Clinical features of pneumonia caused by 2009 influenza A(H1N1) virus in Beijing, China.
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).
Bai
Lu
L
Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Gu
Li
L
Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Cao
Bin
B
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.
Zhai
Xiao-Li
XL
Department of Radiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Lu
Min
M
Department of Pathology, School of Basic Medical Sciences, Peking University, Beijing, People's Republic of China.
Lu
Yong
Y
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.
Liang
Li-Rong
LR
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.
Zhang
Lei
L
Department of Radiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Gao
Zi-Fen
ZF
Department of Pathology, School of Basic Medical Sciences, Peking University, Beijing, People's Republic of China.
Huang
Ke-Wu
KW
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.
Liu
Ying-Mei
YM
Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Song
Shu-Fan
SF
Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Wu
Lin
L
Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Yin
Yu-Dong
YD
Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
Wang
Chen
C
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.
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