Molecular Diagnosis of Beak and Feather Disease in Native Brazilian Psittacines

Abstract

The incidence of the psittacine beak and feather disease virus (BFDV) was investigated in Brazilian native parrots with normal feathering arriving at rescue and triage centers for wild animals (CETAS, IBAMA) in the state of Minas Gerais, Brazil. BFDV DNA was investigated by previously described PCR technique for the partial amplification of BFDV ORF-1 in DNA extracts from blood, cloacal swab or liver of psittacines. Some birds provided more than one sample. Nine species of psittacines were sampled between January 2009 and October 2010. Blood (n=46) or cloacal swab (n=128) samples were obtained from psittacines immediately upon arrival at the triage centers. Liver samples were collected from necropsied birds dead on arrival (n=167). All swab samples were negative, except for one Ara ararauna individual (n=3) which blood presented the BFDV DNA. On the other hand, 11 liver samples were positive for BFDV DNA, with a prevalence of 7.8% in Amazona aestiva (n=140). No BFDV DNA was detected in the liver of Amazona amazonica (n=11), A. vinacea (n=5), A. rhodochorytha (n=4), Anodorhynchus hyacinthinus (n=3), Ara ararauna, (n=3), Aratinga leucophtalma (n=2), Guarouba guarouba (n=1) and Pionus maximiliani (n=1). In most cases, alopecia was not associated with BFDV detection in liver, and liver histopathology was inconclusive. Although all cloacal swab samples were negative, a few psittacines (n=19) that died at CETAS-Belo Horizonte were retested, and 21% were detected as positive in liver. A group of psittacines (n=16) was clinically evaluated, and despite showing feather dystrophy, all birds were negative in the cloacal swabs, except for one, which blood sample was positive (A. ararauna). The obtained sequences of the BFDV strains BH 215 and BH 732 were deposited in the GenBank (JQ649409 and JQ649410). A 98% similarity with strain sequences described in Australia, Japan, and New Zealand was observed. It is possible that these strains arrived in Brazil through the legal and illegal trade of parrots. However, it was not possible to associate BFDV infection with the geographical origin of birds and no local marker was detected. The rates of detection, although similar to other studies, indicate the tendency of a high incidence of the disease, possibly associated with stress, and high bird density and wide transmission in captivity conditions.

High Prevalence of Novel Beak and Feather Disease Virus in Sympatric Invasive Parakeets Introduced to Spain From Asia and South America

“…Positive samples for the virus only amplified with the primers reported by Ritchie et al [32], likely due to variations in viral copy numbers or mutations in the primer binding sites in some BFDV genotypes. However, several studies only focused on one primer set for BFDV screening [10,12,17], and thus may have underestimated the actual prevalence in these populations. Further research using different molecular markers is thus needed to increase the robustness of the BFDV diagnosis test.…”

“…To our knowledge, no surveillance of BFDV has been conducted on free-living parrots in South America, the other main stronghold for parrots. A screening conducted on captive individuals seized from illegal trade in Brazil showed evidence of BFDV at low prevalence in two native species [10]. The genomic similarity of the isolates with reference strains from Asia and Oceania suggested an exotic origin of BFDV strains disseminated in captivity in South America [10,11].…”

Molecular Survey of Pathogens in Wild Amazon Parrot Nestlings: Implications for Conservation

“…However, avipoxvirus outbreaks have been reported in captive native [15] and exotic [39] Psittaciformes in Brazil, showing low and high mortality rates, respectively. BFDV has been recently detected in captive exotic and native species [17,18] in Brazil. Based on the initial findings of the present study, it is likely that wild parrot populations can still be unreached by the global spread of BFDV [40].…”

“…A neglected virus in wild birds, the avipoxvirus, has also caused an outbreak in psittacine species located in a facility in Brazil [15]. In addition, the Psittacine Beak and Feather Disease (PBFD) caused by a circovirus, is an exotic pathogen introduced in the country [16], that has been reported in exotic and native pet birds [17,18].…”

Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

“…Co-workers who are veterinary practitioners and also work with captive birds, strictly refrained from contact with the above-mentioned facilities in the weeks before sampling. We considered these precautions mandatory, since parasites are common in captive birds, probably as an effect of captivity [ 86 , 89 – 91 ]. We took special precautions to avoid both the contamination of samples and spreading of disease into wild populations during sampling.…”