Epidemiological Investigation Of Major Porcine Infectious Disease Of Changsha Country And The Responding Approaches For Prevention And Control

Changsha country is a major region for porcine production in China. There are 3.5million pigs raised and sold out in this region in 2005, and value of output for husbandryindustry reached to 2 billions RMB, counting for 50% incomes from all agricultural.However, veterinary infectious diseases greatly influenced the stability of the husbandryproduction, and the economic losses induced by infectious disease upgrading 10 millionsRMB yearly. To control porcine infectious diseases in the country, the main infectiousdiseased influencing swine production were investigated through retrospectiveepidemical investigation, current disease surveillance and serologic and pathogenicdiagnostic, summarizing the major clinical symptoms and pathological changes. Inaddition, the diseases related to porcine reproductive disturbance were serological andpathogenic tested, analyzing epidemic characteristics and trend of porcine infectiousdiseases in Changsha country and pointing out the responding measures for control.23 diseases were found in this investigation and 16 of them belong to infectiousdisease. For 4 diseases, Transmissible gastroenteritis of pigs (TGE), Mycoplasmalpneumonia of swine, Hog cholera (HC) and Foot and mouth disease (FMD), theirepidemic histories and properties were described, and diagnostic, preventive and curativemethods were clarified. As for clinical symptoms, fever, anorexy and depression ispantosomatous fetures; respiratory and digestive system showed abnormal in part. Forathological changes, there mainly appeared on lung, such as haemorrhagia, emphysemaand fiberic effusion. Secondly, there was haemorrhagia and anabrosis in mucosa andectoptygma of digestive system. Thirdly, absorbent gland presented haemorrhagia andcutaneous.Serum samples were collected from swinery distinct in the size and the diseasesrelated to porcine reproductive disturbance, such as Porcine parvovirus (PPV) infection,Porcine Reproductive & Respiratory Syndrome (PRRS), Physique et Chimie du Vivant(PCV), Hog cholera (HC), Pseudorabies Virus (Prv) were tested. The results indicatedserological positive in immunized swine was rather low (3.3～56.7%), otherwise, the 4 diseases in unimmunized pigs displayed serological positive (0～44.4%), which wouldbecome potential factors leading to the above diseases outbreak momentarily.The 48 tissue samples from putative diseases were pathologically tested, and theresults revealed the positive samples included 22 HC, 11 PCV, 11 PRRS, 4 PPV, 3Mycoplasmal pneumonia of swine, 2 PRV and 1 TCG, of which combined infectionoccupied 20 cases. The most type of combined infection was HC, PRRS, PCV and PPV,and usually HC, PRRS and PCV or HC, PRRS and PPV 3 types combined infection alsoappeared. In sum, these studies once confirmed that the diseases related to porcinereproductive disturbance as well as other some respiratory and digestive system diseasedreally occurred.