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United States Department of Agriculture

Agricultural Research Service

Research Project: STUDIES TO REDUCE TRANSMISSION OF H5N1 HPAI VIRUS, AND ASSESS INFECTIVITY AND TRANSMISSIBILITY OF H5N1 HPAI VIRUSES FOR PIGS

Location: Exotic and Emerging Avian Viral Diseases Research Unit

2010 Annual Report


1a.Objectives (from AD-416)
1. Investigate modified simple slaughter methods to reduce aerosol generation during home slaughter process and determine the impact of such improvements on reducing virus transmission. 2. Improved methods of evaluating vaccine efficacy in poultry AI vaccines. 3. Determining infectivity, transmissibility, and pathogenicity of 5 isolates of H5N1 highly pathogenic avian influenza virus (HPAIV) for pigs.


1b.Approach (from AD-416)
Aerosol generation and virus levels will be measured in rooms conducting simulated home processing of asymptomatic H5N1 HPAI virus infected chickens. A simple, plastic-bag method for processing will be evaluated for reducing aerosol and virus generation and reducing transmission to chicken and ferret models. Develop attenuated H5 AI viruses that will be used to produce reference antibodies from chickens for testing cross neutralization of H5 HPAI viruses in a chicken egg neutralizing test as a means to assess vaccines seed strain efficacy against drift variant field viruses. Five H5N1 HPAI viruses will be intrabronchally inoculated into pigs and examined for contact transmission. Pigs will be examined for infection by serology, virus isolation, and RRT-PCR assays.


3.Progress Report

This research relates to inhouse objective 2: Develop vaccines that effectively stop outbreaks, allow differentiation from natural infection and can be administered in a cost effective manner.

Some strains of animal influenza virus have been zoonotic agents necessitating joint research between veterinary medicine and human health to solve the problems including the H5N1 high pathogenicity avian influenza (HPAI) virus. During 2010, lung lavage samples and lung tissues from pigs, challenged in the respiratory tract with various avian influenza viruses, were assayed by virus isolation in eggs. Twenty-seven samples were real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) positive using avian influenza (AI) matrix gene test. Of these 27, 25 had virus recovered by isolation in embryonating chicken eggs. Most had low levels of virus, 0.97log10 mean embryo infectious doses, in lavage samples, indicating that replication of AI virus was low level in respiratory tract of pigs. Further studies are underway to gain further information.

Progress was monitored via regular email and telephone conversations with the cooperator.


Last Modified: 4/18/2014
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