title: Viral etiology of acute exacerbations of COPD in Hong Kong.
abstract: BACKGROUND
  Viral respiratory infections may precipitate acute exacerbations of COPD (AECOPD). However, little is known about viral etiology related to AECOPD in Asia. We aimed to study the viral etiology of AECOPD in Hong Kong.
  
  
  METHODS
  Patients admitted to an acute hospital in Hong Kong with AECOPD were recruited prospectively from May 1, 2004, to April 30, 2005. Nasopharyngeal aspirate was collected and assessed by polymerase chain reaction (PCR) and viral culture. Spirometry was performed in the stable phase at 2 to 3 months after hospital discharge.
  
  
  RESULTS
  There were 262 episodes of AECOPD among 196 patients (mean age, 75.7 +/- 7.7 years [+/- SD]; 160 men). Mean FEV(1) was 39.6 +/- 18.9% of predicted normal, and FEV(1)/FVC ratio was 58.0 +/- 15.2%. Fifty-eight episodes (22.1%) yielded positive viral PCR results. The viruses identified were influenza A (7.3%), coronavirus OC43 (4.6%), rhinovirus (3.1%), influenza B (2.7%), and respiratory syncytial virus (2.3%). The diagnostic yield of viral identification by PCR was 2.7 times higher than that based on conventional viral culture. The rates of identifying a positive viral etiology by PCR were similar among the subjects with FEV(1) >or= 50%, >or= 30 to 50%, and < 30% of predicted normal. Viral infection appeared to have no effect on subsequent readmissions or mortality rate over a study period of 1 year
  
  
  CONCLUSIONS
  Influenza A and two less-attended viruses, coronavirus OC43 and rhinovirus, were the common etiologic agents in patients hospitalized with AECOPD in Hong Kong. These should be considered in developing diagnostic and intervening strategies pertaining to AECOPD.
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing St, Shatin, New Territories, Hong Kong.
authors.forename: Fanny W S
authors.initials: FW
authors.lastname: Ko
authors.forename: Margaret
authors.initials: M
authors.lastname: Ip
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Chan
authors.forename: Michael C H
authors.initials: MC
authors.lastname: Chan
authors.forename: Kin-Wang
authors.initials: KW
authors.lastname: To
authors.forename: Susanna S S
authors.initials: SS
authors.lastname: Ng
authors.forename: Shirley S L
authors.initials: SS
authors.lastname: Chau
authors.forename: Julian W
authors.initials: JW
authors.lastname: Tang
authors.forename: David S C
authors.initials: DS
authors.lastname: Hui
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006723:Hong Kong; D006760:Hospitalization; D006801:Humans; D008297:Male; D009305:Nasopharynx / Q000821:virology*; D016133:Polymerase Chain Reaction; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality / Q000503:physiopathology / Q000821:virology*; D012328:RNA Viruses / Q000302:isolation & purification*