Ogden Nicholas H, Arsenault Julie, Hatchette Todd F, Mechai Samir, Lindsay L Robbin
National Microbiology Laboratory, Public Health Agency of Canada, Saint-Hyacinthe, Québec, Canada.
Groupe de recherche en épidémiologie des zoonoses et santé publique (GREZOSP), Saint-Hyacinthe, Québec, Canada.
PLoS One. 2017 Feb 9;12(2):e0171731. doi: 10.1371/journal.pone.0171731. eCollection 2017.
Lyme disease is emerging in eastern and central Canada, and most cases are diagnosed using the two-tier serological test (Enzyme Immuno Assay [EIA] followed by Western blot [WB]). Simplification of this algorithm would be advantageous unless it impacts test performance. In this study, accuracy of individual proteins of the IgG WB algorithm in predicting the overall test result in samples from Canadians was assessed. Because Borrelia burgdorferi strains vary geographically in Canada, geographic variations in serological responses were also explored. Metrics of relative sensitivity, specificity and the kappa statistic measure of concordance were used to assess the capacity of responses to individual proteins to predict the overall IgG WB result of 2524 EIA (C6)-positive samples from across Canada. Geographic and interannual variations in proportions of samples testing positive were explored by logistic regression. No one protein was highly concordant with the IgG WB result. Significant variations were found amongst years and geographic regions in the prevalence of samples testing positive using the overall IgG WB algorithm, and for individual proteins of the algorithm. In most cases the prevalence of samples testing positive were highest in Nova Scotia, and lower in samples from Manitoba westwards. These findings suggest that the current two tier test may not be simplified and continued use of the current two-tier test method and interpretation is recommended. Geographic and interannual variations in the prevalence of samples testing positive may be consistent with B. burgdorferi strain variation in Canada, and further studies are needed to explore this.
莱姆病在加拿大东部和中部地区呈上升趋势，大多数病例通过两级血清学检测（酶免疫测定[EIA]随后进行免疫印迹[WB]）进行诊断。简化该检测流程将具有优势，除非这会影响检测性能。在本研究中，评估了IgG免疫印迹检测流程中各个蛋白质在预测来自加拿大的样本总体检测结果方面的准确性。由于加拿大不同地区的伯氏疏螺旋体菌株存在差异，因此还探讨了血清学反应的地理差异。使用相对敏感性、特异性指标以及一致性的kappa统计量来评估对各个蛋白质的反应预测来自加拿大各地2524份EIA（C6）阳性样本总体IgG免疫印迹结果的能力。通过逻辑回归分析探讨了检测呈阳性样本比例的地理和年度间差异。没有一种蛋白质与IgG免疫印迹结果高度一致。在使用总体IgG免疫印迹检测流程以及该流程中的各个蛋白质时，发现检测呈阳性样本的患病率在年份和地理区域之间存在显著差异。在大多数情况下，新斯科舍省检测呈阳性的样本患病率最高，而从马尼托巴省向西的样本患病率较低。这些发现表明当前的两级检测可能无法简化，建议继续使用当前的两级检测方法及解读方式。检测呈阳性样本患病率的地理和年度间差异可能与加拿大伯氏疏螺旋体菌株的差异一致，需要进一步研究来探讨这一点。
