Epidemiological Research Of Chicken Stunt And Immunosupression Syndrome

Chicken stunt and immunosupression syndrome virus(CSISV) is caused the growth and immune suppression as the main characteristics of important infectious diseases of poultry in recent years, This thesis is based on preliminary studies, carried out epidemiological studies CSIS.1. Using home-made chicken growth and immune suppression syndrome virus positive serum, to establish an indirect ELISA. The optimal reaction conditions that: antigen coating dilution of 1:100, HRP secondary antibodies dilution of 1:1000, antibody to be tested dilution of 1:50, the serum antibody action time of 2h, Chromogenic substrate solution action time of 20min, samples antigen after antigen coating the total time required to 5h. The specificity and repeatability test showed that the method has good specificity, repeatability, the Simple operation, high sensitivity and shorter time.2. CSISV on layers, broilers, ducks to infect disease, but morbidity, mortality, growth inhibition and antibody production after infection as well as some differences. Incidence rates of Roman, Highland, AA broiler were 62%, 58%, 85%, death rates were 24%, 30%, 37.5%, from the statistical data can be seen, layers susceptible and high mortality rate than broilers. The infection rate of Roman higher than Highland, but the mortality rate of Roman lower than hanland. the incubation period of 3~4 days after CSISV infected Roman and Highland, Precursor period is not obvious, the obvious symptoms of 6~9 d, 11~21 day recovery period for the disease; the average body weight compared with the control group reduced 55.39% and 60.4%, the difference was significant (P <0.01), it shows that significantly inhibited. The antibody after infection of the Roman and Highland test, able to detect antibodies in 192h~384h after infection(P/N>2).feces 96h~240h after infection and can detect antigen by RT-PCR ,this shows that antibody dynamic in 192h~384h of CSISV infection, detoxification of the infection 96h~240h. AA broiler chickens infected after an incubation period of 3~4 days, the symptoms clear after the infection period 7~9d, 11~20 days recovering from the disease, the average body weight compared with the control group reduced 27.06%, significant difference (P<0.05), significant growth inhibition. Antibody and stool test after infection results show that the consumer long after infection antibodies 192h~384h, detoxification of the infection 72h~288h. Cherry Valley Duck of infection had obvious symptoms are severely inhibited the growth, of 28 days to weigh the test group, the average body weight than the control group loss 17.72%, significantly different (P<0.05), but not appear death, the 144h after infection, the experimental group showed positive antibodies (P/N>2), after 240h infection can be detected in their stool positive for the virus, detoxification period in 240h~312h. Gushi goose of infected, experimental group and control group showed no obvious clinical symptoms. in the whole observation period over the same period, the test group and control group after necropsy, and no pathological changes, compared with the weight, and the difference was not significant(P>0.05), antibodies produce period in 96h ~ 288h after infection, detoxification of about 216h ~ 288h. Pathological change of dead poultry were found most nipple enlargement, mucosal shedding, intestinal different levels of needle-like or flaky bleeding, intestinal swelling, bleeding seriously of appendix, kidney swelling and bleeding, and finally necrosis, and forms a piebald kidney.3. CSISV to infect by the digestive tract and respiratory tract, to spread with air, stool, AA broiler infection CSISV after 96h by drinking water began to die, the mortality peak was that 168h ~ 240h after infection of chicken, mortality reached to 32%, 48h after the infection began to disease, the incidence rate was 100%. Antibodies after infection in the test results showed that, raising to 21d, antibody of the test group were positive by ELISA. It shows that the body after infection produced strong antibodies.4. Through Serological investigation of the different regions and different seasons of 300 days old Highland hens and 20 days old AA + broiler shows that almost province-wide widespread about CSIS, the positive detection rate of 53.63%. In which areas with the highest positive rate was LUOYANG and PUYANG, the positive rate was 74.21% and 64.26%. The lowest detection rate was in ZHENGZHOU, the positive rate was 38.88%. In the seasonal survey, it was that year-round disease, the average incidence rate was 35%. From the result of observation about the scale and backyard farms of Highland and AA+ broiler antibody test, morbidity and mortality of scattered farm was higher than the scale, but the detection of serum antibody positive rate of less than large-scale .ELISAdetection of various varieties, the positive rate layers above the broiler.