Potential reverse spillover of infectious bursal disease virus at the interface of commercial poultry and wild birds

Rania F El Naggar,Muhammad Munir,Mohammed A Rohaim

doi:10.1007/s11262-020-01793-x

Rania F El Naggar, Muhammad Munir + Show 1 more

Open Access

https://doi.org/10.1007/s11262-020-01793-x

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Abstract

Recently, multiple spillover events between domesticated poultry and wild birds have been reported for several avian viruses. This phenomenon highlights the importance of the livestock-wildlife interface in the possible emergence of novel viruses. The aim of the current study was to investigate the potential spillover and epidemiological links of infectious bursal disease virus (IBDV) between wild birds and domestic poultry. To this end, twenty-eight cloacal swabs were collected from four species of free-living Egyptian wild birds (i.e. mallard duck, bean goose, white-fronted goose and black-billed magpie). Genetic and phylogenetic analysis of three positive isolates revealed that the IBDV/USC-1/2019 strain clustered with previously reported very virulent IBDV (vvIBDV) Egyptian isolates. Interestingly, two other wild bird-origin isolates (i.e. IBDV/USC-2/2019 and IBDV/USC-3/2019) grouped with a vaccine strain that is being used in commercial poultry. In conclusion, our results revealed the molecular detection of vaccine and vvIBDV-like strains in Egyptian wild birds and highlighted the potential role of wild birds in IBDV epidemiology in disease-endemic regions.

Highlights

Infectious bursal disease (IBD) is an acute and highly contagious disease of chicks, and the clinical impact of IBD is mainly attributed to its severe immunosuppression especially in young chickens
Based on serological evidences of infectious bursal disease virus (IBDV) serotype I in wild birds, it has been suggested that wild birds may be critical player in the epidemiology of IBDV and may act as reservoir for the IBDV [39,40,41,42,43]
In spite of restricted epidemiological studies for viruses in wild birds, spilling over of poultry vaccines has been documented in wild birds [24]

Summary

Introduction

Infectious bursal disease (IBD) is an acute and highly contagious disease of chicks, and the clinical impact of IBD is mainly attributed to its severe immunosuppression especially in young chickens. The IBDV infection targets and annihilates the precursors of antibody-producing B cells within the bursa of Fabricius (BF) [1]. The damages to the BF are permanent, resulting in vaccination failure and expanded defencelessness to other diseases [2].

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