First Detection of Chicken Proventricular Necrosis Virus Associated with Transmissible Viral Proventriculitis in Bangladesh

Transmissible viral proventriculitis (TVP) is an emerging disease in chickens, linked to chicken proventricular necrosis virus (CPNV), a recently identified birnavirus. Here, we describe the first molecular-confirmed case of TVP in Bangladesh, affecting both a white layer flock and a coloured meat-type parent stock (PS). Affected birds exhibited growth retardation, diarrhoea, and increased mortality, alongside hallmark gross changes of proventricular enlargement and wall thickening. From the meat-type PS, proventricular samples were collected for histopathology and molecular diagnostics. Histological analysis revealed severe glandular epithelial damage, necrosis, mononuclear infiltration, epithelial hyperplasia, and metaplasia. Using RT-PCR on nucleic acid extracted from FTA card samples, we detected CPNV, in addition to infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), and avian reovirus (ARV). The amplified CPNV VP1 fragment was sequenced, and phylogenetic analysis placed the Bangladeshi strain within clades of previously reported CPNV isolates. This study represents the first report of CPNV and TVP in Bangladesh, highlighting the need for active surveillance in commercial and breeder poultry flocks to understand the virus’s epidemiology and support the development of control strategies.