Epidemiological Investigation Of Porcine Circovirus Disease Infection In Pigs In Wulin Mountainous Area

The Porcine circovirus (PCV) is one kind of non-pouch membrane single laidring-like DNA virus, divides into Porcine circovirus type 1 (PCV-1) and porcinecircovirus type 2 (PCV-2). PCV-1 was generally considered nonpathogenic, but PCV-2may cause postweaning multisystemic wasting syndrome (PMWS), porcine dermatis andnephropathy syndrome (PDNS), porcine respiratory disease complex (PRDC), centralnervous system (CNS) sydrome of young pigs (PCV-2 relevant central nervous systemdisease) and so on. After PMWS correlating with PCV-2 was discovered in 1991 inNorthern Canada and firstly reported in 1997, PMWS has already been one of the mosteconomically important diseases of the global swine industry and is pay increasingattention. Since PCV-2 infection was firstly reported in our country in 2001, theepidemioc of the disease caused by PCV-2 displays the increased trend in our country. Inrecent several years, the PMWS borderline cases from the partial pig farms in Hefeng,Enshi, Jianshi in the Hubei Province, Qianjiang area in the Chongqing, Xiangxi state inthe Hunan Province and so on, had also continually happened and resulted in grosseconomic loss.In view of the great danger caused by PCV-2, and in order to understandingcomprehensively and evaluating systemicly the infection and epidemic of PCV-2 in theWuling mountainous area, and to laying the foundation on synthetic prevention, weinvestigated the infection of PCV-2 with the enzyme-linked immunosorbent assay(ELISA) in 38 pigs fields, 9 slaughter houses (amount 2,047 sera) at 32 towns close to theEnshi state (both in the Wuling mountainous area)from August, 2004 to November, 2005.In the pig fields infected by PCV-2, serology investigation against Porcine Reproductiveand Respiratory Syndrome virus (PRRSV), Pseudorabies virus(PRV), Classical SwineFever Virus (CSFV) were further done.In this investigation, 679 positive sera against PCV-2 were detected and rate was33.17%. Twenty-seven positive pig fields were detected and total positive rate was71.05%. Nine positive slaughter houses were detected and total positive rate was 100%.The serology investigation results showed that, PCV-2 has generally existed in theWuling mountainous area. And in the pig fields infected by PCV-2, the positiveseroconversion against PRRSV, PRV, and CSFV displayed low, indicating uneffectimmunization against these diseases.