| BackgroundDue to untypical clinic symptom, hepatitis C was made a diagnosis mainly based on the laboratory detection in order to avoid missed diagnoses. The laboratory detection played an important role in blocking infection. ELISA , as a dominating test, was applied to population screening because of low cost, high sensitivity and specificity, but it had false positive being used to large population. The supplement experiment of RIBA was applied to doing research in china, with higher in specificity than ELISA, lower sensitivity, which was complex operation, wasting time and high cost. Because of high demands on test and equipment, it was difficult for HCV RNA test to be used in routine works or base laboratory. There have not perfect test strategy for HCV by now in china. In order to resolve the problems of single anti-HCV test and meet the need of works, it was necessary for various populations to make reasonable test strategy with tests based on different targets.ObjectiveTo evaluate the method of anti-HCV ELISA; To provide evidence for perfecting testing for HCV and choose test strategy for various kinds of populations by analyzing the application of 5 tests strategy.MethodsFist of all, 3 serum panels including national HIV/AIDS reference lab basic serum panel,BBI seropostive serum panel and CAP proficiency test serum panel evaluated domestic and foreign kits with se, sp, ppv and npv.Then, kits were chosen to evaluate the test strategy for HCV. 402 samples were collected from four kinds of infected populations. Every sample was tested by 8 anti-HCV ELISA kits, then any screening positive sample was repeat tested by RIBA in order to confirm every sample. A threshold S/CO ratio identified for each ELISA kit need to be analysied, which correlated with the >95 percent supplemental test-positive rate. According to tests strategy, evaluation was calculated by comparing the test results of every strategy with the true results of sample. Evaluation indexes of every strategy were analyzed between different populations by rank sum test.Based on the price of kits and experiment material, the cost of testing a sample for every strategy was calculated and compared with each other. ResultsThe sensitivity in 11 anti-HCV ELISA kits was 100%, while the specificity of most was larger than 90%. The results of seroconversion panel showed mean delay days of 5 kits, which was in detection of the bleeds of the seroconversion panels compared to the first bleed detected positive by any of the tests, were less than 2 days. All of kits could test anti-core, while most of which could not detect anti-NS3. The results of American CAP serum panel indicated the tests of all kits were consistent with expected results.The difference between S/CO of 6 kinds of domestic anti-HCV ELISA was significant from 3.6 to 11.8. S/CO ratios of 2 kinds of foreign kits were 4.3. The sensitivity of signal test strategy was mostly 100%, lower specificity. There was no significant difference in four indexes of parallel strategy and sequence strategy. The ppv of S/CO substitute strategy was higher than other strategy, less sensitivity. The ppv of three kits test strategy was higher than signal test strategy, parallel strategy or sequence strategy, however lower than S/CO substitute strategy. There were no significant difference in tests power between domestic kits combination and combination of domestic and foreign kits. The cost of domestic kits was lower than foreign kit.Conclusion1,The study further confirmed ELISA high sensitivity and specificity, which was applied toscreening in general population.2,It was unsuitable that making uniform regulation about S/CO of each domestic kit, whichcorrelated with the >95 percent supplemental test-positive rate.3,The advice that the samples whose the S/CO of test results of ORTHO and ABBOTT waslarger than 3.8 need not to be confirmed by RIBA need to be further studied in China. 4,There was no significant difference between domestic and foreign kits, so the test foranti-HCV was not completely relied on foreign kits.5,The study suggested that single test strategy was applied to population surveillance . 6,The study provided support that the parallel testing could be used in blood donors test. 7,When S/CO substitute strategy was applied to clinic diagnoses, the difference between kitsshould be considered.
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