title: False-positive PCR results linked to administration of seasonal influenza vaccine.
abstract: False-positive PCR results usually occur as a consequence of specimen-to-specimen or amplicon-to-specimen contamination within the laboratory. Evidence of contamination at time of specimen collection linked to influenza vaccine administration in the same location as influenza sampling is described. Clinical, circumstantial and laboratory evidence was gathered for each of five cases of influenza-like illness (ILI) with unusual patterns of PCR reactivity for seasonal H1N1, H3N2, H1N1 (2009) and influenza B viruses. Two 2010 trivalent influenza vaccines and environmental swabs of a hospital influenza vaccination room were also tested for influenza RNA. Sequencing of influenza A matrix (M) gene amplicons from the five cases and vaccines was undertaken. Four 2009 general practitioner (GP) specimens were seasonal H1N1, H3N2 and influenza B PCR positive. One 2010 GP specimen was H1N1 (2009), H3N2 and influenza B positive. PCR of 2010 trivalent vaccines showed high loads of detectable influenza A and B RNA. Sequencing of the five specimens and vaccines showed greatest homology with the M gene sequence of Influenza A/Puerto Rico/8/1934 H1N1 virus (used in generation of influenza vaccine strains). Environmental swabs had detectable influenza A and B RNA. RNA detection studies demonstrated vaccine RNA still detectable for at least 66 days. Administration of influenza vaccines and clinical sampling in the same room resulted in the contamination with vaccine strains of surveillance swabs collected from patients with ILI. Vaccine contamination should therefore be considered, particularly where multiple influenza virus RNA PCR positive signals (e.g. H1N1, H3N2 and influenza B) are detected in the same specimen.
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: T
authors.initials: T
authors.lastname: Curran
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: C
authors.initials: C
authors.lastname: McCaughey
authors.affiliation: Respiratory Virus Unit, Virus Reference Department, Microbiology Services, Health Protection Agency, Colindale, London NW9 5HT, UK.
authors.forename: J
authors.initials: J
authors.lastname: Ellis
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Mitchell
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Feeney
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: A P
authors.initials: AP
authors.lastname: Watt
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: F
authors.initials: F
authors.lastname: Mitchell
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: D
authors.initials: D
authors.lastname: Fairley
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: L
authors.initials: L
authors.lastname: Crawford
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: J
authors.initials: J
authors.lastname: McKenna
authors.affiliation: Regional Virus Laboratory, Microbiology Dept, Kelvin Building, Royal Victoria Hospital, Belfast BT12 6BA, UK.
authors.forename: P V
authors.initials: PV
authors.lastname: Coyle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004783:Environmental Microbiology; D005189:False Positive Reactions; D005260:Female; D006282:Health Personnel; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification*; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000302:isolation & purification*; D009981:Influenza B virus / Q000235:genetics / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000175:diagnosis* / Q000821:virology; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000821:virology; D016133:Polymerase Chain Reaction / Q000379:methods*; D017422:Sequence Analysis, DNA; D014763:Viral Matrix Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines; C488936:M1 protein, Influenza A virus; D014763:Viral Matrix Proteins