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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.
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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
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@#Abstract: Objective To evaluate the value and significance of rifampicin-resistant real-time fluorescence quantitative nucleic acid amplification detection technology (GeneXpert MTB/RIF) in the diagnosis of pulmonary tuberculosis. Methods The clinical data of 228 patients with suspected pulmonary tuberculosis, who admitted to Hebei Chest Hospital from January 2018 to December 2019, were analyzed retrospectively. The sputum was collected for GeneXpert MTB/RIF, sandwich cup liquid-based bacterial acid-fast staining smear microscopy (referred to as “sandwich cup method”) and Loop-Mediated isothermal amplification (referred to as “LAMP method”) and the results were statistically analyzed by SPSS 17.0 software. Results Among the 228 patients with suspected cases, 200 cases were clinically diagnosed as pulmonary tuberculosis and 28 were non-tuberculosis. The positive detection rate of GeneXpert MTB/RIF (81.0%, 162/200) was significantly higher than that of sandwich cup method (62.5%, 125/200) and LAMP method (72.5%,145/200) (χ2=16.885, 4.049, P<0.05). Taking clinical diagnosis as gold standard, the sensitivity of GeneXpert MTB/RIF (80.00%,160/200) was significantly higher than that of sandwich cup method (60.00%, 120/200) and LAMP method (70.50%, 141/200) (χ2=19.048, 4.846, P<0.05). The diagnostic consistency of GeneXpert MTB/RIF (K=0.73) was higher than that of sandwich cup method (K=0.39) and LAMP method (K=0.56). Conclusions The GeneXpert MTB/RIF detection method is rapid and simple, and can diagnose pulmonary tuberculosis rapidly and simultaneously detect rifampicin resistance of Mycobacterium tuberculosis with high sensitivity. It has high clinical value for early diagnosis of pulmonary tuberculosis and guidance of treatment in general and specialized hospitals.
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@#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.
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Objective:To compare the cost-effectiveness of hospitalized Chinese patients undergoing nucleic acid screening strategies for hepatitis B and hepatitis C, immunological screening strategy, and no screening strategy under different willingness to pay (WTP). The results might aid to decision-making for the optimal strategy.Methods:In this study, nucleic acid screening, immunological screening and no screening were used as screening strategies, and China′s GDP in 2021 (80 976 yuan) was used as the threshold of WTP to construct a Markov model. After introducing parameters related to the diagnosis and treatment of hepatitis B and C in inpatients, a cohort population of 100 000 inpatients was simulated by TreeAge Pro 2021 software, the total cost, total health effects, incremental cost-effectiveness ratio and average cost-effectiveness ratio of different screening strategies were calculated, and cost-effectiveness analysis was conducted. Univariate and probabilistic sensitivity analysis were used to assess the impact of parameter uncertainty on the final results.Results:Compared with the non-screening strategy, the incremental total cost of the hepatitis B immunological screening strategy for cohort patients was 11 049 536 yuan, and the incremental cost-effectiveness ratio was 24 762 yuan/quality-adjusted life years (QALY), while the total incremental cost of nucleic acid screening was 19 208 059 yuan, and the incremental cost-effectiveness ratio was 29 873 yuan/QALY; the incremental cost-effectiveness ratio of nucleic acid screening and immunological screening was 45 834 yuan/QALY. Compared with the non-screening strategy, the incremental cost-effectiveness ratio of hepatitis C immunological screening strategy was 5 731 yuan/QALY, the incremental cost-effectiveness ratio of nucleic acid screening strategy was 8 722 yuan/QALY, the incremental cost-effectiveness ratio of nucleic acid screening and immunological screening was 45 591 yuan/QALY. The results of probabilistic sensitivity analysis showed that when the cost of nucleic acid testing exceeded 214.53 yuan, it was not cost-effective to perform hepatitis B nucleic acid screening under the WTP as 1 fold GDP. When the cost of nucleic acid testing exceeded 132.18 yuan, it was not cost-effective to conduct hepatitis C screening under the WTP as 1 fold GDP.Conclusions:Nucleic acid screening strategy can achieve more cost-effectiveness and is worthy of vigorous promotion. Compared with no screening, both the nucleic acid and immunological screening strategies are cost-effective, and hepatitis nucleic acid screening is the optimal strategy for hospitalized patients.
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Objective:This multi-centre study was conducted to assess the efficacy of various preoperative/pre-transfusion screening methods for blood transmitted disease.Methods:From July 2021 to December 2021, plasma samples of patients admitted to 10 hospitals were collected for screening preoperative/pre-transfusion blood transmitted disease. Nucleic acid detection technology was used to detect hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus (HIV)(1+2) RNA, and the results were compared with the immuno-serological methods. χ 2 test and Kappa test were used to analyze the efficacy of these two methods. Results:A total of 8 655 valid specimens were collected from 10 hospitals. There was a statistically significant difference in the positive detection rate of HCV between the two methods ( P<0.001). There was no significant difference in the positive detection rate of HBV and HIV assessed by the two methods ( P>0.05), but the number of positive cases detected by HBV DNA and HIV RNA (218 and 4 cases) was significantly higher than the corresponding serological results (216 and 2 cases). At the same time, there were HBV, HCV and HIV immuno-serological omissions by the immuno-serological methods, among which 28 cases were HBsAg negative and HBV DNA positive, 2 cases were HCV antibody negative and HCV RNA positive, and 2 cases were HIV antigen/antibody negative and HIV RNA positive. In addition, in the 66 samples with inconsistent results from the two detection methods, 83.3% (55/66), 68.2% (45/66), 63.6% (42/66) and 62.1% (41/66) of patients aged was>45 years, tumor, surgery and male, respectively. Conclusions:Compared with immuno-serological tests, nucleic acid tests have the advantage in terms of sensitivity on detecting HBV, HCV and HIV infection and could reduce missed detection. The risk of transmission can be reduced by adding HBV, HCV, and HIV nucleic acid tests to preoperative/pre-transfusion immuno-serological tests screening for patients over 45 years of age and tumor patients.
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Objective:To explore clinical value of nucleic acid detection for hepatitis B virus (HBV) screening in hospitalized patients.Methods:This cross-sectional study collected and analyzed plasma samples from patients admitted to 10 domestic medical institutions from July 2021 to December 2021. Serological immunoassay and nucleic acid screening were used to simultaneously detect hepatitis B markers such as hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), hepatitis B e Antigen (HBeAg), hepatitis B e antibody (HBeAb), hepatitis B core antibody (HBcAb),and HBV DNA. Statistical analysis was performed on the serology, nucleic acid test results and clinical information of the patients.Results:Of the 8 655 collected samples, HBsAg was positive in 216 (2.50%) samples,HBV DNA was positive in 238 (2.75%) samples ( P>0.05); 210 (2.43%) samples were positive for both HBsAg and HBV DNA, 28 (0.32%) were HBsAg negative and HBV DNA positive, 6 cases (0.07%) were HBsAg positive and HBV DNA negative. Conclusion:These results indicate that the HBV DNA testing is equally effective as hepatitis B virus serological detection for hepatitis B virus screening in hospitalized patients.
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Objective:To explore the clinical significance of hepatitis B virus (HBV) DNA detection in screening patients with hepatitis B.Methods:Clinical data of 682 331 hepatitis B patients were retrospectively analyzed. The HBV DNA of these patients was detected in the Fifth Medical Center of the PLA General Hospital from January 2017 to December 2021, there were 481 159 males and 201 172 females in this cohort, the average age was (41.34±16.13) years. Patients were divided into HBV DNA positive group (219 879 cases) and HBV DNA negative group (462 452 cases). Clinical characteristics, data of five serologic markers of hepatitis B and hepatitis B surface antigen quantification (HBsAg-QN), liver function, alpha fetoprotein (AFP) and prothrombin time (PT) results were collected and analyzed and compared between the two groups.Results:The positive rate of HBV DNA was 32.22% (219 879/682 331) in this cohort. Among the different age groups, the positive rate of HBV DNA was the highest (40.34%, 128 038/317 380) in young people aged 18-44 years. The proportion of patients was lower among aged <1, 45-59 and ≥60 years patients in HBV DNA positive group than that in HBV DNA negative group, while the proportion of patients was higher among aged 1-17 and 18-44 years patients in HBV DNA positive group than that in HBV DNA negative group (all P<0.001). Among 2 291 <1-year-old infants tested for HBV DNA, 71 infants were HBV DNA positive. The positive rates of HBV DNA from 2017 to 2021 were 4.86% (27/556), 3.68% (14/380), 3.47% (17/490), 1.55% (6/386) and 1.46% (7/479) respectively, showing a downward trend year by year. The positive rate of HBV DNA in acute hepatitis B (AHB) patients was the highest (49.88%, 208/417) among 680 040 patients with hepatitis B. The proportion of AHB patients (0.09%, 208/219 808) and chronic hepatitis B (80.44%, 176 806/219 808) in HBV DNA positive group was higher than that in HBV DNA negative group [0.05% (209/460 232) and 65.45% (301, 216/460 232)], while the proportion of patients with HBV-related liver cirrhosis (11.28%, 24 793/219 808), HBV-related liver cancer (6.72%, 14 775/219 808), liver cancer surgery (1.39%, 3 055/219 808) and liver transplantation (0.08%, 171/219 808) were lower than that in HBV DNA negative group [22.99% (105 813/460 232), 7.25% (33 385/460 232), 3.50% (16 129/460 232) and 0.76% (3 480/460 232)] (all P<0.001). At the same time, positive rate of hepatitis B surface antigen (HbsAg), HBsAg-QN, hepatitis B e antigen (HbeAg), level of total bilirubin, total bilirubin, AFP and PT were higher in HBV DNA positive group than those in HBV DNA negative group, while the age, male ratio and albumin results in HBV DNA positive group were lower than those in HBV DNA negative group (all P<0.01). The HBV DNA loads were higher in HBsAg positive group, hepatitis B surface antibody positive group and HBeAg positive group than those in respective negative groups, while the HBV DNA loads were lower in hepatitis B e antibody positive group and hepatitis B core antibody positive group than those in respective negative groups (all P<0.001). Conclusions:The mother to child transmission rate of<1-year-old infants decreases year by year. HBV DNA is an important factor for the progression of hepatitis B disease. HBV DNA positive hepatitis B patients with higher HBsAg-QN values are more likely to have abnormal serum markers such as liver dysfunction. HBV DNA detection is therefore of clinical importance in screening patients with hepatitis B.
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For patients with chronic hepatitis B, the indications of antiviral treatment are gradually expanding, and the pursuit of various degrees of cure (partial cure, functional cure and complete cure) is consistently improving, which enhances the urgent clinical need for improving the detection sensitivity of hepatitis B virus (HBV) surface antigen and DNA. Based on the availability of commercial highly sensitive hepatitis B surface antigen and HBV DNA detection reagents, we summarized their applications in the diagnosis of HBV infection, their role on guiding selection of antiviral treatment agents and treatment plans, their prediction efficacy and indication for drug withdrawal, their role on monitoring therapy efficacy and the prediction of disease outcomes. Taken together, highly sensitive hepatitis B virus surface antigen and DNA assays and related detection technology play an important role in the whole management process of chronic HBV infection.
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Omicron is currently shaking the world to its core. The disease is mainly transmitted via the respiratory route when people inhale droplets and small airborne particles (that form an aerosol) that infected people exhale as they breathe, talk, cough, sneeze, or sing. “UK becomes first country in Europe to pass 1,50,000 COVID deaths Omicron clouds forecasts for Covid end game.Omicron is a variant of nSARS-CoV-2 that has been identified initially in COVID19 patients in Botswana and South Africa. The chief of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, has said that the combination of Delta and Omicron variants of coronavirus is driving a tsunami of COVID-19 cases. The statement came as record new cases were reported from the United States and countries across Europe. France recorded the highest ever daily numbers in Europe for the second consecutive day, at 208,000 new cases.Vaccines offer strong protection from serious illness.
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Resumen: Introducción: el inicio temprano de la antibioticoterapia adecuada en infecciones graves se asocia con reducción de la mortalidad. La identificación precoz del microorganismo es fundamental para realizar un tratamiento dirigido y disminuir la terapéutica inicial inapropiada. Objetivo: valorar la utilidad de una técnica de biología molecular por amplificación de ácidos nucleicos mediante reacción en cadena de polimerasa en tiempo real para diagnóstico microbiológico temprano y adecuación de la antibioticoterapia en pacientes con neumonías graves. Metodología: estudio retrospectivo observacional llevado a cabo en la unidad de cuidados intensivos del Hospital Maciel. Se analizaron muestras respiratorias de pacientes con diagnóstico o sospecha de neumonía. Se compararon los resultados microbiológicos obtenidos por técnicas convencionales y por biología molecular multiplex (panel neumonía). Resultados: se incluyeron 53 muestras obtenidas de 51 pacientes. El multiplex detectó al menos un microorganismo en 38 (71,7%) muestras frente a 30 (56.6%) desarrollos en cultivos tradicionales. La mayoría de las muestras se obtuvieron bajo antibioticoterapia previa (86.8%). El panel neumonía mostró un porcentaje de concordancia positiva combinado de 100% y un porcentaje de concordancia negativa del 94% para la identificación bacteriana en comparación con los métodos microbiológicos tradicionales. En 27 (51%) casos el resultado del panel de neumonía determinó un cambio en la conducta terapéutica. Conclusiones: la técnica de PCR permite la identificación temprana de microorganismos causantes de neumonía optimizando la terapéutica empírica inicial y racionalizando el uso de antimicrobianos. Un panel negativo aleja el planteo de infección respiratoria a gérmenes habituales y permite considerar diagnósticos diferenciales en cuanto a foco y/o etiología.
Summary: Introduction: the early initiation of the adequate antibiotic therapy in severe infections is associated to a reduction in mortality. Early identification of the microorganism is essential to define directed therapy and decrease the initial inadequate treatment. Objective: to assess usefulness of a molecular biology technique by nucleic acid amplification through a polymerase chain reaction in real time for an early microbiological diagnosis and correction of the antibiotic therapy in patients with severe pneumonias. Method: retrospective, observational study conducted in the intensive care unit of Maciel Hospital. The respiratory samples of patients with a diagnosis of pneumonia or suspicious to have pneumonia were analyzed. The microbiological results obtained were compared using conventional techniques and multiplex molecular biology (pneumonia panel). Results: 53 samples obtained from 51 patients were included in the study. Multiplex detected at least one microorganism in 38 (71.7%) samples compared to 30 (56.6%) in traditional cultures. Most samples were obtained under the previous antibiotic therapy (86.8%). The pneumonia panel showed a combined positive agreement percentage of 100% and a negative agreement of 94% for the identification of bacteria when compared to the traditional microbiological methods. In 27 cases (51%) the pneumonia panel results determined changing the therapeutic behavior. Conclusions: the PCR technique allows for the early identification of microorganisms causing pneumonia, thus optimizing initial empirical therapy and rationalizing the use of antibiotics. A negative panel reduces the suspicion of a respiratory infection caused by the usual germs and enables considering differential diagnosis in terms of etiology or cause.
Resumo: Introdução: o início precoce da antibioticoterapia adequada em infecções graves está associado à redução da mortalidade. A identificação precoce do microrganismo é essencial para realizar o tratamento dirigido e reduzir o uso inicial inadequado de antimicrobianos. Objetivo: avaliar a utilidade de uma técnica de biologia molecular para amplificação de ácidos nucleicos por reação em cadeia da polimerase em tempo real para diagnóstico microbiológico precoce e adequação da antibioticoterapia em pacientes com pneumonia grave. Metodologia: estudo observacional retrospectivo realizado na unidade de terapia intensiva do Hospital Maciel. Amostras respiratórias de pacientes com diagnóstico ou suspeita de pneumonia foram analisadas. Os resultados microbiológicos obtidos por técnicas convencionais e por biologia molecular multiplex (painel de pneumonia) foram comparados. Resultados: foram incluídas 53 amostras obtidas de 51 pacientes. O multiplex detectou pelo menos um microrganismo em 38 (71,7%) amostras em comparação com 30 (56,6%) usando culturas tradicionais. A maioria das amostras foi obtida com antibioticoterapia prévia (86,8%). O painel de pneumonia mostrou uma concordância percentual positiva combinada de 100% e uma concordância percentual negativa de 94% para identificação bacteriana em comparação com métodos microbiológicos tradicionais. Em 27 (51%) casos, o resultado do painel de pneumonia determinou mudança no comportamento terapêutico. Conclusões: a técnica de PCR permite a identificação precoce de microrganismos causadores de pneumonia, otimizando a terapia empírica inicial e racionalizando o uso de antimicrobianos. Um painel negativo afasta a suspeita de infecção respiratória pelos germes usuais e permite considerar diagnósticos diferenciais em termos de foco e/ou etiologia.
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Pneumonia/microbiology , Pneumonia/drug therapy , Multiplex Polymerase Chain Reaction , Intensive Care Units , Pneumonia/diagnosis , Critical CareABSTRACT
Background. Xpert-MTB/RIF assay or Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) helps in rapid diagnosis of tuberculosis (TB). Methods. Specific samples were collected and carried to Regional Medical Research Centre where these were taken up for CBNAAT and culture in Lowenstein-Jensen media. Appropriate samples were sent to the Designated Microscopy Centre (DMC) of our institute for acid-fast bacilli (AFB) smear examination. Diagnostic measures, such as sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of Xpert-MTB/RIF were reported considering mycobacterial culture and a composite reference standard (CRS) as Gold standard. Results. We studied 335 samples. Lymph node fine needle aspirate was the most common sample (32.5%) followed by pleural fluid (29.3%). The overall sensitivity and specificity of Xpert-MTB/RIF was determined to be 26.5% (95% CI [confidence interval] 20.8�.8) and 100% (95% CI 96.8�0), respectively. The sensitivity and specificity of CBNAAT in relation to mycobacterial culture, however, was 78.8% (95% CI 61.1�.0) and 89.1% (95% CI 85�.4), respectively. Both were highest for pus, cerebrospinal fluid and lymph node fine needle aspirate samples. Conclusions. Xpert-MTB/RIF may be useful for samples, like cold abscess and lymph node fine needle aspirate or biopsy specimens. However, its routine use in case of serosal fluids is not recommended because of its lower sensitivity.
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Diagnostic testing plays a fundamental role in the mitigation and containment of coronavirus disease 2019(COVID-19),as it enables immediate quarantine of those who are infected and contagious and is essential for the epidemiological characterization of the virus and estimating the number of infected cases worldwide.Confirmation of viral infections,such as COVID-19,can be achieved through two general approaches:nucleic acid amplification tests(NAATs)or molecular tests,and serological or antibody-based tests.The genetic material of the pathogen is detected in NAAT,and in serological tests,host antibodies produced in response to the pathogen are identified.Other methods of diagnosing COVID-19 include radiological imaging of the lungs and in vitro detection of viral antigens.This review covers different approaches available to diagnosing COVID-19 by outlining their advantages and short-comings,as well as appropriate indications for more accurate testing.
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Acute respiratory tract infection is the most common infectious disease in children, which seriously threatens children′s health.Rapid and accurate etiological diagnosis is of great significance for the clinical treatment and control of these diseases.Pathogen nucleic acid test was applied and became the main method of respiratory tract infection diagnosis for its high sensitivity and specificity.To regulate the application of pathogen nucleic acid amplification test in respiratory tract infection in children, improve the diagnosis level, expert consensus on nucleic acid amplification test of respiratory pathogens in children was prepared to guide the application and promote pathogens diagnosis ability.
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Objective:This multicenter clinical evaluation analyzed the clinical performance of five fast nucleic acid detection systems for 2019-nCoV.Methods:Clinical performance of the five fast nucleic acid detection reagents approved in China was evaluated in the present study. Fifty-seven throat swabs samples from COVID-19 patients and fifteen throat swabs samples from healthy people were collected from the First Affiliated Hospital of Zhejiang University school of Medicine, Tongji Hospital of Tongji Medical College of HUST, and National Institute of Viral Disease Control and Prevention of CDC to evaluate the positive coincidence rate, negative coincidence rate, total coincidence rate, the detection time and retest rate as well as the relation between positive intensity and positive coincidence rate of the five fast nucleic acid detection systems in November 2020.Results:The positive coincidence rates of the five kits were 92.59% (50/54), 83.64% (46/55), 98.25% (56/57), 94.44% (51/54) and 98.18% (54/55); and the negative coincidence rates were 93.33% (14/15), 93.33% (14/15), 86.67% (13/15), 100% (14/14) and 93.33% (14/15); and the total coincidence rates were 92.75% (64/69), 85.71% (60/70), 95.83% (69/72), 94.20% (65/69) and 97.14% (68/70), respectively. The positive coincidence rate of the five kits reached 100% for the strong-positive (90/90) and medium-positive samples (84/84), but only 82.18% (83/101) for weak-positive samples (cycle threshold value>33), and the retest rate of two kits were 15.28% (11/72) and 12.50% (9/72), which were both higher than 10%. Total time from sample extraction to amplification was between 32.33-65.33 minutes for these five kits.Conclusion:The five fast nucleic acid detection reagents have good performance and can be used as a supplement to routine nucleic acid detection reagents.
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Recombinase polymerase amplification (RPA) is a novel technology for nucleic acid isothermal amplification. It can achieve the rapid amplification and detection of a target gene under 37-42 ℃. This amplification method is highly sensitive, more specific and less instrument-dependent than other existing methods, and it can also integrate multiple detection modes. Therefore, it is especially suitable for applying in low-resource settings and conducting point-of-care tests. Starting from the reaction principles and the experimental design of RPA, this article pointed out some key points when using RPA in a clinical setting. The current development and related problems of RPA were concluded and the various future uses of this method were also prospected.
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【Objective】 To study the detection performance of HBsAg single-ELISA-reactive samples of blood donors. 【Methods】 Two kinds of ELISA reagents from different manufacturers (named as reagents A and B) were used for HBsAg screening. A total of 276 samples, from January 2017 to May 2021, with HBsAg single-ELISA-reactive results were collected for further nucleic acid detection technology (NAT) and chemiluminescence immunoassay (CLIA) testing, to undergo HBV-DNA and five hepatitis B tests, respectively. The relationship between HBsAg single-ELISA-reactivity, NAT and CLIA was statistically analyzed. 【Results】 Among the 276 HBsAg single-ELISA-reactive samples, 14 were NAT reactive, with the positive rate of 5.07% (14/276). Fisher′s exact test was used to compare the compliance of reagents A and B with NAT reactivity, and the difference was not statistically significant (P<0.05). Among 14 HBsAg+ /NAT+ samples retested by CLIA, 2 were HBsAg reactive(14.29%, 2/14), 13 were anti-HBc reactive (92.86%, 13/14), 9 had the quantitative value of anti-HBs <10 mIU/mL, 5 had the quantitative value of anti-HBs between 10 to 100mIU/ mL. A total of 5 serological patterns were detected, and anti-HBe+ /anti-HBc+ pattern was the dominant. There were 262 cases of HBsAg+ /NAT- samples, but only 1 (0.38%, , 1/262) case was HBsAg reactive by CLIA, 100 were anti-HBc reactive (38.17%, 100/262), 144 (54.96%, 144/262) were anti-HBs reactive, and 1 was HBeAg reactive. A total of 8 serological patterns were detected. 【Conclusion】 Most of HBsAg single-ELISA-reactive results are false, and NAT could effectively reduce the residual risk of transfusion transmitted diseases.
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Objective:To compare the detection rate of genital Chlamydia trachomatis (CT) DNA between urine and urethral/cervical swab samples. Methods:From December 2018 to December 2019, a total of 1 475 outpatients were collected from sexually transmitted disease clinics in 7 medical institutions, such as Department of Venereology, Guangzhou Institute of Dermatology, including 1 118 males and 357 females. One urethral/cervical swab sample and one urine sample were collected successively from each patient. Real-time fluorescence-based PCR was performed to detect CT DNA in urine and urethral/cervical swab samples, and paired chi-square test was used to compare the positive rate of CT DNA between the 2 kinds of samples. Random- or fixed-effect meta-analysis was conducted for the test of heterogeneity and merging of positive rates of CT DNA in the urine and urethral/cervical swabs among 7 medical institutions.Results:The positive rate of CT DNA in the urine samples was significantly higher than that in the swab samples from 4 medical institutions (all P < 0.05) , while there was no significant difference in the positive rate of CT DNA between the 2 kinds of samples from 3 medical institutions (all P > 0.05) . The heterogeneity ( I2) estimates of the CT-DNA positive rate in urine and swab samples among different medical institutions were 78.6% (95% CI: 55.9% - 89.6%) and 73.7% (95% CI: 43.7% - 87.7%) , respectively; meta-analysis showed that the total merged positive rate of CT DNA in the urine samples was 10.8% (95% CI: 7.2% - 15.9%) , which was significantly higher than that in the swab samples (7.8%, 95% CI: 4.9% - 12.1%; χ2 = 39.2, P < 0.05) . Compared with the swab sample-based CT-DNA detection method, the sensitivity, specificity, positive predictive value, negative predictive value and consistency rate of the urine sample-based CT-DNA detection method were 97.0% (128/132) , 96.3% (1 293/1 343) , 71.9% (128/178) , 99.7% (1 293/1 297) , and 96.3% (1 421/1 475) , respectively. The positive rate of CT DNA in the urine samples from 1 118 male patients was 11.0% (95% CI: 7.2% - 16.5%) , which was significantly higher than that in the swab samples (7.6%, 95% CI: 4.9% - 11.8%; χ2 = 34.3, P < 0.05) . There was no significant difference in the positive rate of CT DNA between the urine (11.9%, 95% CI: 7.7% - 17.9%) and cervical swab samples from 357 female patients (10.4%, 95% CI: 7.6% - 14.0%; χ2 = 3.2, P > 0.05) . Conclusions:The positive rate of CT DNA in urine samples is higher than or similar to that in urethral/cervical swab samples. The urine sample-based CT-DNA detection method has characteristics of convenience, non-invasiveness, painlessness and low cost, and is worthy of clinical promotion.
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Central tuberculomas, occurring because of the haematogenous spread of' M. tuberculosis, can present variably with the symptoms ranging from headache, decreased level of consciousness, neck stiffness to altered mental status, seizures and focal deficits. Diagnostic investigations include but are not limited to CSF analysis, MRI Brain, CT head, and AFB smear, mycobacterial cultures or CBNAAT of the CSF sample. Magnetic resonance spectroscopy can help distinguishing the tuberculoma from its differentials by showing a peculiar lipid peak. Treatment with the antituberculosis drugs over a prolonged period of time along with dexamethasone usually shows significant clinical improvement. Authors present to you the case report of an 8 year old boy who presented to the pediatric emergency with generalized tonic clonic seizures and was subsequently detected with the tuberculoma with the help of MRI Brain and CBNAAT (cartridge based nucleic acid amplification test) of CSF sample. The objective of this case report is to discuss the symptoms, pathogenesis, detection and management of tuberculomas, which are still quite common in the developing countries and if left untreated are associated with high morbidity and mortality.
ABSTRACT
Background: The roles of Chlamydia trachomatis and Neisseria gonorrhoeae in the aetiology of infertility due to tubal occlusion have been established by various studies. These organisms may lead to pelvic infection by ascending into the upper genital tract through any instrumentation like hysterosalpingography. The objectives were to determine the prevalence of asymptomatic chlamydial and gonorrhoeal infections of the genital tract among women being investigated for infertility referred for hysterosalpingography; the relationship of these infections with tubal pathologies; and if routine endo-cervical screening and prophylactic antibiotics be recommended for these patients.Methods: This was a descriptive cross-sectional study. The study population consisted of consecutive 220 infertile women that met the inclusion criteria for this study. Consent was obtained. Endo-cervical swab was taken for NAAT-PCR for Chlamydia trachomatis and Neisseria gonorrhoeae. Hysterosalpingography was carried out. Data was analyzed using SPSS (version 22).Results: Amongst the 220 women, 9 (4.1%) had asymptomatic chlamydia infection. None had gonorrhoea infection and 211 (95.9%) had none of these two organisms. Forty-eight (21.9%) of the 220 women had bilateral tubal blockage and 9 (18.8%) out of these 48 women had asymptomatic infection with Chlamydia trachomatis.Conclusions: There is a statistically significant association between tubal blockage and chlamydia infection (p = 0.00) [RR 4.31 (3.37-5.50)]. There was no evidence to recommend routine screening/antibiotics considering the low prevalence of microbes and the absence of post-HSG pelvic infection. Results from a multicenter randomized controlled trial will be more representative.