Goldman M, Long A
Vox Sang. 2000;78 Suppl 2:249-52.
Since March 1990, all blood donations in Canada are screened by enzyme-linked immunosorbent assay (EIA) for antibodies to HCV, with confirmatory testing done using a recombinant immunoblot assay (RIBA). Because HCV may cause chronic asymptomatic hepatitis, in 1995, the Canadian Red Cross began targeted HCV lookback studies on all confirmed positive donations. These have been continued by the two new operators of the blood system in Canada, Héma-Québec and the Canadian Blood Services. Subsequent to recommendations made in the public inquiry into the Canadian blood system, led by judge Krever, general lookback through letter notification of all patients transfused in the years prior to the introduction of anti-HCV testing was initiated in several pediatric hospitals, and later in several Canadian provinces.
Targeted HCV lookback was done for all donors confirmed positive by RIBA testing from the start of HCV testing in 1990. In 1999, stored RIBA 2 indeterminate samples were re-tested by RIBA 3, and lookback performed on confirmed positive donations. In the province of Quebec, hospitals were surveyed to determine methods and resources involved in lookback. Provinces performing general letter notification entered hospital transfusion records into a central transfusion data bank, and performed linkage with other provincial data banks to remove deceased patients and obtain current addresses.
As of January 2000, targeted lookback had been completed on 4,859 components of 1,628 anti-HCV positive repeat donors. 2,991 recipients were deceased, and 451 were not found or tested. Of the 1,422 recipients tested, 954 (67%) were anti-HCV positive. Approximately half were already aware of their HCV status. Lookback efforts in hospitals were hampered by lack of resources and manual records. General letter notification in British Columbia (BC) and Prince Edward Island (PEI) led to the testing of 38,960 and 1,953 recipients respectively, with 5.0 and 2.2% of tested recipients found to be anti-HCV positive.
In completed targeted lookback investigations, 19% of components are eventually linked to an anti-HCV positive recipient. These results are very similar to those obtained in other countries, such as Denmark and the UK. In general letter notification lookbacks, the frequency of anti-HCV in the tested recipients is approximately twice the frequency of the general population.
自1990年3月起，加拿大所有献血均通过酶联免疫吸附测定（EIA）筛查丙型肝炎病毒（HCV）抗体，并使用重组免疫印迹测定（RIBA）进行确证检测。由于HCV可能导致慢性无症状肝炎，1995年，加拿大红十字会开始对所有确诊阳性献血进行针对性的HCV追溯研究。加拿大血液系统的两家新运营商魁北克血液中心（Héma-Québec）和加拿大血液服务中心延续了这些研究。在由克雷弗法官领导的对加拿大血液系统的公开调查提出建议之后，几家儿科医院随后在几个加拿大省份开始通过信函通知对引入抗HCV检测之前几年接受输血的所有患者进行全面追溯。
从1990年开始对HCV检测起，对所有经RIBA检测确诊为阳性的献血者进行针对性的HCV追溯。1999年，对储存的RIBA 2不确定样本用RIBA 3重新检测，并对确诊阳性的献血进行追溯。在魁北克省，对医院进行了调查，以确定追溯所涉及的方法和资源。进行全面信函通知的省份将医院输血记录录入中央输血数据库，并与其他省级数据库进行关联，以排除已故患者并获取当前地址。
截至2000年1月，已对1628名抗HCV阳性重复献血者的4859份成分进行了针对性追溯。2991名受血者已故，451名未找到或未接受检测。在接受检测的1422名受血者中，954名（67%）抗HCV呈阳性。约一半人已经知晓自己的HCV状况。医院的追溯工作因资源短缺和手工记录而受阻。不列颠哥伦比亚省（BC）和爱德华王子岛省（PEI）的全面信函通知分别导致38960名和1953名受血者接受检测，检测的受血者中分别有5.0%和2.2%抗HCV呈阳性。
在已完成的针对性追溯调查中，19%的成分最终与抗HCV阳性受血者相关联。这些结果与丹麦和英国等其他国家获得的结果非常相似。在全面信函通知追溯中，接受检测的受血者中抗HCV的频率约为普通人群频率的两倍。
