Abstract:
We conducted a matched case–control study to evaluate risk factors for infection with
highly pathogenic avian influenza (HPAI) H5N1 virus in poultry farms during the epidemic
of 2006–2007 in Nigeria. Epidemiologic data were collected through the use of a questionnaire
from 32 case farms and 83 control farms. The frequency of investigated exposure
factors was compared between case and control farms by using conditional logistic regression
analysis. In the multivariable analysis, the variables for (i) receiving visitors on farm
premises (odds ratio [OR] = 8.32; 95% confidence interval [CI] = 1.87, 36.97; P < 0.01), (ii)
purchased live poultry/products (OR = 11.91; 95% CI = 3.11–45.59; P < 0.01), and (iii) farm
workers live outside the premises (OR = 8.98; 95% CI = 1.97, 40.77; P < 0.01) were identified
as risk factors for HPAI in poultry farms. Improving farm hygiene and biosecurity should
help reduce the risk for influenza (H5N1) infection in poultry farms in Nigeria.
