中文摘要：

为了解鸡传染性贫血病毒（CAV）、禽网状内皮增生病病毒（REV）和呼肠孤病毒（REOV）在我国白羽肉用型鸡中的感染状态，在2003—2004年，检测了来自5省市8个公司不同年龄鸡群血清样品中3种病毒抗体的存在状况。结果表明，在送检的75个鸡群中，对CAV、REV和REOV呈现抗体阳性的鸡群分别有64个（85．3％）、36个（48％）和74个（96％）。在总共检测的1764份血清样品中，对这3种病毒的平均抗体阳性率分别为51．4％、9．8％和75．1％。在1日龄雏鸡，对CAV和REOV的平均母源抗体阳性率可达100％和81．1％，但对REV只有7．4％。抗体阳性率随年龄变化的动态分析表明，对REV和REOV的母源抗体在出壳后2～3周内消失，而对CAV的母源抗体则可持续3～4周。对CAV和REOV的抗体从5周龄起再次出现，到20周龄时，所有送检鸡群全部阳性，平均阳性率在90％以上。有近一半送检鸡群对REV呈现抗体阳性，抗体阳性率普遍较低，即使在达到开产年龄后，仍还有很高比例鸡为抗体阴性，即对REV仍为易感鸡。研究表明，我国多数鸡群中都同时存在着这3种病毒的感染，但它们在感染的程度和动态等流行病学特点上显著不同，应根据鸡群中抗体的阳性率分别采取不同的措施。

英文摘要：

To explore current infection statuses of chicken anemia virus （CAV）, avian reticuloendotheliosis virus （REV） and avian reovirus （REOV） in white meat-type chicken flocks in China, antibodies to the 3 viruses were tested based on serum samples that collected from meat-type chickens at different ages of 8 companies in 5 provinces during 2003-2004. Among the 75 flocks, 64（85.3%） , 36（48%） and 74（96%） flocks were positive in antibody tests to CAV, REV and REOV respectively. Of total tested 1 764 serum samples, the positive rates to CAV9 REV and REOV were 51.4%, 9.8% and 75.1%. Of serum samples from 1-day-old chicks, the maternal antibody positive rates to CAV and REOV were as high as 100% and 81.1%, but only 7.5% to REV. Analysis of the kinetics in antibody positive rates with the ages indicated that maternal antibodies to REV and REOV disappeared in 2- 3 weeks, but maternal antibody to CAV could last for 3-4 weeks. Then antibodies to CAV and REOV started to be positive again from 5 weeks old, all tested flocks became positive with average positive rates exceed 90% at the age of 20 weeks . There were only half flocks were positive with antibodies to REV, and high percentages of birds were still negative to REV antibody in the positive flocks even after sexually maturity. The results indicated that co-infection of the 3 viruses existed commonly in chicken flocks in China, but some epidemiological characteristics such as extensity and kinetics of the infections were quite different for 3 viruses. Different preventive measurements should be carried out based on the antibody positive rates for the 3 different viruses.