A novel group A rotavirus associated with acute illness and hepatic necrosis in pigeons (Columba livia), in Australia.

Christina Mccowan,Jianning Wang,Honglei Chen,David Forshaw,Sandra Crameri,Dennis Rubbenstroth,Jana Batovska,Colin Walker,Megan Dearnley,Ayfer Kocak,Jemma Bergfeld,Songhua Shan,Clare Holmes,Mark Fegan,Jenni Harper,Karol Sestak

doi:10.1371/journal.pone.0203853

Abstract

Cases of vomiting and diarrhoea were reported in racing pigeons in Western Australia in May, 2016. Morbidity and mortality rates were high. Similar clinical disease was seen in Victoria in December and by early 2017 had been reported in all states except the Northern Territory, in different classes of domestic pigeon–racing, fancy and meat bird–and in a flock of feral pigeons. Autopsy findings were frequently unremarkable; histological examination demonstrated significant hepatic necrosis as the major and consistent lesion, often with minimal inflammatory infiltration. Negative contrast tissue suspension and thin section transmission electron microscopy of liver demonstrated virus particles consistent with a member of the Reoviridae. Inoculation of trypsin-treated Vero, MDBK and MA-104 cell lines resulted in cytopathic changes at two days after infection. Next generation sequencing was undertaken using fresh liver samples and a previously undescribed group A rotavirus (genotype G18P[17]) of avian origin was identified and the virus was isolated in several cell lines. A q-RT-PCR assay was developed and used to screen a wider range of samples, including recovered birds. Episodes of disease have continued to occur and to reoccur in previously recovered lofts, with variable virulence reported. This is the first report of a rotavirus associated with hepatic necrosis in any avian species.

Highlights

Avian rotaviruses were first detected in turkeys with diarrhoea, in the USA in 1977 and, the following year, in the UK [1]
We investigated vomiting and diarrhoea associated with high mortality in domestic pigeons (Columba livia). report the isolation and characterisation of a previously undescribed rotavirus associated with intestinal signs and hepatic necrosis in domestic and feral pigeons (Columba livia)
Using electron microscopy (EM), virus isolation and molecular techniques including generation sequencing (NGS) we identified a previously undescribed rotavirus associated with intestinal signs and hepatic necrosis

Summary

Introduction

Avian rotaviruses were first detected in turkeys with diarrhoea, in the USA in 1977 and, the following year, in the UK [1]. Experimental infection has shown that chickens less than 56 days old are likely to be subclinically infected [2,3,4], while turkeys and older chickens may develop diarrhoea [4]. Rotavirus-associated hepatic necrosis in pigeons from 18.8% to 69.7% of turkey flocks and 9.9% to 46.5% of chicken flocks worldwide [5,6,7,8]. In most surveys both clinically affected and clinically unaffected birds were found to be shedding rotavirus RNA in faeces, so the significance of this is uncertain. Simultaneous or sequential infections with different rotaviral groups is frequently observed in broiler chicken and turkey flocks [1, 9,10,11]

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Results

Conclusion