title: Conventional blood tests in predicting influenza A (H1N1) rapidly.
abstract: OBJECTIVE
  Although real-time reverse transcriptase-polymerase chain reactions (rRT-PCR) are gold standard for the diagnosis of influenza A (H1N1), the results can be delayed up to several days, which is problematic during a pandemic. Because of this limitation of rRT-PCR, clinicians have often had to set a treatment plan that was solely based on clinical suspicion. We investigated the hematological and biochemical factors that are associated with rRT-PCR results, in order to help clinicians deal with acute febrile patients during influenza pandemics.
  
  
  METHODS
  We conducted a retrospective, cross-sectional study of 465 emergency department patients who underwent both rRT-PCR and blood tests at the same time. Hematological and biochemical findings were compared between the rRT-PCR-positive group and rRT-PCR-negative group.
  
  
  RESULTS
  Levels of leukocytes, hemoglobin, platelets, blood urea nitrogen (BUN), total bilirubin, lactate dehydrogenase, serum glucose, C-reactive protein (CRP), and procalcitonin were significantly different between the two groups in the univariate analyses. In the multivariate analyses, leukocyte counts ≤ 10.8 (× 10(9))/L [odd ratio (OR) = 8.2, sensitivity = 93.7%, NPV = 85.3%], BUN levels ≤ 7.1 μmol/L (OR = 3.0, sensitivity = 93.7%, NPV = 85.3%), and CRP levels ≤ 60 mg/L (OR = 2.4, sensitivity = 93.7%, NPV = 85.3%) were independently associated with positive rRT-PCR results.
  
  
  CONCLUSIONS
  Leukocyte counts, BUN levels and CRP levels were important predictors of rRT-PCR-positive results for 2009 influenza A (H1N1) in adults.
authors.affiliation: Departments of Emergency Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dong Hyuk
authors.initials: DH
authors.lastname: Shin
authors.forename: Sang Kuk
authors.initials: SK
authors.lastname: Han
authors.forename: Pil Cho
authors.initials: PC
authors.lastname: Choi
authors.forename: Hee-Yeon
authors.initials: HY
authors.lastname: Woo
mesh_terms: D000293:Adolescent; D000328:Adult; D001806:Blood Urea Nitrogen; D002097:C-Reactive Protein / Q000032:analysis; D003430:Cross-Sectional Studies; D005260:Female; D005334:Fever / Q000097:blood / Q000209:etiology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000097:blood* / Q000175:diagnosis; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D002097:C-Reactive Protein