中文摘要：

为了解2008年1月～2012年6月山东胶东青岛、潍坊和烟台三地区新城疫病毒（NDV）、传染性支气管炎病毒（IBV）和H9亚型禽流感病毒（AIV（H9））的感染情况，采用RT—PCR对送检的5001份患有呼吸道症状的病料进行了检测。结果显示，3地区3种病毒的总阳性率为48．49％，其中AIV（H9）感染率最高，为26．15％。青岛地区NDV和IBV的阳性率均最高，分别为15．94％和11．63％，潍坊地区AIV（H9）阳性率最高（29．23％）。4年半间AIV（Hg）感染下降明显，但NDV近3年感染明显抬头。寒冷月份3种病毒感染较高，3月份NDV和AIV（H9）阳性率均最高，分别为21．07％和38．17％；10月份1BV阳性率最高为15．40％。3种病毒混合感染阳性率为6．66oA，以NDV＋AIV（H9）二重感染最常见（2．98％），NDV＋IBV＋AIV（H9）三重感染为0．40％。结果表明，山东胶东地区NDV、IBV和AIV（Hg）的感染情况较普遍，存在一定程度的混合感染，为有效防控山东省规模鸡场该3种主要疾病提供了依据。

英文摘要：

To investigate NDV, IBV and AIV（H9） infection, 5001 suspicious samples collected from large-scale chicken farms in Weifang, Qingdao and Yantai district were detected by RT-PCR during 2008. 01~2012.06. The results showed that the positive rates of three viruses was up to 48.49% totally with the highest positive rate of AIV（H9）（26.15%）. The positive rates of NDV（15.94%） and IBV（ll. 63%） were both highest in Qingdao and the positive rate of AIV（H9）（29.23 %） was highest in Weifang. The in- fection of AIV（H9） decreased significantly during the last four and a half years, but the NDV infection rose clearly in the past three years. Three virus infections were higher in the cold months. In March the highest positive rates of NDV and AIV （H9） were 21.07% and 38. 17%, respectively. In October the highest positive rate of IBV was 15.40%. Chickens co-infected with viruses accounted for 6.66 %. The du- al infection of NDV＋AIV（H9）（2.98%） was most serious and the triple infection of NDV＋IBV＋AIV （H9） was 0.40%. The results demonstrated that NDV, IBV and AIV（H9） were prevalent in the commer- cial chickens in Jiao-dong District. The investigation can offer the evidence to prevent and control these diseases in Shandong Province.