Laboratório Nacional Agropecuário, Ministério da Agricultura, Pecuária e Abastecimento , Campinas, SP , Brasil ; Faculdade de Ciências Médicas, Universidade Estadual de Campinas , Campinas, SP , Brasil.
Braz J Microbiol. 2010 Apr;41(2):349-57. doi: 10.1590/S1517-838220100002000014. Epub 2010 Jun 1.
This study was carried out during 2002/2003, aiming to determine the prevalence of virulent Newcastle disease virus strains (NDV) in Brazilian commercial poultry farms. Clinical samples were obtained from the Southeastern, Southern and Central-Western regions, which comprise the main area of the Brazilian poultry production. Serum samples and tracheal and cloacal swabs of 23,745 broiler chickens from 1,583 flocks, including both vaccinated chickens and those with no vaccination information, were tested for NDV using a diagnostic ELISA kit. The seropositivity was 39.1%, and the isolation percentage by flock varied from 1.0 to 7.6%, and by region from 6.5 to 58.4%. Higher isolation rates (74.3-83.3%) were obtained after three passages in embryonated chicken eggs. All isolates preliminarily identified as NDV were characterized as nonpathogenic strains, as their Intracerebral Pathogenicity Index (ICPI) was below 0.7. Based on results of this study, Brazil can claim a virulent NDV-free status for commercial flocks.
这项研究于 2002/2003 年进行，旨在确定巴西商业家禽养殖场中强毒新城疫病毒（NDV）的流行情况。从东南部、南部和中西部地区采集临床样本，这些地区构成了巴西家禽生产的主要区域。使用诊断 ELISA 试剂盒检测了来自 1583 个鸡群的 23745 只肉鸡的血清样本以及气管和泄殖腔拭子，这些鸡群包括接种疫苗的鸡和没有接种疫苗信息的鸡。NDV 的血清阳性率为 39.1%，鸡群的分离率从 1.0%到 7.6%不等，地区的分离率从 6.5%到 58.4%不等。在鸡胚中连续传代 3 次后，获得了更高的分离率（74.3-83.3%）。所有初步鉴定为 NDV 的分离株均为非致病性株，因为它们的脑内致病指数（ICPI）低于 0.7。基于这项研究的结果，巴西可以声称商业鸡群中没有强毒 NDV。
