Risk Factors for Avian Influenza H9 Infection of Chickens in Live Bird Retail Stalls of Lahore District, Pakistan 2009-2010

Sci Rep. 2018 Apr 4;8(1):5634. doi: 10.1038/s41598-018-23895-1.

Abstract

This study was conducted to identify risk factors associated with AIV infections in live bird retail stalls (LBRS) in Lahore District, Pakistan. A cross-sectional survey of LBRS was conducted from December 2009-February 2010 using two-stage cluster sampling based on probability proportional to size. A total of 280 oropharyngeal swab sample pools were collected from 1400 birds in 8 clusters and tested by qRT-PCR for the matrix (M) gene of type A influenza virus and HA gene subtypes H9, H5 and H7. Thirty-four (34) samples were positive for the M gene, of which 28 were also positive for H9. No sample was found positive for H5 or H7. Data for 36 potential risk factors, collected by questionnaire, were analyzed by survey-weighted logistic regression and prevalence odds ratios (OR) for associated risk factors were calculated. A final multivariable model identified three risk factors for H9 infection in LRBS, namely obtaining birds from mixed sources (OR 2.28, CI95%: 1.4-3.7), keeping birds outside cages (OR 3.10, CI95%: 1.4-7.0) and keeping chicken breeds other than broilers (OR 6.27, CI95%: 1.7-23.2). Sourcing birds from dealers/wholesalers, keeping birds inside cages and avoiding mixing different breeds in cages could reduce the risk of H9 infections in LRBS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens
  • Commerce*
  • Cross-Sectional Studies
  • Influenza A virus / isolation & purification*
  • Influenza in Birds / epidemiology*
  • Influenza in Birds / transmission
  • Influenza in Birds / virology*
  • Pakistan / epidemiology
  • Prevalence
  • Risk Factors
  • Time Factors