Molecular characterisation of beak and feather disease virus (BFDV) in New Zealand and its implications for managing an infectious disease

Abstract

Beak and feather disease virus (BFDV) infections are often fatal to both captive and wild parrot populations. Its recent discovery in a wild population of native red-fronted parakeets has raised concerns for the conservation of native parrots, all of which are threatened or endangered. The question of a recent introduction versus a native genotype of the virus poses different conservation-management challenges, and thus, a clear understanding of the molecular phylogeny of BDFV is a crucial step towards integrated management planning. This study represents the first comprehensive attempt to screen New Zealand's endangered and threatened psittacines systematically for BFDV. We sampled and screened kakapos (Strigops habroptilus), kakas (Nestor meridionalis), keas (N. notabilis), Chatham parakeets (Cyanoramphus forbesi), Malherbe's parakeets (Cyanoramphus malherbi), yellow-crowned parakeets (C. auriceps) and red-fronted parakeets (Cyanoramphus novaezelandiae), as well as eastern rosellas (Platycercus eximius), an introduced species that is now common throughout the North Island, for BFDV. Out of all species and populations sampled (786 individuals), we found 16 BFDV-positive red-fronted parakeets from Little Barrier Island/Hauturu, seven eastern rosellas from the Auckland region, and eight yellow-crowned parakeets from the Eglinton Valley in the South Island. The full genomes of the viral isolates from the red-fronted parakeets share 95-97 % sequence identity to those from the invasive eastern rosellas and 92.7-93.4 % to those isolates from the South Island yellow-crowned parakeets. The yellow-crowned parakeet BFDV isolates share 92-94 % sequence identity with those from eastern rosellas. The low level of diversity among all BFDV isolates from red-fronted parakeets could suggest a more recent infection among these birds compared to the yellow-crowned parakeets, whereas the diversity in the eastern rosellas indicates a much more established infection. Pro-active screening and monitoring of BFDV infection rates in aviaries as well as in wild populations are necessary to limit the risk of transmission among threatened and endangered parrot populations in New Zealand.

Evidence of Psittacine Beak and Feather Disease Virus Spillover Into Wild Critically Endangered Orange-Bellied Parrots (Neophema Chrysogaster)

“…The species has been observed reusing nest hollows (Stojanovic et al, 2012) when flowering conditions are favorable. It is not surprising that PBFD infects birds through shared nest hollows, for although a degree of host specificity is seen in psittacine circoviruses, considerable host generalism is also observed in several lineages (Varsani et al, 2011;Kundu et al, 2012;Massaro et al, 2012). Furthermore, the likely prolonged environmental persistence of circovirus virions (Raidal and Cross, 1994;Yilmaz and Kaleta, 2004) provides a mechanism by which transmission can occur in otherwise ecologically disconnected species.…”

“…Like RNA and other ssDNA viruses, BFDV is prone to a high rate of genetic mutation, although the Rep gene is relatively conserved, which conveniently assists with diagnosing infection by PCR detection methods (Ypelaar et al, 1999). Within Psittaciformes, BFDV exhibits quasispecies characteristics with emerging geographic or host specificity demonstrable within various clades (Varsani et al, 2011) and the observed occurrence of closely related clades in highly divergent parrot species is evidence of host switching or host generalism in several BFDV lineages (Varsani et al, 2011;Julian et al, 2012;Kundu et al, 2012;Massaro et al, 2012).…”

Phylogenetic analysis of beak and feather disease virus across a host ring-species complex

“…Fig. S1 shows that P. elegans BFDV isolates branch out from all other Australian endemic species and that they show a common ancestor with BFDV isolates from Platycercus eximius that were introduced into New Zealand (35). One exception is the presence of a BFDV isolated from Calyptorhynchus lathami, an endangered species that was in captivity.…”

Long Antibody Persistence and Transgenerational Transfer of Immunity in a Long-Lived Vertebrate

“…In addition to mortality generated directly and indirectly by human activities (Lewison et al 2004;Le Bohec et al 2008), several disease outbreaks are potentially threatening many species (Rolland et al 2009;Descamps et al 2012;Massaro et al 2012). Long-lived organisms are characterized by delayed maturities, low reproductive rates, and high adult survival.…”