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【Objective】 To investigate the unqualified rate of anti-HIV detection of blood screening laboratories in Beijing-Tianjin-Hebei region, and explore the differences in anti-HIV detection ability and influencing factors in each laboratory. 【Methods】 Through filling questionnaires via e-mail, the anti-HIV ELISA unqualified rate and confirmed (WB) positive results (data) from January to December 2018 from 15 blood screening laboratories in Beijing-Tianjin-Hebei region were collected. Our laboratory was responsible for data collection and confirmation, and statistics software SPSS22.0 was used for analysis. 【Results】 1) There was a statistically significant difference among the unqualified rate of anti-HIV ELISA(6.77‱~35.71‱) and confirmed positive rate(0.60‱~3.56‱) in 15 blood screening laboratories in Beijing-Tianjin-Hebei region (P<0.05); 2) There were significant differencse among the ELISA unqualified rate and the confirmed positive rate of 8 reagents for anti-HIV detection(P<0.01), and the sensitivity of the 4th generation detection reagent and the imported reagent was higher than that of the 3rd generation reagent and the domestic reagent. The anti-HIV ELISA unqualified rate of R5 was the highest (19.08‱). 3)There were significant differences in the anti-HIV ELISA unqualified rate of R1, R2, R3, R5 and R7 reagents among different blood station laboratories(P<0.05), and there were no significant differences in the anti-HIV ELISA unqualified rate of R4, R6 and R8 reagents among different blood station laboratories(P>0.05). 4)The unqualified rate of anti-HIV ELISA of laboratories using different regents showed significant differences(P<0.05), except H, J, M. The unqualified rate of imported reagent was significantly higher than that of domestic reagents of laboratories using imported and domestic reagents combinations(P<0.05), except O. 62.5% (5/8) laboratories using domestic 3rd and 4th generation reagent combination showed significant differences in the unqualified rates among different reagents(P<0.05); 5) The positive rate of single-reagent(62.02%~95.45%)in 15 blood screening laboratories showed significant difference(P<0.001), and A was the lowest (62.02%). 【Conclusion】 The anti-HIV detection ability among 15 blood screening laboratories in Beijing-Tianjin-Hebei region is quite different. The application of different reagents is the main factor for the difference, and other factors such as personnel, instruments and test strategies also has a great impact on the detection of anti-HIV. It is still necessary to promote the process of homogenization of blood testing quality among blood screening laboratories in Beijing-Tianjin-Hebei region.
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ObjectiveTo assess the accuracy of indirect enzyme-linked immunosorbent assay (ELISA) for hepatitis C virus (HCV) antibody as a routine test in the blood center, discuss how to optimize the reporting process for HCV antibody, and protect donors′ enthusiasm and precious blood resources. MethodsA total of 116 samples were screened by two indirect anti-HCV ELISA kits available from Shanghai Kehua (reagent A) and Beijing Wantai (reagent B), respectively. Samples that yielded positive results or gray-zone results were further validated using a confirmation reagent to establish definitive results and compare confirmed positive results and the results with the two reagents for indirect ELISA. Differences in the ELISA results of the 116 samples between the two anti-HCV reagents were compared using the paired chi-square test and the agreement between the results with the two reagents were compared using the Kappa test. ResultsThere were significant differences in the test results between the two reagents used for indirect ELISA (P=0.04), but the two reagents varied greatly from each other. The false positive rates of samples strongly or weakly positive with both reagents were 0 and 35.7%, respectively; the false positive rates of samples positive with either reagent or samples with gray-zone results were 94.3% and 100% for reagent A and 842% and 88.9% for reagent B. ConclusionReagents used for indirect ELISA have high false positive rates and poor specificity and considerable differences exist between homemade indirect reagents. The existing HCV reporting process should be modified. Weakly positive specimens should be further validated by a confirmatory test to protect blood donors′ enthusiasm.
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Objective To compare the sensitivity and specificity between indirect enzyme -linked immunosorbent assay (ELISA)and double -antibody sandwich ELISA kits produced in China and to select the best ELISA kit.Methods Samples for evaluation included 60 serum plates and 40 serum samples positive or weakly positive for antibody to hepatitis C virus (anti -HCV)which were confirmed by re-combinant immunoblot assay.These samples were tested with a sandwich ELISA kit and three indirect ELISA kits,all of which were pro-duced in China.Comparison between ELISA kits was made by paired chi -square test;comparison of false negative rate was made by R × C contingency table test.Results The sensitivities of three indirect ELISA kits and a sandwich ELISA kit were 90.2%,78.0%,95.1%, and 97.6%,respectively,and the specificities were 78.1%,72.6%,94.1%,and 100%,respectively.The sandwich ELISA kit had a 4-8 times higher sensitivity than indirect ELISA kits.The R ×C contingency table test revealed significant differences in false negative rate between ELISA kits and combinations of ELISA kits (χ2 =29.898,P <0.05).Conclusion Sandwich ELISA kit has higher sensitivity and specificity than indirect ELISA kits.Combined use of sandwich ELISA and indirect ELISA kits can significantly reduce the false negative rate and effectively prevent missed anti -HCV detection.
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Objective To explore the characteristics of drug resistance of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus SCCmec genotyping.Methods The disc agar diffusion method was taken to test 500 Staphylococcus aureus susceptibility and methicillin-resistant Staphylococcus aureus by multiplex PCR SCCmec genotyping assay.Results The rate of methicillin-resistant Staphylococcus aureus was 40.0％ (200/500),and had a high resistance rate to clindamycin,sulfamethoxazole and tetracycline,which celebrate neomycin and quinolones resist ance rates,while a completely resistant to clindamycin and β-lactam drug,and other performance of multi-drug resist ance,resistance to vancomycin had not uncovered any prime strains; through SCCmec genotyping of MRSA,which mainly SCCmec Ⅲ and SCCmec Ⅳ well SCCmec Ⅴ type,another seven unclassified.Conclusion The separation of Staphylococcus aureus,methicillin-resistant Staphylococcus aureus performance of multiple drug resistance performance of its SCCmec genotyping is SCCmec Ⅲ type and SCCmec Ⅳ and SCCmec Ⅴ type.