Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, OH 44691, USA.
Prev Vet Med. 2010 Oct 1;97(1):45-50. doi: 10.1016/j.prevetmed.2010.07.010.
The presence of infectious bursal disease virus (IBDV) in broilers entering processing plants was examined. The dissemination of IBDV and the introduction of non-native strains for example very virulent (vv) IBDV have had a negative economic impact on poultry production in many countries. Restrictions have been placed on the import and export of poultry products by some countries. There is a perceived risk that IBDV can be spread through transportation and contamination of processing equipment, poultry protein products and processing plant personnel. This risk, however, is fundamentally unknown because scientific studies have not been conducted on the presence of IBDV in birds entering processing plants or the variables that may affect this risk during and post-harvest. The goal of this study was to determine if infectious IBDV was present in broilers entering processing plants. A total of 47 pooled bursa samples from 26 processing plants in the Eastern U.S. were examined. Molecular testing indicated that an IBDV specific RT-PCR was positive in 12 (25.5%) of the samples from 11 different processing plants. Nucleotide sequence analysis was conducted on the 12 RT-PCR positive samples and indicated the IBDV was not commercially available attenuated vaccine strains. Most of the sequences were unique and a phylogenic analysis indicated they were most closely related to variant strains of IBDV. Five RT-PCR positive samples were selected at random for testing in specific-pathogen-free chickens. All five samples contained infectious IBDV as evidenced by macroscopic lesions and bursa/body weight ratios that were significantly lower in infected birds than in the non-inoculated controls. The five viruses were re-identified in bursa tissue from chickens in their respective groups at necropsy using RT-PCR and nucleotide sequencing. The results indicate that infectious and pathogenic IBDV are entering processing plants in this geographic region of the U.S. Additional studies are needed on post-harvest variables that could increase or decrease the risk that these viruses are being disseminated during this process.
本研究旨在确定进入加工厂的肉鸡中是否存在传染性法氏囊病病毒（IBDV）。从美国东部的 26 家加工厂采集了 47 份鸡法氏囊混合样本。分子检测结果显示，11 家不同加工厂的 12 份样本的 IBDV 特定 RT-PCR 检测结果呈阳性。对 12 份 RT-PCR 阳性样本进行核苷酸序列分析表明，IBDV 不是市售的减毒疫苗株。大多数序列是独特的，系统发育分析表明它们与 IBDV 的变异株最为密切相关。随机选择了 5 份 RT-PCR 阳性样本，用于无特定病原体鸡的检测。所有 5 份样本均含有传染性 IBDV，感染鸡的法氏囊/体重比明显低于未接种对照组。在剖检时，使用 RT-PCR 和核苷酸序列分析，从各自组别的鸡的法氏囊组织中重新鉴定了这 5 种病毒。结果表明，传染性和致病性 IBDV 正在进入美国这一地理区域的加工厂。需要进一步研究收获后变量，这些变量可能会增加或降低这些病毒在加工过程中传播的风险。
