Prevalence of HCV Antibody and its Associated Factors: A Study from Sentinel Hospitals in China

Objective The prevalence and related factors of serum anti-HCV in different regions and hospitals have not been studied extensively in China. We used routine screening data to determine the prevalence of HCV antibody in hospital patients, evaluate the epidemic trend of hepatitis C and formulate screening strategies.Methods Patient information and HCV antibody testing results were collected from January 2017 to December 2019 in 77 HCV sentinel hospitals in China. Univariate and multivariate logistic regression was used to determine the characteristics and associations.Results HCV antibody prevalence rates were distinct among patients in different departments, with a range of 0.33%–6.93%. Patients who were admitted to the liver disease-related departments(aOR =10.76;95% CI, 10.27–11.28), Internal Medicine(aOR = 2.87;95% CI, 2.75–3.00), and Department of Surgery(aOR = 1.95;95% CI, 1.87–2.04), were more likely to be tested for HCV antibody positive. HCV antibody prevalence was associated with patients aged 45 years and older(aOR = 2.74;95% CI,2.69–2.80), testing in infetious disease hospitals(aOR = 2.33;95% CI, 2.26–2.40) and secondary hospitals(aOR = 1.72;95% CI, 1.69–1.75). Patients in sentinel hospitals of the Northeast(aOR = 12.75;95% CI,12.40–13.11), the Central(aOR = 1.65;95% CI, 1.61–1.70), and the West(aOR = 1.78;95% CI, 1.73–1.83)China had higher HCV prevalence than those who were in the Eastern coastal area. Conclusion Those who were over 45 years old and saw doctors for liver diseases, and invasive diagnosis and treatment should be referred to HCV antibody testing.

Performance of Comparative Cervical Tuberculin Test and Serological Methods with Culturing of Nasal Swab in Diagnosis of Bovine Tuberculosis in Cross Breed Cattle Baghdad Iraq: A Comparative Evaluation

This study was designed to assess the diagnostic value of Rapid Antigen bovine TB antibody test kit (RAT) and any association with cervical comparative tuberculin test (CCTT), (iELISA) and nasal swabs culturing, among based detection of M. bovis infection. A herd of 21 animals aged 1 - 8 years cross bread cattle of college of veterinary medicine. 19 (90.47%) animals had good body condition scores, two bulls included, and 2 (9.52%) cows were fair. Serum samples were collected, analyzed for anti-bovine TB antibody using RAT and iELISA. Also the herd was screened by CCTT. The tests were carried out twice, more than ten month interval, and twelve nasal swabs were taken within second survey. The first survey results revealed prevalence rate: 4 (19.04%) animals considered positive results (one positive and 3 suspected results) for CCTT, while the prevalence rate according to RAT was 10 (47.61%). The difference between the two prevalence rate was significant (McNemar chi-statistic = 4.50, p-value = 0.03) Kappa = 0.215 95% confidence interval: from -0.128 to 0.558;the strength of agreement is considered to be “fair”. The study interprets: sensitivity 30%;specificity 99%. The second survey results revealed prevalence rate according to CCTT was 4 (36.36%), while prevalence rate according to RAT was 5 (45.45%). The difference between the two prevalence was not significant (McNemar chi-statistic = 0.33, p-value = 0.56). Kappa = 0.441 95% confidence interval: from -0.087 to 0.968;the strength of agreement is considered to be “moderate”;sensitivity: 60%;specificity: 83%. All serum samples and nasal swabs gave negative results for iELISA and culturing respectively. The study concluded that RAT was highly specific, easy, labor and time saving, suggesting its use as screening test in bovine tuberculosis, and CCTT could be used to confirm positive animals screened by RAT, while there was no association between RAT, CCTT with body condition scores, iELISA and nasal swabs culture results.

Reliability of urinary tests for antibody to Helicobacterpylori in patients with pulmonary tuberculosis

AIM: Although the quality of currently available urinary tests for detecting antibody to Helicobacter pylori(H pylori) have been proved in some populations, the accuracy has not been studied regarding patients who suffer from pulmonary tuberculosis with multi-drug treatments. The present study was conducted to evaluate the accuracy of these urinary tests for antibody to H pylori in these patients. METHODS: Serum samples from 61 inpatients with pulmonary tuberculosis were tested using enzyme immunoassay, and urine samples were assayed by enzyme-linked immunosorbent assay method (URINELISA) and immunochromatography method (RAPIRAN). Medicines prescribed to the patients were recorded for medical charts, to evaluate the influences on the results of urinary tests. RESULTS: The sensitivity, specificity, and consistency of URINELJSA against the serum test were 93.1%, 65.6%, and 78.6% respectively, and those of RAPIRAN were 86.2%, 93.7%, and 90.1% respectively, which were almost equal to the data previously reported. Prescribed medicines had little influence on the results. CONCLUSION: The two urinary tests for detecting H pylori antibody have a diagnostic accuracy in patients with pulmonary tuberculosis given multiple anti-tuberculosis drugs.

Role of serological rapid antibody test in the management of possible COVID-19 cases

Although the detection of viral particles by reverse transcription polymerase chain reaction(RT-PCR)is the gold standard diagnostic test for coronavirus disease 2019(COVID-19),the false-negative results constitute a big challenge.AIM To examine a group of patients diagnosed and treated as possible COVID-19 pneumonia whose multiple nasopharyngeal swab samples were negative for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)by RT-PCR but then serological immunoglobulin M/immunoglobulin G(IgM/IgG)antibody against SARS-CoV-2 were detected by rapid antibody test.METHODS Eighty possible COVID-19 patients who had at least two negative consecutive COVID-19 RT-PCR test and were subjected to serological rapid antibody test were evaluated in this study.RESULTS The specific serological total IgM/IgG antibody against SARS-CoV-2 was detected in twenty-two patients.The mean age of this patient group was 63.2±13.1-yearsold with a male/female ratio of 11/11.Cough was the most common symptom(90.9%).The most common presenting chest computed tomography findings were bilateral ground glass opacities(77.2%)and alveolar consolidations(50.1%).The mean duration of time from appearance of first symptoms to hospital admission,to hospital admission,to treatment duration and to serological positivity were 8.6 d,11.2 d,7.9 d,and 24 d,respectively.Compared with reference laboratory values,serologically positive patients have shown increased levels of acute phase reactants,such as C-reactive protein,ferritin,and procalcitonin and higher inflammatory markers,such as erythrocyte sedimentation rate,lactate dehydrogenase enzyme,and fibrin end-products,such as D-dimer.A left shift on white blood cell differential was observed with increased neutrophil counts and decreased lymphocytes.CONCLUSION Our study demonstrated the feasibility of a COVID-19 diagnosis based on rapid antibody test in the cases of patients whose RT-PCR samples were negative.Detection of antibodies against SARS-CoV-2 with rapid antibody test should be included in the diagnostic algorithm in patients with possible COVID-19 pneumonia.

Evaluation of Interferon-Gamma Release Assay Testing and Tuberculin Skin Test for Early Diagnosis of Tuberculosis in Children and Adolescents

Background: This study aimed to evaluate the diagnostic value of interferon-γ release assay (IGRA), a sensitive microbiological diagnostic method, in children and adolescents with suspected tuberculosis in a country with a high burden of tuberculosis. Method: This study included 581 children and adolescents aged 4 - 19 years who were suspected of having tuberculosis, were latently infected with Mycobacterium tuberculosis, and had received at least one dose of BCG vaccine between April 17, 2019, and February 24, 2021. The study evaluated the TST results of 106 patients who had a positive Quantiferon test and were suspected of having tuberculosis. Results: The study included 581 patients aged between 4 and 19 years. Of these, 106 patients tested positive for the Quantiferon test, while 19 were indeterminate and 456 were negative. The Quantiferon test positivity rate was 18.24%. Among the 106 QFT-Plus-positive cases, 23 patients also tested positive for TST. The difference in distribution was found to be statistically significant. Conclusion: The QFT-Plus test is considered an alternative to TST and other microbiological diagnostic methods for early tuberculosis diagnosis, particularly in children and adolescents.

Investigation of the cell composition and gene expression in the delayed-type hypersensitivity tuberculin skin test

Dear Editor,The tuberculin skin test(TST)reagents have continuously improved,with the ESAT6-CFP10(EC)test having recently been introduced,but are seldom based on the direction of the delayed-type hypersensitivity(DTH)mechanism.Previous studies only partially showed the infiltration and activation of immune cells and the production of cytokines of the skin induration[1,2],and lack the detailed measurements of cell proportions and gene expression in the DTH response.Therefore,in this study,we revealed the comprehensive characteristics of DTH by single-cell RNA sequencing(scRNA-seq)in the guinea pig tuberculosis(TB)model[Experimental Animal Welfare Ethics Committee,Beijing Tuberculosis and Thoracic Tumor Research Institute(2021-064)].

Monitoring Report of Maternal Antibody of Broiler Avian Influenza Virus H5 Subtype Re-8 Strain

[ Objective ] The paper was to prevent the occurrence of broiler avian influenza virus HS subtype Re-8 strain effectively in the breeding process of broilers. [Method] The maternal antibodies of broilers in Beijing Baochen Hongwang farm were monitored. According to the disappearance law of maternal antibody, the optimal immune time of broiler avian influenza virus H5 subtype Re-8 strain was determined. [ Result] The maternal antibody level of 2-day-old broilers was relatively high, concentrated at 6 log2 -9 log2, and the antibody positive rate was 100%. The maternal antibody level of 8-day-old broilers concentrated at 4 log2 -6 log2, and the antibody positive rate was 100%. The maternal antibody level of 17-day-old broilers concentrated at 0 log2 -3 log2 , and the antibody positive rate was 0. The average maternal antibody level of 24 - 37 days old broilers was 〈 1 log2, and the antibody positive rate was 0. [ Conclusion ] Although the av- erage maternal antibody level of 8-day-old broilers was higher than 5 log2 , 20% of chickens was 4 log2, and maternal antibody could not protect the flock completely. Therefore, the best primary immunization day age of chicks against avian influenza virus was 8 - 10 days of age.

Comparison on Detection Results of PRV Wild Virus Antibody Provided by Different Institutions

The detection results from different institutions were performed at the first stage of PRV wild virus antibody supervision in swine breeding. The serum samples were collected from 71 individuals and each individual was sampled twice at one week interval. The results showed that the positive coincidences for gE antibody between two institutions were 35.71% and 45.45 % ：espectively, with the total detection coincidences of 87.32% and 91.55% correspondingly. The positive coincidences for gE antibody between the two detections of each institution were 40.00% and 75.00% respectively, with the total detection coincidences of 87.32% and 97.18% correspondingly. It indicates that it is very necessary to screen the detection institution at the first supervision stage of PRV wild vires for swine population.

Diagnostic performance and problem analysis of commercial tuberculosis antibody detection kits in China

Background: The diagnosis of bacterium-negative pulmonary tuberculosis(TB) and extra-pulmonary TB is challenging clinically. The detection of the anti-TB antibody has an important, auxiliary, clinical diagnostic value. Therefore, TB antibody detection kits should be screened and evaluated, and the reagents with the highest sensitivity and specificity should be chosen and used clinically.Methods: The diagnostic performance of 7 commercially available TB antibody detection kits(kits A, B, C, D, E, F and G) based on the gold immunoassay detection of immunoglobulin(Ig) G or IgM antibodies were simultaneously evaluated and compared in 62 TB cases and 56 non-TB cases in a laboratory. A retrospective analysis including 2549 cases was carried out to assess the clinical diagnosis values of bacteriological examinations and TB antibody tests(kits B and H used in the clinic).Results: The sensitivities of TB antibody kits A, B, C, D, E, F and G in the sera from 62 TB patients were 50.0%, 83.9%, 38.7%, 9.7%, 48.4%, 69.4% and 79.0%, respectively; the sensitivities in the sera from 24 smear-negative TB patients were 29.2%, 79.2%, 29.2%, 12.5%, 29.2%, 54.2% and 79.2%, respectively; the specificities in the sera from 56 nonTB patients were 73.2%, 25.0%, 85.7%, 96.4%, 78.6%, 78.6% and 50.0%, respectively. Of the 2549 clinically diagnosed cases, there were 1752 pulmonary TB cases, 505 extra-pulmonary TB cases, 87 old pulmonary TB cases and 205 non-TB cases. The positive results for smear, culture, TB antibody kit B and kit H in pulmonary TB cases were 39.8%(543/1365), 48.6%(372/765), 45.8%(802/1752) and 25.2%(442/1752), respectively; the results in extra-pulmonary TB cases were 3.4%(6/178), 5.8%(4/69), 35.4%(179/505), and 11.3%(57/505), respectively; the results in old pulmonary TB cases were 0%(0/64), 0%(0/30), 32.2%(28/87), and 9.2%(8/87), respectively; and the results in non-TB cases were 0%(0/121), 0%(0/56), 21.5%(44/205), and 2.4%(5/205), respectively. Of 624 smear-positive and/or culture-positive pulmonary TB cases, the sensitivities of antibody test kits B and H were 53.0% and 36.4%, respectively. Of 901 smear-negative and/or culture-negative pulmonary TB cases, the sensitivities of antibody test kits B and H were 42.5% and 19.0%, respectively. The positive rate of antibody detection in the bacterium-positive pulmonary TB cases was significantly higher than that in the bacterium-negative pulmonary TB cases(P<0.05).Conclusion: The colloidal gold-labeled TB antibody IgG detection assay is a simple, rapid and economical method that provides a better clinical auxiliary diagnosis value on TB, especially in smear-negative pulmonary TB and extrapulmonary TB. The production, quality control, screening and evaluation of antibody detection kits are very important for its clinical application.

Recent Developments in SARS-CoV-2 Neutralizing Antibody Detection Methods

The ongoing Coronavirus disease 19 pandemic has likely changed the world in ways not seen in the past.Neutralizing antibody(NAb)assays play an important role in the management of the severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)outbreak.Using these tools,we can assess the presence and duration of antibody-mediated protection in naturally infected individuals,screen convalescent plasma preparations for donation,test the efficacy of immunotherapy,and analyze NAb titers and persistence after vaccination to predict vaccine-induced protective effects.This review briefly summarizes the various methods used for the detection of SARS-CoV-2 NAbs and compares their advantages and disadvantages to facilitate their development and clinical application.

Effect of Se-enriched Lactobacillus on Antibody of NDV of Broilers

This study was conducted to investigate the effect of Se-enriched lactobacillus on antibody of Newcastle Disease Virus(NDV)of broilers.One thousand day-old AA broiler chickens were selected from a chicken farm of Jinghai County,and the chickens were divided randomly into two groups,which respectively had five repeat groups with 100 chickens each,one named basal diet group,and the other named Se-enriched lactobacillus group.Corn soybean meal diet was selected for basal diet group,while 2%se-enriched lactobacillus was added into corn soybean meal diet for the other group.The method of feeding was free diet,drinking,and routine immunization program was adopted.This test period was 42 d.Two chickens were selected randomly in each repeat for slaughtering and collecting serums on the 14th,28th and 42nd d.Assessments on the effect of Se-enriched lactobacillus in antibody titer of NDV of broilers were made by hemagglutination-inhibition test.The results indicated that antibody titer of NDV was increased significantly by Se-enriched lactobacillus.

Is there a need for universal double reflex testing of HBsAg-positive individuals for hepatitis D infection?

Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.

Electrochemical biosensors for point-of-care testing

Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.

Performance and correlation of QuantiFERON-TB Gold, T-SPOT.TB and tuberculin skin test in young children with or exposed to tuberculosis

Objective:To evaluate the performance of interferon gamma release assays and tuberculin skin test in Bacillus Calmette-Guerin vaccinated young children.Methods:A cross-sectional study was conducted in healthy children younger than 5 years who were recently diagnosed with tuberculosis or had recent exposure to active tuberculosis.QuantiFERON-TB Gold,T-SPOT.TB and tuberculin skin test were performed in each patient.Results:Of the 60 children,median age 3.3 years,17 had tuberculosis and 43 had recent tuberculosis exposure.Overall,15(25.0%)children had tuberculin skin test reaction≥10 mm;8(13.3%)were positive by QuantiFERON-TB Gold In-Tube test,and 12(20.0%)by T-SPOT.TB.Nineteen(31.7%)children had at least one positive test.There was a moderate agreement between interferon gamma release assays and tuberculin skin test.Conclusions:The positive rates of interferon gamma release assays and tuberculin skin test were low in young children who were infected with tuberculosis,supporting the management strategy of not testing children younger than 5 years.

Performance and correlation of interferon gamma release assays and tuberculin skin test in HIV-infected children and adolescents with immune reconstitution

Objective:To evaluate the performance of interferon gamma release assays and tuberculin skin test in HIV-infected children and adolescents with immune reconstitution.Methods:A cross-sectional study was conducted in HIV-infected patients aged 5-18 years receiving antiretroviral treatment with CD4 T-lymphocytes>25%or>500 cells/mm3 for at least 6 months.QuantiF ERON-TB Gold,T-SPOT.TB,and tuberculin skin test were performed in each patient.Results:A total of 50 patients were enrolled with median age of 13.7 years,CD4 counts of 753(IQR:587-989)cells/mm3.Among 27 patients with tuberculosis(16)or tuberculosis exposure(11),8(29.6%)were positive to at least one test,2(7.4%)were positive QuantiFERON-TB Gold,3(11.1%)positive T-SPOT.TB,and 7(25.9%)had tuberculin skin test≥5 mm.Among 23 patients without history of tuberculosis or exposure,all had negative interferon gamma release assays,while 2(8.7%)had positive tuberculin skin test.Conclusions:All tests had low sensitivity despite immune reconstitution.

Comparison of Sputum Smear Microscopy and Rapid Tuberculosisantibody Detection Test Kits for Diagnosis of Pulmonary Tuberculosis in Abia State, Nigeria

The SSM （sputum smear microscopy） and five immunochromatographic tuberculosis antibody detection tests （DiaSpot TB, Spodex TB, SD Rapid TB, Clinotech TB Screen and Precious One-step TB） were compared for diagnosis of active TB at the Leprosy and Tuberculosis Referral Hospital, Uzuakoli, Abia State, Nigeria. Sputum specimens from 150 study participants （male/female ratio, 0.81） were cultured on Lowenstein-Jensen slopes and direct smears were stained by Ziehl-Neelsen technique and examined by light microscopy. Sera were tested for anti-TB antibodies using the rapid TB tests. A total of 91 participants were culture positive, 79 （86.8%） for M. tuberculosis and 12 （13.2%） for nontuberculous mycobacteria. The sensitivity of SSM was 50% （95% CI： 39.0-61.0） and specificity was 92.3% （95% CI： 86.4-98.2） in those culture positive for M. tuberculosis. The sensitivity and specificity of the Rapid TB tests ranged from 24.1-39.2% and 78.4-87.8%, respectively. None of the five rapid TB tests had acceptable level of accuracy for diagnosis of active TB. The sensitivity of SSM though moderate is inadequate for long term TB control in this setting.

Indications, Interpretation and Clinical Consequences of Tuberculin Skin Tests in Resource Limited Settings

Objective: to evaluate the policy of TST testing in Suriname. As there is no gold standard to diagnose latent tuberculosis infection (LTBI), the tuberculin skin test (TST) is used to diagnose LTBI. However, internationally, the cut-off values of the TST are not uniform and depend on local tuberculosis (TB) epidemiology and guidelines for test initiation. In Suriname, where currently several indications exist for TSTs, cut-off values are set at 5 mm or 10 mm, depending on the age and/or medical history of the patient. LTBI classification is performed by pulmonologists primarily based on the American Thoracic Society targeted TB testing guidelines. Method: retrospective analysis of outpatient TST data between 2011 and 2019 from Suriname’s sole pulmonary medicine clinic. Result: 1373 patients were evaluated. 590 patients were from the screening group of whom 253 had a positive TST result, 46 of whom were classified as LTBI. In the contact tracing group of 649 patients, 616 had a positive TST, 352 of whom were classified as LTBI. In the medical condition group of 134 patients, 96 had a positive TST, 38 of whom were classified as LTBI. Eventually, positive TST results were found for 965 tested patients: 436 patients were classified as LTBI and 529 non-LTBI patients were not prescribed chemoprophylaxis. None of the non-LTBI TST-positive patients were diagnosed with active TB, including 174 patients with a TST result of 15 mm or greater and in need of IPT, but not prescribed by judgement of the pulmonologist or because of loss to follow-up. Conclusion: the overrepresentation of positive TST results in Suriname is attributable to stringent cut-off values, especially among patients who do not disclose TB risk factors. In our opinion the TST cut-off value for such patients in Suriname and other similar settings could be set at 15 mm. We also promote that for all patients with a TST result of 15 mm or greater, offering IPT should be considered (after excluding active TB).

Comparison between Quanti-FERON-TB Gold In-Tube test and tuberculin skin test for diagnosis of latent tuberculosis in children: A cross-section study

Objective: To compare Quanti-FERON-TB Gold In-Tube (QFT-GIT) test and tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection in children. Methods: In this cross-sectional study, 64 participants who were between 3 months and 14 years old and had close contact with smear-positive pulmonary tuberculosis were included. Both QFT-GIT test and TST were done and the results were analyzed by SPSS software and Kappa test. Results: The distribution of gender and age according to QFT-GIT and TST results were matched (P>0.05). Overall agreement between QFT-GIT and TST for diagnosis of latent tuberculosis infection in children was 75%. In addition, the contingency coefficient was 0.257, and the Kappa measure of agreement was 0.246 (P=0.034). Conclusions: Compared to TST, QFT-GIT shows no apparent advantage for diagnosis of latent tuberculosis infection in children.

Development of a rapid neutralizing antibody test for SARS-CoV-2 and its application for neutralizing antibody screening and vaccinated serum testing

Background:Since the outbreak of coronavirus disease(COVID-19),the high infection rate and mutation fre-quency of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the causative agent,have contributed to the ongoing global pandemic.Vaccination has become the most effective means of controlling COVID-19.Tra-ditional neutralizing tests of sera are complex and labor-intensive,therefore,a rapid test for detecting neutralizing antibodies and antibody status post-immunization is needed.Methods:Based on the fact that antibodies exhibit neutralizing activity by blocking the binding of the S protein receptor-binding domain(S-RBD)to ACE2,we developed a rapid neutralizing antibody test,ACE2-Block-ELISA.To evaluate the sensitivity and specificity,we used 54 positive and 84 negative serum samples.We also tested the neutralizing activities of monoclonal antibodies(mAbs)and 214 sera samples from healthy individuals im-munized with the inactivated SARS-CoV-2 vaccine.Results:The sensitivity and specificity of the ACE2-Block ELISA were 96.3%and 100%,respectively.For neu-tralizing mAb screening,ch-2C5 was selected for its ability to block the ACE2-S-RBD interaction.A plaque assay confirmed that ch-2C5 neutralized SARS-CoV-2,with NT 50 values of 4.19,10.63,and 1.074μg/mL against the SARS-CoV-2 original strain,and the Beta and Delta variants,respectively.For the immunized sera samples,the neutralizing positive rate dropped from 82.14%to 32.16%within 4 months post-vaccination.Conclusions:This study developed and validated an ACE2-Block-ELISA to test the neutralizing activities of an-tibodies.As a rapid,inexpensive and easy-to-perform method,this ACE2-Block-ELISA has potential applications in rapid neutralizing mAb screening and SARS-CoV-2 vaccine evaluation.

原发性颈淋巴结结核诊治分析

目的探讨原发性颈淋巴结结核的临床特征、确诊方式及诊疗方案。方法回顾性分析宁波市医疗中心李惠利医院确诊的39例原发性颈淋巴结结核患者临床资料,总结其临床特点、治疗方法及随访情况。结果所有患者均以颈部无痛性质韧肿块为首发症状,肿块多位于颈部Ⅲ、Ⅳ、Ⅴ区,部分位于Ⅰ、Ⅱ区,均完善CT、MRI或B超等检查。根据影像学检查和临床经验,21例患者行结核菌素试验(PPD)或结核感染T细胞斑点试验(T-SPOT),其中2例PPD阳性,13例T-SPOT阳性,15例均经穿刺病理结果确诊,6例经手术病理确诊;1例经细针穿刺细菌培养发现结核杆菌确诊;17例影像学考虑肿瘤性病变,经颈淋巴结清扫或肿块部分切除术后病理确诊结核。39例患者均予标准抗结核治疗半年,随访1年未见复发。结论原发性颈淋巴结结核缺乏特异性症状,初步诊断可借助T-SPOT检查,确诊仍需结核杆菌培养阳性、穿刺细胞学或组织病理结果,治疗应采用世界卫生组织(WHO)推荐的6个月治疗方案,当伴有脓肿、窦道或溃疡型结核时,应结合手术治疗,可有效缩短术后抗结核治疗时间、减少药物用量及不良反应。