title: Clinical features of pneumonia caused by 2009 influenza A(H1N1) virus in Beijing, China.
abstract: BACKGROUND
  Data on symptoms and radiographic changes in patients with pandemic 2009 influenza A(H1N1) (A[H1N1]) pneumonia during convalescence have not been reported.
  
  
  METHODS
  During October 26, 2009, and January 23, 2010, adult patients with pneumonia with laboratory-confirmed or clinically suspected A(H1N1) infections were observed for clinical characteristics, high-resolution chest CT scan, and lung function test changes during acute and 3-month convalescent phases.
  
  
  RESULTS
  Of the 65 case subjects, the median age was 41 (interquartile range [IQR], 28-57) years, 60.0% were men, and 55.4% had at least one underlying medical condition. Sixty-two patients started oseltamivir therapy within a median of 5 (IQR, 4-6) days from the onset of illness, and 31 received IV corticosteroids. ARDS developed in 33 patients, and 24 were treated initially with noninvasive positive pressure ventilation (NPPV). In this group, NPPV was successful in 13 patients (54.2%). Nine patients died at a median of 16 (IQR, 10-24) days after onset of illness. Multivariate Cox regression identified two independent risk factors for death: progressive dyspnea after resolution of fever (relative risk, 5.852; 95% CI, 1.395-24.541; P = .016) and a higher APACHE (Acute Physiology and Chronic Health Evaluation) II score on presentation (relative risk for each point, 1.312; 95% CI, 1.140-1.511; P < .001). At 3-month follow-up of survivors with A(H1N1), ground-glass opacities were still present, although diminished, in 85.7%, and diffusing capacity for carbon monoxide was mildly reduced in 61.5%.
  
  
  CONCLUSIONS
  Ground-glass opacities and decreased diffusing capacity were the main abnormalities observed at 3-month follow-up of survivors of A(H1N1).
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Bai
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Gu
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China; Beijing Key Laboratory of Respiratory and Pulmonary Circulation, Beijing, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Cao
authors.affiliation: Department of Radiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Zhai
authors.affiliation: Department of Pathology, School of Basic Medical Sciences, Peking University, Beijing, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Lu
authors.affiliation: Department of Respiratory and Intensive Care Medicine, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Respiratory and Intensive Care Medicine, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Liang
authors.affiliation: Department of Radiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Pathology, School of Basic Medical Sciences, Peking University, Beijing, People's Republic of China.
authors.forename: Zi-Fen
authors.initials: ZF
authors.lastname: Gao
authors.affiliation: Department of Respiratory and Intensive Care Medicine, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Ke-Wu
authors.initials: KW
authors.lastname: Huang
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Ying-Mei
authors.initials: YM
authors.lastname: Liu
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Shu-Fan
authors.initials: SF
authors.lastname: Song
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Yin
authors.affiliation: Department of Respiratory and Intensive Care Medicine, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China; Beijing Key Laboratory of Respiratory and Pulmonary Circulation, Beijing, People's Republic of China. Electronic address: cyh-birm@263.net.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002681:China; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000175:diagnosis / Q000188:drug therapy / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000188:drug therapy / Q000401:mortality; D011446:Prospective Studies; D012189:Retrospective Studies; D055815:Young Adult