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

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.

Genotyping and Molecular Characterization of Infectious Bursal Disease Virus Identified in Important Poultry-Raising Areas of China During 2019 and 2020

“…Indeed, recent studies have shown that when IBDV strains of two genotypes co-infect the same cell, their respective viral replication factories co-accumulate, thereby providing an opportunity for segment reassortment among the different genotypes ( 40 ). Recent studies have shown that wild birds can act as carriers of IBDV to transmit the virus to chickens ( 41 , 42 ), which might increase the risk of chickens infecting multiple genotypes of IBDV.…”

Infectious bursal disease virus in free‐living wild birds: A systematic review and meta‐analysis of its sero‐viroprevalence on a global scale

“…Naggar et al. (2020) and Jeon et al. (2008) both attempted viral isolation via chorioallantonic membrane (CAM) inoculation of embryonated specific pathogen free (SPF) chicken eggs.…”

“…Whereas the CAM harvested material in Naggar et al. (2020) was confirmed of IBDV isolation through a real‐time quantitative RT‐PCR (qRT‐PCR), Jeon et al. (2008) used both RT‐PCR and agar gel immunoprecipitation test (AGP) for confirmation.…”

“…According to sequence analyses, wild bird isolates of IBDVs are closely related to IBDV genogroup 3 strains (Jeon et al., 2008; Kasanga et al., 2008; Naggar et al., 2020) or IBDV genogroup 1 strains (Naggar et al., 2020), suggesting epidemiological links between domestic chicken and wild birds. Unique aminoacidic residues found in the VP2 hypervariable region (HVR) of some isolates also indicates that IBDV can undergo mutational changes in the wild hosts (Kasanga et al., 2008; Naggar et al., 2020). Furthermore, wild birds might harbour strains that could eventually reassort with poultry ones leading to the emergence of novel IBDV outbreaks in the future.…”

“…Regarding the technique applied, the RT-PCR or RT nested PCR assays were used as a screening method in all the studies. Primers and genes amplified are listed in Table6 Naggar et al (2020). and Jeon et al (2008) both attempted viral isolation via chorioallantonic membrane (CAM) inoculation of embryonated specific pathogen free (SPF) chicken eggs.…”