Beak and feather disease virus in wild and captive parrots: an analysis of geographic and taxonomic distribution and methodological trends.

Deborah J Fogell,Jim J Groombridge,Rowan O Martin

doi:10.1007/s00705-016-2871-2

Abstract

Psittacine beak and feather disease (PBFD) has emerged in recent years as a major threat to wild parrot populations and is an increasing concern to aviculturists and managers of captive populations. Pathological and serological tests for screening for the presence of beak and feather disease virus (BFDV) are a critical component of efforts to manage the disease and of epidemiological studies. Since the disease was first reported in the mid-1970s, screening for BFDV has been conducted in numerous wild and captive populations. However, at present, there is no current and readily accessible synthesis of screening efforts and their results. Here, we consolidate information collected from 83 PBFD- and BFDV-based publications on the primary screening methods being used and identify important knowledge gaps regarding potential global disease hotspots. We present trends in research intensity in this field and critically discuss advances in screening techniques and their applications to both aviculture and to the management of threatened wild populations. Finally, we provide an overview of estimates of BFDV prevalence in captive and wild flocks alongside a complete list of all psittacine species in which the virus has been confirmed. Our evaluation highlights the need for standardised diagnostic tests and more emphasis on studies of wild populations, particularly in view of the intrinsic connection between global trade in companion birds and the spread of novel BFDV strains into wild populations. Increased emphasis should be placed on the screening of captive and wild parrot populations within their countries of origin across the Americas, Africa and Asia.

Highlights

Pathogens responsible for emerging infectious diseases (EIDs) have become a major concern in conservation biology owing to their potential for rapid evolution and the effect that an epidemic may have on vulnerable species [1]
There has been a linear increase in the number of publications involving testing for beak and feather disease virus (BFDV) since the first scientific description of Psittacine beak and feather disease (PBFD) (Fig. 1, R2 = 0.96), with the total number of screening-based publications reaching 83 by July 2015
Research has been focused predominantly on captive populations, encompassing 33 different countries, with the highest number of specimens originating from the United States of America (USA), followed by South Africa, Australia and Japan (Fig. 2)

Summary

Introduction

Pathogens responsible for emerging infectious diseases (EIDs) have become a major concern in conservation biology owing to their potential for rapid evolution and the effect that an epidemic may have on vulnerable species [1]. Psittacine beak and feather disease (PBFD) has been detected in both wild and captive parrot populations since the mid-1970s. Most commonly affecting immature and fledgling birds, classical symptoms include symmetrical loss of contour, tail and down feathers and subsequent replacement by dystrophic and necrotic feathers that fail to grow soon after emergence from the follicle [7,8,9]. Beak deformities such as fractures, abnormal elongation and palatine necrosis are typical symptoms of PBFD, but their presence and severity vary from species to species [10]. Other clinical symptoms include lethargy, depression, diarrhoea and immunosuppression, which are individually variable, sometimes lead to death, and may depend on the virulence of the viral strain or the route of viral exposure [11]

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