Detection of Influenza A Viruses in Eggs Laid by Infected Turkeys

Studies are limited on evaluating the potential of influenza viruses for egg-borne dissemination. In our previous studies, experimental infection of breeder turkeys with A/turkey/Ohio/313053/04 resulted in drastic declines in egg production, and we confirmed high levels of virus replication and an abundant distribution of avian-specific α2,3 sialic acid-gal receptors in the oviduct of these turkeys. In the present study, following experimental inoculation of A/turkey/Ohio/313053/04 in breeder turkeys, we detected these viruses in the albumin of eggs using real-time RT-PCR (RRT-PCR) and virus isolation in embryonated chicken eggs. Swabs from egg shells were also found positive by RRT-PCR. This is the first report of the detection of low pathogenic influenza viruses from internal egg contents following experimental infection. The possibility of hatchery contamination by egg-borne influenza viruses, and the spread of virus during movement of contaminated cracked eggs and egg flats, pose concerns regarding viral dissemination of influenza.