Application of Quantitative PCR (qPCR) for the Detection of Psittacine Beak and Feather Disease Virus (PBFDV) in Air Conditioning Systems: A Model Study from a Veterinary Hospital in Thailand

Psittacine beak and feather disease virus (PBFDV), a member of the family Circoviridae, is a major pathogen affecting psittacine birds worldwide; however, its potential for airborne dissemination in veterinary environments remains poorly understood. This study aimed to investigate PBFDV contamination in air conditioning systems within a veterinary hospital and to compare the distribution and levels of viral load across different functional areas. Environmental swab samples were collected from 17 air conditioning units located in examination rooms, surgical suites, wards, and laboratory areas. Viral nucleic acids were extracted and analyzed using quantitative polymerase chain reaction (qPCR) on the Genesig q16 (Version 4) platform. PBFDV DNA was detected in multiple units, with viral loads ranging from <10 to >25,000 PBFDV genome copies per qPCR reaction. The highest levels were observed in an examination room (26,172 copies) and a surgical room (25,730 copies), whereas several locations showed low or negligible contamination (<100 copies). These findings indicate that air conditioning systems may act as a possible environmental contamination pathway and potential sources of viral dissemination within clinical settings. The results underscore the importance of routine environmental monitoring and targeted disinfection strategies. As a preliminary model, this study provides baseline data to support the development of effective biosecurity measures to reduce the risk of airborne transmission of PBFDV in veterinary facilities.