An updated review on chicken infectious anaemia

Chicken infectious anaemia (CIA), an emerging disease of poultry, is caused by Chicken infectious anaemia virus (CIAV) of Gyrovirus genus and Anelloviridae family. CIAV is a single stranded, circular DNA virus and is highly resistant to disinfectants and external environment. The disease mainly affects young chickens of 2–4 weeks of age; however, after attaining the sexual maturity, clinical signs become less evident. The disease is the leading cause of immunosuppression in poultry which results in synergistically enhanced immunopathology along with other pathogens. The virus is transmitted vertically to the progeny and therefore is an important rising concern in the specific pathogen free poultry industry. Emerging genotypes and recombination events in CIAV genome have been reported from different countries. The spectrum of genotypic variations suggests the need for detailed genetic study of currently circulating CIAV genotypes and designing of updated diagnostics and vaccines, if required. The increasing genetic variability in the genotypes is also resulting in significant variations in pathogenecity of CIAV isolates. These variations might lead to immune escape and alter the transmission and virulence pattern of the virus in future. Therefore, the study of emergence of CIAV and its effect on phenotype is an important research gap to be filled in.