Retrospective study on transmissible viral proventriculitis and chicken proventricular necrosis virus (CPNV) in the UK

Abstract

Chicken proventricular necrosis virus (CPNV) is a recently described birnavirus, which has been proposed to be the cause of transmissible viral proventriculitis (TVP). The understanding of the epidemiology of both the virus and the disease is very limited. A retrospective investigation on TVP and CPNV in broiler chicken submissions from the UK from between 1994 and 2015 was performed with the aims of assessing the longitudinal temporal evolution of TVP and CPNV and to review the histological proventricular lesions in the studied chickens. Ninety-nine of the 135 included submissions (73.3%) fulfilled the TVP-diagnostic criteria, while the remaining 36 submissions (26.7%) displayed only lymphocytic proventriculitis (LP). The first detection of CPNV by PCR dated from 2009. Results showed a rise in the number of both TVP and positive CPNV RT-PCR submissions from 2009 with a peak in 2013, suggesting that they may be an emerging or re-emerging disease and pathogen, respectively. Twenty-two out of the 99 submissions displaying TVP lesions (22%) and 4 out of the 36 (11%) ones with LP gave positive CPNV RT-PCR results, further supporting the association between CPNV and TVP and confirming that CPNV is present in a low proportion of proventriculi that do not fulfil the TVP diagnostic criteria. In addition, intranuclear inclusion bodies were observed in 22 of the submissions with TVP. The vast majority of these cases (21 of 22, 96%) gave negative CPNV RT-PCR results, raising the question of whether another virus different from CPNV is responsible for some of these TVPaffected cases. Research highlights • TVP and CPNV are present in the British broilers since at least 1994 and 2009, respectively • TVP and CPNV seem to be an emerging and re-emerging disease and pathogen, respectively • CPNV was detected in proventriculi with both TVP and LP-lesions • Other viruses different from CPNV may be responsible for some TVP-affected cases

Chicken proventricular necrosis virus related transmissible viral proventriculitis in broiler chickens in Poland

“…Recent research from the UK also suggests the involvement of CPNV in the development of TVP in chickens. In two studies, the authors reported that CPNV was detected in 22 and 47% of con rmed clinical cases of TVP [11,12]. It remains unknown, however, if all cases of this disease are of the same infectious origin.…”

“…It remains unknown, however, if all cases of this disease are of the same infectious origin. There are cases of TVP in which CPNV cannot be identi ed, as well as disease cases in which CPNV can be identi ed but which do not meet the diagnostic criteria of TVP [7,11,12]. In addition, it is suggested that the pathogenesis of TVP could be more complex and may result from other viral, bacterial or fungal co-infections [1].…”

“…This virus was named chicken proventricular necrosis virus (CPNV), and an RT-PCR method has been developed which enables its detection [13]. Unfortunately, cases of TVP which were negative for CPNV as well as cases positive for CPNV presence without typical TVP changes has also been reported [12], which makes the etiology of TVP unresolved and further research are still necessary.…”

Novel Cyclovirus Identified in Broiler Chickens With Transmissible Viral Proventriculitis in China

“…In the recent research, intranuclear inclusion bodies were observed in case of the submissions with TVP. The vast majority of these cases gave negative CPNV RT-PCR results, raising the question of whether another virus different from CPNV is responsible for some of these TVP-affected cases ( 29 ).…”

Transmissible Viral Proventriculitis Caused by Chicken Proventricular Necrosis Virus Displaying Serological Cross-Reactivity with IBDV

“…The etiology of TVP has not been explicitly defined so far. Studies on TVP etiopathology imply the involvement of infectious bursal disease viruses (IBDV) of the Birnaviridae family, IBDV-like viruses, infectious bronchitis viruses (IB) of the Coronaviridae family, reoviruses (REO), picornaviruses, fowl adenoviruses (FAdV), adeno-like viruses, or mixed infections in the development of typical pathological lesions [ 3 , 4 , 5 , 6 , 8 , 10 , 11 , 12 , 13 , 14 , 15 ]. Recently, a novel virus identified as a member of the Birnaviridae family has been isolated from clinical cases of TVP.…”