Priscilla H. Joyner

Avian coronavirus in wild aquatic birds

ABSTRACT We detected a high prevalence (12.5%) of novel avian coronaviruses in aquatic wild birds. Phylogenetic analyses of these coronaviruses suggest that there is a diversity of gammacoronaviruses and deltacoronaviruses circulating in birds. Gammacoronaviruses were found predominantly in Anseriformes birds, whereas deltacoronaviruses could be detected in Ciconiiformes, Pelecaniformes, and Anseriformes birds in this study. We observed that there are frequent interspecies transmissions of gammacoronaviruses between duck species. In contrast, deltacoronaviruses may have more stringent host specificities. Our analysis of these avian viral and host mitochondrial DNA sequences also suggests that some, but not all, coronaviruses may have coevolved with birds from the same order.

West Nile virus in raptors from Virginia during 2003: clinical, diagnostic, and epidemiologic findings.

Sixty-one birds of prey admitted to The Wildlife Center of Virginia (WCV; Waynesboro, Virginia, USA) from June to November 2003 were tested for West Nile virus (WNV) infection. Choanal and/or cloacal swabs were obtained and submitted to Virginias Division of Consolidated Laboratory Services (Richmond, Virginia, USA) for analysis with real-time reverse transcriptase polymerase chain reaction (RT-PCR). Forty birds of prey were positive for WNV by RT-PCR. Five avian families and nine species of raptors were represented, with great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) most frequently affected. Presenting clinical signs were consistent with previous reports of WNV infection in raptors; however, these differed between species. Of WNV positive birds, nonspecific signs of illness were the most common clinical findings, particularly in red-tailed hawks; signs included dehydration (n=20), emaciation (n=18), and depression (n=15). Neurologic abnormalities were frequently identified, especially in great horned owls, and included head tremors (n=17), ataxia (n=13), head incoordination (n=7), torticollis (n=3), nystagmus (n=3), and head tilt (n=3). Great horned owls exhibited anemia and leukocytosis with heterophilia, eosinophilia, and monocytosis consistent with chronic inflammation. Red-tailed hawks were anemic with a heterophilic leukocytosis and regenerative left shift. The majority of WNV cases occurred during August and September; there was a marked increase in the number of raptors admittedto WCV during these months followed by a marked decrease during October, November, and December. This pattern differed from mean monthly admissions during the previous 10 years and suggests a negative impact on local raptor populations. The effects of WNV on avian populations are largely unknown; however, because of their ecological importance, further investigation of the effects of WNV on raptor populations is warranted.

Induction and recovery characteristics and cardiopulmonary effects of sevoflurane and isoflurane in bald eagles

OBJECTIVE To compare induction and recovery characteristics and cardiopulmonary effects of isoflurane and sevoflurane in bald eagles. Animals-17 healthy adult bald eagles. PROCEDURES Anesthesia was induced with isoflurane or sevoflurane delivered in oxygen via a facemask in a crossover design with 4 weeks between treatments. Eagles were intubated, allowed to breathe spontaneously, and instrumented for cardiopulmonary measurements. Time to induction, extubation, and recovery, as well as smoothness of recovery, were recorded. RESULTS Administration of sevoflurane resulted in a significantly quicker recovery, compared with isoflurane. Temperature, heart rate, and respiratory rate significantly decreased over time, whereas systolic (SAP), diastolic (DAP), and mean arterial blood pressure (MAP) significantly increased over time with each treatment. Temperature, heart rate, SAP, DAP, and MAP were significantly higher with isoflurane. Blood pH significantly decreased, whereas PaCO(2) significantly increased over time with each treatment. Bicarbonate and total carbon dioxide concentrations significantly increased over time with each treatment; however, there was a significant time-treatment interaction. The PaO(2) and arterial oxygen saturation increased over time with isoflurane and decreased over time with sevoflurane with a significant time-treatment interaction. Six eagles developed cardiac arrhythmias with isoflurane, as did 4 with sevoflurane anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE Isoflurane and sevoflurane administration resulted in smooth, rapid induction of and recovery from anesthesia similar to other species. Isoflurane administration resulted in tachycardia, hypertension, and more arrhythmias, compared with sevoflurane. Sevoflurane was associated with fewer adverse effects and may be particularly beneficial in compromised bald eagles.

A Novel Group of Avian Astroviruses in Wild Aquatic Birds

ABSTRACT Using a pan-astrovirus reverse transcription-PCR assay, a great diversity of novel avastroviruses was detected from wild bird and poultry samples. Two groups of astroviruses detected from wild birds are genetically related or highly similar to previously known viruses in poultry. Most interestingly, a novel group of astroviruses was detected in wild aquatic birds. Our results also reveal that different groups of astroviruses might have difference host ranges. This study has expanded our understanding regarding avastrovirus ecology.

Phaeohyphomycosis in a Free-Living Eastern Box Turtle (Terrapene carolina carolina)

A free-ranging eastern box turtle (Terrapene carolina carolina) was referred to the Wildlife Center of Virginia with a three-month history of marked swelling of the right hind limb initially diagnosed as chromomycosis by histopathology. Hematology revealed severe anemia (9%), leukocytosis (12.8 cells×103/μl), heterophilia (6.14 cells×103/μl), and monocytosis (0.51 cells×103/μl). Gross necropsy revealed a firm, encapsulated 3×1 cm subcutaneous mass filled with dark brown-black, friable necrotic material of the distal right hind limb. Microscopically, the mass was characterized by a granulomatous inflammatory process with numerous multinucleated histiocytic giant cells. Fungal elements were present within necrotic centers and associated with multinucleated cells. Special stains revealed numerous phaeoid hyphae and yeast; Exophiala jeanselmei was isolated by routine mycologic culture. Phaeohyphomycosis was diagnosed based on the histologic appearance of the fungal elements within the mass and culture results. There was no histopathological evidence of systemic infection. This is the first report of phaeohyphomycosis caused by fungi of the genus Exophiala in free-living reptiles.

Characterization of the Bacterial Microflora of the Tympanic Cavity of Eastern Box Turtles With and Without Aural Abscesses

Aerobic bacterial cultures of the tympanic cavity of the middle ear were performed in eight eastern box turtles (Terrapene carolina carolina) with aural abscesses and 15 eastern box turtles without aural abscesses (controls) that were admitted to The Wildlife Center of Virginia, Virginia, USA during 2003. Twenty-two bacterial isolates were identified from 17 turtles including 10 gram-negative and 12 gram-positive bacteria. Ten of 15 control animals had bacterial growth, resulting in identification of 13 bacteria, including six gram-negative and seven gram-positive agents. Seven of eight turtles with aural abscesses had bacterial growth, and 10 isolates were identified, including four gram-negative and six gram-positive organisms. The most frequently isolated bacteria from control animals were Micrococcus luteus (n=3) and Pantoea agglomerans (n=2). Morganella morganii (n=2) was the only species isolated from the tympanic cavity of more than one turtle with aural abscesses. Staphylococcus epidermidis (n=2) was the only species isolated from both groups. A trend toward greater bacterial growth in tympanic cavities of affected turtles compared with turtles without aural abscesses was noted. No single bacterial agent was responsible for aural abscesses in free-ranging eastern box turtles in this study, an observation consistent with the hypothesis that aerobic bacteria are not primary pathogens, but secondary opportunistic invaders of environmental origin.

Detection of a novel astrovirus from a black-naped monarch (Hypothymis azurea) in Cambodia

BackgroundAstroviruses are comprised of two genera with Avastrovirus infecting birds and Mamastrovirus infecting mammals. Avastroviruses have primarily been associated with infections of poultry, especially chicken, turkey, duck, and guineafowl production systems, but also infect wading birds and doves. Outcomes result in a spectrum of disease, ranging from asymptomatic shedding to gastroenteritis with diarrhea, stunting, failure to thrive and death.FindingsVirological surveillance was conducted in birds from two sites in Cambodia in 2010. Samples were screened for influenza, astroviruses, coronaviruses, flaviviruses, and paramyxoviruses. A total of 199 birds were tested and an astrovirus was detected in a black-naped monarch (Hypothymis azurea).ConclusionsThis is the first astrovirus detection in a passerine bird. Phylogenetic analysis and nucleotide distances suggest that this avastrovirus forms a distinct lineage and may constitute a fourth avastrovirus group.

INABILITY TO INDUCE TYMPANIC SQUAMOUS METAPLASIA USING ORGANOCHLORINE COMPOUNDS IN VITAMIN A-DEFICIENT RED-EARED SLIDERS (TRACHEMYS SCRIPTA ELEGANS)

Previously, we reported that wild eastern box turtles (Terrapene carolina carolina) with aural abscesses contained higher body burdens of organochlorine (OC) compounds than those without the lesion. This lesion in captive chelonians is associated with turtles that are fed diets deficient in vitamin A. To examine the pathophysiology of this lesion and evaluate the relationship between OC burdens and vitamin A metabolism, we maintained red-eared sliders (Trachemys scripta elegans) under different conditions of OC exposure and dietary vitamin A concentrations from August 2005 to February 2006. Dietary vitamin A concentration (0 or 5 international units/g in the diet) and OC exposure (no OC compound or the mixture of 2 mg/kg chlordane, 0.25 mg/kg aroclor, and 1 mg/kg lindane) did not affect histologic score based on degree of squamous metaplasia of the tympanic epithelium or levels of plasma or liver vitamin A among the study groups. The results of this study suggest that 6 mo of exposure to the selected OC compounds, or similar duration of reduced dietary vitamin A concentrations do not influence the formation of squamous metaplasia and aural abscesses in red-eared sliders. Further studies are required to determine whether the duration of the experiment was insufficient, the OC compounds selected were inappropriate, the dosing was incorrect, and whether there are other unknown mechanisms causing the reported association between OC exposure and aural abscesses seen in eastern box turtles.