Use of ligase chain reaction for the rapid diagnosis of lymph node tuberculosis

Ligase chain reaction amplification (LCx Abbott Laboratories) was used to detect the presence of M. tuberculosis in 101 adenopathy specimens obtained from 98 patients. A total of 30 cases of lymph node tuberculosis were diagnosed, and the data were compared with results obtained using conventional techniques. The sensitivity of auramine staining and culture were 50.0% and 66.7%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the LCx assay were 80.0, 98.6, 96.0, and 92.1% respectively. The results confirm the reliability of ligase chain reaction amplification for the detection of lymph node tuberculosis.     

Amplisensor-聚合酶反应定量检测脑脊液中结核分支杆菌DNA的研究

目的　探讨Amplisensor-聚合酶反应 (Amplisensor-PCR)定量检测脑脊液中结核分支杆菌DNA(TB-DNA)对结核性脑膜炎的诊断价值。方法 采用Amplisensor-PCR对117例结核性脑膜炎患者及36例非结核性脑膜炎患者的脑脊液标本进行检测,并与PCR(凝胶电泳后,经溴化乙锭染色)、涂片、培养法比较。结果 Amplisensor-PCR的敏感性显著高于涂片及培养,阳性率分别为57.13%、1.7%、6.7% (P＜0.001)。结论 Amplisensor-PCR可以通过标准曲线划定检出下限,并可换算出标本中原始的靶DNA值,同时具有较高的特异性和敏感性,对结核性脑膜炎的诊断有一定的临床意义。     

TaqMan-PCR技术诊断结核病的临床应用研究

目的　探讨TaqMan-聚合酶链反应 (TaqMan-PCR)技术在结核病快速诊断中的临床价值。方法 对 155例活动性肺结核患者的痰和外周血、130例结核性胸膜炎患者的胸腔积液和外周血以及 61例结核性脑膜炎患者的脑脊液和外周血应用TaqMan -PCR检测结核分支杆菌DNA ,痰、胸腔积液和脑脊液进行抗酸染色涂片检查 ,另外 ,痰标本还进行了BACTEC和改良罗氏培养；同期以52例肺癌患者的痰和外周血、50例恶性胸腔积液患者的胸腔积液以及 33例健康人的外周血作为对照进行TaqMan-PCR检测。 结果 155例活动性肺结核患者的痰和外周血、130例结核性胸膜炎患者的胸腔积液和外周血以及 61例结核性脑膜炎患者的脑脊液和外周血TaqMan-PCR的阳性率分别为 49.0%和 51.6%、45.4%和 38.5%以及 50.8%和 42.6% ,痰、胸腔积液和脑脊液TaqMan-PCR的阳性率显著高于抗酸染色涂片以及BACTEC和罗氏培养 (P＜0.05)。TaqMan-PCR检测痰、胸腔积液和外周血的特异性分别为 96.2%、98%和 96.5%。结论 TaqMan-PCR具有较高的敏感性和特异性 ,对结核病的快速诊断具有一定的价值。     

Polymerase chain reaction and ligase chain reaction in the diagnosis of gynecological tuberculosis

The polymerase chain reaction (PCR) and the ligase chain reaction (LCR) were evaluated and compared on 55 gynecological samples collected from women with active gynecological tuberculosis (Group 1), gynecological diseases other than tuberculosis (Group 2), and active tuberculosis elsewhere in the body without evidence for gynecological tuberculosis (Group 3). Acid fast staining and culture of Mycobacteria appeared to be ineffective in all specimens. The sensitivity of both amplification methods was 94.7% (one of the 19 patients with non-tuberculosis). The LCx method showed a very high inhibition by specimens (64.1% of negative samples versus 16.7% for PCR and LCx could be useful tools in the diagnosis of gynecological tuberculosis.     

脂阿拉伯甘露聚糖诊断结核性脑膜炎的评价

目的　评价分枝杆菌脂阿拉伯甘露聚糖(LAM)的诊断价值并给出受试者工作特征曲线(ROC)。方法 应用斑点金免疫渗滤技术平行检测结核性脑膜炎(TBM)及非结核性神经精神系统疾病血清(Serum)和脑脊液(CSF)中抗LAM抗体。Serum稀释25倍,CSF分别按1、2、4、8、16、32倍稀释。进行抗LAM抗体检测。结果 Serum敏感性(Sencitivity,Se)为96.9%,特异性(Specificity,Sp)58.3%。CSF在稀释倍数为12、4、、8、163、2时Se分别为93.6%,90.6%,56.3%,37.5%,12.5%,3.1%,Sp分别为83.3%、95.8%、95.8%、100%、100%、100%。最佳截切值(Cut-Off)为2倍稀释。统计分析表明,CSF在2倍稀释时其Se与Serum无显著性差异,但Sp有显著性差异。结论 应用斑点金免疫渗滤技术检测抗LAM抗体诊断价值较高。     

不同检测方法在结核性脑膜炎诊断中的应用价值

搜集陕西省结核病防治院2015年5月至2017年5月疑似结核性脑膜炎的住院患者519例,最终根据2010年国际结核性脑膜炎协作组制定的诊断标准,354例被诊断为结核性脑膜炎,其余165例排除结核性胸膜炎的诊断。评价BACTEC MGIT 960液体快速培养(简称“MGIT 960培养”)、RNA恒温扩增实时荧光检测技术(SAT-TB技术)、聚合酶链式反应-荧光探针检测技术(简称“PCR技术”)、GeneXpert MTB/RIF(简称“GeneXpert”)技术对结核性脑膜炎的诊断价值。MGIT 960培养、SAT-TB技术、PCR技术、GeneXpert技术检测结核性脑膜炎的敏感度及其95%CI值分别为23.7%(84/354;19.5%~28.4%)、7.6%(27/354;5.2%~10.7%)、12.4%(44/354;9.3%~16.2%)、39.5%(140/354;34.6%~44.7%),特异度分别为100.0%(165/165)、100.0%(165/165)、100.0%(165/165)、99.4%(164/165)。GeneXpert技术检测的敏感度明显高于MGIT 960培养、SAT-TB和PCR技术。     

酶联免疫斑点法诊断结核性脑膜炎临床研究

目的探讨酶联免疫斑点法（enzyme linked immune spot assay,ELISpot）对结核性脑膜炎的诊断价值。方法选取我院根据临床表现疑为结核性脑膜炎的患者26例,以ELISpot检测分泌IFN—γ的结核分枝杆菌ESAT-6及CFP-10抗原特异性T细胞水平。结果在所有入组患者中,根据诊断标准,明确诊断为结核性脑膜炎者15例,诊断为非结核性中枢神经系统感染者11例,ELISpot检测的敏感度为80．00％[95％可信区间（confidence interval,CI）51．9％-95．7％1,特异度为100％（95％CI71．5％-100．0％）;阳性预测值为100％（95％CI73．5％～100．0％）,阴性预测值为78．6％（95％CI49．2％～95．3％）。结论EHSpot对结核性脑膜炎有较高的诊断价值。     

RNA恒温扩增实时荧光检测技术对结核性胸腔积液的诊断价值

目的 探讨RNA恒温扩增实时荧光检测技术(simultaneous amplification and testing, SAT-TB)对结核性胸腔积液的诊断价值。方法 选取2014年6月至2016年6月聊城市传染病医院收治的有胸腔积液的患者210例作为研究对象,其中143例临床诊断为结核性胸膜炎,作为结核性胸膜炎组;其余67例患者作为对照组。应用涂片法、改良罗氏培养法、SAT-TB法检测研究对象胸腔积液标本,比较各检测方法的检测效能。结果 SAT-TB检测的敏感度、特异度、阳性预测值、阴性预测值分别为36.36%(52/143)、98.51%(66/67)、98.11(52/53)、42.04%(66/157)。SAT-TB检测的敏感度明显高于涂片法[3.50%(5/143)]及罗氏培养法[20.28%(29/143)],差异均有统计学意义(χ ²=19.08,P=0.021;χ ²=9.12,P<0.01)。SAT-TB法检测完成时间为1~2h,罗氏培养法完成时间为6~8周。 结论 SAT-TB法能快速检测胸腔积液中的结核分枝杆菌,敏感度高于涂片法和罗氏培养法。     

联检脑脊液中LAM-IgG和TB-DNA在诊断结核性脑膜炎中的应用

目的　了解脑脊液 (CSF)中阿拉伯糖甘露糖脂IgG抗体 (LAM-IgG)和TB-DNA指标对结脑的诊断价值。方法 以CSF为标本,用酶联免疫吸附试验 (ELISA)检测LAM-IgG,用聚合酶链反应(PCR)检测TB-DNA。结果 102份结脑病人CSF标本,LAM-IgG阳性率51.0% (52102),TB-DNA阳性率81.4% (83102),LAM-IgG阳性及 或TB-DNA阳性共93例 (91.2%)。40份非结核性的中枢神经系统疾病病例的CSF标本,均未检出LAM-IgG和TB-DNA.结论 LAM-IgG和TB-DNA均是诊断结脑的较好的指标,两者联检可进一步提高检测敏感性。     

Cerebrospinal fluid adenosine deaminase activity for the diagnosis of tuberculous meningitis in adults

We studied adenosine deaminase (ADA) activity in cerebrospinal fluid (CSF) of 16 cases of tuberculous meningitis, 4 cases of cryptococcal meningitis, 5 cases of bacterial meningitis, 12 cases of eosinophilic meningitis, 26 cases of aseptic meningitis, 6 cases of carcinomatous meningitis and 108 cases with normal CSF. The mean CSF ADA values for the different groups were: 39.44 +/- 41.46, 13.00 +/- 7.43, 34.20 +/- 40.81, 3.17 +/- 4.82, 10.03 +/- 9.23, 8.67 +/- 13.60, and 2.58 +/- 2.90 U/I, respectively. Comparing the ADA activity between patients with tuberculous meningitis and non-tuberculous meningitis, the receiver-operating characteristic (ROC) curve identified a CSF ADA level of 15.5 U/I as the best cut-off value to differentiate between the two, with a sensitivity of 75% and a specificity of 93%, with an area under the curve of 0.92. When tuberculous meningitis was compared with aseptic and carcinomatous meningitis, the ROC curve identified a CSF ADA level of 19.0 U/I as the best cut-off value for differentiation, with a sensitivity of 69% and a specificity of 94%, with an area under the curve of 0.83. The level of CSF ADA may be useful as a complementary tool in the early diagnosis of tuberculous meningitis.     

Tuberculous radiculomyelitis: review and presentation of five patients.

BACKGROUND: The southeast region of Iran is an endemic area for tuberculosis. Tuberculous radiculomyelitis (TBRM) was considered a rare form of parenchymal neurotuberculosis. OBJECTIVE: To analyze the clinical, laboratory and electrophysiological data of patients with TBRM. We report five patients and review the literature. METHOD: We searched Medline since 1966 and reviewed all cases of TBRM, excluding those with Pott's disease. We then evaluated the clinical and electrophysiological data of our patients. RESULTS: Five patients (two men), with a mean age of 25 years, were assessed. The mean duration of symptoms before diagnosis was 4.5 weeks. Three patients had clinical manifestation of tuberculous meningitis (TBM). Diagnosis was based on sputum smear and culture, cerebrospinal fluid (CSF) culture and polymerase chain reaction (PCR) gene amplification of Mycobacterium tuberculosis. Paraparesis or paraplegia, sphincter incontinence and Babinski sign were the main clinical features. CSF analysis was compatible with chronic meningitis. Electromyography showed radiculopathy in all patients and peripheral nerve disease secondary to axonal damage in only three, while myelography showed adhesive arachnoiditis in three. CONCLUSION: Despite the rarity of TBRM, clinical features were well described. To prevent neurological sequelae, early diagnosis and treatment is mandatory. Electrophysiological study may predict the prognosis.     

4种检测脑脊液结核分枝杆菌法对结核性脑膜炎诊断价值的探讨

目的探讨脑脊液抗酸杆菌涂片、3D、PhaB和PCR检测对结脑的诊断价值。方法检测60例结脑和30例非结脑患者脑脊液涂片、3D、PhaB和PCR阳性率,经统计学处理后,评价4种方法对结脑诊断的灵敏度、特异度。结果结脑组和其他组脑脊液涂片阳性率均为0,3D阳性率分别为23.3%和0,PhaB的阳性率分别是23.3%和26.7%,PCR的阳性率分别是6%和0,4种方法差异无统计学意义。脑脊液3D灵敏度为23.3%,特异度为100%,PhaB灵敏度为23.3%,特异度为73.3%,PCR的灵敏度10%,特异度为100%。结论脑脊液结核分枝杆菌涂片、3D、PhaB和PCR4种检测方法灵敏度低,积极寻找脑脊液结核分枝杆菌的检测方法和提高阳性率是实验室亟需解决的问题。     

荧光定量PCR技术对前驱期小儿结核性脑膜炎的应用价值

目的 了解荧光定量PCR（FQ-PCR）技术对前驱期（早期）小儿结核性脑膜炎（简称“结脑”）的快速诊断、疗效观察和预后判断的作用和意义。方法 选择被金标准（快速Mtb培养）确诊未经抗结核治疗的117例前驱期结脑组患儿和排除结脑的30例对照组患儿脑脊液标本,数字表法随机编号进行FQ-PCR检测Mtb DNA,计算其敏感度、特异度、诊断指数、阳性预测值、阴性预测值、符合率等统计指标并进行分析;治疗3周后结脑组盲法行培养和FQ-PCR检测,计算二者阳性检出率;随访出院时两种方法检测为阴性的结脑组患儿2年后各自复发率,进行统计学分析。结果 初诊患儿FQ-PCR检测结果与金标准比较敏感度、特异度、符合率为100.0%（117/117）、96.7%（29/30）、99.3%（146/147）,诊断指数达196.7%,经卡方检验,两者差异无统计学意义（χ²=0.000,P=1.000）,相关性分析r=0.9790,两种方法间有相关性（χ²=140.9,P=0.000）。结脑组治疗3周后培养法和FQ-PCR法阳性检出率分别为27.35%（32/117）和58.12%(68/117),两者差异有统计学意义（χ²=22.63,P=0.000）;随访结脑组患儿出院时两种方法检测阴性2年后复发结果为：78例培养法阴性患儿复发7例（8.97%）,69例FQ-PCR检测阴性患儿未见复发患者,差异有统计学意义（χ²=4.6736,P=0.0306）。结论 FQ-PCR检测脑脊液TB-DNA,准确、简便、快速,有助于早期诊断结脑,对疗效监测和预后评估比培养法更具优势。     

环介导等温扩增法快速检测结核分枝杆菌的临床应用评估

目的 进行环介导等温扩增法（LAMP法）快速检测结核分枝杆菌的临床验证与应用,评估该方法在结核病临床诊断中的效能。方法 选取广东6地市专业结核病防治机构（简称“结防机构”）的肺部不同疾病及健康人员的痰标本2129份,分别采用直接涂片法、罗氏固体培养法及LAMP法检测痰标本中结核分枝杆菌;另广州、汕头两市337例结核病患者的痰标本浓缩处理后进行实时荧光定量（qPCR）及LAMP两种方法检测。 结果 2129例痰标本中,直接涂片法、罗氏固体培养法和LAMP法的阳性检出率分别为13.2%（282/2129）、21.7%（463/2129）和20.3%(432/2129);同罗氏培养法相比,LAMP法灵敏度、特异度、阳性和阴性预测值分别为89.1%(432/485)、95.5%(1570/1644)、85.4%(432/506)和96.7%(1570/1623);337例浓缩处理后的痰标本qPCR阳性率为35.0% (118/337),LAMP阳性率为35.9% (121/337);LAMP法同直接涂片法检测、罗氏固体培养法和qPCR法比较,检测结果实际一致率分别为87.9%（Kappa值＝0.612）、96.1%（Kappa值＝0.89）和91.4%（Kappa值＝0.812）。 结论 LAMP法用于痰标本中结核分枝杆菌检测,其效能同罗氏培养法及qPCR法相当,同直接涂片法相比,LAMP法能够大幅提高阳性检出率,具有很好的临床应用和推广前景。     

rRNA扩增方法对结核分枝杆菌临床诊断作用的评估

目的 评价rRNA扩增方法 在临床应用的效果。 方法 选取到北京胸科医院、山东省胸科医院、河南疾控中心结核病防治所3个机构就诊的肺结核可疑症状者及健康志愿者的痰标本为研究对象,共纳入551例痰标本,对每例痰标本均进行涂片显微镜检查、罗氏培养、rRNA扩增试验以及实时荧光定量PCR。与罗氏培养方法 比较分析rRNA扩增方法 的敏感性、特异性、阳性预测值和阴性预测值以及与实时荧光定量PCR扩增方法 的一致性。 结果rRNA扩增方法 的敏感性为98.5%,特异性为95.0%,阳性预测值为95.0%,阴性预测值为98.5%,rRNA扩增方法 在涂阳标本和涂阴标本间的敏感度和特异度差异均有统计学意义（χ²=9.60,P=0.002;χ²=79.80,P<0.01）。与PCR检测结果的一致性为93.8%,涂阳和涂阴标本中2种方法 的一致性差异有统计学意义（χ²=4.45,P=0.035）。 结论 rRNA扩增方法 的敏感度和特异度均较好,且能明显缩短诊断时间,该方法 是一种较有前景的结核病实验室诊断方法 。     

TB PCR in the early diagnosis of tuberculous meningitis: evaluation of the Roche semi-automated COBAS Amplicor MTB test with reference to the manual Amplicor MTB PCR test. .

SETTING: Cecilia Makiwane Hospital, Mdantsane, Eastern Cape, Republic of South Africa. OBJECTIVE: To assess the role of the semi-automated Roche COBAS AMPLICOR(TM)Mycobacterium tuberculosis PCR test in the diagnosis of tuberculous meningitis (TBM). DESIGN: Eighty-three specimens of cerebrospinal fluid (CSF) were collected prospectively from 69 patients with suspected TBM. The COBAS AMPLICOR TB PCR test was compared with the manual AMPLICOR(TM)TB PCR test, clinical and cerebrospinal fluid (CSF) findings, direct ZN smear and radiometric TB culture. RESULTS: CSF from 7/40 (17.5%) patients treated for TBM were positive by TB COBAS AMPLICOR(TM). The sensitivity of the test was not significantly different (p=0.375) from the manual TB AMPLICOR(TM)PCR test. The comparative sensitivities of the TB COBAS AMPLICOR(TM)PCR and the manual AMPLICOR PCR for detecting cases of definite and probable TBM from CSF collected within 9 days of commencing antituberculosis treatment were 40% and 60% respectively. All 29 patients not treated for TBM were negative by COBAS AMPLICOR(TM), giving a specificity of 100%. CONCLUSION: The COBAS AMPLICOR(TM)TB PCR test is a rapid and highly specific diagnostic test for TBM. However, there was a non-significant trend favouring slightly greater sensitivity using the manual AMPLICOR(TM)TB PCR test.     

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??Abstract??Objective To investigate the applicability of Hristea diagnostic scoring in differentiated diagnosis between viral meningitis (VM) and tuberculous meningitis (TBM).Methods The study was performed retrospectively in resident patients with TBM (n=87) or VM (n=76) in our hospital.The prediction of TBM was determined by Hristea diagnostic scoring using parameters such as duration of symptoms before admission??neurological stages??cerebrospinal fluid (CSF)/blood glucose ratio and CSF protein concentrations.The diagnostic value of the scoring was assessed by calculating the area under the receiver operating characteristic (ROC) curves.Results The Hristea scores of all parameters were significantly different between TBM and VM patients.The sensitivity??specificity??positive predictive value and negative predictive value of Hristea scoring for TBM were 89.7%??86.8%??88.6% and 88.0%??respectively.The area under the ROC curve value for the diagnostic scoring was 0.92.Conclusion Hristea diagnostic scoring is helpful in early diagnosis and differential diagnosis of TBM and VM??and the usefulness of the scoring should be validated in larger series.     

超声引导下获取标本行病理学与结核相关检测对结核性胸膜炎的诊断价值

目的 比较分析超声引导下胸膜穿刺获取的病理组织及胸腔积液标本在疑似结核性胸膜炎中的诊断价值。方法 搜集2016年1月至2018年5月在西安市胸科医院初次就诊的298例疑似结核性胸膜炎患者,其中临床确诊结核性胸膜炎患者112例,非结核性胸膜炎患者186例。所有患者均通过超声引导下胸膜穿刺获取病理组织和胸腔积液标本,对活检组织进行病理学切片检查(简称“病理检查”),胸腔积液分别进行结核分枝杆菌培养(浓缩集菌法,采用液体培养BACTEC MGIT 960操作系统,简称“MGIT 960培养”)、全自动医用PCR分析系统(GeneXpert MTB/RIF,简称“GeneXpert检测”)和抗酸杆菌染色涂片检查(简称“涂片检查”)。上述各种方法以临床确诊患者为参考标准,得出各自的诊断敏感度、特异度、阳性预测值、阴性预测值、约登指数,以评价各种检测方法诊断结核性胸膜炎的效能。结果 病理检查、MGIT 960培养、GeneXpert检测、涂片检查以临床确诊结果为参考标准的诊断敏感度分别为41.96%(47/112)、73.21%(82/112)、58.93%(66/112)和2.68%(3/112);特异度分别为99.46%(185/186)、100.00%(186/186)、100.00%(186/186)、100.00%(186/186);约登指数分别为0.41、0.73、0.59、0.02。结论 超声引导下胸膜穿刺获取标本采用各种技术与方法进行检测,结果证明胸腔积液标本采用浓缩集菌法进行MGIT 960培养相对其他检测技术与方法具有较好的敏感度、特异度,约登指数最高,具有良好的临床诊断结核性胸膜炎的价值。     

Polymerase chain reaction of pleural biopsy is a rapid and sensitive method for the diagnosis of tuberculous pleural effusion

BACKGROUND: Tuberculous pleural effusion occurs in 30% of patients with tuberculosis (TB). Rapid diagnosis of a tuberculous pleural effusion would greatly facilitate the management of many patients. Polymerase chain reaction (PCR) has been used to detect Mycobacterium tuberculosis in pleural fluid with highly variable sensitivity. OBJECTIVE: To improve our laboratory diagnosis of tuberculous pleural effusion. METHODS: We applied PCR to detect DNA specific for M tuberculosis in 33 of the studied pleural biopsy specimens using an IS986-based primer that was specific for mycobacterium complex, and compared it to the results of pleural fluid and biopsy cultures performed on either Lowenstein-Jensen (LJ) medium or BACTEC 12B liquid medium (Becton Dickinson Microbiology Systems; Cockeysville, MD), Ziehl-Neelsen (ZN) staining, and histopathology in 45 patients with pleural effusion. RESULTS: Of the 45 patients with pleural effusion who were studied, 26 patients received diagnoses of tuberculous pleural effusion that had been confirmed by either culture and or histopathology, 10 patients received diagnoses of exudative effusion due to causes other than TB, and 9 patients received diagnoses of transudative effusion. Histopathology of the pleural biopsy specimen had a sensitivity of 53.8%. The sensitivity of the ZN staining of pleural fluid and biopsy specimens was 0.0% and 3.8%, respectively. The sensitivity of the culture on both BACTEC 12B liquid medium and LJ medium was higher in pleural biopsy specimens (92.3%) than in pleural fluid specimens (15.4%; p > 0.001). The improvements of the BACTEC culture system improved and shortened the detection time of M tuberculosis in pleural biopsy specimens. PCR of pleural biopsy specimens had 90% sensitivity and 100% specificity. The positive predictive value and the negative predictive value for pleural biopsy specimen cultures were 100% and 90.5% vs 100% and 86.7% for pleural biopsy specimen PCRs. CONCLUSION: The overall accuracy of PCR of pleural biopsy was similar to the results of pleural biopsy culture, however, PCR of the pleural biopsy was much faster in reaching diagnosis. PCR of pleural biopsy is a useful method when used in combination with the BACTEC culture system and histopathologic examination of pleural biopsy to reach a rapid diagnosis of tuberculous pleural effusion.     

Diagnosis of tuberculous meningitis: clinical and laboratory parameters.

BACKGROUND: Confirming the clinical suspicion of tuberculous meningitis (TBM) has always been problematic. Whilst smear and culture positivity are diagnostic, these tests have low sensitivity. The polymerase chain reaction (PCR) assay has given variable results. AIM: This study attempted to improve the diagnostic yield by: (a) increasing the cerebrospinal fluid (CSF) volumes; (b) testing the yield from three specimens of CSF assumed to represent lumbar, cervico-thoracic cord, and base of brain CSF samples; (c) undertaking PCR assays using multiple primer sets; and (d) using real-time PCR. METHOD: Patients suspected of having cranial or spinal meningeal tuberculosis were entered into the study. Three aliquots of CSF were subjected to smear, culture, and conventional and real-time PCR. Three sets of primers - IS6110, MPB64, and PT8/9 - were used. Patients were retrospectively classified into four categories: 'definite TB' (culture positive), 'probable TB' (clinical and other tests suggestive of TB), 'not TB', and 'uncertain diagnosis'. RESULTS: A total of 68 patients were studied. There were 20 patients classified as definite TB, 24 probable TB, 17 not TB, and seven uncertain diagnosis. Forty-eight of 57 (84.2%) patients tested were HIV seropositive. The IS6110 PCR was positive in 27 patients which included 18/20 culture positive cases, six in the probable TB group, and three in the not TB group. The MPB64 and PT8/9 primers did not increase the yield. Real-time PCR was positive in seven additional patients. Combining the definite and probable TB, the sensitivity of all PCR assays was 70.5% (31/44) and specificity 87.5% (21/24). CONCLUSION: Targeting multiple sites of the TB genome using conventional PCR did not increase the number of positive cases. Real-time PCR was more sensitive. However, all the current techniques are still too insensitive to confidently exclude the diagnosis on laboratory grounds.