Chvala S, Bakonyi T, Hackl R, Hess M, Nowotny N, Weissenböck H
Department of Pathobiology, Institute of Pathology and Forensic Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
J Vet Med B Infect Dis Vet Public Health. 2006 May;53(4):171-5. doi: 10.1111/j.1439-0450.2006.00942.x.
Usutu virus (USUV) is a mosquito-borne flavivirus of the Japanese encephalitis virus group, which has been associated with avian mortality in Austria since 2001. The affected birds are predominantly Eurasian blackbirds (Turdus merula). In the present study, the pathogenicity of USUV for domestic geese (Anser anser f. domestica) was investigated. Eleven 2-week-old geese were inoculated intramuscularly with 5 x 10(4) 50% tissue culture infectious dose of USUV strain Vienna-2001 blackbird. No clinical signs were seen during the observation period. Four inoculated and one in-contact geese died without preceding clinical signs. Two of the deaths could be attributed to bacterial septicaemia and strangulation, respectively. The cause of death of two experimental and one in-contact animals remained unclear, but lack of evidence for viral lesions and viral antigen in their tissues argued against association with the USUV infection. Although in organs of the majority of inoculated geese (9/11) USUV was detected by reverse transcriptase-polymerase chain reaction, immunohistochemistry for USUV antigen was negative in all tissues of all geese. Evidence of plasma viraemia or viral excretion was found in one goose only. Seroconversion was detected in three inoculated geese 10 days post-inoculation. Geese placed in contact with inoculated geese and control animals did not exhibit USUV in their internal organs or plasma and lacked USUV-specific antibodies. This experiment shows that USUV is able to replicate in geese, but does not induce clinical disease, is unlikely to induce mortality, and only infrequently leads to viraemia or virus shedding.
乌苏图病毒（USUV）是一种由蚊子传播的乙型脑炎病毒属黄病毒，自2001年以来在奥地利与鸟类死亡有关。受影响的鸟类主要是欧亚黑鹂（乌鸫）。在本研究中，调查了USUV对家鹅（Anser anser f. domestica）的致病性。给11只2周龄的鹅肌肉注射5×10⁴ 50%组织培养感染剂量的USUV维也纳-2001黑鹂毒株。在观察期内未观察到临床症状。4只接种的鹅和1只接触的鹅未出现前驱临床症状而死亡。其中两例死亡分别归因于细菌性败血症和窒息。两只实验动物和一只接触动物的死亡原因仍不清楚，但在它们的组织中缺乏病毒损伤和病毒抗原的证据，这表明与USUV感染无关。尽管通过逆转录聚合酶链反应在大多数接种鹅（9/11）的器官中检测到了USUV，但所有鹅的所有组织中USUV抗原的免疫组织化学检测均为阴性。仅在一只鹅中发现了血浆病毒血症或病毒排泄的证据。接种后10天在三只接种的鹅中检测到血清转化。与接种鹅和对照动物接触的鹅在其内脏器官或血浆中未检测到USUV，也缺乏USUV特异性抗体。该实验表明，USUV能够在鹅体内复制，但不会诱发临床疾病，不太可能导致死亡，且很少导致病毒血症或病毒脱落。
