广西猪圆环病毒3型流行病学调查与分析

本研究旨在了解新发猪圆环病毒3 型（porcine circovirus 3，PCV3）在广西猪群的感染情况及流行特点，为有效防控PCV3提供科学依据。试验采用PCR检测方法对2017年9月至2019年3月广西482个规模猪场送检的917份病猪样品进行PCV3检测，并分析PCV3阳性率在广西不同地区、年份、季节和年龄段猪群之间的差异。对145份PCV3阳性病料进行猪瘟病毒（CSFV）、猪繁殖与呼吸综合征病毒（PRRSV）、猪圆环病毒2型（PCV2）、猪伪狂犬病病毒（PRV）和猪流行性腹泻病毒（PEDV）检测。结果显示，PCV3除在百色、防城港未检出，在广西其他12个地市均存在不同程度的感染；2017~2019年广西PCV3样品阳性率和PCV3猪场阳性率均呈逐渐上升趋势；夏季PCV3阳性率最低，且明显低于其他3个季节；育肥猪PCV3阳性率最高，为21.70%，其次是流产母猪、保育猪、流产胎儿，阳性率分别为20.00%、19.05%和11.02%，哺乳仔猪PCV3阳性率最低，为8.21%；PCV3单一感染率较高，为30.34%，与其他病原混合感染情况也较为常见，甚至出现四重感染。调查结果表明，PCV3感染在广西普遍存在，且近年来感染呈增加趋势，可能有一定的季节性，对各生长阶段猪群均有一定程度的危害，以育肥猪最为严重，对母猪和保育猪危害也较大；PCV3单一阳性率较高，但仍以混合感染为主，尤其是与PRRSV和PCV2的混合阳性率较高，提示这3种病原在感染致病过程中可能存在协同作用。

Epidemiological Investigation Analysis of Porcine Circovirus Type 3 in Guangxi

The purpose of this study was to investigate the infection situation and epidemic characteristics of porcine circovirus 3 (PCV3) in the pig population of Guangxi,so as to provide scientific basis for effective prevention and control.PCR method was used to detect PCV3 in 917 pig tissue samples with pathological changes from 482 large-scale pig farms in Guangxi from September 2017 to March 2019,and the difference of positive detection rate of PCV3 in different regions,years,seasons and age groups of pigs were considered.145 PCV3 positive samples were simultaneously tested for CSFV,PRRSV,PCV2,PRV and PEDV.The results showed that except for Baise and Fangchenggang,which were not detected,PCV3 had different degrees of infection in other 12 cities in Guangxi.From 2017 to 2019,the positive rate of PCV3 infection and the positive rate of PCV3 infected pig farms in Guangxi showed a trend of gradual increase.The infection rate of PCV3 was the lowest in summer,which was significantly lower than that in spring,autumn and winter.The infection rate of PCV3 was the highest in finishing pigs (21.70%),followed by aborted sows,protected pigs and aborted fetuses (20.00%,19.05% and 11.02%,respectively),and the lowest in suckling pigs (8.21%).PCV3 had the highest single infection rate (30.34%).Mixed infection of PCV3 with other pathogens was also relatively common,even with quadruple infection.The investigation results showed that PCV3 infection was more common in Guangxi,and increased in recent years,and might be seasonal,it had a certain degree of harm to pig groups in all growth stages,especially in finishing pigs,and it also had a great harm to sows and conservation pigs.The single positive rate of PCV3 was higher,but it was mainly mixed infection,especially with PRRSV and PCV2,which suggested that there might be synergism among the three pathogens in the process of infection.