ABSTRACT
【Objective】 To investigate the prevalence of hepatitis D virus in Dalian blood donors. 【Methods】 The samples reactive to HBV in blood screening were selected with the following confirmed results: 1)HBsAg+ &HBV DNA+ ; 2)HBsAg+ & HBV DNA-; 3)HBsAg-&HBV DNA+ ; 4)NAT-yield uncertain. Qualified samples in routine blood screening were additionally tested with anti-HBc+ and anti-HBs+. All samples selected were tested HDV IgG further. Initial reactive samples would be tested by another HDV IgG assay and HDV IgM assay. HDV IgG positive was confirmed when samples were reactive to two HDV IgG assays. 【Results】 None HDV antibodies were detected among 1 344 unqualified samples (507 HBsAg+ &HBV DNA+, 33 HBsAg+ &HBV DNA-, 477 HBsAg-&HBV DNA+ and 327 NAT-yield uncertain samples) or 766 qualified samples (397 anti-HBc+ and 369 anti-HBs samples) in blood screening. 【Conclusion】 The prevalence of HDV infections among Dalian blood donors eligible in pre-donation screening seemed extremely low. However, for areas with high HBV prevalence, the risk of blood safety caused by OBI co-infection with HDV should not be ignored.
ABSTRACT
【Objective】 To evaluate the role of anti-HBc detection in current blood screening strategy by the follow-up of repeated donors with antibody to hepatitis B virus core antigen. 【Methods】 Plasma samples were collected randomly from Dalian Blood Center. to test anti-HBc(dual reagents) and anti-HBs via ELISA. The re-donation of eligible donors who were anti-HBc+ and donors reactive to HBV detection were followed up. 【Results】 A total of 1 291 plasma samples were collected randomly from May 2017 to March 2018, among which 405 samples(31.4%)were anti-HBc+. The median age of anti-HBc+ group was observed much higher than that of anti-HBc-group (39 vs 31 years old) (P0.05). Among the 405 anti-HBc+ donors, 3 donors were OBI (0.7%), of which one was screened out in second donation. No HBV DNA was detected out in 3 OBI cases. 【Conclusion】 Although anti-HBc detection is not suitable in blood screening currently, it is of great value in the assessment of blood donor re-entry for HBV reactive donors in blood screening due to the high anti-HBc prevalence among blood donors.
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【Objective】 To investigate whether the current retention methods in blood stations can fully meet the traceability requirements of blood test results by analyzing the traceability of retained samples for syphilis antibody testing. 【Methods】 Thirty-four one-assay-positive deep-well plate retention samples, 68 double-assay-positive deep-well plate retention samples and 263 negative retention blood braids and corresponding deep-well plate retention samples that expired retention period for syphilis antibody testing from 2014 to 2020 in our center were collected. The TP-ELISA assays of two manufacturers were used for retesting, and the results were recorded and compared with the original results statistically. 【Results】 The concordance rate of the double-assay-positive and single-assay-positive samples with their corresponding deep-well plate samples was 98.53%(67/68) and 67.65%(23/34), respectively(P<0.05). Specific results for single-assay-positive syphilis antibody samples and their corresponding deep-well plate retention samples were as follows: 1) Single positive (reagent A): 13 out of 14 original samples were 0.65
ABSTRACT
【Objective】 To validate the performance of a nucleic acid testing(NAT) system for blood screening in the high-altitude Nagqu region of Tibet, in order to assess the capability of NAT in high-altitude areas and further enhance blood safety. 【Methods】 Various methods were employed to evaluate the analytical sensitivity, reproducibility, ability to prevent cross-contamination, and comparison between different NAT systems. 【Results】 The NAT system in the Nagqu region of Tibet achieved a 100% detection rate for high-concentration HBV DNA and HIV-1 RNA samples, and over 90% for medium-concentration samples. PROBIT analysis revealed the lower limits of detection (LOD) for HBV DNA and HIV-1 RNA to be 8.29 IU/mL (95% CI, 5.88~20.55 IU/mL) and 40.52 IU/mL (95% CI, 30.26~85.92 IU/mL), respectively. For HCV RNA genotype 2a, the LOD was 97.14 IU/mL (95% CI, 71.00~182.67 IU/mL), all of which were lower than the declared minimum detectable concentrations in the instructions. Reproducibility analysis demonstrated a 100% level of consistency within the system. Cross-contamination performance verification showed a strong ability to resist cross-contamination. Comparative analysis of repeated testing of low-concentration HBV DNA samples and multi-system testing in plain areas revealed consistency rates of 77.78%(14/18) and 77.27%(17/22), respectively, indicating certain differences between the NAT system in Nagqu region and other systems. 【Conclusion】 The NAT system exhibited excellent performance in blood screening at high altitudes. The results of performance validation in high-altitude blood screening NAT systems were largely consistent with those in plain areas, providing a reliable basis for enhancing blood safety in high-altitude regions.
ABSTRACT
【Objective】 To establish a reasonable and effective blood screening strategy for Hepatitis C virus (HCV), so as to reduce the risk of blood transfusion transmission, ensure blood safety and improve the quality of blood screening. 【Methods】 In order to evaluate HCV screening strategies comprehensively, the unqualified blood donations due to anti-HCV alone positivity in Dalian from 2017 to 2021 was tracked, with combined detection methods of electro-chemiluminescence immunoassay (ECLIA) and HCV-RNA nucleic acid test (NAT). 【Results】 A total of 851 (0.20%) unqualified donations due to anti-HCV alone positivity were screened from 2017 to 2021, with a decreasing trend in both numbers and rate. Among them, the unqualified rate of samples with anti-HCV reactivity in both dural-ELISA-reagent and NAT decreased significantly (P<0.05). A total of 117(0.028%) samples were anti-HCV reactive in dural-ELISA-reagent but nonreactive in NAT; 664 reactive in one-ELISA-reagent, with 70(10.54%) in Reagent Ⅰ and 594(89.46%) in Reagent Ⅱ; 122 (35.88%) out of 340 donations were reactive in ECLIA. Among the 28 participants in the follow-up test, 15 still were reactive in ELISA and 2 reactive in ECLIA. 【Conclusion】 Although the unqualified rate of HCV is decreasing, serological screening of anti-HCV is still an important method for ensuring blood safety, and its complementarity with HCV-RNA NAT should be evaluated. As a new serological assay, ECLIA has high sensitivity and specificity. Miss detection may occur if only one ELISA reagent is adopted for anti-HCV detection. Appropriate ELISA and NAT system for HCV screening should be reasonably chosen, and HCV screening strategy should be developed and adjusted according to the local conditions.
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【Objective】 To investigate HIV-1 subtype distribution and trend among Dalian blood donors between 2011 and 2020, in order to provide information to improve blood safety and HIV prevention. 【Methods】 HIV RNA was purified from plasma samples of Dalian blood donors with confirmed HIV infection, which were collected between 2011 and 2020. The HIV pol gene was amplified and sequenced. HIV-1 subtypes were determined by phylogenetic analysis. 【Results】 HIV RNA was successfully genotyped in 174 samples from HIV-infected donors. The main subtypes among Dalian blood donors were CRF01_AE(69.5%), CRF07_BC(17.2%), B(5.2%), CRF02_AG(2.9%), C(1.1%), CRF55_01B(1.1%), CRF08_BC(0.6%), CRF59_01B(0.6%) and CRF79_0107(0.6%). There were still 2 cases (1.1%) unclassified. Significant difference was observed when comparing with the published national data. The prevalence of CRF01_AE strains decreased over the years, while CRF07_BC increased significantly. CRF02_AG carriers differed from donors infected with other HIV subtypes by being mostly females (40.0% vs. 2.4%), aged (median: 35y vs. 26y) and lower educational background(junior school degree or below). And 96.7% of local CRF01_AE cases were related to HIV strains, which were reported to circulate in Northeast China and in the MSM population. 【Conclusion】 HIV-1 among Dalian blood donors had unique molecular epidemiology and the trends of 07_BC increasing and 01_AE decreasing lagged behind the overall national data. Donor education on blood safety and consultation services to high risk group before donation still need improvement.
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【Objective】 To investigate the serological and molecular characteristics of HBsAg+ /HBV DNA non-reactive (NR) infections. 【Methods】 Samples tested as HBsAg+ and HBV DNA NR were confirmed by individual NAT repeat testing, viral particle concentration by PEG precipitation combined with in-house nested PCR and real-time quantitative PCR, anti-HBc testing, and HBsAg quantification. HBV sequences were compared with those from donors with chronic and occult infection as controls. 【Results】 A total of 792 195 samples were screened between January 2011 and December 2020, of which 53 (1: 14 947) were confirmed HBsAg+ /HBV DNA NR. HBV DNA was detected further in five (9.4%) samples; three S sequences and four Pre Core/Core sequences were obtained. Unique amino acid substitutions (P130T, P135Q/S, R151Q, G153S and S155F) were found in the Core protein that may affect virus packaging and replication. 【Conclusion】 Extremely low HBV DNA level was detected in plasmas of HBsAg+ /HBV DNA NR donors. Barely detectable HBV DNA might be associated with unusual mutations in the Pre Core/Core protein affecting viral replication. More sensitive HBV DNA and/or HBsAg assays may be considered to further reduce the potential HBV transfusion-transmission residual risk.
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【Objective】 To analyze the environmental monitoring results of NAT laboratory from 2016 to 2019 and evaluate the influence of environmental quality on blood screening. 【Methods】 Monthly/Quarterly environmental monitoring was carried out in NAT laboratory regularly by means of air deposition and surface wiping. The monitoring results were statistically analyzed and comprehensively evaluated in combination with the pool/multiplexNATreactiverate and discriminatory/resolutionrate. 【Results】 A total of 48 batches of environmental monitoring tests were conducted from 2016 to 2019, 11 (25 reactive sites) were unqualified, including 15 reactive sites (60%) as the hallway doorknob or access control, which were the public areas shared with serology laboratory, and these sites were not reactive for 6 consecutive months after intensive cleaning and disinfection. In Nov.2017, the air deposition in biosafety cabinet and surface wiping of Cobas s 201 were reactive, and the restwere the doorknobs. Pearson correlation analysis showed that there was no correlation between the positive rate of environmental monitoring and the detection amount, the pool/ multiplex NAT reactive rate and discriminatory/resolution rate. 【Conclusion】 The accidental environmental pollution in the laboratory is not related to the detection amount and positive rate, indicating that the cleaning and anti-pollution measures are timely and effective to ensure the accuracy and reliability of the screen results. NAT laboratory should gradually establish and improve the environmental monitoring system according to the layout and environment so that the environmental quality meets the testing conditions.
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【Objective】 To confirm Hepatitis B virus (HBV) infections and identify infection status by excluding false positive in blood donors reactive to nucleic acid testing (NAT) but without serological markers (Seroneg-NAT). 【Methods】 Seroneg-NAT yields were selected among blood donors in Dalian Blood Center from November 1, 2010 to February 28, 2021, and their HBV DNA was further confirmed with TaqMan HBV DNA quantification or virions concentration by polyethylene glycol (PEG) precipitation combined with in-house nested PCR targeting the S, BCP, PreS/S and Precore/core regions of the viral genome, and follow-up test was carried out, including blood routine screening and HBsAg, anti-HBs and anti-HBc testing. HBV infection was confirmed by HBV DNA yielding and anti-HBs/anti-HBc seroconversion in follow-up testing, and HBV DNA was further sequenced if necessary. 【Results】 During the period of 10 years and 4 months, 0.03% (126/466 911) Seroneg-NAT yields were selected, of which 46.8% (59/126) were HBV DNA+ and 53.2% (67/126) were unconfirmed. Among 126 Seroneg-NAT yields, 40.5% (51/126) were involved in follow-up test, of which 28 were HBV DNA+ and 23 were unconfirmed. HBV infections were confirmed in 48% (60/126) of Seroneg-NAT yields. Of follow-up donors, 54.9% (28/51) were identified as early infection before seroconversion, 2.0% (1/51) seronegative occult HBV infection (OBI), and 37.3% (19/51) NAT false positive. There were still 5.9% (3/51) classified as the indetermination. 【Conclusion】 Nearly half Seroneg-NAT yields in Dalian blood donors were infected with HBV and more than 50% were early infections before seroconversion. The majority of HBV DNA unconfirmed without serological markers were false positives.
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【Objective】 To explore the basic situation and advantages of blood banks in Russia through analyzing the differences and similarities of basic standards for blood banks(referred to as standards) between China and Russia. 【Methods】 The main differences and similarities were analyzed by comparing the classification of blood banks and the requirements for staff and equipments. 【Results】 The macro contents such as the main functions and responsibilities of blood banks, the basic requirements for staff and equipments were both described in the standards in China and Russia, but such details as classification criteria of blood banks, the allocation criteria of staff and equipments were not the same. 【Conclusion】 The macro contents of the standards in China and Russia were basically the same, but some of the details of Russia standards were more clear and scientific than those of Chinese standards, and some contents were worth learning.