title: Late diagnosis of congenital toxoplasmosis based on serological follow-up: A case report.
abstract: Toxoplasma gondii is a protozoan parasite infecting up to one third of the world's population. T. gondii infection is usually benign in immunocompetent patients but can be life-threatening when congenitally transmitted. Congenital toxoplasmosis presentation ranges from severe central nervous system and ocular features, to a well appearing newborn with onset of complications late in childhood. The diagnosis of subclinical form remains important since early treatment reduces later complications such as chorioretinitis. We report an atypical case of congenital toxoplasmosis with a delayed diagnosis, based on Toxoplasma-specific serological follow-up. The infant was born to a mother who became infected during pregnancy, thus inducing infant biological and clinical follow-up. Neither biological nor clinical arguments favored a diagnosis of congenital toxoplasmosis until ten months of life. Congenital toxoplasmosis was then suspected because of an unusual increase of specific IgG levels. Diagnosis was confirmed by detection of newly synthesized newborn Ig isotypes using complementary comparative mother-to-child immunological profile techniques and specific treatment therefore administered. This report highlights the importance to follow up newborns at risk of congenital toxoplasmosis with specific and newborn-appropriate techniques until Toxoplasma-IgG titers are completely negative. This allows not only the exclusion of congenital toxoplasmosis when serology becomes negative, but also the diagnosis and treatment of congenital toxoplasmosis when infection is detected later in development.
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Grenoble Alpes, CS 10217, 38043 Grenoble cedex 9, France; Institute for Advanced Biosciences, Team Host-Pathogen interactions and immunity to infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, 38700 Grenoble, France. Electronic address: cdard@chu-grenoble.fr.
authors.forename: Céline
authors.initials: C
authors.lastname: Dard
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre National de Référence Toxoplasmose, Centre Hospitalier Universitaire de Reims, 45 rue Cognacq-Jay, 51092 Reims, France; EA 3800, UFR Médecine, SFR CAP-SANTE, Université Reims Champagne Ardenne, 51092 Reims, France. Electronic address: cchemla@chu-reims.fr.
authors.forename: Cathy
authors.initials: C
authors.lastname: Chemla
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Grenoble Alpes, CS 10217, 38043 Grenoble cedex 9, France. Electronic address: HFricker-Hidalgo@chu-grenoble.fr.
authors.forename: Hélène
authors.initials: H
authors.lastname: Fricker-Hidalgo
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Grenoble Alpes, CS 10217, 38043 Grenoble cedex 9, France; Institute for Advanced Biosciences, Team Host-Pathogen interactions and immunity to infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, 38700 Grenoble, France. Electronic address: MPPinchart@chu-grenoble.fr.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Brenier-Pinchart
authors.affiliation: Service de Pédiatrie, Centre Hospitalier de Voiron, 14 Route des Gorges, 38500 Voiron, France. Electronic address: pediatrie.baret@ch-voiron.fr.
authors.forename: Marie
authors.initials: M
authors.lastname: Baret
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre National de Référence Toxoplasmose, Centre Hospitalier Universitaire de Reims, 45 rue Cognacq-Jay, 51092 Reims, France; EA 3800, UFR Médecine, SFR CAP-SANTE, Université Reims Champagne Ardenne, 51092 Reims, France. Electronic address: amzabi@chu-reims.fr.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Mzabi
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre National de Référence Toxoplasmose, Centre Hospitalier Universitaire de Reims, 45 rue Cognacq-Jay, 51092 Reims, France; EA 3800, UFR Médecine, SFR CAP-SANTE, Université Reims Champagne Ardenne, 51092 Reims, France. Electronic address: ivillena@chu-reims.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Villena
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Grenoble Alpes, CS 10217, 38043 Grenoble cedex 9, France; Institute for Advanced Biosciences, Team Host-Pathogen interactions and immunity to infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, 38700 Grenoble, France. Electronic address: hpelloux@chu-grenoble.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Pelloux
mesh_terms: D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood*; D057210:Delayed Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic; D012698:Serologic Tests; D014122:Toxoplasma / Q000276:immunology*; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis* / Q000276:immunology* / Q000469:parasitology
chemical_list: D000913:Antibodies, Protozoan; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: Compared Immunological Profiles; Congenital toxoplasmosis; Immunoassays; Serology; Toxoplasma gondii