Chicken anemia virus (CAV) and avian gyrovirus type 2 (AGV2)
are members of the family Circoviridae, genus Gyrovirus [1,2]. CAV
is the causative agent of chicken infectious anemia, an important
avian disease characterized by anemia, immunosuppression and
mortality in young chickens [3e5]. The virus is widely distributed
in virtually all countries with significant poultry production [1].
Regarding AGV2, it was incidentally discovered by our group
during a diagnostic search for CAV in chickens [2]. Infections with
AGV2 have been identified in several different locations in Brazil
and Netherlands, suggesting a worldwide distribution