title: The use of saliva specimens for detection of influenza A and B viruses by rapid influenza diagnostic tests.
abstract: Diagnostic tests for influenza infection commonly use nasopharyngeal swabs (NPS) even though these are invasive to obtain. As an alternative specimen, we evaluated the diagnostic usefulness of saliva samples with rapid influenza diagnostic tests (RIDTs).
  
  
  
  Both NPS and saliva samples were collected from 385 influenza suspected patients and analyzed using Sofia Influenza A+B Fluorescence Immunoassay (Quidel Corporation, San Diego, CA, USA), ichroma TRIAS Influenza A+B (Boditech, Chuncheon, Korea), SD Bioline Influenza Ag (Standard Diagnostic, Yonggin, Korea), BinaxNOW Influenza A/B antigen kit (Alere Inc., Waltham, MA, USA), and real-time reverse transcriptase PCR (RT-PCR).
  
  
  
  Of the 385 patients, 31.2% (120/385) were positive for influenza A, and 7.5% (29/385) were positive for influenza B virus with saliva or NPS by RT-PCR. The diagnostic sensitivity was slightly higher in NPS than in saliva samples for both influenza A and B by all of the four RIDTs. The diagnostic sensitivities of Sofia and ichroma TRIAS were significantly superior to those of the other conventional influenza RIDTs with both types of sample. The sensitivities of Sofia and ichroma TRIAS with saliva specimens were comparable to the sensitivities of the other two conventional RIDTs with NPS specimens. The simultaneous use of saliva and NPS samples exhibited improved sensitivity from 10.0% to 13.3% for influenza A and from 10.3% to 17.2% for influenza B compared to using NPS alone.
  
  
  
  This study demonstrates that saliva is a useful specimen for influenza detection, and that the combination of saliva and NPS could improve the sensitivities of influenza RIDTs.
authors.affiliation: Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jung
authors.initials: J
authors.lastname: Yoon
authors.affiliation: Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Gyu
authors.initials: SG
authors.lastname: Yun
authors.affiliation: Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Nam
authors.affiliation: Department of Emergency Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung-Hyuk
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Republic of Korea. Electronic address: malarim@korea.ac.kr.
authors.forename: Chae Seung
authors.initials: CS
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000821:virology; D007723:Korea; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D012463:Saliva / Q000821:virology*; D012680:Sensitivity and Specificity; D013997:Time Factors; D014481:United States; D055815:Young Adult
keywords: Influenza virus; Nasopharyngeal swab; RT-PCR; Rapid influenza detection kits; Saliva