Richard K. Hoop

Avian Bornaviruses in Psittacine Birds from Europe and Australia with Proventricular Dilatation Disease

Birds with this disease display bornaviral antigen in neural and extraneural tissues.

High resolution typing of Chlamydophila psittaci by multilocus VNTR analysis (MLVA)

A multilocus VNTR analysis (MLVA) system for detection of tandem repeats across the whole genome of Chlamydophila psittaci has been developed. Twenty selected genetic loci were initially tested on 9 avian reference strains including representatives of all major serotypes (A to F). Thereafter, 8 loci were retained for a more complete study performed on over 150 C. psittaci isolates from different bird species and geographical origins. Comparative analysis of the MLVA results and those obtained from currently available methods including serotyping and/or ompA sequencing indicate that the MLVA system provides an additional level of discrimination, with 20 distinct patterns identified to date. The newly developed MLVA system therefore provides a highly sensitive, high resolution test for the differentiation of C. psittaci isolates from different origins that is suitable for molecular epidemiological studies.

Mycobacterium tuberculosis Infection in a Canary (Serinus canaria L.) and a Blue-Fronted Amazon Parrot (Amazona amazona aestiva)

SUMMARY. I report two cases of mycobacteriosis in pet birds due to Mycobacterium tuberculosis and discuss the zoonotic implications. The canary with a tuberculous knot in the lung is the first description of M. tuberculosis in a nonpsittacine bird species.

Serological monitoring of 40 Swiss fancy breed poultry flocks

Rapid serum agglutination, haemagglutination inhibition and enzyme-linked immunosorbent assays were used to screen Swiss fancy breed chicken flocks for antibodies against 12 avian infectious agents. For this purpose, 1002 blood samples from 40 flocks were collected and tested. Ten percent of the samples were positive for Salmonella gallinarum-pullorum and 62.5% of the flocks were affected. More than 75% of the flocks had antibodies against Mycoplasma gallisepticum/Mycoplasma synoviae , infectious bronchitis, infectious bursal disease, avian encephalomyelitis, infectious chicken anaemia and reoviral arthritis. Low prevalence of antibodies was recorded for Salmonella enteritidis , avian influenza, avian leukosis and Newcastle disease (2.0 to 4.0%).

POSSIBLE HUMAN-AVIAN TRANSMISSION OF MYCOBACTERIUM TUBERCULOSIS IN A GREEN-WINGED MACAW (ARA CHLOROPTERA)

Abstract This report describes a case of Mycobacterium tuberculosis infection in a green-winged macaw (Ara chloroptera), confirmed by microbiologic and pathologic diagnostics, and notes a possible human–avian transmission. Clinical signs included cutaneous swellings, profound leukocytosis, and signs of osteomyelitis in the long bones. Proliferation consisted of several nodules with small greenish-caseous foci in cross-section and revealed a severe granulomatous inflammation with intralesional acid-fast rods. Mycobacterium tuberculosis was isolated from subcutaneous nodules and biochemically confirmed. The disease in avian species is of zoonotic importance.

Public health implications of exotic pet mycobacteriosis

The most common species of mycobacteria occurring in avian and exotic pet animals are as follows: Mycobacterium genavense and M avium-complex (MAC) in birds; MAC, M marinum, M chelonae, M fortuitum, M smegmatis , and M phlei in reptiles; M tuberculosis in nonhuman primates; and M fortuitum, M xenopi and M marinum in amphibians. Spontaneous mycobacteriosis in rabbits, gerbils, mice, hamsters, and guinea pigs is very rare and not associated with a specific mycobacterial species. M tuberculosis or M bovis , both known as zoonotic agents, play no important role in exotic pets. The public health significance of the other mycobacteria remains to be elucidated. Newly developed laboratory techniques such as media for fastidious mycobacteria, gene probes, and nucleic acid amplification methods will allow the identification and closer characterization of agents found in this group of animals.

THE 2005/2006 AVIAN INFLUENZA MONITORING OF WILD BIRDS AND COMMERCIAL POULTRY IN SWITZERLAND

Abstract In October 2005, the second Swiss national avian influenza monitoring in wild waterfowl and commercial poultry with free range management started. Cloacal swabs were examined by real-time reverse transcription-polymerase chain reaction for both M gene of influenza A virus and H5 subtype. The monitoring (more than 2000 samples tested) documented the introduction of H5N1 in Swiss wild waterfowl in mid-February 2006. Until the end of March, 29 water bird carcasses were found H5 positive. In the same period, domestic poultry flocks with a permit of free-range management were kept under surveillance, with negative results.

Prevalence of Chlamydophila psittaci in wild birds—potential risk for domestic poultry, pet birds, and public health?

To determine the prevalence of Chlamydophila psittaci in wild birds, cloacal swabs from 527 songbirds, 442 waterfowl, 84 feral pigeons, and 38 cormorants were examined by Chlamydiaceae-specific real-time polymerase chain reaction (PCR) and ArrayTube microarray assays for chlamydial species determination and genotyping of C. psittaci. Inconclusive cases were further characterized by conventional PCR methods targeting the chlamydial outer membrane protein A, 16S, 23S, and intergenic spacer genes followed by sequencing of the PCR product. Swabs of 19 water birds (tufted ducks and pochards), 12 pigeons, and one songbird were tested positive by the Chlamydiaceae-specific real-time PCR. While C. psittaci genotypes B (n = 5) and E (n = 1) were identified in feral pigeons (n = 9), the genotype could not be identified in the remaining three cases. Sequence data of Chlamydiaceae-positive cases (n = 23; 19 waterfowl, three pigeons, one songbird) indicated the presence of nonclassified chlamydial agents (n = 20) and C. psittaci (n = 3) by 16S rRNA PCR and sequencing. In conclusion, C. psittaci was not detected in waterfowl and songbirds, but C. psittaci proved prevalent in urban feral pigeons, where it poses a significant risk for humans.

Chlamydiae and Atherosclerosis: Can Psittacine Cases Support the Link?

Abstract Atherosclerosis is a common disease in pet birds, particularly in psittacines. Little is known about the role of risk factors predisposing birds to this disease. In our study, we tried to detect chlamydiae in formalin-fixed and paraffin-embedded atherosclerotic tissue from 103 pet birds to clarify their role in atherosclerosis. Methods used were polymerase chain reaction (PCR), sequencing, and immunohistochemistry. Histopathologic examination served to classify the extent of atherosclerotic lesions. In the PCR, 4 (3.9%) of 103 cases, all of them with advanced stages of atherosclerosis, were positive. Subsequent sequence analysis revealed high identities (94%–100%) with Chlamydophila psittaci in three cases. Interestingly, two of these birds came from C. psittaci–infected populations. Because of the low incidence (3.9%), the occurrence only in advanced stages, and the association with C. psittaci–infected avian populations, a causal relationship between chlamydiae and atherosclerosis in pet birds is rather improbable.

Humoral Immune Response to Avian Influenza Vaccination Over a Six-Month Period In Different Species of Captive Wild Birds

Abstract In December 2005, the four major Swiss zoos carried out the vaccination of selected zoo birds with the adjuvant inactivated vaccine H5N2 Nobilis influenza. Pre- and post-vaccination antibody titers were determined either by hemagglutination inhibition (HI) test (non-Galliformes) or by enzyme linked immunosorbent assay (ELISA) (Galliformes) at Week 0, 5, 10, and 26 (Day 0–1, 35–36, 70–71, and 182 respectively) to determine the humoral immune response to H5 antigen. After the first vaccination, the overall geometric mean titer of non-Galliformes was 65 (n = 142), which increased to 187 (n = 139) after booster vaccination and dropped to 74 (n = 65) six months after first vaccination. For the Galliformes group, the mean titers were found to be 2.09 at Week 5 (n = 119), 3.24 at Week 10 (n = 113), and 1.20 at Week 26 (n = 39). Within the non-Galliformes, significant differences in geometric mean titers were found among different species representatives. In general, the flamingos (Phoenicopteriformes) showed a strong response to vaccination, reaching a geometric mean titer of 659 at Week 10, while the Sphenisciformes did not show high antibody titers even after booster vaccination, reaching a maximum geometric mean titer of only 65. Based on the antibody titer profiles of all investigated species, we recommend at least annual revaccination for the species that we investigated.