Tissue Distribution and Shedding Profiles of Chicken Anaemia Virus in Specific Pathogen-Free and Commercial Broiler Chickens

Chicken infectious anaemia is caused by a circovirus called chicken anaemia virus (CAV), and it has become an emerging threat to the poultry industry worldwide. CAV may cause clinical symptoms in young chickens. At the same time, it can maintain subclinical infection in all chickens, causing immunosuppression resulting in vaccination failure and facilitating other diseases. In the absence of clinical manifestation, a reliable method for monitoring of CAV infection is needed for the poultry industry. Two experiments were conducted, one in specific-pathogen-free-layer chickens and the other in commercial broiler chickens, to detect and quantify the viral genome in various tissues and environmental samples. CAV was detectable in a number of tissues with a high titre in thymus and bone marrow; therefore, these two tissues will be preferred samples for molecular diagnosis. The virus was detected in dust and litter samples, although at a low level. The monitoring of CAV infection using environmental samples such as dust and litter has potential, but needs further optimization.