Liu P, Shi Z X, Zhang Y C, Xu Z C, Shu H S, Zhang X Y
Department of Public Health, Xuzhou Medical College, Jiangsu, China.
Transfusion. 1997 Jul;37(7):732-6. doi: 10.1046/j.1537-2995.1997.37797369450.x.
To examine the feasibility and to perform a cost-benefit analysis of a pooling protocol of enzyme immunoassay (EIA) screening for antibody to hepatitis C virus (anti-HCV) under real conditions, a prospective study was carried out using sera from 1875 local blood donors.
In the absence of knowledge of the anti-HCV reactions, the donor's sera were pooled into groups of five consecutive samples for testing by EIA. The dilution and final volume of the serum pool were adjusted to equal those recommended for single-serum EIA by the manufacturer of the test kit. The results obtained were compared with those of single-serum EIA to assess the feasibility of the pooling protocol. By applying probability theory, the percentage of reduction in the number of tests performed (L value) when the serum-pooling strategy was used was calculated for several anti-HCV seroprevalences and for varied sizes of pool. The calculations were performed on a computer using a program compiled by the authors.
The results showed that seroprevalence was 2.24 percent (95% CI, 1.57-2.91%); the rate of false negativity was 0 (95% CI, 0-8.4%), the sensitivity of the pooling protocol was 100 percent (95% CI, 91.6-100.0%), the rate of false positivity was 0.8 percent (95% CI, 0-1.8%), and the specificity of the pooling protocol was 99.2 percent (95% CI, 98.2-100.0%). Cost-benefit analysis showed that the pooling protocol could save 69.3 percent of the cost. A table of L values can be used conveniently by serologists to determine the optimum pool size if estimates of seroprevalence are available.
The pool EIA did not perform worse than individual EIAs, and the pooling strategy was markedly less expansive. The pooling protocol was recommended for screening of anti-HCV-positive subjects from large populations with low seroprevalence.
为了在实际情况下检验酶免疫测定（EIA）筛查丙型肝炎病毒抗体（抗-HCV）混合检测方案的可行性并进行成本效益分析，使用1875名当地献血者的血清开展了一项前瞻性研究。
在不知抗-HCV反应结果的情况下，将献血者血清按连续5个样本一组进行混合，采用EIA检测。血清混合样本的稀释度和最终体积按照检测试剂盒制造商推荐的单血清EIA检测的标准进行调整。将所得结果与单血清EIA检测结果进行比较，以评估混合检测方案的可行性。应用概率论，针对几种抗-HCV血清流行率和不同的混合样本量，计算采用血清混合策略时检测次数减少的百分比（L值）。计算过程通过作者编写的程序在计算机上完成。
结果显示，血清流行率为2.24%（95%可信区间，1.57 - 2.91%）；假阴性率为0（95%可信区间，0 - 8.4%），混合检测方案的灵敏度为100%（95%可信区间，91.6 - 100.0%），假阳性率为0.8%（95%可信区间，0 - 1.8%），混合检测方案的特异性为99.2%（95%可信区间，98.2 - 100.0%）。成本效益分析表明，混合检测方案可节省69.3%的成本。如果已知血清流行率估计值，血清学家可方便地使用L值表来确定最佳混合样本量。
混合EIA检测的效果不低于单独的EIA检测，且混合检测策略成本显著更低。对于从血清流行率较低的大量人群中筛查抗-HCV阳性个体，推荐采用混合检测方案。
