Relationship between chicken proventricular necrosis virus prevalence and transmissible viral proventriculitis in broiler chickens in Poland

Transmissible Viral Proventriculitis (TVP) is a disease of chickens which contributes to significant production losses. Recent reports indicate the role of chicken proventricular necrosis virus (CPNV) in the development of TVP. However, the relationship between CPNV and TVP is inconclusive and it has been addressed in just a few reports. Given the above, a study was conducted to identify the relationship between TVP and CPNV prevalence in broiler chickens in Poland. The study was carried out on 35 proventriculi samples sent for histopathological (HP) examination to the Faculty of Veterinary Medicine in Olsztyn between 2017 and 2019. After HP examination, TVP positive samples were processed for CPNV identification by RT-PCR. TVP was the most common pathological condition of proventriculi (23 cases). CPNV was identified in 10 out of those 23 cases. The average HP score, and the average necrosis and infiltration score for CPNV-positive samples was significantly higher than in CPNV-negative ones. The average age of the CPNV-positive chickens was significantly lower than in CPNV-negative birds. Our study confirms the role of CPNV in TVP pathogenesis and it seems that preservation of the proventriculi in the early stages of the disease, when the lesions are more pronounced, should result in a greater probability of CPNV detection.