|COSTA-HURTADO, MAR - US Department Of Agriculture (USDA)|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2014
Publication Date: N/A
Technical Abstract: Highly pathogenic avian influenza viruses (HPAIV’s) remain a threat to poultry worldwide. Avian influenza viruses, including HPAIV, are usually non-pathogenic for ducks and other wild aquatic birds, with the exception of some Asian lineage H5N1 HPAIVs which can cause severe disease in ducks. With the continuous occurrence of HPAI outbreaks in poultry it’s necessary to address the role of wild birds in the transmission and spreading of HPAIV’s. We conducted a study in which we inoculated 2-weeks-old mallard ducks (Anas platyrhynchos) intranasally with 106 EID50 of one of eleven strains of HPAIV subtypes H5 or H7, including isolates from different years and countries. Pathogenesis (clinical signs, lesions), presence of the viruses in tissues, duration and titer of virus shedding for each virus, transmission to contact birds, and seroconversion to all viruses was evaluated. Although no clinical signs or mortality were observed, ducks became infected with most of the viruses given and transmitted the viruses to contacts. Viral shedding occurred by both the oropharyngeal and cloacal routes indicating adaptation to poultry. Viruses that had circulated for longer periods of time in poultry, like the Mexican H5N2 HPAIV, were less infectious for ducks. These results raise concerns about possible spreading of HPAIV’s by infected wild ducks.