| Newcastle disease (ND) and avian influenza (AI),respectively,from the Newcastle disease virus (NDV),the avian influenza virus (AIV) are avian acute,highly contagious and lethal diseases,which harm the poultry in China and the world extremely seriously. A broiler farm of Rousi Ji 20,000 from Xintai City in 2009,was immunized of Newcastle disease in 21-day-old,after 3 days,the chickens had respiratory symptoms,swollen eye tears,discharged feces like lime water Xifen. sick and dead chickens emerged continuously,the peak mortality rate was about 1% per day for 7 to 10 days. Until 42 days to slaughter,the incidence of death was a total of 4,000. To understand the epidemiology of the disease in chickens,we regularly collected chicken serum and dead material of chicken diseases in 28 days,35 days,42 days,Pathogen Detection was undertaken by hemagglutination inhibition (HI) assay of Newcastle disease,avian influenza (H5,H9) changes of antibody levels,while the autopsy on the dead chickens were sick,pathological examination,the use of HA,RT-PCR,indirect immuno fluorescence,PCR,gene sequencing and other methods. Gene cloning,sequence analysis was applied to three strains of virus of high titer NDVTS1,TS2,TS3.The results showed that: the mixed infection of NDV and AIV H9 subtype took for as much as 40%,Newcastle disease,influenza antibody titer,tended to increase and exceed the normal immune levels with the disease day-old body and dispersed larger Sevral field strains suspected a greater chance of infection. After necropsing chickens we could see that the end of the chicken duodenum,jejunum yolk remains after the beginning part of the ileum and cecum concentration at the mucosal lymphoid tissue tonsil swelled,Congestive,bleed. Some of the late onset of chicken pancreatic necrosis were seen gray,and some edges bleed.Heart,liver,kidney,lung,trachea,duodenum,meninges,spleen,glandular stomach and other organs nipple extensive bleed; non-suppurative encephalitis ; necrotizing myocarditis , hepatitis , pancreatitis ,dermatitis,etc.;or fibrinous yolk peritonitis,salpingitis,metritis and so on.. Histological examination: the majority of tissues and organs bleed,degenerate,necrosis,inflammatory cell infiltration within the necrotic foci,cerebral vascular congestion,mild viral disease. According to the pathogen detection of IFA,and mixed-infection of H9 influenza and Newcastle disease took for the proportion of 40%,only 12% were infected with Newcastle disease,and the avian influenza H9 were 15%.Virulence test to titer of the isolated high three NDV showed that the three NDV isolates can be determined to be virulent,and based on MDT index ,they can be divided into fast hair strains (TS1 and TS2,MDT <60) and in the hair strains (TS3,MDT> 60) categories further.By amplifing three virus F gene by PCR TS1,TS2,TS3,connected,transformed,cloned and sequenced,and then the genetic analysed. And differences between F48E9,Goose ZJ1,and Ch983 genetic representative strains were 3%,while the differences between LaSota,swine SP13,and semi-muscovy duck FM1 genetic representative strains were higher than 17.8%; in the computer software to draw a tree of genetic occurrence,TS1,TS2,TS3 and F48E9,Goose ZJ1,Ch983 were in the same branch,and TS2,TS3 were at the same branch.Investigation showed that the flock was diagnosed by the mixed-infection of the occurrence of Newcastle disease in chickens and low pathogenic avian influenza,the incidence of Newcastle disease in chickens and low pathogenic avian influenza antibody levels significantly increased,and we should take integrated control over the mixed-infection of Newcastle disease in chickens and low pathogenic avian influenza. |
