Lateral Transmission of Chicken Anaemia Virus: Is It Faecal-Oral or Dust Inhalation?

Chicken anaemia virus (CAV), the causal agent of chicken infectious anaemia, usually transmits vertically from parents to chicks. The virus is shed through faeces and also transmits laterally to the flock mates but the route of transmission has never been confirmed. Faeces were collected from specific pathogen free chickens at days 5, 10 and 15 post-infection with CAV and stored at -80°C. In a subsequent experiment, one-day old SPF chickens were inoculated orally with the previously collected faecal samples. Another group of chickens were exposed to air from an isolator containing CAV infected chickens. All birds were kept in isolators and serum samples were collected weekly up to day 42 post-infection to detect seroconversion to CAV. Tissue samples were also collected at day 42 post-infection for qPCR enumeration of CAV genomic DNA. Rapid transmissibility CAV in faeces was confirmed, as was transmission of the virus via inhalation of contaminated air, although the latter was slower than faecal-oral route.