Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
PLoS One. 2011 Jan 24;6(1):e16236. doi: 10.1371/journal.pone.0016236.
Rapid PCR-based tests for the diagnosis of leptospirosis can provide information that contributes towards early patient management, but these have not been adopted in Thailand. Here, we compare the diagnostic sensitivity and specificity of two real-time PCR assays targeting rrs or lipL32 for the diagnosis of leptospirosis in northeast Thailand.
METHODS/PRINCIPAL FINDINGS: A case-control study of 266 patients (133 cases of leptospirosis and 133 controls) was constructed to evaluate the diagnostic sensitivity and specificity (DSe & DSp) of both PCR assays. The median duration of illness prior to admission of cases was 4 days (IQR 2-5 days; range 1-12 days). DSe and DSp were determined using positive culture and/or microscopic agglutination test (MAT) as the gold standard. The DSe was higher for the rrs assay than the lipL32 assay (56%, (95% CI 47-64%) versus 43%, (95% CI 34-52%), p<0.001). No cases were positive for the lipL32 assay alone. There was borderline evidence to suggest that the DSp of the rrs assay was lower than the lipL32 assay (90% (95% CI 83-94%) versus 93%, (95%CI 88-97%), p = 0.06). Nine controls gave positive reactions for both assays and 5 controls gave a positive reaction for the rrs assay alone. The DSe of the rrs and lipL32 assays were high in the subgroup of 39 patients who were culture positive for Leptospira spp. (95% and 87%, respectively, p = 0.25).
CONCLUSIONS/SIGNIFICANCE: Early detection of Leptospira using PCR is possible for more than half of patients presenting with leptospirosis and could contribute to individual patient care.
基于 PCR 的快速检测方法可用于诊断钩端螺旋体病，为患者的早期治疗提供信息，但该方法尚未在泰国应用。本研究比较了针对 rrs 或 lipL32 的两种实时 PCR 检测方法在泰国东北部诊断钩端螺旋体病的诊断敏感性和特异性。
方法/主要发现：本病例对照研究纳入了 266 例患者（133 例钩端螺旋体病患者和 133 例对照者），评估了两种 PCR 检测方法的诊断敏感性和特异性（DSe 和 DSp）。病例组入院前的中位病程为 4 天（IQR 2-5 天；范围 1-12 天）。以阳性培养和/或显微镜凝集试验（MAT）作为金标准，确定 DSe 和 DSp。rrs 检测方法的 DSe 高于 lipL32 检测方法（56%（95%CI 47-64%）比 43%（95%CI 34-52%），p<0.001）。单独使用 lipL32 检测方法未发现阳性病例。rrs 检测方法的 DSp 似乎低于 lipL32 检测方法，有边缘统计学意义（90%（95%CI 83-94%）比 93%（95%CI 88-97%），p=0.06）。有 9 例对照者两种检测方法均呈阳性，5 例对照者仅 rrs 检测方法呈阳性。在 39 例培养出钩端螺旋体的患者亚组中，rrs 和 lipL32 检测方法的 DSe 均较高（分别为 95%和 87%，p=0.25）。
使用 PCR 技术早期检测钩端螺旋体对半数以上的钩端螺旋体病患者可能有效，有助于对患者进行个体化治疗。
