Epidemiology Investigation Of Three Kinds Avian Tumor Diseases In Shandong Province

The pathological of Avian leukosis(AL) Marek’s disease(MD) Avian reticuloendotheliosis(RE) is the occurrence of cancer in different organs affter the body inffected by the Avian Leukosis Virus(ALV)or Marker’s disease virus(MDV)or Reticuloendotheliosis Virus(REV). ALV main cause the different blood cells become cancerous,MDV is mainly cause the Lymphoproliferative tumor formation in the body,REV is mainly cause the body showed short stature syndrome or reticulum cell hyperplasia or Lymphoid tissue and other tissues proliferate and various manifestations of a pathological syndrome. The three diseases all can be transmitted.Shandong province as a major cultivation province in China, in order to understand for the epidemic characteristics of four virus which can cause three kinds tumor diseases and the infection situation of the three tumor diseases in shandong province since nearly three years,our research used ELISA, clinical diagnosis,observation of pathological histology,hematology analysis, virus separation and multiplex PCR detection means randomly checks12 cities in the province of 1 grandparent generation chicken farm, 11 parent generation chicken farms, 12 commercial generation chicken farms. Chicken varieties include broilers and layers and local broilers. We collected 1274 serum/cotton swabs and 111 chickens in total.Serological detection of AL showed that AL is common in shandong province, and all sorts of breeding chickens were infected, mainly exist in 4 states:(1)antibody positive and antigen negative(Ab +, Ag-) : 11.85%(151/1274), indicates this class fiocks body contains effective circulating antibodies which can inhibit virus growth and reproduction,it safer;(2)antibody negative and antigen positive(Ab-, Ag +) : 7.14%(91/1274), indicates this class flocks exist viremia and detoxify,they have the threat of horizontal spread of virus;(3)antibody positive and antigen positive(Ab +, Ag +) : 0.16%(2/1274), indicates the virus occur motation in body after infection,they have threat of flock but the rate of motation is not high.(4)antibody negative and antigen negative(Ab-, Ag-) : 80.85%(1030/1274),indicates the flock had notinfected by the virus,they are health. By acquisitions of 111 chickens clinical autopsy found that infected chicken clinical manifestations are mainly depressed of spirit, angular, white or green loose stool, the tumor pathological changes in the liver, spleen, kidney, glandular stomach mainly, in lungs, heart occasionally. Liver and spleen are mainly hyperplastic and swelling or have obvious tumor, glandular stomach is mainly hyperplastic and swelling.Hemangioma lesions which infected by ALV- J is not seen,it showed that in the body after virus infection, tumor spectrum had no significant change. Pathology histology detection of the organization from typical cases showed that viscera tumor cells composition were mainly lymphocytes, myelocyte and erythroblast. Haematology tests found that after infected by the virus, the number of white blood cells in the blood was significantly increased, in the typical cases, after ALV infection the lymphocyte or myelocyte increased, MDV infection significantly increased lymphocyte number. After PCR detection, we found 111 living chickens all had virus infection, in which ALV- A positive rate was 14.4%(16/111), the ALV- J positive rate was 38.7%(43/111), REV positive rate was 17.1%(19/111), the positive rate was 49.5%(55/111) of MDV, MDV infection rates rise significantly. ALV- J and REV double infection rate was 6.3%(7/111). ALV- J and MDV double infection rate was 3.6%(4/111),not trebling or quadruple infection. 5 strains of ALV –J were isolated from typical cases of storage, after gene cloning sequencing, conducting the base and the amino acid sequence alignment of 5 virus strains found that they had close evolutionary relationships with domestic strain NX0101.