Epidemiology Analysis Of Virus Diarrhea Of Piglet And Application Of Egg Yolk Antibody On Preventing And Curing PEDV

Beginning in November2010, acute diarrhea of piglet emerged inChina in an outbreak characterized by acute onset, spread rapid, high incidence andsignificant mortality, thereby incurring heavy economic losses. This outbreak wasdistinguished over90%illness among piglet after birth (predominantly within7days)and death rates of100%. In order to investigate the main etiology of acute diarrhea ofnewborn piglet in Henan province. With the established RT-PCR and PCR methods, atotal of181clinical samples from98farms were tested for presence of PEDV, TGEV,PoRV, CSFV and PRV. The results showed that the positive rate of PEDV was up to71.27%, the positive rates of TGEV, PoRV, CSFV and PRV were5.52%,2.21%,69.06%, and44.20%, respectively. The coinfection rates of PEDV/TGEV,PEDV/PoRV, PEDV/CSFV, PEDV/PRV, PEDV/CSFV/PRV, PEDV/TGEV/PoRV,CSFV/PRV were2.76%,2.21%,56.91%,17.13%,17.10%,0.55%, and32.04%,respectively. The result showed that PEDV-positive farms were well-distributed inHenan province. There was a higher positive proportion in autumn and winter, and agradual upward trend in spring and summer. The positive proportion of large scale pigfarms was higher than small and medium-sized farms. The results showed that theinfection and prevalence of acute diarrhea of newborn piglets in Henan province wasvery common and no obvious seasonal. PEDV is the leading cause, but CSFV andPRV also play an important role in this epidemic. Most farms prevent acute diarrheaof piglet by TGE-PED-PoRV triple attenuated vaccine of4times per year, and can notoffer protection. Once diarrhea broken out, it was impossible to control by antibioticand antiviral. In this study, inactivated vaccine was prepared by intestinal tissue whichcollected from diarrhea piglets. After the hens were immunized with the inactivatedvaccine of PEDV and eggs of hyperimmunity were collected, the hyperimmunizedyolk antibodies against PEDV were prepared. The artificial and clinical resultsshowed that the protection rate reached to90%, and the therapeutic effect werelimited to onset piglets raged to2～3days. As age grew, the cure rate of IgY wereincreased. In34farms (65.38%), the protection rate reached to90%, and in5farms(9.62%) the protection rate ranged from50%to90%. All these results demonstratedthat the IgY produced better clinical protection effects. But in13farms (25.00%) theprotection rates of IgY were less than50%, because of the coinfection rate ofCSFV/PRV was high. We should analysis the causes of disease by detecting thepathogen of pig farm and take measures of comprehensive treatment.