Pathogenicity and antigenicity of an American avian pneumovirus.

摘要

Turkey poults were used to study the pathogenicity, antigenicity, and transmissibility of an American avian pneumovirus (APV). The poults were inoculated with APV alone or in combination with Bordetella avium. In the dually infected group, there were more sever clinical signs, the virus persisted longer, the bacteria invaded more respiratory tissues, and the birds had higher antibody titer than the group exposed to APV or B. avium alone. The distribution of APV in different tissues was studied. Only samples from sinuses, tracheas, and lungs were positive for APV. The ability of APV to spread among birds was studied. The APV was isolated and the viral RNA was detected in inoculated and directed contact birds. The APV was not isolated, viral RNA was not detected, and no antibodies were detected in the indirect contact birds.; Virus neutralization (VN) test and two different whole virus enzyme linked immunosorbent assays (ELISA), developed in Ohio (OH) and Minnesota (MN) using two different viruses were used to test 270 turkey serum samples from MN, and 77 and 128 serum samples from turkey and ostrich, respectively, from OH. None of the turkey or ostrich samples had antibodies to APV. For the MN samples, 107,115 and 120 were positive using the VN test, the OH ELISA, and the MN ELISA, respectively. The Kappa value of 0.938 and 0.825 showed excellent agreement between the VN test and the OH ELISA and the MN ELISA, respectively. The ELISA and the MN ELISA had a sensitivity of 1.0 and 0.953, specificity of 0.950 and 0.889 and accuracy of 0.970 and 0.914, respectively. Our results indicate that the three methods are sensitive and specific for diagnosis of the APV infection.; The antigenic relationships between APV and four avian paramyxoviruses (PMVs) (PMV-1, PMV-2, PMV-3, and PMV-7) were studied. All the viruses were isolated in the USA or Canada. No antigenic relationships between APV and the PMVs were detected.