猪蓝耳病的几种血清学诊断方法

调查云南省猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus，PRRSV)的流行规律和混合感染情况。

采用分子生物学方法对2013—2021年间的3112份血液样品进行PRRSV核酸检测，并进一步分析其流行和混合感染情况。

检测样品中，有801份样品为PPRSV阳性，阳性率为25.74%，二重、三重和四重混合感染率分别为41.20%、12.48%和1.87%；不同生长阶段猪群的PRRSV感染程度差异较大，生长育肥猪感染最严重(33.24%)；相对于育肥场和散养户，种猪场的感染程度较轻，三者的感染率分别为27.94%、28.94%和14.29%。对不同毒株类型分析发现：高致病性毒株和经典毒株仍是主要的流行毒株，分别占毒株数的58.49%和22.64%，但占比呈逐年下降趋势。于2019年和2021年在云南省内分别发现了类NADC30毒株和类NADC34毒株，分别占毒株数的15.09%和3.77%，其感染率呈逐渐上升趋势。

猪繁殖与呼吸综合征仍是影响云南省生猪产业健康发展最重要的疫病之一，表现形式以和其他疾病混合感染为主。随着新毒株的发现，云南省PRRSV基因更加多样，防控形势愈加复杂。

Porcine reproductive and respiratory syndrome virus (PRRSV): pathogenesis and interaction with the immune system

To investigate the prevalence tendency and co-infection of porcine reproductive and respiratory syndrome virus (PRRSV) in Yunnan Province. PRRSV nucleic acid was detected in 3112 blood samples from 2013 to 2021 by molecular biology methods, and the prevalence and mixed infection of PRRSV were further analyzed. Among the detected samples, 801 samples were positive for PPRSV, with a positive rate of 25.74%. The double, triple and quadruple mixed infection rates were 41.20%, 12.48% and 1.87%, respectively. The degree of PRRSV infection in pigs at different growth stages varied greatly, and the infection of growing fattening pigs was the most serious (33.24%). Compared with fattening farms and backyard farmers, the infection degree of pig farms was lighter, and the infection rates of the three were 27.94%, 28.94% and 14.29%, respectively. Analysis of different types of strains found that: highly pathogenic strains and classical strains were still the main epidemic strains, accounting for 58.49% and 22.64% of the number of strains, respectively, but the proportion was decreasing year by year. In 2019 and 2021, NADC30-like and NADC34-like strains were found in Yunnan Province, accounting for 15.09% and 3.77% of the number of strains, respectively, and their infection showed a gradual upward trend. Porcine reproductive and respiratory syndrome is still one of the most severe diseases threatening the healthy development of pig industry development in Yunnan Province, and the manifestations are mainly mixed infections with other diseases. With the discovery of new strains, PRRSV genes in Yunnan Province are more diverse, and the prevention and control situation is more complicated.