Risk Factors for Human Infection with Avian Influenza A H5N1, Vietnam, 2004 Academic Article uri icon


  • To evaluate risk factors for human infection with influenza A subtype H5N1, we performed a matched case-control study in Vietnam. We enrolled 28 case-patients who had laboratory-confirmed H5N1 infection during 2004 and 106 age-, sex-, and location-matched control-respondents. Data were analyzed by matched-pair analysis and multivariate conditional logistic regression. Factors that were independently associated with H5N1 infection were preparing sick or dead poultry for consumption < or =7 days before illness onset (matched odds ratio [OR] 8.99, 95% confidence interval [CI] 0.98-81.99, p = 0.05), having sick or dead poultry in the household < or =7 days before illness onset (matched OR 4.94, 95% CI 1.21-20.20, p = 0.03), and lack of an indoor water source (matched OR 6.46, 95% CI 1.20-34.81, p = 0.03). Factors not significantly associated with infection were raising healthy poultry, preparing healthy poultry for consumption, and exposure to persons with an acute respiratory illness.


  • Pham, Nga
  • Dinh, Pham
  • Long, Hoang
  • Tien, Nguyen
  • Hien, Nguyen
  • Mai, Le
  • Phong, Le
  • Van Tuan, Le
  • Van Tan, Hoang
  • Nguyen, Nguyen
  • Van Tu, Phan
  • Phuong, Nguyen

publication date

  • 2006