|Pusch, Elizabeth - Orise Fellow|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2018
Publication Date: 7/13/2018
Citation: Pusch, E.A., Suarez, D.L. 2018. Infection and transmission of LPAIV H9N2 viruses in SPF chickens. Meeting Abstract. American Veterinary Medical Association Annual Meeting, July, 13-16, 2018, Denver, Colorado. CDROM.
Technical Abstract: Low pathogenic avian influenza viruses (LPAIV), subtype H9N2 are responsible for economic losses in the poultry industry worldwide. Using multiple strains of H9N2 LPAIV isolates from different years and countries, we inoculated 3-week old SPF laying hens intranasally to evaluate infectivity and transmissibility of these viruses. Oropharyngeal swabs and blood were collected to determine virus shedding and antibody production. Birds inoculated with a 104 and/or 106 EID50 of multiple U.S. H9N2 isolates showed no clinical signs of infection. However, swab and serological analysis showed that one bird challenged with A/Turkey/TX/89 was shedding virus 2 and 4 dpi and seroconverted based on HI titers. Additionally, one bird challenged with A/Mallard/MN/304/98 was positive based on HI titer but was not shedding detectable virus. SPF chickens inoculated with a 102 or 104 EID50 of foreign H9N2 LPAIV isolates resulted in infection and transmission in chickens with differences in seroconversion, virus shedding, and transmission seen between isolates and doses. Chickens inoculated with isolates at the higher dose (104 EID50) had higher HI titers and virus shedding with increased transmission. However, only one isolate resulted in infection and transmission at the low dose (102 EID50). These results suggest that recent foreign G1 lineage or Chinese lineage H9N2 isolates are more poultry adapted than U.S. H9N2 isolates which showed low infectivity and transmission compared to the foreign isolates.