| Chicken infection anemia(Chicken infection anemia,CIA)is caused by the Circovirus families chicken infectious anemia virus(chicken infectious anemia virus,CIAV),Chicken is the only natural host of CIAV,Chickens of all ages are susceptible and widespread in the flock.With the age increases,their susceptibility,morbidity and mortality gradually decrease.The chicken infectious anemia virus was first isolated by Yuasa et al In 1979,and now pandemic all over the world,this disease has been on a rising trend and has become one of the major diseases present serious harm to the poultry industry.CIAV antibodies were detected by enzyme-linked immunosorbent assay(ELISA)in this research,,a sero-epidemiological surey of Chicken Infectious Anemia from Jiangsu Province was systematically investigated,and the pathogens were isolated and identified.1.The survey of chicken infectious anemia(CIA)in various regions of jiangsu provinceThe Multi-stage random sampling method was used to collect blood samples from 191 chicken farms in 50 different cities and counties of Jiangsu Province from 2012.9 to 2014.8.A total of 5152 samples were collected.At the same time,the age,species,and farm conditions of the chickens were recorded in detail.The positive rate of CAV was determined by enzyme linked immunosorbent assay(ELISA),The results showed that there were 1643 positive chickens serum samples and the positive rate was 31.89%.Among them,the positive rates of serum antibodies in Pukou,Jiangning and Liuhe of Nanjing were 16.30%,18.48%,and 23.91%;the positive rates of serum antibodies in Binhu and Yixing of Wuxi were 19.57%and 20.65%;the positive rates of serum antibodies in Xinyi,Pizhou,Fengxian,Peixian and Suining of Xuzhou were 33.70%,31.52%,29.35%,32.61%and 29.35%;the positive rates of serum antibodies in Xinbei,Wujin and Liyang of Changzhou were 20.65%,19.57%and 20.65%;the positive rates of serum antibodies in Gusu and Zhangjiagang of Suzhou were 19.57%and 16.30%;the positive rates of serum antibodies in Qidong,Haimen,Haian,Rudong and Rugao of Nantong were 21.74%,10.87%,30.43%,22.83%and 23.91%;the positive rates of serum antibodies in Ganyu,Guanyun,Donghai and Guannan of Lianyungang were 29.35%,18.48%,27.17%and 17.39%;the positive rates of serum antibodies in Huaian,Lianshui and Xuyi of Huaian were 23.91%,21.74%and 20.65%;the positive rates of serum antibodies in Jianhu,Binhai,Dafeng,Sheyang,Funing and Dongtai of Yancheng were 20.65%,32.61%,27.17%,53.26%,35.87%and 22.83%;the positive rates of serum antibodies in Jiangdu,Zhengyi,Baoying and Gaoyou of Yangzhou were 20.65%,19.57%,23.91%and 19.57%;the positive rates of serum antibodies in Dantu,Danyang,Yangzhong and Jurong of Zhenjiang were 20.65%,19.57%,21.74%and 22.83%;the positive rates of serum antibodies in Hailing,Gaogang,Jiangyan,Taixing,Jingjiang and Xinghua of Taizhou were 78.26%,66.85%,69.02%,54.89%,43.48%and 53.80%;the positive rates of serum antibodies in Suyang,Siyang and Sihong of Suqian were 21.74%,20.65%and 29.35%;respectively.It shows that chicken infectious anemia virus infection is common in 13 regions of Jiangsu.The results of this sero-epidemiological survey provided a scientific basis for prevention and control of the disease.2.The relationship between the positive rate and age of chicken infectious anemia(CIA)Through the analysis of serum samples,536 serum samples were collected from Chickens less than 30 days old,76 of which were positive(positive rate was 14.18%);1372 serum samples were collected from 30-140 days old chicken,293 of which were positive(positive rate was 21.36%);1772 serum samples were collected from 141-240 days old chicken,642 of which were positive(positive rate was 36.23%);1472 serum samples were collected from Chickens more than 240 days old,633 of which were positive(positive rate was 43%).The results showed that The antibody positivity of CAV was closely related to age in Jiangsu Province;in Chickens of different ages,the positive rate of serum antibodies was a significant difference;With the increase of age,the infection rate was significantly higher.The result showed that CIAV may infect chickens through horizontal and vertical transmission.3.The relationship between the positive rate of chicken infectious anemia(CIA)and the variety of chickenThis study collected serum samples from 9 breeds of chicken,analyzed the relationship between positive rates and breeds,the positive rate of antibody of Wolf Mountain Chicken,Highland Chicken,Jinghong 1,Nongda 3,Silky Chicken,Three Yellow Chicken,AA Chicken,Avian Broiler,Yellow Feather Chicken,Local Chicken was respectively 17.73%(159/897)、29.89%(200/669)、31.67%(165/521)、28.57%(172/602)、19.61%(20/102)、38.72%(290/749)、38.36%(206/537)、43.03%(213/495)、37.59%(218/580).982 serum samples were collected from Egg breeder,241 of which were positive(positive rate was 24.54%);1707 serum samples were collected from Product layer chicken,455 of which were positive(positive rate was 26.65%);1022 serum samples were collected from Meat breeders,398 of which were positive(positive rate was 38.94%);1441 serum samples were collected from Commercial broiler,549 of which were positive(positive rate was 38.10%).The result showed that Chicken infectious anemia virus infected different breeds of chicken in Jiangsu,The positive rate of broiler chickens is higher than that of egg chickens.4.Isolation and identification of chicken infectious anemia virusFive groups of chickens were selected from a positive rate of 90%to 95.24%for chicken anemia virus antibody,the 24 chickens were randomly collected from 10-50 days old different breeds with slow growth,hypogenetic,emaciate,anemia and Low antibody titer,Virus isolation and identification were carried out by using PCR,SPF virus isolation,MDCC-MBS1 cell virus isolation,immunofluorescence test,animal regression test,gene sequencing and other methods.The results show that,the suspected chicken emulsion vaccinated 1 day-old SPF chicks,the serum positive rate was 95.83%,the sample blood test HCT<27%,the number of hemoglobin,red blood cells and white blood cell count were lower than the control group,clinical symptoms and pathological autopsy as the typical pathological changes characteristics of chicken infection anemia.The SPF chicken tissue can be amplified to the target fragment by PCR.The SPF chicken tissue fluid inoculated into MSB1 cells,the cells died in the fifth generation,fluorescence microscopy showed irregular fluorescent particles in the test group and positive control group,After PCR detection,the recipient cells can be amplified to the target segment.SPF chickens were inoculated with virus cells,Clinical symptoms and pathological examination have typical pathological features of chicken infectious anemia.The isolated viral strain was named CAV MY1305-30(Taizhou strain),The genetic sequencing of this strain was 96.5%-99.8%with the nucleotide gene of the other 32 strains of CAV virus.The biological open reading frame(ORF)of VP1,VP2 and VP3 was compared singly,CAV MY1305-30 compared with the other 32 strains,the nucleotide homology was 95.7%,99.1%and 98.7%,the 32 strains that were compared with VP1 and VP2 were divided into two branches,each of which had the existence of strains in Asia and Europe,and there was no obvious geographical differentiation.It showed that the isolated virus strain was chicken infectious anemia virus,and the isolates had little variation. |
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