A simple and sensitive test for field diagnosis of post kala-azar dermal leishmaniasis

BACKGROUND: Current methods for diagnosis of post kala-azar dermal leishmaniasis (PKDL) do not offer adequate sensitivity and specificity. OBJECTIVES: To develop a simple and sensitive test for field diagnosis of PKDL. METHODS: Immunochromatographic nitrocellulose strips precoated with recombinant k39 antigen were evaluated for the detection of circulating antibodies to leishmanial k39 in PKDL sera. A drop of serum applied to the strip followed by buffer led to the development of two visible bands indicating the presence of anti-k39 IgG. RESULTS: The strip test was able to detect cases of PKDL with 91% sensitivity. The specificity of the test was evaluated using controls with other skin diseases, other common infections and healthy persons from endemic and non-endemic regions. Of 125 controls examined, all were negative on the strip test, indicating 100% specificity of the test. CONCLUSIONS: The immunochromatographic nitrocellulose strips provide a non-invasive, rapid and accurate method for diagnosing PKDL.     

间日疟间接荧光抗体试验观察者变异与正常值上限研究

将间日疟阳性血清作系列倍比稀释进行间接荧光抗体试验,不同观察者平行读数或同一观察者先后读数的终点滴度之变异在一个倍比稀释度之内。对无疟疾感染史的正常人群522份血清作间日疟间接荧光抗体试验,其荧光抗体滴度正常值上限按99%位点估计为<1:10。     

TP-ELISA法在梅毒临床诊断中的应用

目的:评价梅毒螺旋体酶联免疫吸附试验(Enzyme-linked immunosorbent assay,TP-ELISA)检测梅毒螺旋体抗体IgG/IgM的临床意义。方法:收集经临床确诊的各期梅毒血清80份,自身免疫性疾病并排除梅毒的患者血清样本40份,以及100份献血员血清样本。全部血清标本分别进行RPR、TPPA和TP-ELISA试验,检测梅毒螺旋体抗体。结果:TP-ELSIA在梅毒患者组中的阳性率为100%(80//80),确证试验TPPA的阳性率为98.8%(79/80),两种方法的检测阳性率无统计学差异(P>0.05)。TP-ELSIA检测阳性率明显高于初筛试验RPR的检测阳性率87.5%(70/80)。在自身免疫性疾病组RPR试验出现假阳性,其他两种方法无假阳性出现。结论:TP-ELISA检测梅毒螺旋体特异性IgG/IgM抗体具有较高的敏感性和特异性,适用于临床大批量样本初筛和确诊,TP-ELISA试验阳性标本建议进一步作RPR试验。     

岳阳市无偿献血者4项传染病指标检测结果分析

目的 通过对岳阳市无偿献血者4项传染病检验结果的分析,探求无偿献血管理的有效方法,从根本上降低血液报废率.方法 对2006年1月至2010年12月岳阳市无偿献血者乙型病毒性肝炎表面抗原(HBsAg)、丙型病毒性肝炎病毒抗体(抗-HCV),人类免疫缺陷病毒抗体(抗-HIV)、梅毒螺旋体抗体(抗-TP)的血液检验结果进行分析.结果 无偿献血者4项传染病检验总不合格率呈上升趋势,从2006年的1.85％上升到2010年的2.65％.抗-TP、抗-HIV、抗-HCV不舍格率呈上升趋势,HBsAg的不合格率呈下降趋势.检测项目不舍格主要集中在抗-HCV、抗-TP、HBsAg.结论 无偿献血总不合格率呈上升趋势,但HBsAg的不合格率呈下降趋势.     

免疫酶染色试验诊断日本血吸虫病价值的研究

应用感染30条血吸虫尾蚴后7wk的鼠肝组织内虫卵冰冻切片抗原作免疫酶染色试验,采取单盲法检测606例经粪检确诊的日本血吸虫病人和310名健康人,阳性率和假阳性率分别为89.9％和4.2％;检测239例已治疗过的日本血吸虫病人,阳性率为24.7％,转阴率为75.3％;检测10例肺吸虫病人及60例华支睾吸虫病人,交叉反应率为0～6.7％。对不同感染期及不同感染度的血吸虫病兔血清中特异性抗体的动态检测,能显示抗体的消长,免疫酶染色的反应性和反应强度与感染期和感染度密切相关。本文进一步证明该法具有较高的诊断效果,并有疗效考核的价值。     

应用TP-lgM-WB法诊断早期先天梅毒

目的 研究新生儿中胎传梅毒感染的血清梅毒螺旋体蛋白印迹试验（TP-IgM-WB）水平，探讨其临床意义。方法 对58例梅毒孕妇所产60例（2例双胞胎）新生儿血清，应用梅毒螺旋体蛋白印迹试验（TP-IgM-WB）检测，并与TRUST、明胶颗粒凝集试验（TPPA）方法平行测定。结果 60例新生儿TP-IgM-WB法检出阳性27例，占45％（27／60），TRUST和TTPA阳性各59例。结论 确诊27例新生儿为早期先天梅毒婴儿，为临床提供了明确的诊治依据，对防治梅毒有重要意义。     

布鲁氏菌病血清学诊断研究进展

本文综述了16种布鲁氏菌病血清学诊断方法,并对其优、缺点进行了分析。     

The Multispot rapid HIV-1/HIV-2 differentiation assay is comparable with the Western blot and an immunofluorescence assay at confirming HIV infection in a prospective study in three regions of the United States

BackgroundA new HIV diagnostic algorithm has been proposed which replaces the use of the HIV-1 Western blot and HIV-1 immunofluorescence assays (IFA) as the supplemental test with an HIV-1/HIV-2 antibody differentiation assay.ObjectivesTo compare an FDA-approved HIV-1/HIV-2 antibody differentiation test (Multispot) as a confirmatory test with the HIV-1 Western blot and IFA.Study designParticipants were screened with an HIV-1/HIV-2 combination Antigen/Antibody (Ag/Ab) screening assay. Specimens with repeatedly reactive results were tested with Multispot and either Western blot or IFA. Specimens with discordant screening and confirmatory results were resolved with HIV-1 RNA testing.ResultsIndividuals (37,876) were screened for HIV infection and 654 (1.7%) had a repeatedly reactive Ag/Ab assay result. On Multispot, 554 (84.7%) were HIV-1 reactive, 0 (0%) were HIV-2 reactive, 1 (0.2%) was reactive for both HIV-1 and HIV-2 (undifferentiated), 9 (1.4%) were HIV-1 indeterminate, and 90 (13.8%) were non-reactive. HIV-1 RNA was detected in 47/90 Multispot non-reactive (52.2%) specimens. Among specimens confirmed to have HIV infection (true positives), Multispot and Western blot detected HIV-1 antibody in a similar proportion of cases (93.7% vs. 94.4% respectively) while Multispot and IFA also detected HIV-1 antibody in a similar proportion of cases (84.5% vs. 83.4% respectively).ConclusionsIn this study, Multispot confirmed HIV infections at a similar proportion to Western blot and IFA. Multispot, Western blot, and IFA, however, did not confirm all of the reactive Ag/Ab assay results and underscores the importance of HIV NAT testing to resolve discordant screening and confirmatory results.     

Identification of soluble and membrane antigenic markers of acquired toxoplasmosis by immunoblot

The overall performance of quantitative assays in the detection of anti‐Toxoplasma IgG is satisfactory, but discrepancies between assays are not uncommon especially when IgG concentrations are close to the limit of detection of the tests. The purpose of our study was to identify soluble and membrane antigens extracted from Toxoplasma gondii tachyzoites by immunoblot to select the most relevant antigenic bands to be used for qualitative serodiagnosis of acquired toxoplasmosis. We selected five relevant bands (98, 36, 33, 32 and 21 kDa) with soluble antigens and four relevant bands (42, 35, 32 and 30 kDa) with membrane antigens which gave high sensitivity and/or specificity in immunodiagnosis. The association on the same blot of at least three of the five relevant bands in the soluble antigen immunoblot showed the highest sensitivity/specificity (97·4%/99·0%, respectively). Our results indicate that immunoblot using soluble tachyzoite extract with simultaneous detection of at least three of the five bands (98, 36, 33, 32 and 21 kDa) represents a valuable test for serodiagnosis of acquired toxoplasmosis and should be further evaluated as a confirmatory test for sera which give discrepant results in quantitative assays.