title: False positive legionella serology in campylobacter infection: campylobacter serotypes, duration of antibody response and elimination of cross-reactions in the indirect fluorescent antibody test.
abstract: Sera from 83 patients with campylobacter gastroenteritis were examined for the presence of legionella antibodies by indirect immunofluorescence. Twenty-one patients (25%) had positive titres (> or = 16) including 11 patients with titres of > or = 128. Legionella seropositivity persisted in 5 of 9 patients (55%) studied for 6-9 months. Campylobacter isolates were serotyped by the Penner scheme. Isolates associated with legionella seropositivity included Penner types 1, 2 and 4, the common endemic serotypes in England. Campylobacter blocking fluids were prepared from a range of Penner reference strains. The blocking fluid prepared from Penner type 11 was the most efficient at inhibiting the false-positive legionella titres. Using this absorption step legionella titres were inhibited from 24 of 26 patients (92%) with campylobacter but not from 8 patients with culture-proven legionnaires' disease. We recommend that this method is incorporated into routine diagnostic legionella serology in order to eliminate false-positive reactions due to campylobacter.
authors.affiliation: Public Health Laboratory, Northern General Hospital, Sheffield.
authors.forename: L E
authors.initials: LE
authors.lastname: Marshall
authors.forename: T C
authors.initials: TC
authors.lastname: Boswell
authors.forename: G
authors.initials: G
authors.lastname: Kudesia
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology*; D002167:Campylobacter / Q000145:classification* / Q000276:immunology*; D002169:Campylobacter Infections / Q000097:blood / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D003429:Cross Reactions; D004739:England / Q000453:epidemiology; D005189:False Positive Reactions; D005260:Female; D005455:Fluorescent Antibody Technique; D005759:Gastroenteritis / Q000097:blood / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D016952:Legionella pneumophila / Q000145:classification* / Q000276:immunology*; D008297:Male; D012703:Serotyping; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial