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@#Objective To prepare the national reference panel of hepatitis B virus(HBV) for nucleic acid testing(NAT)donor screening.Methods A number of plasma samples from donors positive for HBV antibody and patients with HBV infection collected from blood centers,plasma stations and biological products companies in Shanghai,Gansu,Henan,Hunan,Hubei and other regions were tested for HBV DNA viral load agent,and negative and positive reference candidates were screened;The HBV DNA national standard was diluted to 10~3 IU/ml with human negative plasma,as a candidate for limit of detection(LOD).National negative and positive reference candidates of HBV for NAT donor screening and LOD reference to be calibrated were distributed to 8 enterprise laboratories for joint detection of HBVHCVHIV NAT donor screening.The homogeneity and stability of the national reference panel were investigated.Results A total of 8 negative samples with HBV viral load of 0 were screened as negative references and 9 positive samples with viral load of 10~3～10~4 IU/mL were used as positive references;One LOD reference was calibrated with WHO HBV DNA standard,and the virus content was 1.0 × 10~3 IU/ml.The national reference panel showed good stability and the homogeneity inspection met the requirements.Conclusion The national reference panel of HBV DNA for NAT donor screening was prepared,which provided a basis for the quality control and standardization of HBV DNA reagents for donor screening.
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【Objective】 To analyze the influencing factors of the repeat reactive (RR) rates of minipools implicated in minipool (MP) nucleic acid testing(NAT) in Xiamen Blood Center, in order to provide reference for NAT. 【Methods】 Samples of blood donors from January 1, 2019 to October 31, 2022 were collected in Xiamen Blood Center and tested by MP-NAT(pools of six). Statistical analysis and comparison of MP-NAT RR rates was performed among different years, testers, reagent batches, instrument combinations, CT values of MP-NAT reactive pools and sample backgrounds. 【Results】 A total of 234 715 blood samples were tested by MP-NAT, and 428 pools were reactive, in which 248 pools were individual-donor NAT reactive, with a MP-NAT RR rate of 57.9%. The difference of MP-NAT RR rates were not statistically significant among different years, testers, reagent batches, instrument combinations, and sample backgrounds (P> 0.05). The difference of MP-NAT RR rates among different CT values of MP-NAT reactive pools was statistically significant (χ2=69.587, P<0.05). Significantly abnormal RR rate accurred in two months in 2022, and returned to normal after timely handling. 【Conclusion】 The MP-NAT RR rates is one of the important indicators to monitor the quality of NAT. Once there is a significant change in the MP-NAT RR rates, comprehensive analysis and timely handling should be carried out to ensure the quality of blood detection.
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【Objective】 To analyze the difference of Ct value of HBsAg-/HBV DNA + in blood samples from different types of voluntary blood donors by double ELISA and HBV DNA (MP6) detection, and to investigate the correlation between Ct value and the frequency of repeated blood donation, the first nucleic acid reactivity and the interval time of previous blood donation, so as to provide reference for laboratory evaluation of the effectiveness of nucleic acid testing(NAT) strategy for repeated blood donors occult hepatitis B virus infection(OBI). 【Methods】 The Ct value and information of blood donors from February 2019 to January 2022 in our laboratory were collected. According to the cumulative number of blood donations, they were divided into two groups:first-time blood donor group (Group A) and repeated blood donor group (Group B). Group B was subdivided into Group C 1( twice of blood donation) and group C 2(three or more times of blood donation) according to the cumulative times of blood donation, and Group D 1(< 1 year), Group D 2(1-3 years), Group D 3(3 years or more) according to the first NAT reactivity and the time of previous blood donation, the difference of Ct value and resolution yeild of HBV DNA in each group was compared. The yeild of HBV DNA in two groups was compared by chi-square test, and the difference of Ct values were compared by Nonparametric test. 【Results】 From February 2019 to January 2022, a total of 270 283 blood donors were tested, including 135 695 in Group A and 134 588 in Group B. The yeild of HBV DNA in Group A was 0.150% (203/135 695), which was higher than that in Group B [0.083% (111/134 588)] (P <0.05).All Ct values were non-normal distribution by normal distribution test, and were expressed as median (quartile), the median values of MP6 and resolution Ct were 37.0(35.9,38.2) and 35.5(33.7,36.9) in Group A, 37.2(36.4,38.1) and 36.5(35.5,37.6) in Group B, respectively. Ct values of MP detection and resolution in Group A, of MP detection and resolution in group B, and of resolution in group A and B were all significant (P<0.05) From the cumulative number of blood donations to compare, the median values of MP detection and resolution Ct were 37.5(36.6,38.3) and 36.5(35.4,37.6) in Group C1,37.1(36.4, 37.9) and 36.6(35.6,37.8) in Group C2, respectively. Significant difference in resolution Ct value between Group A and Group C1, Group A and C2 was noticed(P<0.05), the median values of MP detection Ct in D1, D2 and D3 groups were 37.2(36.3,38), 37.1(36.5,37.9), 37.8(36.6.38.9),respectively, with median resolution CT values at 37.0(35.7,37.8), 35.9(34.8,36.9), 36.9(36.1,37.7), respectively. There was a significant difference in the resolution Ct values between between Group A and D1 and D3 groups (P<0.05), and there was a significant difference between the MP detection and resolution Ct values in D2 Group (P<0.05). The resolution Ct values in D2 and D3 Group were lower than those in D1 Group (P<0.05).The interquartile distribution of Ct values in Group A was wider than that in other groups, and the interquartile distribution of Ct values in Group B was more concentrated. Conclusion The Ct value of HBV DNA detected by nucleic acid in blood donors was correlated with different times of blood donation and different intervals of blood donation. The laboratories of blood station should pay attention to the nucleic acid test results of different types of blood donors to ensure blood safety.
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【Objective】 To analyze the SARS-CoV-2 detection results among blood donors in different periods of COVID-19 pandemic control in Shenzhen and assess the antibody levels and infection status of blood donors in different periods, so as to provide reference for subsequent blood testing strategies. 【Methods】 A total of 4 768 plasma samples of blood donors were subjected to pooled testing by nucleic acid testing(NAT) with 8 samples per pool. Additionally, these samples were subjected to a 1000-fold dilution, and the detection of SARS-CoV-2 total antibody was performed by enzyme-linked immunosorbent assay (ELISA). The 4 768 plasma samples were collected from blood donors at different time points in Shenzhen, with inquiries made to determine whether donors during the COVID-19 pandemic were in the convalescence. The antibody positive rates in blood screening samples during different periods of the pandemic and samples from individuals in the convalescence of COVID-19 infection were analyzed. Furthermore, the antibody levels were examined for differences based on gender, age, and blood type. 【Results】 All 4 768 plasma samples from blood donors were negative by NAT, while 2 342 samples were detected positive by the SARS-CoV-2 total antibody detection, with a positive rate of 49.1%. These samples from four periods (September 30 to October 3, 2022; November 3 to 6, 2022; December 27 to 31, 2022; January 6 to 18, 2023) were subjected to a 1 000-fold dilution for COVID-19 antibody detection, and the positive rates were 21.3%, 15.8%, 65.9%, and 93.9%, respectively. 【Conclusion】 The prevalence of COVID-19 antibodies among blood donors in Shenzhen during different periods of the pandemic varied significantly. There was no difference in antibody prevalence among different genders and blood types, while younger individuals exhibited a higher prevalence of antibodies. The risk of COVID-19 transmission through blood transfusion was found to be extremely low.
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【Objective】 To explore the role and significance of nucleic acid testing(NAT) in blood transfusion. 【Methods】 The NAT data from March 2015 to December 2019 were collected and analyzed by inquiring the monthly analysis table of NAT-yielding results and the information management system of Qiao Blood Station (shinow9.5). The NAT capability of Kehua and Roche nucleic acid screening systems were compared. 【Results】 A total of 19 8348 samples were screened by Kehua and Roche nucleic acid screening systems, 67 reactive samples were detected, including 65 HBV DNA reactive samples, 2 HIV RNA reactive samples, and no HCV RNA reactive sample. 151 096 samples and 47 252 samples were detected by Kehua system and Roche system, with the resolution ratio at 44.55% vs 56.25% (P>0.05) and the reactive rate at 0.032% vs 0.038 % (P>0.05), respectively. The effective resolution ratio were 42.86%, 45.45%, 50%, 40% and 57.14% each year from 2015 to 2019, and the reactive rates were 0.041%, 0.042%, 0.027%, 0.021% and 0.038%, respectively. There was no statistical significance among each year by the effective resolution ratio and the reactive rate (P>0.05). The reactive yield at resolution was the highest (77.42%, 24/31) in minipool with CT <33 and the lowest(13.64%, 3/22) in minipool with CT≥40, mostly(73.13%, 49/67) remaining in CT<35. 【Conclusion】 Both Kehua and Roche screening system can detect NAT reactive samples in enzymatic non-reactive samples. The lower the CT value of mini pool, the greater the resolution probability of reactive samples. NAT can further guarantee the safety of blood transfusion.
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【Objective】 To investigate the status of blood safety and the effectiveness of preventive measures. 【Methods】 The data of Fengxian Blood Bank from 2018 to 2020 were extracted from Shanghai blood collection and supply information system. HBsAg sero-conversion samples of repeated blood donors were confirmed, and HBV serologic supplemental test were performed to obtain the number of new infections during the blood donation interval. The incidence and residual risk of HBV infection were evaluated by the sero-conversion model in donation intervals for repeated donors, and residual risk trend between the study period of 2002 to 2005, 2007 to 2011, 2011 to 2013 and 2018 to 2020 was compared. 【Results】 During 2018~2020, nine new HBV infections occurred among repeated donors during blood donation interval, with an incidence rate of 2.71 per 10 000. The residual risk of window period HBV transmission by transfusion could be reduced by 58.33% using HBsAg test plus NAT (HBsAg test 1∶30 637 vs HBsAg test plus NAT 1∶73 529). The residual risk of HBV transmission was decreasing when stratifying by periods, especially one order of magnitude dropped in 2018~2020 as in comparison of 2002 to 2005. 【Conclusion】 The residual risk of HBV transmission by transfusion showed a decrease trend. Although NAT could greatly reduce the risk, comprehensive preventive measures are needed to further reduce the risk.
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【Objective】 To analyze the HIV-, HCV- and HBV- NAT yield rate in different areas of Henan province, so as to provide the basis for disease prevention and control as well as the establishment of a unified quality control standard for nucleic acid testing(NAT) in the Henan province. 【Methods】 The number and prevalence of NAT yielding samples with isolated infectious virus, namely HIV, HCV and HBV, in 18 blood stations in Henan province from 2017~2019, as well as the trends were analyzed. The NAT quality of each laboratory and each testing system was analyzed according to the ratio of reactive individual donation(ID) results to reactive minipools(MP). 【Results】 The HBV, HCV and HIV ID-NAT yield numbers in 3 501 251 blood donations were HBV 2 606(74/100 000), HCV 21 (0.63/100 000), and HIV 34(1.00/100 000). The HBV ID-NAT yield rate showed an upward trend in the whole province from 2017 to 2019, while the prevalence of HIV and HCV ID-NAT yield didn′t differ significantly during three years. 5 kinds of NAT detection systems were applied in 18 blood centers. among which Ⅰ, Ⅱ, Ⅳ and Ⅴ were triplex detection systems. 2661 ID-reactive samples were implicated in 5 595 MP-reactive samples, with a resolution rate of 47.56%. The resolution rate of triplex NAT system Ⅰ, Ⅱ, Ⅳ and Ⅳ was 39.63%~47.95%, 40.43%~54.36%, 51.61% and 70.00%~45.45%, respectively. An upward trend in triplex NAT resolution rate was observed in 8 laboratories, i. e.B, D, E, F, I, K, L and Q, and an descending trend in A and C. The NAT system Ⅲ, a ID-NAT system, was used only by laboratory C, presenting a NAT-yield rate of 0.19% (282/145 474) and resolution rate of 46.45% (131/282). 【Conclusion】 The majority of NAT-yield of one infectious virus in Henan province is HBV, presenting annual increasing trend. The quality management of NAT laboratories should be strengthened as the divergence was seen in the performance of different NAT laboratories.
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【Objective】 To compare the detection performance of Cobas s201, a minipool(MP) nucleic acid test(NAT) system, and Panther, a individual donation(ID) NAT system, in blood donor screening. 【Methods】 NAT was conducted on 126 359 blood samples, and initially reactive (IR) samples were either discriminated or resolved by ID testing.The non-discriminated reactive (NDR) samples implicated in Panther sysytem were subjected to ID-NAT by Cobas s201. Some non-repeatable reactivet(NRR) and repeatable reactive (RR) samples implicated in Cobas s201 system were subjected to ID-NAT by Panther. 【Results】 61 MP-IR cases were implicated in a total of 85 128 samples that detected by Cobas 201, and 29(0.34‰) were RR after resolved by ID testing. 74(1.79‰)IR samples were implicated in 41 231 samples that detected by Panther, and 22 (29.73%) were DR-HBV after discriminatory test. Among the NDR 28 samples detected by Panther multiplex system, 7 were positive by Cobas s201 single sample (PP1) whereas non-reactive in simulated MPs of six by Cobas 201.In 28 RR samples resolved by Cobas 201, 24 positive and 4 negative samples were retested by Panther. Among the 11 samples presenting inconsistent retest results by Panther and Cobas 201, 10 were anti-HBc positive, carrying low viral load HBV. 【Conclusion】 The NAT-yield by Panther was significantly higher than that by Cobas s201. Some samples with negative discriminatory results were OBI, and it is necessary to further track and verify the unidentified samples. Cobas s201 is more suitable for a wide array of MP-NAT testing while Panther sample loading, which is flexible and easy to operate, is more suitable for ID-NAT with medium sample size.
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BACKGROUND: In 2005, the Korean Red cross introduced mini-pool nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV), which upgraded to individual donation (ID) NAT including HBV in 2012. In this study, we analyzed the trend of HCV infection among blood donors after introduction of NAT by estimating the residual risk (RR) of transfusion transmitted infection (TTI) of HCV. METHODS: Donation data from 2003 to 2014 were analyzed using the Blood Information Management System (BIMS). Each donation was tested for antibodies and viral RNA for HCV. Prevalence and incidence rate (IR) among repeat donors were determined. RR was determined using the incidence rate/window period model. RESULTS: During the 12-year period, a total of 29,058,436 donations were screened with 34 HCV NAT yield donations. Calculated RR per million donations for HCV was significantly reduced from 13.41 in the pre-NAT period (2003~2004) to 0.52 in the post NAT period (2006~2007) (P<0.001). Most recently (2013~2014), RR for HCV with TTI was estimated by 0.16 per million donations (1:6,289,308). CONCLUSION: RR of TTI with HCV was remarkably decreased since introduction of NAT. However, the prevalence and IR of HCV RNA among first time donors was still high and yield cases were more frequent among repeat donors. Therefore, establishment of a sensitive and accurate screening system and measures for maintaining healthy donors should be considered in order to ensure blood safety.