title: Diagnosis of influenza from lower respiratory tract sampling after negative upper respiratory tract sampling.
abstract: In this retrospective cohort study, we demonstrate that PCR-confirmed diagnoses of influenza were made solely by lower respiratory sampling in 6.9% of cases, as traditional upper respiratory tract tests were negative, indeterminate or not performed. Clinical features of these cases are presented. Clinicians should consider lower respiratory tract sampling in select cases of influenza-like illness for diagnosis.
authors.affiliation: Divisions of Internal Medicine and Infectious Diseases, Toronto General Hospital, Toronto, ON, Canada. Isaac.Bogoch@uhn.ca
authors.forename: Isaac I
authors.initials: II
authors.lastname: Bogoch
authors.forename: Jason R
authors.initials: JR
authors.lastname: Andrews
authors.forename: Kimon C
authors.initials: KC
authors.lastname: Zachary
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Hohmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000175:diagnosis* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D009975:Orthomyxoviridae / Q000302:isolation & purification*; D012137:Respiratory System / Q000821:virology*; D012189:Retrospective Studies; D055815:Young Adult