title: Risk factors for severe cases of 2009 influenza A (H1N1): a case control study in Zhejiang Province, China.
abstract: Few case control studies were conducted to explore risk factors for severe cases of 2009 influenza A (H1N1) with the mild cases as controls. Mild and severe cases of 2009 influenza A (H1N1), 230 cases each, were randomly selected from nine cities in Zhejiang Province, China, and unmatched case control study was conducted. This study found that it averagely took 5 days for the severe cases of 2009 influenza A (H1N1) to start antiviral therapy away from onset, 2 days later than mild cases. Having chronic underlying diseases and bad psychological health combined with chronic underlying diseases were two important risk factors for severe cases, and their OR values were 2.39 and 5.85 respectively. Timely anti-viral therapy was a protective factor for severe cases (OR = 0.35, 95% CI: [0.18-0.67]). In conclusion, psychological health education and intervention, as well as timely anti-viral therapy, could not be ignored in the prevention, control and treatment of 2009 influenza A (H1N1).
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China. lefangchina@yeah.net
authors.forename: Le
authors.initials: L
authors.lastname: Fang
authors.forename: Junfen
authors.initials: J
authors.lastname: Lin
authors.forename: Chengliang
authors.initials: C
authors.lastname: Chai
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology* / Q000821:virology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000998:Antiviral Agents