Epidemiological Surveillance Of Classical Swine Fever And Integrated Control In Henan

Classical swine fever(CSF), caused by Classical swine fever virus(CSFV),is an important acute, potent, highly contagious and fatal pig disease with widespreadeconomic losses. Strict control measures had been adopted in the world, while thedisease is still uninterrupted prevalent in China although legal measures forcompulsory vaccination had also been taken. Classical swine fever epidemic situationis quite complicated in Henan-the large farming Province. Therefore the experimentswere carried for swine fever serology and molecular epidemiology aiming at thecomprehensive understanding of classical swine fever epidemic in Henan province.Tests included:By enzyme-linked immunosorbent assay (ELISA) for swine fever antibodies inserum samples were collected from18Cities form March2012to February2014,including24scale pig farms (3242copies)and38non-scale pig farms (2045copies)in Henan Province, and the results show that the antibodies pass rates of large-scaleand non-scale pig farms (pig-positive rate>90%, commercial pig>85%, herddispersion <30) were lower and the discrete degree is larger. The non-scale pig farmsimmune effect is poor compared with the large-scale pig farms. It indicates that theswine fever immunization was not ideal in the various stages of different sizes farmsin Henan, especially in conservation herds stage.The274copies of suspected diseased swine fever were detected with the reversetranscription-polymerase chain reaction (RT-PCR) method, which were collected from88large-scale pig farms in Henan Province,249copies of materials and159patientswith suspected swine fever non-scale pig farms. The results show that the infectionrates were45.5%,59.7%, and the positive rates were36.9%,39.4%of the large-scaleand non-scale pig farms. These results indicate that is still under the threat of swinefever and there is a high incidence in non-scale pig farms the last two years in HenanProvince.In order to the further study on the genetic variation of classical swine fever, Weselect two classical swine fever strains to augment the E0gene and to compare theirsequences. At the same time,they were constructed the phylogenetic tree with some other isolates. The results show that:the E0nucleotide homology was98.7%betweenthe2swine fever epidemic strains. Comparing with6foreign strains were89.3%andthey were98.1%compared with five domestic strains homology. The2pandemicstrains belong to the subgroup2.1.Based on the above findings, Integrated prevention and control measures wereinitial taken in four scale pig farms of Henan Province. Including bio-security,vaccination, Immunoassay, medicines, and based on antibody, pathogen detection andproduction results ultimately.(including the death and elimination rate, survival rate,slaughter weight, et al). We provided some help about controlling the disease andstable production in four large-scale pig farms, further more, controlled of classicalswine fever laid the foundation for the future.