ARS | Publication request: Different routes of transmission of low pathogenicity avian influenza viruses in chicken layers

Submitted to: American Association of Veterinary Laboratory Diagnosticians
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 2010
Publication Date: N/A

Technical Abstract: In previous studies in which the infectivity and transmissibility of the pandemic H1N1 virus was examined in different poultry species, it was determined that no or minimal infection occurred in chickens and turkeys intranasally inoculated with the virus. However, the virus could infect laying turkey hens by the intracloacal and intrauterine route causing decreased egg production. Such novel routes of exposure to the virus have not been previously examined in chickens and could explain outbreaks of low pathogenicity avian influenza (LPAI) causing drops in egg production in chicken layers. In the present study, chicken layers were infected by the intranasal (n=10), intracloacal (n=10) or intrauterine route (n=10) with one of two LPAI viruses: a chicken adapted virus (A/Ck/CA/1255/02 H6N2) and a live bird market isolate (A/Ck/NJ/1220/97 H9N2). All chickens became infected with the H6N2 virus when exposed by any of the three routes, and transient drops in egg production were observed. On the other hand, only 1 or 2 hens from each of the groups inoculated with the H9N2 virus presented evidence of infection. In conclusion, LPAI viruses can also transmit to chickens through other routes besides the intranasal route, which is considered the natural route of exposure; however this transmission also depends on the virus.