RESUMEN
ABSTRACT Introduction: In Brazil, the blood donor screening for hepatitis B virus (HBV) includes laboratory testing for serological (HBsAg and Anti-HBc) and molecular (HBV DNA) markers. This study aims to correlate serology reactive results with HBV DNA detection among blood donors with at least one HBV infection marker detected in a blood bank in northern Brazil. Method: A retrospective search for HBV reactive blood donor data from January 2017 to December 2019 was performed. Serological screening was performed by chemiluminescent microparticle immunoassays Architect HBsAg and Architect Anti-HBc, whereas molecular screening was performed by the HBV nucleic acid test (HBV NAT). Main results: A total of 556 HBsAg reactive results were detected, between positive (47.66%) and inconclusive (52.34%). A total of 3,658 Anti-HBc reactive results were detected, between positive (83.71%) and inconclusive (16.29%). None of the inconclusive results were associated with HBV DNA detection. The HBV DNA detection rates were 47.55% among HBsAg positive samples and 4.08% among Anti-HBc positive samples. The signal-to-cutoff (S/CO) ratio median of HBV NAT positive samples was superior in comparison to HBV NAT negative samples (p < 0.0001). The thresholds found to optimize sensitivity and specificity were 404.15 for Architect HBsAg and 7.77 for Architect Anti-HBc. Three blood donors were in the window period and 1 occult HBV infection case was detected. Conclusion: High S/CO ratios were more predictive of HBV DNA detection. However, a number of HBV NAT positive samples gave low values, while some HBV NAT negative samples showed high values, reaffirming the significance of molecular testing to enhance transfusion safety.
RESUMEN
Background: Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is still a major public health concern around the world. Prompt detection of active tuberculosis cases helps in timely therapeutic intervention and reduces community transmission. Despite limited sensitivity, conventional microscopy is still used to diagnose pulmonary tuberculosis in high-burden nations such as India. This study, therefore, was aimed at assessing the diagnostic performance of microscopy by Ziehl Neelsen (ZN) and auramine (AO) staining in the diagnosis of pulmonary tuberculosis. Materials and methods: A prospective comparative study was done on the sputum samples of 2,395 adult patients from November 2018 to May 2020 suspected of having pulmonary tuberculosis visiting the Designated Microscopic Centre of SGT Medical College, Budhera, Gurugram. Each sample was subjected to ZN staining, and AO staining as per NTEP guidelines. Results: Out of the 2,395 samples studied, 161 (6.76%) and 224 (9.35%) were positive by ZN and AO staining methods respectively. Pauci-bacillary cases detected by AO were more than ZN staining. There were 63 more sputum samples detected by AO staining which were missed by ZN microscopy. Conclusion: When compared to conventional ZN staining, the auramine staining technique is more sensitive and takes less time to diagnose pulmonary tuberculosis
RESUMEN
Backgroung: Brazil was slow to implement an expanded testing policy for COVID-19, which may have affected the most vulnerable population's access to testing services.Objective: to evaluate the factors associated with performing the molecular test for COVID-19.Methods: cross-sectional study of secondary data from the COVID-19 panel in the state of Espírito Santo. COVID-19 suspicion notification forms were included between September 11, 2020 and March 2, 2021. Hierarchical logistic regression was used to estimate the odds ratio (OR) with 95% confidence interval (CI95%).Results: 419,771 notification forms were analyzed. The prevalence of performing the molecular teste for COVID-19 was 81.1% (CI95% 81.0-81.2). Elderly (OR= 2.70 CI95% 2.56-2.85), health professional (OR=1 .43 CI95% 1.36-1.50), chronic cardiovascular disease (OR=1.13 CI95% 1.09-1.17), diabetes mellitus (OR=1.07 CI95% 1.01- 1.14) and hospitalization (OR=5.95 CI95% 4.53;7.82) were more likely to have undergone the molecular test. Male sex (OR=0.96 CI95% 0.94-0.98), black skin color (OR=0.75 CI95% 0.73-0.78), yellow skin color (OR=0.74 CI95% 0.71-0.77), residing in the northern health region (OR=0.37 CI95% 0.36-0.39) and the homeless population (OR=0.76 CI95% 0.67-0.85) had the lowest chance of having undergone the molecular test.Conclusion: Social, economic, contextual factors and the risk of aggravation of the disease were associated with carrying out the molecular test for COVID-19 in the state of Espírito Santo. Actions are needed to guarantee the access of the most vulnerable population to molecular testing.
Introdução: o Brasil demorou a implementar uma política de testagem ampliada para COVID-19 no qual pode ter afetado o acesso da população mais vulnerável aos serviços de testagem.Objetivo: analisar os fatores associados à realização de testes moleculares para o diagnóstico da COVID-19.Método: estudo transversal de dados secundários do painel COVID-19 do estado do Espírito Santo. Foram incluídas fichas de notificação de suspeita de COVID-19 entre 11 de setembro de 2020 a 02 de março de 2021. Empregou-se regressão logística hierárquica para estimativa de razão de chances (odds ratio, OR) com intervalo de confiança de 95% (IC95%).Resultados: Foram incluídos no estudo 419.771 fichas de notificação. A prevalência da realização do teste molecular para COVID-19 foi 81,1 % (IC95% 81,0%;81,2%). Idosos (OR= 2,70 IC95% 2,56-2,85), profissional da saúde (OR=1,43 IC95% 1,36-1,50), doença cardiovascular crônica (OR=1,13 IC95% 1,09-1,17), diabetes mellitus (OR=1,07 IC95% 1,01-1,14) e hospitalização (OR=5,95 IC95% 4,53;7,82) apresentaram maior chance de ter realizado o teste molecular. Sexo masculino (OR=0,96 IC95% 0,94-0,98), cor da pele preta (OR= 0,75 IC95% 0,73-0,78), cor da pele amarela (OR=0,74 IC95% 0,71-0,77), residir na região norte de saúde (OR=0,37 IC95% 0,36-0,39) e a população em situação de rua (OR=0,76 IC95% 0,67-0,85) apresentaram a menor chance de ter realizado o teste molecular.Conclusão: Fatores sociais, econômicos e o risco de agravamento da doença foram associados a realização do teste molecular para COVID-19 no estado do Espírito Santo. É necessário ações que garantam o acesso da população mais vulnerável ao teste molecular.
RESUMEN
Abstract Objective The present study aims to highlight the significance of the nucleic acid test (NAT) for musculoskeletal tissue donation and to compare the sensitivity of this test on the different available platforms. Method The present study is a retrospective survey in a human tissue bank database and an integrative literature review encompassing the last 10 years. The PubMed portal and the SCOPUS, CINAHL, and Web of Science databases were queried for articles. Results We found no specific studies on the use and sensitivity of NAT in braindead tissue donors. The information presented in the present study consists of specific contents intended for the Brazilian Blood Transfusion Network (Hemorrede Transfusional Nacional, in Portuguese) and internal retrospective data from a tissue bank located at a city in the state of São Paulo, Brazil. Conclusions The NAT is effective in blood samples from living patients. However, since biochemical reactions in braindead patients can be different, specific research, platforms, or both are crucial to tissue banks.
Resumo Objetivo Evidenciar a importância da realização do teste de ácido nucleico (NAT, na sigla em inglês) para doação de tecidos musculoesqueléticos, assim como comparar a sensibilidade deste exame nas diferentes plataformas existentes no mercado. Método Trata-se de um levantamento retrospectivo no banco de dados de um determinado Banco de Tecidos Humanos e de uma revisão integrativa da literatura, operacionalizada nos últimos 10 anos. As buscas de artigos ocorreram no portal PubMed e nas bases de dados SCOPUS, CINAHL e Web of Science. Resultados Não foram encontrados estudos específicos sobre a utilização e a sensibilidade do exame NAT em pacientes doadores de tecidos com morte encefálica (ME), sendo as informações apresentadas no presente estudo conteúdos específicos destinados à Hemorrede Transfusional Nacional e aos dados retrospectivos internos de um Banco de Tecidos do interior do estado de São Paulo, Brasil. Conclusões O exame NAT se apresenta efetivo em amostras de sangue de pacientes vivos. Porém, reações bioquímicas em pacientes com condições de ME podem se apresentar de formas diferenciadas, tornando-se indispensáveis a realização de pesquisas específicas e/ou a indicação de plataformas aos Bancos de Tecidos.
Asunto(s)
Humanos , Ácidos Nucleicos , Selección de DonanteRESUMEN
@#Abstract: Objective To compare the diagnostic efficacy of the upgraded version of the GeneXpert automated fluorescent quantitative PCR system (GeneXpert MTB/RIF Ultra, GeneXpert Ultra) and the original version of the GeneXpert system (GeneXpert MTB/RIF, Xpert), real-time fluorescent quantitative nucleic acid detection (FQ-PCR), real-time fluorescent thermostatic amplification of Mycobacterium tuberculosis RNA (SAT-RNA), real-time fluorescent thermostatic amplification detection of DNA (thermostatic amplification method) and traditional BACTEC MGIT 960 liquid culture (culture method) for special specimens of tuberculosis, in order to analyze its application value in clinical detection. Methods Using prospective research methods, a total of 170 special specimens (including 47 pleural and ascites effusion samples, and 34 24-hour urinary sediment specimens, 49 tissue specimens and 40 fester specimens) were collected i'an Chest Hospital from January to September 2021. GeneXpert Ultra, Xpert, FQ-PCR, SAT-RNA, isothermal amplification, and traditional culture were used for detection. Clinical diagnosis was used as the standard, and sensitivity, specificity, positive predictive value, negative predictive value, coincidence rate, and Kappa value were compared among the methods. Results The sensitivities of GeneXpert Ultra, Xpert, FQ-PCR, SAT-RNA, isothermal amplification, and traditional culture were 65.18% (73/112), 49.11% (55/112), 37.50% (42/112), 19.64% (22/112), 8.04% (9/112), and 22.32% (25/112), respectively. The sensitivity of GeneXpert Ultra was higher than that of the other five methods, and the differences were statistically significant (χ2=66.25, 42.10, 28.89, 13.09, 4.92, 15.18, all P<0.05). GeneXpert Ultra result analysis showed that: 5.48%(4/73) cases had trace, that is, trace Mycobacterium tuberculosis load, 79.45% (58/73) cases were extremely low, 10.96% (8/73) cases were low, 2.74% (2/73) were medium, , and 1.36% (1/73) were high load. In 4 trace samples, the Xpert detection was negative for all. Of the 73 GeneXpert Ultra positive reports, 63 were rifampicin-sensitive, 6 were rifampicin-resistant, and 4 were rifampicin-resistant but of unclear resistance. Of the 55 Xpert positive reports, 45 were rifampicin-sensitive, 2 were rifampicin-resistant, and 8 were rifampicinresistant but of unclear resistance.. Conclusions The new generation of GeneXpert MTB/RIF Ultra has high sensitivity, specificity and drug resistance detection rate, and its advantage is even more apparent in the pathogenic diagnosis of special specimens of tuberculosis. It can be used as one of the preferred methods in samples with low bacterial load.
RESUMEN
【Objective】 In an effort to prevent transfusion-transmitted hepatitis B infection, universal HBsAg screening, HBsAg+ MP nucleic acid test(NAT) for HBV and HBsAg + individual(ID) NAT were analyzed for cost-effectiveness. 【Methods】 On the basis of screening data and the documented parameter, the number of window period infections, chronic infections and occult infections was constructed, and cost-benefit analysis was conducted. 【Results】 Of 132 208 donations, the yield rate of ID NAT for HBsAg-/DNA+ (0.11%) was significantly higher than HBsAg+ MP NAT(0.058%). Furthermore, the predicted preventing transfusion transmitted HBV cases by ID NAT is 1.25 times as that by MP-6 NAT, so did the benefits. The cost-benefit of the three screening models were 1∶63.6、1∶28.6 and 1∶53.4. 【Conclusion】 Universal HBsAg in combination with ID HBV NAT screening was the most effective among all screening strategy. It is necessary to applied HBsAg and ID HBV NAT screening for the safety of blood transfusion.
RESUMEN
【Objective】 To analyze the reasons for the invalidity of blood nucleic acid test results, and to explore the countermeasures to reduce the invalidity of the test. 【Methods】 From 2019 to 2021, the number of tests performed in our laboratory for Cobas s201 blood nucleic acid screening system and the number of batches and tests with invalid results were counted, and the types and reasons of invalid results were analyzed. 【Results】 From 2019 to 2021, the Cobas s201 nucleic acid detection system detected a total of 5, 420 batches and 127, 950 pools, and the invalid rate of batches and pools were 1.83% and 1.97%, respectively. The types of invalid results can be summarized as improper operation, sample quality problems, invalid quality control (IQC), equipment failure and others. Among them, IQC and equipment failure were the main reasons for invalid results, accounting for 44.51% and 39.96%, respectively. IQC was mainly related to cross-contamination of samples and insufficient mixing of quality control products. Equipment failures mostly occurred in the robotic arm gripper of the nucleic acid extraction instrument and the TC module of the amplification instrument. 【Conclusion】 The laboratory should conduct quality monitoring for invalid results, and take targeted improvement measures, especially to reduce invalid results caused by invalid quality control and instrument failure.
RESUMEN
【Objective】 To evaluate the application value of nucleic acid testing (NAT) by studying the NAT-yield of syphilis screening reactive blood from five blood centers. 【Methods】 The blood samples and demographic information of syphilis screening positive donors were collected from five domestic blood centers, i. e. Chongqing, Guangxi, Luoyang, Liuzhou, Mianyang and Urumqi. The treponema pallidum particle agglutination (TPPA) and the established SYBR Green qPCR method were used to analyze the difference between the results of NAT and the other two test results. 【Results】 Among 1 679 reactive blood samples for syphilis screening, 819 were confirmed positive by TPPA, accounting for 49%, with the false positive rate exceeded 50%. As to NAT results, the NAT-yield of syphilis screening reactive samples and confirmed positive samples was the same (both 2.20%); the NAT-yield of TPPA-positive and TPPA-negative samples were 2.20% and 2.74%, respectively. 【Conclusion】 Primary syphilis screening by ELISA has high sensitivity, but also presents high false positive rate. Although TPPA confirmatory test has strong specificity, it cannot reflect the existence of T. pallidum. Therefore, NAT may be used as a supplementary test for syphilis screening so as to more effectively ensure the safety of blood transfusion and blood supply.
RESUMEN
【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.
RESUMEN
【Objective】 To evaluate the viability of nucleic acid test(NAT) of human parvovirus B19 (HPV B19), hepatitis A virus (HAV) and hepatitis E virus (HEV) along with routine NAT for voluntary blood donors, and to analyze HPV B19, HAV and HEV prevalence in Nantong, so as to provide reference for rational blood screening programs. 【Methods】 HPV B19 DNA, HAV RNA and HEV RNA of blood donors in Nantong from November 2021 to May 2022 were detected using NAT, and serological antibody testing was performed on NAT reactive samples. 【Results】 Three HPV B19 DNA was yielded out of 3 440 blood donors, with a positive rate of 0.09%, among which 2 were negative for HPV B19-IgM and 1 was undetermined due to insufficient sample size. HAV RNA and HEV RNA were not detected in 3 440 blood donors. HPV B19, HAV, and HEV NAT were conducted simultaneously with routine HBV, HCV and HIV screening, prolonging the test reports by 20 minutes. 【Conclusion】 Although the HPV B19 DNA, HAV RNA and HEV RNA prevalence among voluntary blood donors in Nantong is low, the risk of transfusion transmitted infection still exsits and can be reduced by NAT.
RESUMEN
【Objective】 To explore the influence of common methods of reducing non-viral nucleic acid on the abundance of plasma virus group. 【Methods】 Three kinds of library construction, five kinds of centrifugation conditions, two kinds of filters, four kinds of enzymes and four concentrations of chloroform were used to treat plasma samples added quantitatively 2.16 mL of pseudorabies virus(PRV) and 2.16 mL of porcine parvovirus(PPV). A total of 21.6 mL of plasma samples were processed, including 54 samples. Subsequently, nucleic acid was extracted, mitochondrial DNA(mtDNA) and two viruses were quantitated, the library of the next generation sequencing was constructed, Illumina NovaSeq 6000 was used for the next generation sequencing. The sequencing data were compared with Kraken Py 2.0 software, and the species annotation analysis was conducted. The corresponding species classification information of each segment was obtained to analyze the impact of different reducing non-viral nucleic acid methods on the relative abundance of microorganisms and two indicator viruses. 【Results】 After sequencing by Illumina NovaSeq 6000, 306.27 GB raw data and 193.17 GB clean data were obtained, with Q20>90%, Q30>85%, Error Rate of 0.03%, and average GC Content of 45.02%. The DNA library construction process significantly increased the proportion of microbial sequences and the PRV abundance [(91.8±0.5)%](P<0.05); RNA library construction and combined library construction can increase the abundance of Pestivirus, an RNA virus, and the PRV abundance was(17.7±3.3)% and(8.1±1.5)% respectively. The Ct value of mtDNA was increased and the proportion of human sequence decreased to less than(89.5±1)%, while the proportion of microbial sequence increased to (2.4±0.03)% after treatment of five centrifugation conditions(P<0.05); After centrifugation at 4℃, 100 g, 30 min, the PRV abundance was increased to (40.6±6)%, and centrifugation at 4℃, 4 000 g, 45 min reduced the PRV abundance to (4.1±0.01)%(P<0.05). Both of 0.22-μm filter and 0.45-μm filter increased the Ct value of mtDNA to above 25.56±0.13, decreased the proportion of human sequence to less than (86.1±0.6)%, increased the proportion of microbial sequence to (3.1±0.1)% and (3.4±0.2)%, and decreased the PRV abundance to (1.6±0.3)% and (4.1±0.7)%(P<0.05), while there was no statistical difference in the effect on PPV concentration and abundance. DNase Ⅰ and Benzonase increased the Ct value of PPV to 25.65±0.06 and 25.36±0.45, decreased the proportion of human sequence to (81.7±5.6)% and (72.8±6.7)%, and increased the proportion of microbial sequence and PRV abundance to (11.0±4.1)% and (16.1±4.7)%, (55.8±2.3)% and (39.0±8.9)%, respectively(P<0 05); After treatment with RNase A, the Ct value of PRV increased to 25.20±0.11, and the human sequence proportion decreased to (85.4±5.6)%(P<0 05); Lysozyme had no effect on removing non-viral nucleic acid. The chloroform of 1%, 5%, 10% and 20% increased Ct value of PRV and mtDNA to no less than 27.17±0.21 and 25.68±0.04; Only 10% chloroform increased the proportion of microbial sequences to (3.1±1.2)%(P<0.05); The abundance of PRV with 1% and 5% chloroform treatment was increased to (48.7±13.3)% and (42.1±5.5)%(P<0.05), while 10% and 20% chloroform reduced PRV abundance to (1.0±0.5)% and (3.4±2.8)%(P<0.05). There was no statistical difference in the effect of chloroform with four contents on PPV abundance. 【Conclusion】 Centrifugation at 4℃, 5 000 g, 10 min is suitable for increasing the overall abundance of virus, and centrifugation at 4℃, 100 g, 30 min is suitable for increasing the content of virus similar to PRV. 0.45-μm filter, DNase Ⅰ, Benzonase and low concentration chloroform can effectively reduce the proportion of non-viral nucleic acid sequence in plasma to increase the abundance of the indicated virus group. Thus, the enrichment effect of plasma meta-virome is closely related to the nature of the virus, and the appropriate virus enrichment method should be selected according to the research purpose to establish the corresponding enrichment strategy.
RESUMEN
【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.
RESUMEN
【Objective】 To retrospectively analyze the serological and nucleic acid testing(NAT) data of voluntary blood donors from six blood banks in Tibet, in order to explore the positive impact of NAT on reducing the risk of infective transfusion in a regional scope. 【Methods】 From 2018 to 2022, 38 718 voluntary blood donors from blood centers of Tibet, Shannan, Shigatse, Naqu, Nyingchi and Ngari were tested for hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibody (anti-HCV), human immunodeficiency virus antigen (HIV) and antibody (Ag/Ab1+2) serological determination by enzyme-linked immunosorbent assay (ELISA). At the same time, Haoyuan and Daan nucleic acid detection systems were used for the combined detection of HBV-DNA, HCV-RNA and HIV-RNA. The results of NAT of reactive ELISA samples were statistically analyzed. 【Results】 A total of 178 ELISA-/NAT+ samples were detected in Tibet over the past five years, including 170 HBV-DNA positive cases, 8 HCV-RNA positive cases, and 0 HIV-RNA positive cases, with the positive rate at 0.460%.The detection rate of 624 ELISA+/NAT+ samples was 1.61%.The age of blood donors with hepatitis B in Shigatse area was slightly higher than that in other areas, and the difference was statistically significant(P<0.05) . 【Conclusion】 The centralized detection of viral nucleic acid in Blood Center of Tibet Autonomous Region can effectively reduce the missed detection of transfusion transmitted diseases and guarantee the blood safety in the region.
RESUMEN
【Objective】 To analyze the preliminary screening and follow-up testing data of HBV in Yantai area, and discuss the rationality of following up and re-entry program of HBV reactive blood donors. 【Methods】 Donors who were single reagent reactive by enzyme-linked immunosorbent assay (ELISA) in initial screening but non-reactive by nucleic acid testing (NAT) were followed up. Individual NAT(ID-NAT) was performed for HBV DNA, ELISA for HBsAg, HBsAb, HBeAb, HBeAg and HBcAb, and ECLIA for the detection of HBsAg. 【Results】 A total of 547 blood donors were HBsAg ELISA-/NAT+, and 97 were followed up, among which 24 met the requirements of re-entry while 73 did not. Of the 24 blood donors who met the re-entry requirements, 13 donated blood again, with test results all qualified. 【Conclusion】 The combination of ELISA, ID-NAT, and ECLIA methods for following up detection for HBsAg ELISA+ blood donors is recommended. Blood donors with HbsAb S/CO ≥ 10 and negative results for other tests met the re-entry requirements, with a re-entry rate at 24.74%, and the re-donation qualified rate of blood donors after re-entry was 100%.
RESUMEN
【Objective】 To explore the performance verification of the Shengxiang automatic NAT system for HBV DNA, HCV RNA and HIV RNA-1 using PCR-fluorescence in the laboratories of blood stations, in order to meet the requirements of T/CSBT and ensure the quality of nucleic acid detection. 【Methods】 Samples used in the external quality assessment (EQA) of National Center for Clinical Laboratories of the year 2022 were taken to verify the concordance. The standard materials of HBV DNA, HCV RNA and HIV RNA-1 were used to verify the analytical sensitivity, endogenous interfering substances, repeatability, anti-cross contamination ability and stability. 【Results】 The concordance rate of 20 EQA samples was 100%. The analytical sensitivity of HBV DNA, HCV RNA and HIV RNA-1 were all reactive and met T/CSBT. The yielding of HBV DNA, HCV RNA and HIV RNA-1 was affected little with lipemia at 3g/L and hemolysis at 4g/L. The coefficients of variation(CV) of intra-assay and inter-assay which met T/CSBT were all less than 5%, and the intra-assay variation coefficient was less than the inter-assay variation coefficient. The test results of 40 negative samples tested for cross contamination resistance were 100% negative, and 40 positive samples of HBV with 10 000 IU/mL were 100% positive. The stability verification results showed that the detection rate of weak positive samples was 100%. The coefficient of variation of the test results of the reagent after 1 and 5 freeze-thaw cycles were less than 5%,and the difference between the detection Ct value of reagent underwent once freeze-thaw and five-time freeze-thaw was not statistically significant. 【Conclusion】 The analytical sensitivity,endogenous interfering substances, repeatability,anti-cross contamination ability,stability and the compliance rate of domestic Shengxiang Gene automatic NAT system and supporting reagents by PCR-fluorescence method all meet T/CSBT, so it can be used for nucleic acid detection in blood screening in blood station laboratory.
RESUMEN
【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.
RESUMEN
【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.
RESUMEN
【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.
RESUMEN
@#Abstract: Objective To establish a sensitive and specific nucleic acid detection method for Schistosoma japonicum based on loop-mediated isothermal amplification (LAMP) and clustered regularly interspaced short palindromic repeats (CRISPR) technology. Methods The LAMP primers, gRNA and ssDNA probe that target Schistosoma japonicum SjR2 genes were designed according to the principles of LAMP and CRISPR. The LAMP-CRISPR reaction system was established and optimized. The sensitivity and specificity of the method were evaluated against the ten-fold serial dilutions of plasmid containing SjR2 target sequences, as well as genomic DNA at different stages of Schistosoma japonicum and other parasites, including Fasciola hepatica, Schistosoma mansoni, Taenia saginata, Clonorchis sinensis, Ascaris lumbricoides, Necator americanus, Paragonimus westermani, and Echinococcus granulosus. Additionally, 15 schistosome-infected snail and 30 uninfected samples were tested by LAMP-CRISPR and LAMP methods, respectively, to evaluate the potential of this method for screening for infected snails. Results The developed LAMP-CRISPR method was able to specifically amplify and detect the SjR2 gene of S. japonicum. The optimal reaction temperature was 37 ℃, and the optimal reaction concentrations were both 40 nmol/L for gRNA and Cas12a protein. No cross-reaction was observed with genomic DNA from other parasites such as F. hepatica. The detection limit of the method was 10 copies/μL when testing 10-fold dilutions of recombinant plasmids as a template. Furthermore, the LAMP-CRISPR method was able to accurately detect genomic DNA from S. japonicum at various stages of development, including eggs, cercariae, schistosomula, juvenile worms, and adult worms. The results of testing 45 snail samples showed no significant difference between the LAMP-CRISPR and LAMP methods for detecting infected snails (χ2=0.05, P>0.05). The sensitivity and specificity of the LAMP-CRISPR method were 100.00% (15/15) and 96.67% (29/30), respectively, compared to the gold standard, while the sensitivity and specificity of the LAMP method were 100.00% (15/15) and 93.33% (28/30), respectively. Conclusions This established LAMP-CRISPR detection method presented good sensitivity, specificity and reliability, making it a promising tool for rapid detection and risk monitoring of S. japonicum.
RESUMEN
@#Abstract: Objective To analyze and compare the effects of different clinical characteristics on the negative conversion time of nucleic acid detection after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection, and to provide a scientific basis for the isolation and treatment of coronavirus disease 2019 (COVID-19). Methods The epidemiological and clinical data of 228 mild SARS-CoV-2 Omicron variant infected patients diagnosed in Shanghai were retrospectively collected from April 27, 2022 to June 8, 2022 in Wujiaochang designated Hospital, Yangpu District, Shanghai. The negative conversion time of nucleic acid detection was used as the outcome variable, and the patients were divided into A (≤18 days) and B (>18 days). Univariate and multivariate logistic regression analysis were used to analyze the influencing factors of the negative conversion time of nucleic acid detection. Results The mean nucleic acid conversion time of 228 patients was (18.7±12.1) d, with the median time of 18 (2-46) d. Among them, 120 patients in group A had an average nucleic acid conversion time of (13.2±2.0) d, and 108 cases in group B had an average nucleic acid conversion time of (20.8±1.3) d. Univariate analysis showed that there were no statistically significant differences in the effects of hypertension, coronary heart disease, diabetes, hypokalemia, malignant tumors, neuropsychiatric diseases, chronic digestive diseases on the negative nucleic acid conversion time (P>0.05); however, there were significant differences in the effects of combined cerebrovascular disease, leukopenia, chronic respiratory system diseases and vaccination on the negative nucleic acid conversion time (P<0.05). Further multivariate logistic regression analysis revealed that the combination of chronic respiratory diseases and non-vaccination were significant risk factors for prolongation of negative nucleic acid conversion time (P<0.05). Conclusions The results of this study show that gender, age and whether hypertension, coronary heart disease, diabetes mellitus, hypokalemia, malignant tumor, neuropsychiatric disease and chronic digestive disease have no significant effect on the nucleic acid conversion time, whereas chronic respiratory disease and no vaccination are significantly correlated with the prolongation of nucleic acid conversion time in SARS-CoV-2 Omicron-infected patients.