title: New Vidas assay for Toxoplasma-specific IgG avidity: evaluation on 603 sera.
abstract: After the development of the new version of the test Vidas Toxo IgG with antigens obtained from tachyzoites cultured on cells, a Vidas avidity test has been recently developed. The aim of this study was to assess the value of the determination of avidity on the new Vidas test. This avidity test was performed on 553 sera obtained from pregnant women whose dates of infection had been determined and on 50 sera obtained from immunosuppressed patients. In the group of infection occurring less than 4 months before sampling, the avidity index was <0.3 on 266 among 267 sera. In the group of infection occurring more than 15 months before sampling, the avidity index was >0.3 for 44/46 sera of pregnant women and for 47/47 sera of immunosuppressed patients. Thus, the new version of avidity test was helpful primarily to rule out that an infection had occurred within the prior 4 months.
authors.affiliation: Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Grenoble, BP217, 38043 Grenoble Cedex 9, France. hfricker-hidalgo@chu-grenoble.fr
authors.forename: Hélène
authors.initials: H
authors.lastname: Fricker-Hidalgo
authors.forename: Coralie
authors.initials: C
authors.lastname: Saddoux
authors.forename: Anne Sophie
authors.initials: AS
authors.lastname: Suchel-Jambon
authors.forename: Stéphane
authors.initials: S
authors.lastname: Romand
authors.forename: Agnès
authors.initials: A
authors.lastname: Foussadier
authors.forename: Hervé
authors.initials: H
authors.lastname: Pelloux
authors.forename: Philippe
authors.initials: P
authors.lastname: Thulliez
mesh_terms: D000818:Animals; D000915:Antibody Affinity / Q000276:immunology*; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007165:Immunosuppression Therapy; D011247:Pregnancy; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000175:diagnosis*
chemical_list: D000981:Antiprotozoal Agents; D007074:Immunoglobulin G