Newcastle disease viruses (NDVs) cause systemic diseases in chickens with high mortality. However, little is known about persistence of NDVs in contaminated tissues from infected birds. In this study, we examined viral replication in the feather pulp of chickens inoculated with viscerotropic velogenic NDV (vvNDV) genotype VII. Reverse transcription real-time PCR and immunohistochemistry were used to investigate viral persistence in the samples. vvNDV was detected in the oropharynx and cloaca and viral antigens were detected in the feathers, suggesting that feathers act as sources of viral transmission.
Animals ; Antigens, Viral/analysis ; Chickens ; Cloaca/virology ; Feathers/*virology ; Microbial Viability ; Newcastle Disease/transmission/*virology ; Newcastle disease virus/isolation & purification/*physiology ; Oropharynx/virology ; Poultry Diseases/transmission/*virology ; Virus Replication/*physiology

H5N2 strains of low-pathogenicity avian influenza virus (LPAIV) have been circulating for at least 17 years in some Mexican chicken farms. We measured the rate and duration of viral excretion from Pekin ducks that were experimentally inoculated with an H5N2 LPAIV that causes death in embryonated chicken eggs (A/chicken/Mexico/2007). Leghorn chickens were used as susceptible host controls. The degree of viral excretion was evaluated with real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) using samples from oropharyngeal and cloacal swabs. We observed prolonged excretion from both species of birds lasting for at least 21 days. Prolonged excretion of LPAIV A/chicken/Mexico/2007 is atypical.
Animals ; Chickens ; Cloaca/virology ; *Ducks ; Influenza A Virus, H5N2 Subtype/*physiology ; Influenza in Birds/*physiopathology/virology ; Oropharynx/virology ; Poultry Diseases/physiopathology/virology ; Real-Time Polymerase Chain Reaction/veterinary ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Time Factors ; *Virus Shedding