新兵260名血清中艾滋病抗体检测假阳性结果分析

目的了解新兵艾滋病抗体初筛检测中假阳性结果真实情况,探讨初筛实验与确认实验之间关系,为提高艾滋病检测技术提供依据。方法采用酶联免疫吸附试验（ELISA）技术,对2000--2007年期间应征入伍的新兵进行艾滋病抗体初筛检测,阴性者判定阴性,阳性者再用另外一种试剂复核,复核阳性标本再送全军艾滋病检测中心采用免疫印迹试剂进行确认。结果6年间共检测新兵血清标本49017份,筛查出260份阳性血清标本,发现初筛所能够捡出的全部抗-HIV阳性标本,经复核和确认实验后,100％为HIV抗体阴性,（S／CO）值在1．000～5．000范围的249份,占95．8％;超过5以上的11份,占4．2％。结论新兵人群艾滋病病毒抗体检测存在一些假阳性结果,复核实验是有效排除假阳性、提高确认效率、节省经费开支的有效措施。     

2007年吉林省艾滋病病毒抗体检测结果分析

目的分析2007年高危人群艾滋病病毒（HIV）抗体检测数据，对现行的检测试剂进行初步评估。方法按照《全国艾滋病检测技术规范》（2004年版）规定的检测方法，对吉林省各艾滋病筛查中心实验室送检的HIV抗体筛查阳性样本进行HIV抗体确认和分析。结果2007年222例HIV抗体筛查阳性样本进行确认试验后，有179例（80．6％）为HIV-1抗体阳性，31例（14．0％）HIV抗体不确定，12例（5．4％）HIV抗体阴性。12例阴性样本中出现假阳性结果ELISA试剂11例，快速试剂1例。结论HIV抗体筛查试剂存在一定的假阳性，导致确认试验抗体不确定和阴性结果数量的增加。对出现抗体不确定结果的样本应加强随访检测，同时考虑使用其它辅助诊断方法。     

Decisions about Pap tests: What influences women and providers?

Despite the success internationally of cervical screening programs debate continues about optimal program design. This includes increasing participation rates among under-screened women, reducing unnecessary early re-screening, improving accuracy of and confidence in screening tests, and determining the cost-effectiveness of program parameters, such as type of screening test, screening interval and target group. For all these issues, information about consumer and provider preferences and insight into the potential impact of any change to program design on consumer and provider behaviour are essential inputs into evidence-based health policy decision making. This paper reports the results of discrete choice experiments to investigate women's choices and providers' recommendations in relation to cervical screening in Australia. Separate experiments were conducted with women and general practitioners, with attributes selected to allow for investigation of how women and general practitioners differ in their preferences for attributes of screening programs. Our results indicate a considerable commonality in preferences but the alignment was not complete. Women put relatively more weight on cost, chance of a false positive and if the recommended screening interval were changed to one year.     

Human immunodeficiency virus (HIV) and Hepatitis C virus (HCV) testing among injecting drug users

In Hungary, there is a need for widely accessible HIV and HCV testing and counseling for injecting drug users. Theoretically, free and confidential rapid HIV and HCV testing would be the most suitable for this purpose. Low threshold agencies, such as needle and syringe programs, would provide ideal premises for such a testing system, Here, participants would be able to undergo regular testing every six months. Making rapid testing widely available raises the following three main issues: 1. validity of the testing results (or: the verification of positive rapid test results), 2. circumstances of taking blood (or: legislation regarding drawing blood), and 3. cost effectiveness (or: how important is it to prevent an HIV epidemic). The authors propose the establishment of a system that offers screening using rapid tests and which would be an expansion of a currently existing system of HIV and HCV testing based on finger prick blood. The current system would thus serve as a means to verify the results of the rapid tests. At the same time, there is a need to obtain permission from a public health body to enable in needle and syringe programs the provision of rapid testing and testing of blood using finger pricks. In many countries, test results are given to injecting drug users not by doctors but by trained social workers - such a system could also be established in Hungary. If preventing an HIV epidemic in Hungary is a priority, then wide access to rapid HIV testing is justified. Widely accessible free and confidential rapid HIV and HCV testing and counseling - combined with screening and verification using finger prick blood - may function not only as a testing and counseling service but also as a good quality public health monitoring system. Such a system, however, requires regular financial support from the government.     

Screening: the legal view

Screening has become central to the effective prevention of several diseases, but implementation suffers from difficulties with targeting and rates of compliance. Such issues are also complicated by the need to consider legal provisions regarding confidentiality of patients and other human rights issues. Screening has been an inexact science in relation to, e.g., faecal occult blood testing for colorectal cancer, false positive and false negative tests for HIV, and there have been inadequate quality controls in breast cancer screening programmes. The public need to be made aware of what the screening programmes really offer, balanced against the expectations they may have. There needs to be a clearer understanding of the nature of the contractual and other legal rights of patients/consumers as against providers. A positive screening test may carry adverse consequences as well as benefits. It could alert an insurance company to a risk and lead to additional weighting or even outright rejection for life insurance policies. Job prospects may also be affected for employees. The method of informing patients in relation to screening and screening failure has already been considered by the courts. Realistic information about both screening and treatment efficiency needs to be offered to patients so that they can have a real understanding of what can and cannot be achieved by current science. The development of understanding of the human genome makes the need for clearer legislation in this are more urgent.     

国产HIV抗体检测试剂盒的评价

本文报作了对目前国产的HIV抗体检测粗筛试剂的评价结果。病毒所生产的IF和IE试剂,及上海生研所生产的ELISA试剂,敏感性为91.2%~96.9%;特异性为94.6%~97.3%。在我国这样的HIV低感染率情况下,这些试剂的阴性预测值可达100%,阳性预测值极低。认为这些试剂都还能满足国内HIV检测粗筛实验的应用。这些试剂的剂型价格,尚须改进。     

HIV抗体初筛实验室质控考评结果分析

目的：评价艾滋病毒检测初筛实验室的检测质量,促进质控水平的提高。方法：用包括ＨＩＶ抗体阳性、弱阳性和阴性共２０例考证血清对５３个医疗防疫单位的艾滋病毒检测初筛实验室进行现场测试。结果：３５个实验室检测结果完全正确,１７个实验室出现了不同程度的阴性结果,近１／３的实验室检测弱阳性标本的Ｓ／ＣＯ值低于质控标准的９５％可信限以下。结论：敏感性达不到标定的范围是ＨＩＶ检测存在的主要问题。未严格遵守艾滋病毒     

Use of HIV and HSV-2 Biomarkers in Sub-Saharan Adolescent Prevention Research: A Comparison of Two Approaches

Self-report of sexual behavior among adolescents is notoriously inconsistent, yet such measures are commonly used as outcomes for human immunodeficiency virus (HIV) prevention intervention trials. There has been a growing interest in the use of HIV and other sexually transmitted disease biomarkers as more valid measures of intervention impact in high HIV prevalence areas, particularly in sub-Saharan Africa. We examine the challenges, benefits, and feasibility of including HIV and herpes simplex virus type 2 (HSV-2) biomarker data, with details about different data collection and disclosure methods from two adolescent prevention trials in Kenya and Zimbabwe. In Kenya, whole blood samples were collected using venipuncture; adult guardians were present during biomarker procedures and test results were disclosed to participants and their guardians. In contrast, in Zimbabwe, samples were collected using finger pricks for dried blood spots (DBS); guardians were not present during biomarker procedures, and results were not disclosed to participants and/or their guardians. In both countries, prevalence in the study samples was low. Although the standard of care for testing for HIV and other sexually transmitted infections includes disclosure in the presence of a guardian for adolescents under age 18, we conclude that more research about the risks and benefits of disclosure to adolescents in the context of a clinical trial is needed. Notably, current serological diagnosis for HSV-2 has a low positive predictive value when prevalence is low, resulting in an unacceptable proportion of false positives and serious concerns about disclosing test results to adolescents within a trial. We also conclude that the DBS approach is more convenient and efficient than venipuncture for field research, although both approaches are feasible. Manufacturer validation studies using DBS for HSV-2, however, are needed for widespread use.     

Prevention of mental retardation due to PKU: selected aspects of program validity.

Phenylketonuria (PKU) screening of the newborn represents the largest preventive program in the history of public health. Yet traditional indices of program validity cannot be estimated with confidence because of insufficient or equivocal evidence. Large variation of results within and between screening programs invalidates general probability statements. Current issues in PKU screening involve aspects of comprehensiveness, effectiveness, and efficiency of the program. Specific concerns include the risk of missing PKU cases, the interpretation of a positive screening test result, the loss to follow-up of infants with positive screening test results, the validity of diagnostic criteria in regard to the risk for mental retardation, the age at which preventive intervention is initiated, and the consequences of the program for the prevalence of mental retardation in future generations. The major evidence bearing on these questions is reviewed, and it is concluded that the screening program has a high potential for effectiveness and efficiency. Program validity can be optimized and maintained by continuous monitoring of individual program experience, which results in appropriate adjustments of procedures and criteria.     

ELISA检测中全自动加样引起拖带假阳性现象的分析

目的：探讨ELISA检测中全自动加样引起拖带假阳性现象的原因以及所要采取的对策。方法别使用试剂检测筛查血液标本，然后根据检测试剂说明书的要求，在全自动样本处理系统控制微机上编辑程序，程序包括初检和复检。使用一次性探针和永久性探针的污染情况对比，再使用2种标本进行3孔复检，在进行判断是否为强阳性所引起的拖带污染现象。结果整个检测过程中，以HIV检测为例所检测的7324份血液检测中出现拖带假阳性现象的为2例，而2013年1月-2014年5月间共检测血液标本66085份，没有出现拖带假阳性现象。结论一次性加样探针的使用能够很好的减少甚至杜绝拖带假阳性污染现象的发生，在检测过程中由于不同的厂家的试剂有所区别，在设计加样参数时应该遵循科学合理的原则，检测仪器要定期进行检验维修，校准，同时对于血液标本要严格质量控制，提高检测的准确性和安全性，使得全自动检测设备的优势充分。     

初筛抗-HIV1+2阳性而确认阴性标本的分析

目的:了解平顶山市2004年1月~2007年5月艾滋病病毒(HIV)抗体检测中筛查试验假阳性结果的真实情况,更加合理地开展HIV抗体日常检测。方法:检测结果及判断按《全国艾滋病检测技术规范》进行,对比分析HIV抗体筛查试验为阳性而免疫印迹试验(WB)为阴性的标本的结果以及相关资料。结果:46份筛查试验为阳性反应、WB确认试验为HIV抗体阴性的标本,占所有检测标本的1.45%,占筛查试验阳性标本的7.57%。46份标本中,胶体硒诊断试剂(PA)阳性的9份,占19.57%;酶联免疫吸附试验(ELISA)阳性40份,占86.96%,S/CO值平均为2.09(1.253~5.056)。结论:日常检测必须遵从先筛查再确认的检测程序,筛查试验阳性的不能直接出HIV抗体阳性报告,应确认后再报出。     

艾滋病筛查阳性标本复检与确认试验结果的对比分析

目的通过HIV抗体酶联免疫吸附（ELISA）初筛试验与蛋白印迹（WB）确认试验结果的比对,探讨目前艾滋病检测存在的问题。方法对芜湖市2011年艾滋病筛查阳性标本复检与确证实验结果进行比对,并分析WB确认试验带型及感染者基本信息。结果 119份HIV抗体初筛阳性血清经WB确认80份阳性,23份阴性,16份不确定。其中,两种初筛试剂测试结果均阳性的93份标本经WB确认80份阳性,7份阴性,6份不确定;两种初筛试剂测试结果一阴一阳的26份血样经WB确认16份阴性,10份不确定。在80份HIV-1确认阳性标本中,P55条带出现次数最少,仅为50.00%。在16份不确定标本中,Gp160条带出现频率最高,占总不确定标本的62.50%。结论筛查弱阳性的标本尽量用筛查试剂排除,从而减少＂HIV抗体不确定＂结果。不确定结果与WB试验的假阳性有关,可结合流行病学资料对结果进行准确解释。     

Prevalence of hepatitis B in an indigent, multi-ethnic community clinic prenatal population

Perinatal infection of hepatitis B virus (HBV) from an infected asymptomatic woman to her offspring is now a preventable disease. A chart review was undertaken to document the prevalence of asymptomatic HBV infection in a high-risk, predominantly minority, indigent, and immigrant family practice clinic population and to evaluate the frequency of accepted known risk factors for those subjects with positive hepatitis B surface antigen (HBsAg) screening tests. Records for 464 pregnant women entering the prenatal program between January 1, 1983, and April 30, 1987, were reviewed. Twenty-three (5.3%) were found positive for the HBsAG, all were asymptomatic. Results of a logistic regression on multiple risk factors for HBV infection revealed that ethnicity was the sole predictor of a positive HBsAg screening test, with 13% of the Asian patients and 1% of the Latino subjects positive for HBsAg. Other historical factors such as previous sexually transmitted disease and past history of transfusion were not predictive. These results reaffirm that a screening program for asymptomatic HBV infection in selected prenatal populations can identify a significant number of infants at risk for risk for perinatal infection.     

External evaluation of serology results in blood banks in Colombia]

OBJECTIVE: To analyze the serological results found in Colombian blood banks that participate in the external quality program (EQP) of that country's National Institute of Health, in order to improve the quality of the screening of blood for the main serological markers of transfusion-transmitted infectious diseases. METHODS: Each blood bank received a panel of six sera with different reactivity and positivity to hepatitis B surface antigen (HBsAg), as well as to antibodies to HIV 1-2, Trypanosoma cruzi (the causative agent of Chagas' disease), Treponema pallidum (the causative agent of syphilis), hepatitis B core (HBc) antigen, hepatitis C virus (HCV), and human T-lymphotropic virus (HTLV). The screening techniques used were enzyme-linked immunosorbent assay (ELISA), microparticle enzyme immunoassay (MEIA), and hemagglutination. With the panel sera, the participating blood banks were asked to apply the same tests that they use on a daily basis to screen blood units and to send their results to the National Blood Banks Unit of the Colombian National Institute of Health. RESULTS: Of the 46 blood banks participating in the EQP, 43 of them (93%) returned their results within the requested timeframe. The ELISA test was the one that was used most often (83.0%). There were a total of 49 (5%) false positive results and 12 (3%) false negative results. Of those 12 false negative results, 6 of them corresponded to the detection of syphilis, 2 to Chagas' disease, 2 to anti-HBc antibodies, 1 to anti-HCV antibodies, and 1 to HBsAg. Eighty percent of the discordant results came from 23 blood banks that each collected fewer than 6 000 units of blood per year, and 15% came from 5 blood banks that collected 6 000 to 12 000 units per year. One of the blood banks that collected more than 12 000 units annually had three false positive results, and none of those larger blood banks had any false positive results. CONCLUSIONS: The percentage of false negative results (3%) found during the EQP can be considered high, since tests that are negative during blood screening are not repeated, and the decision to declare a unit of blood suitable for transfusion is based on that single result. There is a need to thoroughly review the procedures for screening blood in Colombia, particularly at the centers that performed poorly in this EQP exercise.     

艾滋病病毒抗体初筛诊断试剂临床质量评估

目的：了解目前市场供应的艾滋病病毒(HIV)抗体初筛试剂的质量及使用情况。方法：对5种HIV抗体酶联免疫吸附试验(ELISA)诊断试剂用200份血清样品进行统一测试。200份血清标本包括100份经过确认的HIV抗体阳性、弱阳性、阴性标本及100份高危人群血清标本初筛阳性或可疑标本再用免疫印迹法(WB)做确认对比分析。结果：5种参评试剂的敏感性为96．88％--100．00％，特异性为97．02％--100．00％，假阳性率为0--2．98％，假阴性率为0--3．13％，功效率为97．00％--100．00％，阳性预测值为86．11％--100．00％，阴性预测值为99．39％--100．00％。结论：随着第三代ELISA抗体诊断试剂的发展，试剂的质量较之以前已有了明显的提高。     

Optimal allocation of testing dollars: the example of HIV counseling, testing, and referral.

BACKGROUND: Health screening programs can be represented as a pathway of sequential processes: offering a test, obtaining consent, conducting the test, providing results, and linking to appropriate care. Using the example of HIV testing, the authors explore the optimal targeting of funds within this pathway. METHODS: The authors develop a microsimulation of HIV testing services and decompose the likelihood that an unidentified HIV-infected person will receive care into the probability of testing [P(test)] and the probability of follow-up [P(follow)] defined as returning for results and linking to care. The authors examine the clinical impact and cost-effectiveness of alternative investments in these component probabilities. RESULTS: At 1% undiagnosed HIV prevalence, cost-effectiveness ratios for HIV testing cluster around $33,000/QALY (quality-adjusted life year) gained. A program with a yield of 0.16 via P(test)=0.20 and P(follow)=0.80 has a cost-effectiveness ratio of $32,900/QALY compared with $36,300/QALY for a program where P(test)=0.80 and P(follow)=0.20. Interventions that improve the probability of success in later stages in the testing pathway [P(follow)] are more cost-effective than investments devoted to earlier stages [P(test)]. CONCLUSIONS: Equivalent pathway outcomes in a screening program do not confer equal value. Limited screening resources are best targeted toward returning for results and linkage among those already identified with disease rather than offering testing to additional people.     

Guidelines for the use and interpretation of nucleic acid detection tests for Neisseria gonorrhoeae in Australia: a position paper on behalf of the Public Health Laboratory Network

The Public Health Laboratory Network (PHLN) convened a workshop of Australian experts in Melbourne on 23 March 2005 to identify laboratory issues of relevance and suggest guidelines for use of nucleic acid detection tests (NADT) for diagnosis of gonorrhoea in Australia. The proceedings of that meeting were endorsed by the members of the PHLN and the Communicable Diseases Network of Australia. Given the present state of knowledge and experience of conditions currently existing in Australia, the following recommendations were made: Recommendation 1: Assays using detection of the cppB gene should not be used for either screening or supplemental assays. Recommendation 2: All in-house screening assays that are positive should also be positive on a reliable supplemental assay before a positive result is reported. Recommendation 3: All commercial screening assays that are positive should also be positive on a reliable supplemental assay before a positive result is reported. Recommendation 4: If a sample is positive in a screening assay but a suitable supplemental assay is negative, then the result should be reported as negative. Recommendation 5: Laboratories should ensure that the test combination they use would yield a positive predictive value of at least 90 per cent in a population with a prevalence of 1 per cent. Recommendation 6: For the purposes of test evaluation, as distinct from diagnostic testing, true positives be defined by meeting one or more of the following criteria: 1) culture positive using contemporary isolation and identification techniques; 2) positive result on NADTs directed to targets on three separate genes that are known to have discriminatory capacity; 3) sequencing of a gene known to separate gonococcal from non-gonococcal species. Recommendation 7: Inhibitor controls should be routinely included in all NADT. Recommendation 8: Cultures are the preferred test for samples from non-genital sites. If however it is necessary to perform a NADT, then more stringent criteria should be applied, and positive samples should meet the 'test evaluation' criteria for a 'true positive'. Recommendation 9: In order to properly assess the routine diagnostic system in Australia, the following quality assurance samples should be distributed in addition to the routine samples currently used: 1. cppB negative N. gonorrhoeae; 2. Non-gonococcal species known to cause false positive reactions: these should be dispatched both as a single species, as well as mixture with N. gonorrhoeae. In the latter circumstance, the non-gonococcal species should be present in 10-fold excess; 3. Urine samples: preferably a single patient sample, otherwise a spiked sample. 4. Validation panels should be made that include samples that are culture positive but PCR negative. True positive samples should also be made available. In addition, a process should be established for full phenotypic and genotypic characterisation of unidentified species that yield false positive results in NADT for gonococci. Recommendation 10: Strategies should be put in place to ensure that sufficient numbers of gonococcal isolates are obtained to allow reliable monitoring of antimicrobial resistance. Recommendation 11: Public health practitioners need to define the relevant populations that need to be targeted and identify any that require enhanced surveillance.     

中国HIV抗体检测策略的应用评价

目的 评价中国HIV抗体检测策略在不同人群应用的效果和收益.方法 (1)收集103 133份一般人群(临床就诊病例、献血员、新兵)标本、1276份HIV感染高危人群(吸毒人群、HIV感染者的配偶)标本、2323份生化和免疫指标异常的标本,用现行HIV抗体检测策略进行检测.(2)对2002-2008年武警总医院90 289人次临床病例HIV抗体检测数据进行回顾性分析;对3个省级确认中心实验室过去3～5年确认检测的结果进行回顾性分析.结果 (1)筛查试验的收益在高危人群与一般人群显著不同,高危人群筛查阳性者中HIV抗体真阳性的比例约为50%,显著高于一般人群;主要针对一般人群的确认实验室筛查阳性标本中真阳性的比例为19.58%,显著低于主要针对高危人群的确认实验室.(2)2002-2008年临床HIV抗体检测,首次筛查阳性的真阳性率由3.7%上升到16.0%,同时,复检效率由92.6%下降为61.5%.(3)常见的生化和免疫异常未增加HIV抗体检测的非特异反应.结论 HIV抗体筛查阳性预示HIV感染的意义在不同人群有显著差别,高危人群显著高于一般人群.随着近年来HIV抗体检测试剂质量的改进和实验室质量控制水平的提高,HIV抗体首次筛查的准确性大幅度提高,而复检的效率显著下降.应考虑对不同人群采取不同的检测程序.     

中国HIV抗体检测策略的应用评价

目的 评价中国HIV抗体检测策略在不同人群应用的效果和收益.方法 (1)收集103 133份一般人群(临床就诊病例、献血员、新兵)标本、1276份HIV感染高危人群(吸毒人群、HIV感染者的配偶)标本、2323份生化和免疫指标异常的标本,用现行HIV抗体检测策略进行检测.(2)对2002-2008年武警总医院90 289人次临床病例HIV抗体检测数据进行回顾性分析;对3个省级确认中心实验室过去3～5年确认检测的结果进行回顾性分析.结果 (1)筛查试验的收益在高危人群与一般人群显著不同,高危人群筛查阳性者中HIV抗体真阳性的比例约为50%,显著高于一般人群;主要针对一般人群的确认实验室筛查阳性标本中真阳性的比例为19.58%,显著低于主要针对高危人群的确认实验室.(2)2002-2008年临床HIV抗体检测,首次筛查阳性的真阳性率由3.7%上升到16.0%,同时,复检效率由92.6%下降为61.5%.(3)常见的生化和免疫异常未增加HIV抗体检测的非特异反应.结论 HIV抗体筛查阳性预示HIV感染的意义在不同人群有显著差别,高危人群显著高于一般人群.随着近年来HIV抗体检测试剂质量的改进和实验室质量控制水平的提高,HIV抗体首次筛查的准确性大幅度提高,而复检的效率显著下降.应考虑对不同人群采取不同的检测程序.     

中国HIV抗体检测策略的应用评价

目的 评价中国HIV抗体检测策略在不同人群应用的效果和收益.方法 (1)收集103 133份一般人群(临床就诊病例、献血员、新兵)标本、1276份HIV感染高危人群(吸毒人群、HIV感染者的配偶)标本、2323份生化和免疫指标异常的标本,用现行HIV抗体检测策略进行检测.(2)对2002-2008年武警总医院90 289人次临床病例HIV抗体检测数据进行回顾性分析;对3个省级确认中心实验室过去3～5年确认检测的结果进行回顾性分析.结果 (1)筛查试验的收益在高危人群与一般人群显著不同,高危人群筛查阳性者中HIV抗体真阳性的比例约为50%,显著高于一般人群;主要针对一般人群的确认实验室筛查阳性标本中真阳性的比例为19.58%,显著低于主要针对高危人群的确认实验室.(2)2002-2008年临床HIV抗体检测,首次筛查阳性的真阳性率由3.7%上升到16.0%,同时,复检效率由92.6%下降为61.5%.(3)常见的生化和免疫异常未增加HIV抗体检测的非特异反应.结论 HIV抗体筛查阳性预示HIV感染的意义在不同人群有显著差别,高危人群显著高于一般人群.随着近年来HIV抗体检测试剂质量的改进和实验室质量控制水平的提高,HIV抗体首次筛查的准确性大幅度提高,而复检的效率显著下降.应考虑对不同人群采取不同的检测程序.