The Inquisition On Regulation Of The Classical Swine Fever Taken Place In ZhangYe City

The classical swine fever (the other name is hog cholera and the brief name is HC or CSF) is a sort of infectious disease of pigs caused by the classical swine fever virus. ZhangYe City is one of the regions and cities that seriously suffer from HC. Since GaoTai county recorded the occurrence of HC in 1954, continuously using the weak poisonous vaccine of HC for " spring and autumn "two season vaccination to prevent the plague. Under the situation of that inoculation dose became more and more, the density of the vaccination got higher and higher, the average pig immune density in is over 90% per year and the vaccination times increase, still the plague can not be controlled completely. HC's occurrence is not extinguished and spread from one county to six counties of the city contrarily.For the sake of seeking the regulation of the occurrence, spread, development and variety of HC disease in Zhangye City, this item was conducted by means of checking out the immunity, annual report, epidemic situation, quarantine, selective check, assay, original file and data of the veterinary stations in provincial, city and county levels and meanwhile, going to farm households, pig farms, veterinary clinics, the laboratory for carrying out the epidemiological inquisition. Though the summarizing the firsthand materials and synthetic analysis, the occurrence regulation of HC in Zhanye City is found out.The basic reason on occurrence of HC disease in Zhangye City Discovered is that all levels of government did not pay attention to HC Prevention; the spring and autumn two times of immunity a year was their only work for the plague control; policy reason results in a large quantity pigs without immunity; the wild poisonous stub spread; the immune antibody or piglets' mother source antibody was not be monitoring, the suitable scientific program of immunity for the local area had out been established; The sick pigs, dead pigs and the pork of the sick pigs were not been handled thoroughly but continuously got into the society and formed the vicious cycle. No standardized epidemic prevention, no properly quarantine, no strict disinfection etc. resulted in HC occurrence again and again.The regulation of HC occurrence in Zhangye City revealed that described as below. HC occurred in six counties (district) of Zhangye City and the main epidemic counties (district) are along the national way No.312 and 227. HC occurrence is with a positive proportion with the yearly production of pigs and pork. Part of pigs are still infected HC after the vaccination. It is the most serious infectious disease to endanger the swine farming. HC's occurrence is irrelevant with age, sex, species. The plague occurs in all year but there are two peaks in the early spring and the end of autumn respectively. The epidemic of HC changed from frequent and wide into the periodically regional scatter. The way of spread is perpendicular and contact infection with the sick pig. The traders with sick pigs getting into the pigsty can also cause HC occurrence. HC's symptom presents diversification and changes from acute to gentle type,such as slow start with a long course of the disease, the continuous occurrence in the old epidemic-stricken area and the new epidemic-stricken area one after another, The continuous increase of epidemic scope with spread trend. The untypical classical swine fever with complex diversification symptom, uninterrupted infection of HC virus, placenta infection, the Inborn infection of just-born piglet and the immunity bear to suffer, pregnant sows' breeding obstacle. Pathological vary changes from typical to untypical. The mortality is more lower compared with the acute but compared with the other pig Infectious disease, the mortality is higher and at the first place of various pig infectious diseases. HC may develop into a mixed infection with paratyptus suum of piglets, edema disease of piglets, pasteurellosis suum or erysipelas suis.