better estimation of the infection acquisition time and identification of the primary T. gondii infection during pregnancy. Avidity is described as the aggregate strength; by which, a mixture of polyclonal IgG molecules reacts with multiple epitopes of the proteins. This parameter matures gradually within 6 months of the primary infection. A high Toxo IgG avidity index allows a recent infection (less than 4 months) to be excluded, whereas a low Toxo IgG avidity index indicates a probable recent infection with no exclusions of the older infections. This minireview is based on various aspects of T. gondii IgG avidity testing, including (i) description of avidity and basic methods used in primary studies on T. gondii IgG avidity and primary infections; (ii) importance of IgG avidity testing in pregnancy; (iii) result summary of the major studies on the use of T. gondii IgG avidity assay in pregnancy; (iv) brief explanation of the T. gondii IgG avidity values in newborns; (v) result summary of the major studies on T. gondii IgG avidity and PCR; (vi) discussion of commercially available T. gondii IgG avidity assays, including newer automated assays; and (vii) current issues and controversies in diagnosis of primary T. gondii infections in pregnancy.
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Evangelista FF, Mantelo FM, de Lima KK, Marchioro AA, Beletini LF, de Souza AH, Santana PL, Riedo CDO, Higa LT, Guilherme ALF. Prospective evalution of pregnant women with suspected acute toxoplasmosis treated in a reference prenatal care clinic at a university teaching hospital in Southern Brazil. Rev Inst Med Trop Sao Paulo 2020; 62:e46. [PMID: 32667393 PMCID: PMC7359740 DOI: 10.1590/s1678-9946202062046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 06/18/2020] [Indexed: 11/30/2022] Open
Abstract
Infection by the protozoan Toxoplasma gondii during pregnancy demands greater attention from the health authorities due to the risk of placental transmission, which can have devastating consequences to the foetus and newborn. This study was conducted in a high-risk prenatal care outpatient clinic of a university teaching hospital. Pregnant women screened for specific IgM and IgG anti -T. gondii, attended from January 2009 to August 2018 were included. From 530 suspected patients, 218 were followed up and they presented positive IgM and IgG anti- T. gondii. From these patients, 83 (38.0%) had low IgG avidity, 39 (18%) seroconverted in the second or third trimester of pregnancy, 19 (8.7%) had no avidity test, 69 (31.6%) had high IgG avidity after 16 weeks of gestation, five had recurrent chorioretinitis (2.2%) and three (1.3%) were seropositive to HIV. Complementary diagnoses were made in 30/48 (62.5%) of the patients revealing the presence of specific IgA antibodies raised to T. gondii; 3/63 (4.8%) peripheral blood samples and 1/57 (1.8%) amniotic fluid sample. There were eight foetal deaths, one case of neonatal hepatomegaly and one case of T. gondii DNA detected in a peripheral blood sample. Of the 139 newborn deliveries at the teaching hospital, there was a 38% loss of follow-up. The prevalence of congenital toxoplasmosis was 1.2 cases/1,000 live births in this study area, according to the retrospective survey of cases. Prenatal treatment may have helped to reduce the risk of vertical transmission.
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Affiliation(s)
| | | | | | | | | | | | - Priscila Laet Santana
- Universidade Estadual de Maringá, Programa Ciências da Saúde, Maringá, Paraná, Brazil
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Picone O, Fuchs F, Benoist G, Binquet C, Kieffer F, Wallon M, Wehbe K, Mandelbrot L, Villena I. Toxoplasmosis screening during pregnancy in France: Opinion of an expert panel for the CNGOF. J Gynecol Obstet Hum Reprod 2020; 49:101814. [PMID: 32428782 DOI: 10.1016/j.jogoh.2020.101814] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/12/2020] [Indexed: 11/15/2022]
Abstract
Prenatal screening to prevent congenital toxoplasmosis as performed in France for several decades has been questioned in view of the decreasing incidence of this infection and the cost of testing. The French College of Obstetrics and Gynecology mandated a multidisciplinary panel of experts to perform a reassessment of the screening program in accordance with international good practice. In France, about 70% of pregnant women are not immune to T. gondii, and 0.2-0.25% become infected during pregnancy. The risk of maternal-fetal transmission of infection is on average 25-29% and depends greatly on the gestational age at seroconversion. In case of fetal transmission, the outcome is livebirth in 95% of cases, with latent congenital toxoplasmosis in 90% of cases and symptomatic forms in 10% of cases, of which 1/3 are severe and 2/3 moderate. Biological techniques have satisfactory performance regarding serologies for the diagnosis of maternal infections and PCR on amniotic fluid for the prenatal diagnosis of congenital toxoplasmosis. Primary prevention of toxoplasmosis is based on hygiene measures that are relatively simple, but poorly implemented. In case of maternal seroconversion, there is a strong case for prenatal prophylactic treatment as soon as possible (ideally within 3 weeks of seroconversion), spiramycin before 14 weeks of gestation (WG), and with a tendency to superiority of the pyrimethamine/sulfadiazine association over spiramycin beyond 14 W G, in order to reduce the risk of symptomatic congenital toxoplasmosis. In case of congenital toxoplasmosis, prompt initiation of treatment reduces the occurrence of cerebral signs and symptoms, as well as retinal lesions. Several medico-economic evaluations of the French toxoplasmosis screening program have been conducted including an individual cost-effectiveness approach with decision analysis which concluded on the profitability of prenatal screening as carried out in France (monthly surveillance of seronegative women, prenatal treatment in case of seroconversion, termination of pregnancy in severe forms). Though most international societies do not recommend systematic screening for mainly financial reasons, if congenital toxoplasmosis appears benign in France today, it is probably thanks to screening and the possibility of early treatment of fetuses and/or newborns. Thus, the panel recommends continuing for now the program in France for prevention of congenital toxoplasmosis.
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Affiliation(s)
- Olivier Picone
- Assistance Publique-Hôpitaux de Paris, Service de Gynécologie-Obstétrique, Hôpital Louis Mourier, Colombes, France; Université de Paris; Inserm IAME-U1137, Paris, France; FHU PREMA; Groupe de Recherche sur les Infections pendant la grossesse (GRIG)
| | - Florent Fuchs
- Service de Gynécologie Obstétrique CHU de Montpellier, Hopital Arnaud de Villeneuve, Montpellier, France; Inserm, CESP Centre de recherche en Epidémiologie et Santé des Populations, U1018, Reproduction et Développement de l'enfant, 94807 Villejuif, France; EA2415: Aide à la décision médicale Personnalisée, Axe B: Méthode en épidémiologie Clinique, Université de Montpellier
| | | | - Christine Binquet
- Inserm, CIC1432, module Epidémiologie Clinique, Dijon, France; CHU Dijon-Bourgogne, Centre d'Investigation Clinique, Module Epidémiologie Clinique/Essais Cliniques, Dijon, France
| | - François Kieffer
- Assistance Publique-Hôpitaux de Paris, Service de néonatologie, Hôpital Armand Trousseau, Paris, France
| | - Martine Wallon
- Hospices Civils de Lyon, Hôpital de la Croix-Rousse, Service de Parasitologie - Mycologie Médicale, Lyon, France; Université Lyon-1, Equipe Waking, Physiologie Intégrée du Système d'éveil, Centre de Recherche en Neurosciences de Lyon (INSERM U1028 - CNRS UMR 5292), Bron, France
| | - Karl Wehbe
- Centre Hospitalier Universitaire de Strasbourg, Service de Gynécologie-Obstétrique, Strasbourg, France
| | - Laurent Mandelbrot
- Assistance Publique-Hôpitaux de Paris, Service de Gynécologie-Obstétrique, Hôpital Louis Mourier, Colombes, France; Université de Paris; Inserm IAME-U1137, Paris, France; FHU PREMA; Groupe de Recherche sur les Infections pendant la grossesse (GRIG)
| | - Isabelle Villena
- Université Reims Champagne -Ardenne, EA7510 et Centre National de Référence de la Toxoplasmose, Centre de Ressources Biologiques Toxoplasma, Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Reims, Reims, France
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11
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Garnaud C, Fricker-Hidalgo H, Evengård B, Álvarez-Martínez MJ, Petersen E, Kortbeek LM, Robert-Gangneux F, Villena I, Costache C, Paul M, Meroni V, Guy E, Chiodini PL, Brenier-Pinchart MP, Pelloux H. Toxoplasma gondii-specific IgG avidity testing in pregnant women. Clin Microbiol Infect 2020; 26:1155-1160. [PMID: 32334096 DOI: 10.1016/j.cmi.2020.04.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/07/2020] [Accepted: 04/14/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND The parasite Toxoplasma gondii can cause congenital toxoplasmosis following primary infection in a pregnant woman. It is therefore important to distinguish between recent and past infection when both T. gondii-specific IgM and IgG are detected in a single serum in pregnant women. Toxoplasma gondii-specific IgG avidity testing is an essential tool to help to date the infection. However, interpretation of its results can be complex. OBJECTIVES To review the benefits and limitations of T. gondii-specific avidity testing in pregnant women, to help practitioners to interpret the results and adapt the patient management. SOURCES PubMed search with the keywords avidity, toxoplasmosis and Toxoplasma gondii for articles published from 1989 to 2019. CONTENT Toxoplasma gondii-specific IgG avidity testing remains a key tool for dating a T. gondii infection in immunocompetent pregnant women. Several commercial assays are available and display comparable performances. A high avidity result obtained on a first-trimester serum sample is indicative of a past infection, which occurred before pregnancy. To date, a low avidity result must still be considered as non-informative to date the infection, although some authors suggest that very low avidity results are highly suggestive of recent infections depending on the assay. Interpretation of low or grey zone avidity results on a first-trimester serum sample, as well as any avidity result on a second-trimester or third-trimester serum sample, is more complex and requires recourse to expert toxoplasmosis laboratories. IMPLICATIONS Although used for about 30 years, T. gondii-specific avidity testing has scarcely evolved. The same difficulties in interpretation have persisted over the years. Some authors have proposed additional thresholds to exclude an infection of <9 months, or in contrast to confirm a recent infection. Such thresholds would be of great interest to adapt management of pregnant women and avoid unnecessary treatment; however, they need confirmation and further studies.
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Affiliation(s)
- C Garnaud
- Université Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France; Parasitology-Mycology, CHU Grenoble Alpes, Grenoble, France.
| | | | - B Evengård
- Department Clinical Microbiology, Umea University, Umea, Sweden
| | - M J Álvarez-Martínez
- Microbiology Department, Hospital Clínic-ISGLOBAL, University of Barcelona, Barcelona, Spain
| | - E Petersen
- Directorate General for Disease Surveillance and Control, Ministry of Health, Oman; Institute for Clinical Medicine, Faculty of Health Science, University of Aarhus, Denmark; ESCMID Emerging Infections Task Force, ESCMID, Basel, Switzerland
| | - L M Kortbeek
- National Institute for Public Health and the Environment; Centre for Infectious Disease Control (CIb) Bilthoven, the Netherlands
| | - F Robert-Gangneux
- Université Rennes, CHU Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé Environnement et Travail)-UMR_S 1085, Rennes, France
| | - I Villena
- Université Reims Champagne-Ardenne EA 7510, CHU Reims, Centre National de Référence de La Toxoplasmose, CRB Toxoplasma, Reims, France
| | - C Costache
- Microbiology Department 'Iuliu Hatieganu', University of Medicine and Pharmacy Cluj-Napoca, Romania
| | - M Paul
- Department and Clinic of Tropical and Parasitic Diseases, University of Medical Sciences, Poznan, Poland
| | - V Meroni
- University Pavia Internal Medicine and Medical Therapy Department, Microbiology and Virology Department IRCCS, Foundation San Matteo Polyclinic, Pavia Italy
| | - E Guy
- Toxoplasma Reference Unit, Public Health Wales Microbiology, Swansea, UK
| | - P L Chiodini
- Hospital for Tropical Diseases and the London School of Hygiene and Tropical Medicine, London, UK
| | - M-P Brenier-Pinchart
- Parasitology-Mycology, CHU Grenoble Alpes, Grenoble, France; Université Grenoble Alpes, INSERM-CNRS, Institute for Advanced Biosciences, Grenoble, France
| | - H Pelloux
- Parasitology-Mycology, CHU Grenoble Alpes, Grenoble, France; Université Grenoble Alpes, INSERM-CNRS, Institute for Advanced Biosciences, Grenoble, France
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12
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Microsphere-Based IgM and IgG Avidity Assays for Human Parvovirus B19, Human Cytomegalovirus, and Toxoplasma gondii. mSphere 2020; 5:5/2/e00905-19. [PMID: 32188754 PMCID: PMC7082144 DOI: 10.1128/msphere.00905-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Human parvovirus B19, human cytomegalovirus, and Toxoplasma gondii are ubiquitous pathogens. Their infections are often asymptomatic or mild in the general population yet may be transmitted from mother to fetus during pregnancy. Maternal infections by these pathogens can cause severe complications to the fetus or congenital abnormalities. As a rule, the risk of maternal transmission is critically related to the infection time; hence, it is important to determine when a pregnant woman has acquired the infection. In this study, we developed new diagnostic approaches for the timing of infections by three pathogens. All the new assays appeared to be highly sensitive and specific, providing powerful tools for medical diagnosis. Human parvovirus B19 (here B19), human cytomegalovirus (HCMV), and Toxoplasma gondii infections during pregnancy can lead to severe complications. While traditional diagnosis of infections is mostly confined to one pathogen at a time, a multiplex array is a feasible alternative to improve diagnostic management and cost-efficiency. In the present study, for these three pathogens, we developed microsphere-based suspension immunoassays (SIAs) in multiplex and monoplex formats for the detection of antimicrobial IgM antibodies as well as corresponding chaotrope-based IgG avidity SIAs. We determined the diagnostic performances of the SIAs versus in-house and commercial reference assays using a panel of 318 serum samples from well-characterized clinical cohorts. All the newly developed assays exhibited excellent performance compared to the corresponding high-quality reference methods. The positive and negative percent agreements of the IgM SIAs in comparison with reference methods were 95 to 100% and 98 to 100%, and those of the IgG avidity SIAs were 92 to 100% and 95 to 100%, respectively. Kappa efficiency values between the SIAs and the corresponding reference assays were 0.91 to 1. Furthermore, with another panel comprising 391 clinical samples from individuals with primary infection by B19, HCMV, or T. gondii, the IgM SIAs were highly sensitive for the detection of acute infections, and the IgG avidity SIAs were highly specific for the separation of primary infections from past immunity. Altogether, the strategy of IgM multiplex screening followed by IgG avidity reflex testing can provide high-throughput and accurate means for the detection and stage determination of B19, HCMV, and T. gondii infections. IMPORTANCE Human parvovirus B19, human cytomegalovirus, and Toxoplasma gondii are ubiquitous pathogens. Their infections are often asymptomatic or mild in the general population yet may be transmitted from mother to fetus during pregnancy. Maternal infections by these pathogens can cause severe complications to the fetus or congenital abnormalities. As a rule, the risk of maternal transmission is critically related to the infection time; hence, it is important to determine when a pregnant woman has acquired the infection. In this study, we developed new diagnostic approaches for the timing of infections by three pathogens. All the new assays appeared to be highly sensitive and specific, providing powerful tools for medical diagnosis.
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Simon L, Fillaux J, Guigon A, Lavergne RA, Villard O, Villena I, Marty P, Pomares C. Serological diagnosis of Toxoplasma gondii: analysis of false-positive IgG results and implications. ACTA ACUST UNITED AC 2020; 27:7. [PMID: 32031519 PMCID: PMC7006501 DOI: 10.1051/parasite/2020006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 01/29/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Primary infection by Toxoplasma gondii in pregnant women can result in serious outcomes for the foetus. A false-positive IgG result during pregnancy can lead to a misdiagnosis of past infection and to stopping preventive measures. We collected 189 sera with positive Architect® Toxo IgG assay (Abbott Laboratories) and negative IgG results with at least two other serological tests, in order to find an explanation for the suspected false-positive IgG results. We used the recomLine Toxoplasma IgG® immunoblot (Mikrogen Diagnostik) to search for specific antigenic reactivities of the sera, and the LDBio Toxo II IgG® immunoblot (LDBio Diagnostics) as a confirmatory test. RESULTS The bands GRA8 and/or GRA7 were positive for 148 samples (78.3%). GRA8 was the most frequent band, appearing in 133 patterns (70.4%), whereas GRA7 was present for 49 samples (25.9%). Of the 81 samples tested with LDBio®, 23 (28.4%) turned out to be positive. Of the 58 negative LDBio® tests (71.6%) (real false-positive Architect® IgG), 23 samples (39.6%) did not show either a GRA8 or p30 band by recomLine®. Their false positivity with Architect® remains unexplained since Abbott uses these two recombinant antigens for their assay. CONCLUSIONS The Architect® IgG false positivity for T. gondii seems to be due to reactivity against GRA8 for the majority of the sera and GRA7 to a lesser extent. The hypothesis of past contact with parasites genetically close to T. gondii such as Hammondia hammondi or Neospora caninum seems promising and should be assessed further.
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Affiliation(s)
- Loïc Simon
- Service de Parasitologie-Mycologie, CHU de Nice, Université Côte d'Azur, 06202 Nice, France - Inserm U1065, C3M, 06204 Nice, France
| | - Judith Fillaux
- Service de Parasitologie-Mycologie, CHU de Toulouse, 31300 Toulouse, France - PharmaDev, IRD UMR 152, Université de Toulouse, 31062 Toulouse, France
| | - Aurélie Guigon
- Service de Microbiologie, Hôpital La Source, CHR d'Orléans, 45100 Orléans, France
| | - Rose-Anne Lavergne
- Parasitologie-Mycologie, CHU de Nantes, 44093 Nantes, France - Université de Nantes, Nantes Atlantique Universités, EA1155-IICiMed, Institut de Recherche en Santé 2, 44200 Nantes, France
| | - Odile Villard
- Institut de Parasitologie et de Pathologie Tropicale, EA 7292, Fédération de Médecine Translationnelle, Université de Strasbourg, 67000 Strasbourg, France
| | - Isabelle Villena
- EA7510, ESCAPE, Laboratoire de Parasitologie-Mycologie, Université de Reims Champagne-Ardenne, SFR Cap Santé FED 4231, 51096 Reims, France
| | - Pierre Marty
- Service de Parasitologie-Mycologie, CHU de Nice, Université Côte d'Azur, 06202 Nice, France - Inserm U1065, C3M, 06204 Nice, France
| | - Christelle Pomares
- Service de Parasitologie-Mycologie, CHU de Nice, Université Côte d'Azur, 06202 Nice, France - Inserm U1065, C3M, 06204 Nice, France
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How to estimate time of infection with Toxoplasma gondii in pregnant women. Use of specific IgG and IgM kinetics by 7 techniques on 691 sera. Diagn Microbiol Infect Dis 2020; 96:114987. [PMID: 32005405 DOI: 10.1016/j.diagmicrobio.2020.114987] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 11/20/2022]
Abstract
A difficulty when detecting both anti-Toxoplasma gondii-specific IgG and IgM in pregnant women is estimating the date of infection. The aim of this study was to compare the anti-Toxoplasma-specific immunoglobulin kinetics of 7 serological techniques to date the infection and to draw kinetic curves that are easy to use on a daily basis. IgG and IgM antibodies were measured on 691 sera samples. IgM appeared a few days, less than 1 week, after the beginning of the infection. Then, the levels of IgM reached a peak at approximately 3, 4, and 5 weeks with Toxo-ISAGA® IgM, IgM homemade indirect immunofluorescence assays, and Vidas Toxo® IgM, respectively. Furthermore, the Architect Toxo® IgG titers were higher than those of the Vidas Toxo® IgG results in recent infection (less than 6 months). This study provides new average IgM and IgG curves that can help to determine the approximate date of infection.
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15
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Performance of Zika Assays in the Context of Toxoplasma gondii, Parvovirus B19, Rubella Virus, and Cytomegalovirus (TORCH) Diagnostic Assays. Clin Microbiol Rev 2019; 33:33/1/e00130-18. [PMID: 31826871 DOI: 10.1128/cmr.00130-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Infections during pregnancy that may cause congenital abnormalities have been recognized for decades, but their diagnosis is challenging. This was again illustrated with the emergence of Zika virus (ZIKV), highlighting the inherent difficulties in estimating the extent of pre- and postnatal ZIKV complications because of the difficulties in establishing definitive diagnoses. We reviewed the epidemiology, infection kinetics, and diagnostic methods used for Toxoplasma gondii, parvovirus B19, rubella virus, and cytomegalovirus (TORCH) infections and compared the results with current knowledge of ZIKV diagnostic assays to provide a basis for the inclusion of ZIKV in the TORCH complex evaluations. Similarities between TORCH pathogens and ZIKV support inclusion of ZIKV as an emerging TORCH infection. Our review evaluates the diagnostic performance of various TORCH diagnostic assays for maternal screening, fetal screening, and neonatal screening. We show that the sensitivity, specificity, and positive and negative predictive value of TORCH complex pathogens are widely variable, stressing the importance of confirmatory testing and the need for novel techniques for earlier and accurate diagnosis of maternal and congenital infections. In this context it is also important to acknowledge different needs and access to care for different geographic and resource settings.
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Serological and molecular rapid diagnostic tests for Toxoplasma infection in humans and animals. Eur J Clin Microbiol Infect Dis 2019; 39:19-30. [PMID: 31428897 PMCID: PMC7087738 DOI: 10.1007/s10096-019-03680-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 08/11/2019] [Indexed: 02/07/2023]
Abstract
Infection by Toxoplasma gondii is prevalent worldwide. The parasite can infect a broad spectrum of vertebrate hosts, but infection of fetuses and immunocompromised patients is of particular concern. Easy-to-perform, robust, and highly sensitive and specific methods to detect Toxoplasma infection are important for the treatment and management of patients. Rapid diagnostic methods that do not sacrifice the accuracy of the assay and give reproducible results in a short time are highly desirable. In this context, rapid diagnostic tests (RDTs), especially with point-of-care (POC) features, are promising diagnostic methods in clinical microbiology laboratories, especially in areas with minimal laboratory facilities. More advanced methods using microfluidics and sensor technology will be the future trend. In this review, we discuss serological and molecular-based rapid diagnostic tests for detecting Toxoplasma infection in humans as well as animals.
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An updated literature review on maternal-fetal and reproductive disorders of Toxoplasma gondii infection. J Gynecol Obstet Hum Reprod 2017; 47:133-140. [PMID: 29229361 DOI: 10.1016/j.jogoh.2017.12.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Toxoplasma gondii infection is one of the most prevalent infectious disease with worldwide distribution. Congenital toxoplasmosis is annually responsible for 1.20 million disability-adjusted life years around the world, but often it is overlooked many countries. METHODS We performed an updated review to summarize the current researches on fetal, neonatal and maternal consequences of T. gondii infection and also adverse effects of toxoplasmosis on women reproductive organs. RESULTS T. gondii infection could be cause of several abnormalities from hydrocephalus, microcephaly, deafness, abortion and still birth in fetal to psychomotor retardation, intellectual disability, hearing loss, slower postnatal motor development during the first year of life; and chorioretinitis, cryptogenic epilepsy and autism spectrum disorders in newborns. Moreover, this infection is related with neuropsychiatric disorders such as anxiety, schizophrenia spectrum disorders, depression, decreased weight, autoimmune thyroid diseases, self-directed violence, violent suicide attempts in mothers. This literature review emphasized that toxoplasmosis could be an important neglected factor endometritis, ovarian dysfunction, impaired folliculogenesis, ovarian and uterine atrophy, decrease in reproductive organs weight and reproductive performance in women. We reviewed role of the immunological profile such as pro-infiammatory cytokines and hormonal changes as main potential mechanisms related to this infection and development of maternal-fetal and reproductive disorders. CONCLUSION T. gondii is associated with several brain related disorders in both mothers and newborns, and also it is cause of several abnormalities in reproductive organs. Early diagnosis and treatment of the infection could be effective to significantly improve the clinical outcome.
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18
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Evaluation of a New Immunochromatography Technology Test (LDBio Diagnostics) To Detect Toxoplasma IgG and IgM: Comparison with the Routine Architect Technique. J Clin Microbiol 2017; 55:3395-3404. [PMID: 28954897 DOI: 10.1128/jcm.01106-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/08/2017] [Indexed: 11/20/2022] Open
Abstract
A study comparing the ICT (immunochromatography technology) Toxoplasma IgG and IgM rapid diagnostic test (LDBio Diagnostics, France) with a fully automated system, Architect, was performed on samples from university hospitals of Marseille and Saint-Etienne. A total of 767 prospective sera and 235 selected sera were collected. The panels were selected to test various IgG and IgM parameters. The reference technique, Toxoplasma IgGII Western blot analysis (LDBio Diagnostics), was used to confirm the IgG results, and commercial kits Platelia Toxo IgM (Bio-Rad) and Toxo-ISAgA (bioMérieux) were used in Saint-Etienne and Marseille, respectively, as the IgM reference techniques. Sensitivity and specificity of the ICT and the Architect IgG assays were compared using a prospective panel. Sensitivity was 100% for the ICT test and 92.1% for Architect (cutoff at 1.6 IU/ml). The low-IgG-titer serum results confirmed that ICT sensitivity was superior to that of Architect. Specificity was 98.7% (ICT) and 99.8% (Architect IgG). The ICT test is also useful for detecting IgM without IgG and is both sensitive (100%) and specific (100%), as it can distinguish nonspecific IgM from specific Toxoplasma IgM. In comparison, IgM sensitivity and specificity on Architect are 96.1% and 99.6%, respectively (cutoff at 0.5 arbitrary units [AU]/ml). To conclude, this new test overcomes the limitations of automated screening techniques, which are not sensitive enough for IgG and lack specificity for IgM (rare IgM false-positive cases).
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Spann MN, Sourander A, Surcel HM, Hinkka-Yli-Salomäki S, Brown AS. Prenatal toxoplasmosis antibody and childhood autism. Autism Res 2017; 10:769-777. [PMID: 27874276 PMCID: PMC7256017 DOI: 10.1002/aur.1722] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 09/05/2016] [Accepted: 10/15/2016] [Indexed: 11/12/2022]
Abstract
There is evidence that some maternal infections during the prenatal period are associated with neurodevelopmental disorders, such as childhood autism. However, the association between autism and Toxoplasma gondii (T. gondii), an intracellular parasite, remains unclear. The authors examined whether serologically confirmed maternal antibodies to T. gondii are associated with odds of childhood autism in offspring. The study is based on a nested case-control design of a large national birth cohort (N = 1.2 million) and the national psychiatric registries in Finland. There were 874 cases of childhood autism and controls matched 1:1 on date of birth, sex, birthplace and residence in Finland. Maternal sera were prospectively assayed from a national biobank for T. gondii IgM and IgG antibodies; IgG avidity analyses were also performed. High maternal T. gondii IgM antibody was associated with a significantly decreased odds of childhood autism. Low maternal T. gondii IgG antibody was associated with increased offspring odds of autism. In women with high T. gondii IgM antibodies, the IgG avidity was high for both cases and controls, with the exception of three controls. The findings suggest that the relationship between maternal T. gondii antibodies and odds of childhood autism may be related to the immune response to this pathogen or the overall activation of the immune system. Autism Res 2017, 10: 769-777. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.
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Affiliation(s)
- Marisa N Spann
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, The Mailman School of Public Health, New York State Psychiatric Institute, New York, NY
| | - Andre Sourander
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, The Mailman School of Public Health, New York State Psychiatric Institute, New York, NY
- Department of Child Psychiatry Faculty of Medicine, University of Turku, Turku, Finland
- Department of Child Psychiatry, Turku University Hospital, Turku, Finland
| | | | | | - Alan S Brown
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, The Mailman School of Public Health, New York State Psychiatric Institute, New York, NY
- Department of Epidemiology, Columbia University Mailman School of Public Health, New York, NY
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Long-term sera storage does not significantly modify the interpretation of toxoplasmosis serologies. J Microbiol Methods 2017; 134:38-45. [DOI: 10.1016/j.mimet.2017.01.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 11/21/2022]
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21
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Interpretation of the Elecsys Toxo IgG avidity results for very low and very high index: study on 741 sera with a determined date of toxoplasmosis. Eur J Clin Microbiol Infect Dis 2016; 36:847-852. [DOI: 10.1007/s10096-016-2870-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 12/06/2016] [Indexed: 11/25/2022]
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Armengol C, Cassaing S, Roques-Malecaze C, Chauvin P, Iriart X, Berry A, Fillaux J. Time before anti-Toxoplasma IgG seroconversion detection by 7 commercial assays in French pregnant women. Diagn Microbiol Infect Dis 2016; 87:103-107. [PMID: 27884549 DOI: 10.1016/j.diagmicrobio.2016.10.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 11/28/2022]
Abstract
We assessed the ability to early detect a toxoplasmic seroconversion between 1 immunoblot (LDBIO II®) and 6 automated assays (TGS TA®, Architect®, Vidas II®, Liaison II®, Platelia®, and Elecsys®), comparing the time before anti-Toxoplasma gondii IgG detection during infection in pregnant women. From 2007 to 2015, 620 sera of 269 women were included. The median durations before positive IgG detection with Vidas II®, Liaison II®, Platelia®, and Elecsys® were significantly longer than Architect® with differential times from 11 to 28days (P<0.001). This time was significantly shortened by the use of LDBIO®, resulting in a saving of 13days (P<0.001). The detection of a positive rate of IgG with TGS TA® was as early as Architect® (P=0.105). The ability to early detect a toxoplasmic seroconversion is not equivalent between the assays and has to be considered when selecting the reagents to reduce the time to therapeutic intervention.
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Affiliation(s)
- Catherine Armengol
- Service de Parasitologie-Mycologie, Hôpital Purpan, Toulouse, 31059, France
| | - Sophie Cassaing
- Service de Parasitologie-Mycologie, Hôpital Purpan, Toulouse, 31059, France; Pharmacochimie et Biologie Pour le Développement (PHARMA-DEV), IRD UMR 152 Université Paul Sabatier, Toulouse, 31400, France
| | | | - Pamela Chauvin
- Service de Parasitologie-Mycologie, Hôpital Purpan, Toulouse, 31059, France
| | - Xavier Iriart
- Service de Parasitologie-Mycologie, Hôpital Purpan, Toulouse, 31059, France
| | - Antoine Berry
- Service de Parasitologie-Mycologie, Hôpital Purpan, Toulouse, 31059, France
| | - Judith Fillaux
- Service de Parasitologie-Mycologie, Hôpital Purpan, Toulouse, 31059, France; Pharmacochimie et Biologie Pour le Développement (PHARMA-DEV), IRD UMR 152 Université Paul Sabatier, Toulouse, 31400, France.
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Help in the Choice of Automated or Semiautomated Immunoassays for Serological Diagnosis of Toxoplasmosis: Evaluation of Nine Immunoassays by the French National Reference Center for Toxoplasmosis. J Clin Microbiol 2016; 54:3034-3042. [PMID: 27733631 DOI: 10.1128/jcm.01193-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/28/2016] [Indexed: 11/20/2022] Open
Abstract
Toxoplasmosis, a benign infection, is asymptomatic or paucisymptomatic in over 80% of cases, except in immunocompetent patients suffering from ocular toxoplasmosis or in immunocompromised patients with opportunistic or congenital toxoplasmosis. Diagnosis is based mainly on serology testing. Thus, we compared the performance of the nine most commonly used commercial automated or semiautomated immunoassays for IgG and IgM Toxoplasma gondii antibody detection, that is, the Advia Centaur, Architect, AxSYM, Elecsys, Enzygnost, Liaison, Platelia, VIDAS, and VIDIA assays. The assays were conducted on four panels of serum samples derived during routine testing from patients with an interfering disease and who exhibited a low IgG antibody level in one of two clinical settings, namely, acute or chronic toxoplasmosis. As a result, IgG sensitivities ranged from 97.1% to 100%, and IgG specificities ranged from 99.5% to 100%. For IgG quantification, strong differences in IgG titers (expressed in IU/ml) were noted depending on the assay used. IgM sensitivities ranged from 65% to 97.9%, and IgM specificities ranged from 92.6% to 100%. For defining the best serological strategies to be implemented, it appears crucial to compare the diagnostic performance of the different tests with respect to their specificity and sensitivity in detecting the presence of IgG and IgM antibodies.
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Multiplexed Anti-Toxoplasma IgG, IgM, and IgA Assay on Plasmonic Gold Chips: towards Making Mass Screening Possible with Dye Test Precision. J Clin Microbiol 2016; 54:1726-1733. [PMID: 27008879 DOI: 10.1128/jcm.03371-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/16/2016] [Indexed: 11/20/2022] Open
Abstract
Toxoplasmosis is an infection caused by the protozoan parasite Toxoplasma gondii that can lead to severe sequelae in the fetus during pregnancy. Definitive serologic diagnosis of the infection during gestation is made mostly by detecting T. gondii-specific antibodies, including IgG and IgM, individually in a single serum sample by using commercially available kits. The IgA test is used by some laboratories as an additional marker of acute infection. Most of the commercial tests have failed to reach 100% correlation with the reference method, the Sabin-Feldman dye test for the detection of Toxoplasma IgG antibodies. For Toxoplasma IgM and IgA antibodies, there is no reference method and their evaluation is done by comparing the results of one assay to those of another. There is a need for multiplexed assay platforms, as the serological diagnosis of T. gondii infection does not rely on the detection of a single Ig subtype. Here we describe the development of a plasmonic gold chip with vast fluorescence enhancement in the near-infrared region for simultaneous detection of IgG, IgM, and IgA antibodies against T. gondii in an ∼1-μl serum or whole-blood sample. When 168 samples were tested on this platform, IgG antibody detection sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were all 100%. IgM antibody detection achieved 97.6% sensitivity and 96.9% specificity with a 90.9% PPV and a 99.2% NPV. Thus, the nanoscience-based plasmonic gold platform enables a high-performance, low-cost, multiplexed assay requiring ultrasmall blood volumes, paving the way for the implementation of universal screening for toxoplasmosis infection during gestation.
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Bin LLC, Santarém VA, Laposy CB, Rubinsky-Elefant G, Roldán WH, Giuffrida R. Kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with Toxocara canis. ACTA ACUST UNITED AC 2015; 25:99-104. [PMID: 27027550 DOI: 10.1590/s1984-29612015067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/19/2015] [Indexed: 11/22/2022]
Abstract
An evaluation was made of the kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with embryonated Toxocara canis eggs. Seventeen four month old New Zealand White rabbits were distributed into two groups. In the experimental group, twelve rabbits were infected orally with 1,000 embryonated T. canis eggs. A second group (n = 5), uninfected, was used as a control. Serum samples were collected for analysis on days 7, 14, 21, 28 and 60 post-infection (DPI). An indirect ELISA test was performed to evaluate the reactivity index (RI) of IgG anti-T. canis antibodies and to calculate the avidity index (AI). The animals showed seroconversion from the 14th DPI, with high AI (over 50%) except for one animal, which presented an intermediate AI. At 60 DPI, all the animals were seropositive and maintained a high AI. The data indicated that specific IgG antibodies formed early (14 DPI) in rabbits infected with T. canis, with a high avidity index that persisted throughout the course of the infection.
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Affiliation(s)
- Lundia Luara Cavalcante Bin
- Programa de Pós-Graduação em Ciência Animal, Universidade do Oeste Paulista, Presidente Prudente, SP, Brasil
| | - Vamilton Alvares Santarém
- Programa de Pós-Graduação em Ciência Animal, Universidade do Oeste Paulista, Presidente Prudente, SP, Brasil
| | - Cecília Braga Laposy
- Programa de Pós-Graduação em Ciência Animal, Universidade do Oeste Paulista, Presidente Prudente, SP, Brasil
| | - Guita Rubinsky-Elefant
- Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brasil
| | - William Henry Roldán
- Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brasil
| | - Rogério Giuffrida
- Programa de Pós-Graduação em Ciência Animal, Universidade do Oeste Paulista, Presidente Prudente, SP, Brasil
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Significance of a Positive Toxoplasma Immunoglobulin M Test Result in the United States. J Clin Microbiol 2015; 53:3601-5. [PMID: 26354818 DOI: 10.1128/jcm.01663-15] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/03/2015] [Indexed: 11/20/2022] Open
Abstract
A positive Toxoplasma immunoglobulin M (IgM) result is often interpreted as a marker of an acute infection. However, IgM can persist for several years, and Toxoplasma commercial IgM diagnostic test kits can yield a number of false-positive results. For these reasons, a chronic Toxoplasma infection can be erroneously classified as an acute infection, resulting in serious adverse consequences, especially in pregnant women, leading to emotional distress and unnecessary interventions, including termination of pregnancy. Interpretation of Toxoplasma serology at a reference laboratory can help differentiate a recently acquired infection from a chronic infection. Serological test results for 451 patients with positive Toxoplasma IgM and IgG test results obtained at nonreference laboratories (NRLs) that were referred to Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) to determine whether the patient was acutely or chronically infected were retrospectively reviewed. PAMF-TSL results established that of the 451 patients, 335 (74%) had a chronic infection, 100 (22%) had an acute infection, and 7 (2%) were not infected, and for 9 (2%), results were indeterminate. Positive Toxoplasma IgM and IgG test results obtained at NRLs cannot accurately distinguish between acute and chronic infections. To do so, testing at reference laboratories is required, as mandated in 1997 in a letter from the Food and Drug Administration (FDA) to clinicians and laboratories in the United States.
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Performance of the BioPlex 2200 flow immunoassay in critical cases of serodiagnosis of toxoplasmosis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:496-500. [PMID: 24477853 DOI: 10.1128/cvi.00624-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The BioPlex 2200 automated analyzer (Bio-Rad Laboratories, Hercules, CA) is a recently developed multiplex analyzer that enables the detection of anti-Toxoplasma, -rubella, and -cytomegalovirus antibodies in the same assay. The aim of this study was to compare this new technology (using the BioPlex 2200 ToRC IgG/IgM kit) in critical cases of serodiagnosis of toxoplasmosis (acute, chronic, or congenital infections and cases with discrepant results) to the technologies used in our routine practice, i.e., the Platelia IgG/IgM enzyme-linked immunosorbent assays (ELISAs) (Bio-Rad Laboratories) and the Toxo-Screen direct agglutination assay (bioMérieux, Lyon, France). Overall, most cases of false-positive/negative results obtained with the Platelia IgG or Toxo-Screen assay were corrected by the BioPlex 2200 ToRC IgG (87.5%). Furthermore, the analysis of 35 sequences of sera showed a trend toward a more rapid decrease of IgM titers by BioPlex 2200 than by Platelia. These results for IgM detection can be explained by a weaker detection of residual IgM. Indeed, among 23 serum samples from patients with probable past infection with long-lasting IgM (Platelia M positive and IgG avidity index, ≥0.5), the BioPlex 2200 Toxoplasma IgM assay was positive for only 11 serum samples. In our panel of critical cases comprising 156 serum and 6 cord blood samples from 103 patients with acute, chronic, or congenital infection, the BioPlex 2200 IgG assay was a sensitive (97.8%) and specific (91.3%) method for IgG detection. The high specificity (97.4%) of IgM detection combined with the shorter kinetics of IgM titers may considerably reduce the number of residual IgM detections, thus yielding more precise diagnoses of acute infections.
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Murat JB, Fricker Hidalgo H, Brenier-Pinchart MP, Pelloux H. Human toxoplasmosis: which biological diagnostic tests are best suited to which clinical situations? Expert Rev Anti Infect Ther 2014; 11:943-56. [DOI: 10.1586/14787210.2013.825441] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Prevalence of toxoplasmosis in France in 1998: Is there a difference between men and women? At what age do children become infected? Rev Epidemiol Sante Publique 2013; 61:311-7. [DOI: 10.1016/j.respe.2012.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 10/12/2012] [Accepted: 11/15/2012] [Indexed: 11/21/2022] Open
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Comparison of the Vidas system and two recent fully automated assays for diagnosis and follow-up of toxoplasmosis in pregnant women and newborns. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1203-12. [PMID: 23740928 DOI: 10.1128/cvi.00089-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Serological testing to detect toxoplasmosis is of major importance to avoid the possible effects of the disease in newborns. This study assessed anti-Toxoplasma IgG and IgM with the Vidas (bioMérieux), Architect (Abbott), and Liaison (DiaSorin) systems in 631 sera from pregnant women and newborns as well as anti-Toxoplasma IgG avidity with these three systems on 54 sera from pregnant women with positive IgG and IgM. The IgG and IgM results were in agreement in, respectively, 95.2% and 98.3% (Vidas versus Architect) and 96.9% and 95.3% (Vidas versus Liaison) of the samples. Specificities were excellent for all the assays, while Vidas sensitivities ranged (depending on the classification of gray zone results) from 93.8 to 98.4% for IgG (Architect, 84.4 to 93.8%; Liaison, 93.8%) and from 81.8 to 90.9% for IgM (Architect, 63.6%; Liaison, 81.8 to 90.9%). In seroconversion sequences, IgMs were generally detected simultaneously by the three assays, while Architect was the earliest assay to detect IgG. In noninfected children, maternally transmitted IgGs were detected for a longer time with Architect than with the other systems. IgMs were positive in only one infected child with the Vidas and Liaison systems. Significantly more sera were classified in the high-avidity category with Vidas than with Architect. This evaluation shows similar performances for Vidas and more recent systems. The Vidas system adequately detects toxoplasmosis in pregnant women and newborns. This system fits the needs of laboratories working on small routine series for first-line testing as well as expert laboratories, due to a high specificity and a powerful avidity test.
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Toxoplasma seroconversion with negative or transient immunoglobulin M in pregnant women: myth or reality? A French multicenter retrospective study. J Clin Microbiol 2013; 51:2103-11. [PMID: 23616461 DOI: 10.1128/jcm.00169-13] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Classically, Toxoplasma infection is associated with high levels of specific IgM antibody and a rise in specific IgG levels 1 to 3 weeks later. Atypical IgG seroconversion, without IgM detection or with transient IgM levels, has been described during serologic follow-up of seronegative pregnant women and raises difficulties in interpreting the results. To evaluate the frequency and the characteristics of these atypical cases of seroconversion, an investigation was conducted within the French National Reference Center for Toxoplasmosis, from which 26 cases collected from 12 laboratories belonging to the network were identified. The aim of this work was to retrospectively analyze the results of serologic testing, the treatments administered, and the results of prenatal and postnatal follow-up for these women. In each case, IgG antibodies were detected using both screening and confirmatory tests. IgM antibodies were not detected in 15 cases, and the levels were equivocal or low-positive in 11 cases. The IgG avidity results were low in 16 cases and high in one case. Most of the pregnant women (22/26) were treated with spiramycin from the time that IgG antibodies appeared until delivery. Amniotic fluid was analyzed for Toxoplasma gondii DNA by PCR in 11/26 cases, and the results were negative in all cases. Congenital toxoplasmosis was ruled out in 12/26 newborns. There was no abnormality observed at birth for 10 newborns and no information available for 4 newborns. In conclusion, when the interpretation of serological results is so difficult, it seems cautious to initiate treatment by spiramycin and to follow the pregnant women and their newborns.
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Comparison of four commercially available avidity tests for Toxoplasma gondii-specific IgG antibodies. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 20:197-204. [PMID: 23239801 DOI: 10.1128/cvi.00356-12] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Toxoplasma infection in pregnant women may cause congenital toxoplasmosis. Diagnosis of infection is based on serological tests aimed at detecting IgM and IgG antibodies against Toxoplasma gondii. However, IgM antibodies are not an accurate marker for discriminating between acute and latent infection. Detection of residual or persistent IgM may occur months or even years after primary infection, while the IgG avidity test is a rapid means of identifying latent infections in pregnant women who exhibit both IgG and IgM anti-Toxoplasma antibodies on initial testing during pregnancy. In this study, we assessed and compared the performances of four commercially available Toxoplasma IgG avidity tests in immunocompetent and immunocompromised patients with acute and latent toxoplasmosis. The positive predictive value of high avidity to confirm latent toxoplasmosis was 100% for all the assays, indicating that high avidity is a hallmark of latent infection. However, the negative predictive value of high avidity ranged from 99.2% (bioMérieux) to 95.3% (Abbott), indicating that acute toxoplasmosis could not be reliably diagnosed based on low IgG avidity alone. Thus, the avidity test provides a rapid means for identifying latent Toxoplasma infection in immunocompetent pregnant women presenting both IgG and IgM anti-Toxoplasma antibodies on initial testing. In terms of cost-effectiveness, avidity testing is a powerful tool that optimizes screening and follow-up of pregnant women while minimizing the costs of screening by avoiding subsequent costly maternal and fetal investigation and unnecessary treatment. The cheapest assay, Vidas Toxo IgG Avidity, also had the best performance for the diagnosis of latent toxoplasmosis.
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Lim H, Lee SE, Jung BK, Kim MK, Lee MY, Nam HW, Shin JG, Yun CH, Cho HI, Shin EH, Chai JY. Serologic survey of toxoplasmosis in Seoul and Jeju-do, and a brief review of its seroprevalence in Korea. THE KOREAN JOURNAL OF PARASITOLOGY 2012; 50:287-93. [PMID: 23230325 PMCID: PMC3514419 DOI: 10.3347/kjp.2012.50.4.287] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 10/09/2012] [Accepted: 10/09/2012] [Indexed: 11/24/2022]
Abstract
Knowledge of the prevalence of human Toxoplasma gondii infection is required in the Republic of Korea. In this study, we surveyed the seroprevalence of T. gondii infection and analyzed the risk factors associated with seropositivity among residents in 2 administrative districts; Seoul and the island of Jeju-do, which have contrasting epidemiologic characteristics. Sera and blood collected from 2,150 residents (1,114 in Seoul and 1,036 in Jeju-do) were checked for IgG antibody titers using ELISA and for the T. gondii B1 gene using PCR. In addition, participants completed a questionnaire that solicited information on gender, age, occupation, eating habits, history of contact with animals, and travel abroad. The T. gondii B1 gene was not detected in all residents examined. However, ELISA showed 8.0% (89 of 1,114 sera) positive for IgG antibodies against T. gondii in Seoul and 11.3% (117 of 1,036 sera) in Jeju-do. In both districts, the positive rates were higher in males than in females, and those 40-79 years of age showed higher rates than other ages. In Seoul, residents older than 70 years of age showed the highest positive rate, 14.9%, whereas in Jeju-do the highest prevalence, 15.6%, was in those in their sixties. The higher seropositive rate in Jeju-do than in Seoul may be related to eating habits and occupations. The present results and a review of related literature are indicative of an increased seroprevalence of T. gondii in Korea in recent years.
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Affiliation(s)
- Hyemi Lim
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, Seoul 110-799, Korea
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Evaluation of the new Elecsys Toxo IgG avidity assay for toxoplasmosis and new insights into the interpretation of avidity results. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1838-43. [PMID: 22993406 DOI: 10.1128/cvi.00333-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Detection and treatment of acute toxoplasmosis during pregnancy can avoid severe disease of the fetus. In this context, assessment of anti-Toxoplasma IgG avidity has been shown to exclude recent infection. The Elecsys Toxo IgG and IgM assays (Roche Diagnostics) have been validated for screening pregnant women and a new assay, Elecsys Toxo IgG Avidity, was recently developed. Our aims were to investigate the performance characteristics of this new avidity assay and explore whether additional information can be provided by avidity assays. The Elecsys assay was compared with the Vidas (bioMérieux) and Architect (Abbott) Avidity assays using two sets of serum samples (n = 291 and n = 255). The rate of general agreement between the Elecsys and Vidas assays was 74%, and that between the Elecsys and Architect assays was 83%. For 11% of the serum samples, avidity was high with the Vidas assay and within the gray zone with the Elecsys assay. None of the assays detected high-avidity antibodies in serum taken <4 months after infection. Avidity values of >90% were exclusively reported in sera taken >9 months after infection by the Elecsys and Architect assays. Almost all avidities of <19% with the Elecsys assay and <17% with the Architect assay corresponded to sera taken <3 and <2 months after infection, respectively. The Elecsys IgG Avidity assay can be used to exclude recent infection. New ways of interpreting the avidity result are also suggested: very high or low values could exclude infections within the last 9 months or help to confirm a recent infection, respectively. However, these potential interpretations require further investigation.
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Validación de pruebas ELISA IgM anti-Toxoplasma para uso en programas de tamización en recién nacidos. INFECTIO 2011. [DOI: 10.1016/s0123-9392(11)70747-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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36
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Ndao M, Rainczuk A, Rioux MC, Spithill TW, Ward BJ. Is SELDI-TOF a valid tool for diagnostic biomarkers? Trends Parasitol 2010; 26:561-7. [PMID: 20708969 DOI: 10.1016/j.pt.2010.07.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 07/15/2010] [Accepted: 07/19/2010] [Indexed: 01/25/2023]
Abstract
The genome revolution is providing fresh insights into host and parasite genomes, and new tools are becoming available for examining host-parasite interactions at the proteome level. Technologies such as surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) can be applied to discover biomarkers (alterations in both host and parasite proteomes) associated with parasitic diseases. Such biomarkers can represent host proteins, fragments of host proteins or parasite proteins that appear in body fluids or tissues following infection. Individual biomarkers or biomarker patterns not only have diagnostic utility (e.g. in active disease, prognosis, tests of cure) but can also provide unique insights into the mechanisms underlying host responses and pathogenesis.
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Affiliation(s)
- Momar Ndao
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada.
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Use of dense granule antigen GRA6 in an immunoglobulin G avidity test to exclude acute Toxoplasma gondii infection during pregnancy. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1349-55. [PMID: 20631335 DOI: 10.1128/cvi.00199-10] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The usefulness of a specific immunoglobulin G (IgG) avidity enzyme-linked immunosorbent assay (ELISA) based on recombinant GRA6 antigen for distinguishing between acute and chronic Toxoplasma infection was investigated. Two sets of serum samples obtained from pregnant women with acute, chronic, or no Toxoplasma infection collected in France and Iran were used. Among the French subjects, 19 of 20 (95%) women who experienced seroconversion during the past 4 months before sampling displayed low-avidity IgG antibodies against GRA6, while all 17 (100%) women with chronic infection had high-avidity antibodies. When the Euroimmun IgG avidity ELISA was used, 15 of 19 (78.9%) recently infected women had low-avidity antibodies, and 20 of 22 (90.9%) women with chronic infection displayed high-avidity antibodies. The results suggested better performance of the GRA6 avidity ELISA than the Euroimmun avidity ELISA for exclusion of a recent infection occurring less than 4 months previously. Similarly, all 35 Iranian women with acute Toxoplasma infection had low-avidity antibodies against GRA6, whereas all 34 women with chronic infection displayed IgG antibodies of high avidity, indicating the value of GRA6 avidity testing for ruling out a recent infection. Avidity tests based on lysed whole-cell Toxoplasma gondii antigen are currently used to exclude recently acquired infections; however, the use of recombinant antigen(s) might improve the diagnostic performance of avidity tests and facilitate the development of more standardized assays.
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