First molecular detection and partial ORF1 characterization of psittacine beak and feather disease virus (PBFDV) in domesticated parrots of Northern Vietnam.

Psittacine beak and feather disease virus (PBFDV), currently classified within the species Circovirus parrot, is an infectious agent in avian species, particularly psittacine birds. PBFDV is the causative agent of psittacine beak and feather disease (PBFD), leading to feather loss, deformed beaks and nails, immunosuppression, and high mortality. However, there is limited information on PBFDV in Vietnam, particularly in domesticated parrots. This study aims to detect and molecularly characterize PBFDV in psittacine birds in Northern Vietnam. Among the 193 psittacine birds tested by conventional PCR, 48 were PBFDV-positive, corresponding to a positivity rate of 24.87%. Based on partial ORF1 characterization, phylogenetic tree analysis of the ten PBFDV sequences showed that genotype I, which exhibits genetic diversity, is circulating in Vietnam. This study highlights the importance of genomic characterization of PBFDV in domesticated exotic psittacine birds in Vietnam. Together with the recent cases of PBFD in domestic parrots, further surveillance is needed to elucidate the host specificity, transmission, and pathophysiology of PBFDV.