Centers for Epidemiology and Animal Health, USDA-APHIS-VS, 2150 Centre Ave., Bldg. B, MS 2E7 Fort Collins, CO, USA.
Prev Vet Med. 2011 Aug 1;101(1-2):79-88. doi: 10.1016/j.prevetmed.2011.05.001. Epub 2011 May 31.
Porcine circovirus 2 (PCV2) is believed to be a necessary but not sufficient underlying cause of porcine circovirus associated disease (PCVAD) in swine (Opriessnig et al., 2007). Since the potential threat of PCVAD is dependent on the prevalence of PCV2 in swine populations, accurate diagnostic tests are important for epidemiologic surveillance. Therefore, we evaluated the diagnostic sensitivity (Se) and specificity (Sp) of a new indirect ELISA and two quantitative PCR tests for PCV2 in a series of latent class models that used Bayesian estimation procedures. A total of 4140 samples from finisher pigs were tested for evidence of PCV2 by the ELISA and a TaqMan (TM) quantitative PCR, 995 by the ELISA and a SYBR Green (SG) dye-binding PCR, 998 by both PCRs and 993 by all three tests. Overall, the median (95% probability interval) ELISA Se and Sp was 0.85 (0.83-0.87) and 0.74 (0.68-0.79), respectively, when all three tests were analyzed together at an ELISA absorbance (optical density or OD) cutoff of ≥0.3. The TM PCR Se and Sp was 0.86 (0.84-0.88) and 0.94 (0.87-0.97), respectively, and the SG PCR Se and Sp was 0.83 (0.81-0.85) and 0.98 (0.94-1.00), respectively when all three tests were analyzed together at an ELISA OD cutoff of ≥0.3. Sensitivity analysis revealed that Sp estimates in general had less stability than Se estimates, but the SG PCR(Sp) was the most stable. Limited conditional dependence between the two PCR tests was detected. We conclude that the ELISA had the highest diagnostic Se at an absorbance cutoff of ≥0.3, while the SG PCR had the highest diagnostic Sp. The prevalence levels for exposure to PCV2 in finishing swine populations across all analyses ranged from 58 to 100%.
猪圆环病毒 2 型（PCV2）被认为是导致猪圆环病毒相关疾病（PCVAD）的必要但非充分的潜在原因（Opriessnig 等人，2007 年）。由于 PCVAD 的潜在威胁取决于猪群中 PCV2 的流行程度，因此准确的诊断测试对于流行病学监测非常重要。因此，我们使用贝叶斯估计程序评估了一系列潜在类别模型中一种新的间接 ELISA 和两种定量 PCR 检测 PCV2 的诊断敏感性（Se）和特异性（Sp）。总共对来自育肥猪的 4140 个样本进行了 ELISA 和 TaqMan（TM）定量 PCR、ELISA 和 SYBR Green（SG）染料结合 PCR、两种 PCR 以及三种检测方法的检测，以证明 PCV2 的存在。总体而言，当同时分析所有三种检测方法时，ELISA 的中位数（95%概率区间）Se 和 Sp 分别为 0.85（0.83-0.87）和 0.74（0.68-0.79），当 ELISA 吸光度（光密度或 OD）截距≥0.3 时。TM PCR 的 Se 和 Sp 分别为 0.86（0.84-0.88）和 0.94（0.87-0.97），当同时分析所有三种检测方法时，SG PCR 的 Se 和 Sp 分别为 0.83（0.81-0.85）和 0.98（0.94-1.00），当 ELISA OD 截距≥0.3 时。敏感性分析表明，Sp 估计值通常比 Se 估计值更不稳定，但 SG PCR（Sp）最稳定。检测到两种 PCR 检测之间存在有限的条件依赖性。我们得出结论，ELISA 在吸光度截距≥0.3 时具有最高的诊断 Se，而 SG PCR 具有最高的诊断 Sp。在所有分析中，育肥猪群接触 PCV2 的流行率水平从 58%到 100%不等。
