title: Value of serological testing for diagnosis of legionellosis in outbreak patients.
abstract: Serum antibody detection tests and a urine antigen detection technique were compared in samples from 116 patients epidemiologically characterized as belonging to a legionellosis outbreak. Sera were tested by enzyme-linked immunosorbent assays (ELISAs) for immunoglobulin M (IgM) and IgG plus IgM and by immunofluorescent assays (IFAs) for IgG, IgM, IgA, and polyimmunoglobulin using commercial kits (Vircell); concentrated urines were tested with the Binax NOW Legionella test. ELISA for IgM, ELISA for IgG plus IgM, antigenuria detection, and IFA for IgM were able to diagnose 72.3%, 60.5%, 53.3%, and 51.4%, respectively, of patients. Antigenuria was present in 53.8% of first samples, ELISA detected IgM in 29.7%, ELISA detected IgG plus IgM in 7.9%, and IFA detected IgM in 3.9%. Ten antigenuria-negative first samples tested serologically positive, 9 of them to IgM by ELISA. Despite the single source of the samples included in the study, detection of IgM using a sensitive technique such as ELISA seems to be a suitable complement to antigenuria detection for the diagnosis of legionellosis.
authors.affiliation: Vircell S. L., Plaza Domínguez Ortiz 1, 18320 Santa Fé, Granada, Spain.
authors.forename: Almudena
authors.initials: A
authors.lastname: Rojas
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Navarro
authors.forename: Francisca E
authors.initials: FE
authors.lastname: Fornés
authors.forename: Estefanía
authors.initials: E
authors.lastname: Serra
authors.forename: Encarnación
authors.initials: E
authors.lastname: Simarro
authors.forename: José
authors.initials: J
authors.lastname: Rojas
authors.forename: Joaquín
authors.initials: J
authors.lastname: Ruiz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D004196:Disease Outbreaks; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D016952:Legionella pneumophila / Q000276:immunology*; D007876:Legionellosis / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012698:Serologic Tests
chemical_list: D000907:Antibodies, Bacterial; D007075:Immunoglobulin M