Retrospective and prospective studies of transmissible viral proventriculitis in broiler chickens in Brazil

Abstract

We investigated the occurrence and pathologic findings of transmissible viral proventriculitis (TVP) associated with the chicken proventricular necrosis virus (CPNV) in commercial broiler chickens in southeastern Brazil. Seventy-three broilers, 25–36 d old, with a history of reduced growth, were referred to our veterinary pathology services from 2013 to 2017. Broilers were clinically examined, weighed, and euthanized for postmortem examination. Broilers of different ages with proventricular histologic lesions were positive for CPNV by RT-PCR; however, the intensity of histologic lesions was higher among 33-d-old animals, and viral RNA detection was more frequent among those that were 28 d old. In the proventriculi of 35 of 73 (48%) broilers, lesions were characterized by glandular epithelial necrosis, lymphoplasmacytic and histiocytic infiltrates, and metaplasia of glandular epithelium to ductal epithelium. In 24 of 73 (36%) broilers with histologic TVP-compatible lesions, CPNV was detected by RT-PCR for the viral protein 1 ( VP1) gene. Broilers with histologic lesions were lighter than expected compared to the Cobb 500 standard weight. TVP has not been reported previously in broiler chickens in Brazil, to our knowledge.

Long read sequencing revealed proventricular virome of broiler chicken with transmission viral proventriculitis

“…Consequently, the R11/3 strain virus was identified as Birnavirus, and named CPNV [ 6 , 7 ]. Since then, CPNV was reported in the USA, Spain, France, UK, Poland and Brazil [ 8 – 13 ]. Studies on TVP etiopathology also imply the other viruses involvement, including infectious bursal disease viruses (IBDV) of the Birnaviridae family, infectious bronchitis viruses (IB) of the Coronaviridae family, reoviruses (REO), picornaviruses, fowl adenoviruses (FAdV), adeno-like viruses, Gyrovirus homsa1 (GyH1, also known as Gyrovirus 3, GyV3), Cyclovirus (CyCV) of the Anelloviridae [ 14 , 15 ] and chicken Circovirus (CCV) of the Circoviridae [ 16 ].…”