Fluctuation of the prevalence of beak and feather disease virus in captive psittacines in Iran.

Beak and feather disease virus (BFDV) is one of the most life-threatening viral agents infecting parrot species. In this study, we investigated fluctuation in the prevalence of beak and feather disease virus (BFDV) in captive psittacines in Iran. Two series of feather samples from different psittacine species, received between July 2019 and July 2021 (n = 1009) and between July 2021 and July 2022 (n = 2020), were examined for the presence of BFDV using the PCR method, and the host species distribution and temporal prevalence of BFDV within populations were calculated. The results showed a total viral prevalence of 26.86% and 26.88% within sample series 1 and 2, respectively. By examining both sample series, the prevalence of BFDV was found to be  the highest (P < 0.05) in Nymphicus hollandicus and the lowest (P < 0.05) in Psittacus erithacus, Myiopsitta monachus, Pyrrhura molinae, and Aratinga solstitialis. The viral prevalence was significantly higher (P < 0.05) within the series 1 than the series 2 samples only in Nymphicus hollandicus. Within series 2, the viral prevalence was significant (P < 0.05) in samples from Nymphicus hollandicus collected in March. This study indicates significant prevalence of BFDV in captive Nymphicus hollandicus populations and suggests that the fluctuation in the prevalence of BFDV could be due to the combined influence of host-species and temporal factors.