Sample collection and virus isolation
We collected oropharyngeal and cloacal swabs of poultry (including
chickens, ducks, and geese) from live poultry markets in the Guangdong
Province during 2016-2019, which were kept in PBS with penicillin and
streptomycin. We also collected swabs or tissue samples from sick or
dead poultry in farms. The collected swabs were centrifuged, and 0.2 ml
of the supernatant was inoculated into
nine to 10-day-old SPF chicken
embryos. After 48-72 hours of
culture at 37°C, the
allantoic
fluid was collected, and
Hemagglutinin-positive samples were
further confirmed.