342例痰培养阳性肺结核菌株耐药特征分析

目的了解肺结核患者对利福平、异烟肼、氧氟沙星、卡那霉素四种药物耐药分布情况,为肺结核的临床治疗与预防控制提供依据。方法对2012-2013年分离的结核分枝杆菌培养,采用比例法进行利福平、异烟肼、氧氟沙星、卡那霉素药敏试验,并分析耐药分布情况。结果 342例结核菌株耐药率为31.3%,耐多药率为20.5%。初治和复治患者耐药率分别为12.2%和70.5%,耐多药率分别为2.6%和57.1%,差异均有统计学意义。男性(占17.2%)女性(占30.9%)之间耐多药差异有统计学意义。耐多药率有随年龄增长而下降的趋势。耐任何抗结核药物以异烟肼(25.2%)、利福平(21.9%)、氧氟沙星(18.7%)等为主。复治患者耐≥1种药物、任何耐异烟肼、任何耐利福平、任何耐氧氟沙星、耐≥2药物和耐多药均高于初治患者。复治耐多药肺结核患者特征构成主要为复治失败(42.2%)、初治失败,6种治疗结局的分布不均衡,差异有统计学意义。任何耐利福平和任何耐异烟肼患者,耐多药和多耐药的比例分别为97.3%和81.4%,差异有统计学意义。结论复治肺结核患者作为重点人群筛查是一种高效的耐多药筛查策略;快速检测利福平耐药可以作为耐多药肺结核患者初步诊断的重要依据。     

温州市老年复治肺结核患者耐药情况分析

目的了解温州市老年复治肺结核患者耐药情况,为老年结核病防治提供依据。方法选取2012年1月—2017年10月温州市≥60岁的初治和复治涂阳肺结核患者,通过问卷调查和药敏试验比较初、复治肺结核患者的耐药类型和耐药谱分布,分析老年复治肺结核患者的耐药特征。结果最终纳入老年初治和复治肺结核患者各1 280例,初治患者总耐药率为31.72%,耐多药率为4.84%,广泛耐药率为0.63%;复治患者总耐药率为52.27%,耐多药率为25.23%,广泛耐药率为5.63%。老年复治患者链霉素(44.38%)、异烟肼(35.63%)、利福平(33.05%)、乙胺丁醇(22.50%)、氧氟沙星(15.70%)、对氨基水杨酸钠(6.72%)和卷曲霉素(4.69%)耐药率均高于初治患者(P0.05)。女性老年复治患者耐多药率和广泛耐药率分别为28.73%和7.69%,均高于男性的23.39%和4.53%(P0.05)。结论温州市老年复治肺结核患者耐多药率和广泛耐药率较高,女性耐多药率和广泛耐药率高于男性,且对一线抗结核药物的耐药率较高。     

滁州市结核病耐药性基线调查结果

目的获得滁州市耐药结核病疫情流行特征,为制定当地结核病防治工作规划提供依据。方法收集2015年9月16日—2016年8月31日期间滁州市3个耐药基线调查点涂阳肺结核病例痰标本,对分离出的190株结核分枝杆菌菌株采取比例法测定药物敏感性,获取耐药菌株的耐药谱并计算耐药率。结果滁州市涂阳肺结核患者结核分枝杆菌总耐药率达27.37%、耐多药率为6.32%,其中初治肺结核总耐药率为21.88%、耐多药率为2.50%;复治肺结核总耐药率为56.67%,耐多药率为26.67%。复治肺结核患者总耐药率和耐多药率明显高于初治肺结核患者,差异均有统计学意义(χ2=15.38、24.94,均P0.05)。结论滁州市耐药结核病疫情防控形势严峻,今后需加强对复治涂阳肺结核病例等重点人群耐多药结核病监测工作。     

1991—2005年泉州市初治培阳肺结核病人结核菌耐药状况分析

[目的]评价泉州市初治培阳肺结核病人结核杆菌的耐药动态。[方法]收集1991—2005年门诊及住院的初治培阳肺结核病例的菌株做药敏试验,每3年一个阶段,对5个阶段耐药率进行分析。[结果]15年间,初始耐药率由1991—1993年的27.7%降至2003—2005年的10.6%,下降了61.7%;耐INH和耐SM分别下降41.4%和36.8%。耐≥2种药呈逐年下降趋势,耐2种药物以SH、SR耐药率较高,耐3种药物以SHE、HRE耐药率较高。初治耐药的耐多药为3.2%,有逐年上升趋势。[结论]控制结核菌耐药的关键是早发现、早治疗,采用DOTS策略彻底治愈传染性肺结核,并做好耐药监测评价工作。     

嘉兴市耐多药肺结核筛查结果分析

目的分析嘉兴市耐多药肺结核可疑者筛查情况,为制定耐多药肺结核防控策略提供依据。方法选取2013年—2015年6月于嘉兴市第一医院诊治的1 636例涂阳肺结核患者为研究对象,应用BACTEC MGIT960系统进行结核分枝杆菌痰培养和药敏试验。结果 1 636例研究对象中痰培养检出结核分枝杆菌1 162例,阳性率为71.03%,其中初治患者阳性率74.36%,复治患者阳性率58.55%;检出耐多药肺结核45例,检出率为2.75%(45/1 636),其中初治患者21例,检出率1.63%(21/1 636),复治患者24例,检出率6.96%(24/1 636);2013—2015年耐多药肺结核总检出率呈逐年下降趋势(P0.05)。1 162例结核分枝杆菌培养阳性患者中,有494例患者出现一种或几种抗结核药物耐药,耐药率为42.51%;耐药率由高到低依次为异烟肼(10.24%)、链霉素(9.38%)、利福平(5.08%)和乙胺丁醇(2.15%);其中312例患者对一种抗结核药物耐药,复治患者单耐药率为54.95%,高于初治患者的20.94%(P0.01);45例患者同时且至少对异烟肼和利福平2种以上药物耐药,复治患者耐多药率2.19%,高于初治患者的3.87%(P0.01)。结论嘉兴市耐多药肺结核患者已逐渐得到规范诊治,检出率逐年下降;复治患者耐多药率高于初治患者,应重点筛查。     

不同类型复治肺结核的耐药性分析

目的探讨不同类型复治肺结核的耐药情况,为临床复治肺结核患者制定合理的化疗方案提供科学依据。方法收集贵阳市肺科医院2010年1月-2011年12月住院的复治肺结核患者进行结核分枝杆菌培养、菌种鉴定和药物敏感性检测(异烟肼(INH)、利福平(RFP)、乙胺丁醇(EMB)、链霉素(SM),氧氟沙星(OFX)、卡那霉素(KM))。结果复治肺结核患者中耐药共203例,其中初治失败组80例,耐药率39.41%,耐多药率25.86%,治愈后复发组37例,其耐药率18.23%,耐多药率19.83%,不规则治疗1个月以上组26例,其耐药率12.81%,耐多药率12.07%,多次治疗失败痰菌持续阳性组60例,耐药率29.56%;耐多药率42.24%。在耐多药病例中以初治失败和多次治疗失败痰菌持续阳性为主。结论不同类型复治肺结核因既往用药史不同,其耐药率及耐多药率各异,不同类型复治肺结核不能都用标准复治方案,对于不同类型复治肺结核患者必须结合患者既往用药史和药敏试验结果综合分析制定个体化方案,减少耐药和耐多药结核的发生。     

黄冈市1487例肺结核患者耐药分析

目的了解黄冈市结核病患者耐药的特点及流行现状,为今后结核病防控工作提供参考依据。方法以黄冈市耐多药项目实施期间登记的可疑病例作为研究对象,用比例法对利福平(RFP)、异烟肼(INH)、链霉素(SM)、乙胺丁醇(EMB)4种药进行药物敏感性试验。结果 1 487例肺结核患者痰标本培养阳性1 063例,经菌型鉴定1 044株(初治632例,复治412例)为结核分枝杆菌,其中总耐药254株,总耐药率为24.33%,初治患者及复治患者总耐药率分别为12.50%、42.50%;耐多药142株,耐多药率为13.60%,初治患者及复治患者耐多药率分别为4.59%、27.43%,单耐药75例,单耐药率为7.18%,多耐药37例,多耐药率为3.54%;任何耐药顺位是RFP(17.62%)、INH(17.43%)、SM(14.66%)、EMB(7.28%),其中初治患者耐药顺位是INH 8.07%、SM 7.44%、RFP 6.96%、EMB 2.69%,复治患者耐药顺位是RFP 33.98%、INH 31.80%、SM 25.73%、EMB14.32%;初、复治患者各种耐药情况比较有统计学意义。结论黄冈市肺结核患者总耐药低于全国平均水平,但耐多药和复治患者各种耐药均高于全国水平,说明结核病防控工作形势严峻,特别是要加强初治患者的管理以减少耐药结核病的发生。     

2010-2015年株洲市结核分枝杆菌一线抗结核药物耐药研究

目的了解株洲市肺结核患者结核分枝杆菌对一线抗结核药物的耐药情况和影响因素,为耐药结核病的治疗、预防和控制提供参考依据。方法收集2010-2015年株洲市涂阳肺结核患者的结核分枝杆菌,进行四种一线抗结核药物耐药情况检测。结果 589株结核分枝杆菌对一线抗结核药物的耐药比例为39.7%;初治患者耐药比例和复治患者耐药比例分别为25.6%和67.3%;耐多药比例为24.8%,初治患者耐多药比例和复治患者耐多药比例分别为10.5%和52.8%;四种一线抗结核药物的耐药比例顺位依次为异烟肼(32.6%)、利福平(30.1%)、链霉素(17.8%)和乙胺丁醇(9.3%)。非条件logistic回归分析结果显示:肺结核患者类型(初治和复治)和年龄是结核分枝杆菌耐药的主要影响因素,复治患者是耐多药病例产生的主要因素。结论株洲市复治肺结核患者耐药情况比较严重,加强低年龄组肺结核患者的治疗管理可以减少耐药病例的产生,减少复治患者是控制耐多药肺结核病例的一个有效措施。     

114株结核分枝杆菌耐药性分析

目的了解宁波市北仑区涂阳肺结核患者结核分枝杆菌的耐药情况,为肺结核的耐药筛查及防控工作提供依据。方法对2012—2014年北仑区获得的114株结核分枝杆菌进行异烟肼(INH)、利福平(RFP)、链霉素(SM)及乙胺丁醇(EMB)4种药物的耐药性测定。结果 114株结核分枝杆菌中,90株(78.95%)对INH、RFP、SM和EMB 4种抗结核药全部敏感;24株耐药,耐药率为21.05%。其中初治耐药15例,耐药率为15.31%;复治耐药9例,耐药率为56.25%。复治耐药率高于初治耐药率(P0.05)。至少同时对INH和RFP耐药11例,耐多药率为9.65%;其中初治耐多药率为6.12%,低于复治耐多药率的31.25%(P0.05)。结论北仑区肺结核耐药情况与以往监测结果相比,并未发生实质性变化,复治患者仍是北仑区耐药肺结核的高危人群。     

武汉市耐药/耐多药结核病影响因素分析

目的 探索武汉市耐药/耐多药结核患者的影响因素,为制定武汉市耐药结核病防控措施提供科学的参考依据。方法 对2006年12月~2014年6月武汉市登记管理的5 524例耐多药可疑者进行筛查（痰培养、菌型鉴定及药敏检测）,发现耐药病例。描述不同分类的结核病患者耐药率,采用χ2检验和非条件Logistic回归分析进行耐药影响单因素和多因素分析。结果 武汉市结核分枝杆菌总耐药率为33.4%（1 627/4 870）。近4年来,总耐药率和复治患者耐药率均呈下降趋势（均有P<0.05）,初治患者耐药率无上升趋势（χ_趋势2=0.79,P=0.372）;总耐多药率、初治和复治患者耐多药率均呈下降趋势（均有P<0.05）。多因素Logistic回归分析显示,复治患者较初治患者更易产生耐药（OR=2.212,95%CI:1.949~2.491,P<0.001）和耐多药（OR=3.433,95%CI:2.844~4.193,P<0.001）。结论 武汉市耐药和耐多药结核病疫情呈下降趋势,仍需加强对有既往结核病史患者的治疗和管理,以降低耐药/耐多药结核病疫情。     

深圳市南山区近4年结核菌耐药性的监测

目的 :观察和掌握南山区初始和获得性耐药水平与动态 ,评价现行结核病控制策略效果。方法 :连续对新发涂阳和其他涂阳病例全部培养阳性菌株进行菌型鉴定并采用比例法对SM、INH、RFP、EMB 4种抗结核药物进行耐药测定。结果 :1999～ 2 0 0 2年 36 1例结核分枝杆菌培养阳性病例 ,总耐药率由 2 4 7%上升为 4 1 2 % ,初始耐药率由 2 3 8%上升为 39 1% ,获得性耐药率由 30 8%上升为 6 0 0 %。初始耐药和获得性耐药均呈上升趋势 ,初始耐多药率为 2 8% ,获得性耐多药率为 12 5 % ,差异均有显著性 (P <0 0 5～ 0 0 1)。结论 :合理化疗和贯彻全程督导治疗原则对减少耐药至关重要有必要进行定期连续监测及深入研究。     

MDR-TB treatment needs in patients previously treated for TB in Cotonou,Benin

Setting:

Centre National Hospitalier de Pneumo-Phtisi-ologie, Cotonou, Benin.

Objective:

To determine the proportion of individuals needing treatment for multidrug-resistant tuberculosis (MDR-TB) among patients previously treated for TB.

Design:

A retrospective cross-sectional study of all patients previously treated for TB in Cotonou from 2003 to 2011.

Results:

Of 956 patients on retreatment, 897 (94%) underwent culture and/or a line-probe assay. For different reasons, 594 (66%) underwent drug susceptibility testing for rifampicin (RMP), of whom 95 (16%) had RMP resistance (68 multidrug-resistance [MDR] and 27 other RMP resistance) and therefore needed treatment for MDR-TB. These represent 39% of patients who failed/relapsed after standardised retreatment, and 20% of those who failed, 19% of defaulters and 11% of relapses after first-line treatment. Residence outside of Benin was associated with a higher risk of RMP resistance (RR 3.13, 95%CI 2.19–4.48, P < 0.01). From 2003 to 2011, the prevalence of RMP resistance decreased from 25% to 5% among patients living in Benin. Human immunodeficiency virus (HIV) prevalence was 25%; no association was found between HIV and RMP resistance. Of patients failing treatment, 48% were fully susceptible, 22% were monoresistant and 8% polyresistant.

Conclusion:

The majority of patients who fail retreatment or first-line treatment in Cotonou do not require empirical treatment for MDR-TB.     

河南省5县市2007年耐药结核病及危险因素研究

[目的]确定2007年河南省5个县市的结核病耐药率及其危险因素。[方法]5个县市结核病防治中心所有痰涂片阳性病人按顺序入选,痰涂片用萋-尼氏染色法镜检,培养用罗杰氏培养基,对4种一线抗结核药物异烟肼、利福平、链霉素和乙胺丁醇采用比例法进行药敏试验。病人资料由经过培训的医生通过调查问卷获得。[结果]338例肺结核病人中,269例(79.6%)为新病人,69例为(20.4%)复治病人。新病人中任一耐药率和耐多药(MDR)率分别为17.5%和3.0%,复治病人分别为39.1%和21.7%。复治病人首次治疗超过6个月是任一耐药的危险因素(AOR=3.45,95%CI(1.25～9.09),P=0.017),复治病人(AOR=9.06,95%CI(3.62～22.67),P=0.000)以及曾经在其他地方居住1年以上(AOR=2.71,95%CI(1.10～6.69),P=0.030)是MDR的独立危险因素。[结论]河南省5个县市结核病任一耐药率和MDR率仍然很高,是实施DOTS策略和结核病控制面临的一个主要挑战。首次抗结核治疗6个月以上是任一耐药的危险因素,而复治病人以及在其他地方居住超过1年是MDR-TB的两个独立危险因素。全面实施MDR-TB控制以及提高DOTS质量是河南省结核病控制工作的当务之急。     

海南省结核分枝杆菌耐药影响因素分析

目的探讨海南省结核菌耐药影响因素,为制定耐药结核病防控措施提供科学依据。方法将全省18个市县均纳入调查点,通过调查问卷获取患者相关信息,采用比例法进行药敏试验,检测药物包括异烟肼(H)、利福平(R)、链霉素(S)、乙胺丁醇(E)、卡那霉素(Km)和氧氟沙星(Ofx);采用多因素非条件Logistic回归分析耐药的影响因素。结果纳入耐药分析的患者1 155例,其中初治880例,复治275例。总体耐药率和耐多药率分别为20.87%、7.53%。影响因素分析表明,对于初治患者,女性(χ2=4.35,P=0.04,OR=0.51,95%CI=0.27~0.96)和年龄的增长(χ2=4.03,P=0.04,OR=1.02,95%CI=1.00~1.04)是发生耐药、耐多药结核病的危险因素;对于复治患者,接受过2次以上抗结核药物治疗(χ2=4.07,P=0.04,OR=0.61,95%CI=0.38~0.99)、首次在综合医院治疗(χ2=5.28,P=0.02,OR=3.06,95%CI=1.18~7.96)、无人监督服药(χ2=4.99,P=0.03,OR=0.43,95%CI=0.21~0.90)、有药物副反应(χ2=5.71,P=0.02,OR=2.42,95%CI=1.17~4.98)发生耐药的风险较高,而产生耐多药的危险因素主要是有药物副反应发生(χ2=10.14,P=0.00,OR=3.40,95%CI=1.60~7.23)。结论女性及年老的初治患者发生耐药、耐多药结核病的风险较高;患者初次治疗在综合医院、有药物副反应发生、无人监督服药且多次治疗是复治患者产生耐药的危险因素。     

上海市奉贤区结核杆菌耐药性分析

[目的 ]　了解初治和复治肺结核病人对抗结核化学药物的敏感性。　 [方法 ]　收集 2 0 0 2年 1月至 2 0 0 3年7月痰菌阳性标本 ,用改良罗氏培养基绝对浓度法试验 ,最终获取培养阳性标本 2 14份 ,对全部培养阳性标本进行 5种抗结核药物 (SM、INH、PAS、EMB、RFP)的耐药性测定。　 [结果 ]　总耐药率为 3 9.2 5 % ( 84/2 14 ) ;初始耐药率为 11.83 %( 11/93 ) ,初始耐多药率为 7.5 3 % ( 7/93 ) ;获得性耐药率为 60 .3 3 % ( 73 /12 1) ,耐多药率为 47.93 % ( 5 8/12 1)。对抗结核药物的耐受 ,主要是耐受SM ( 75 .0 0 % ,63 /84)和INH( 63 .10 % ,5 3 /84)。　 [结论 ]　获得性耐药率高于初始耐药率 ,应进一步加强对结核杆菌药物敏感性监测。     

Countrywide audit of multidrug-resistant tuberculosis and treatment outcomes in Mongolia

Setting:

Eighteen treatment units for multidrug-resistant tuberculosis (MDR-TB) in Mongolia.

Objective:

To determine the total number of MDR-TB cases detected, their resistance patterns, the proportion and characteristics of cases starting treatment, the delay between diagnosis and treatment initiation, and the relation between treatment outcomes and drug resistance.

Design:

Retrospective cohort study using routine programme data.

Results:

Of 268 MDR-TB cases detected, 168 (63%) were resistant to HRES, 59 (22%) to HRS, 34 (13%) to HR and 7 (3%) to HRE. Of the 268 MDR-TB patients, 139 (52%) started treatment: 69 (50%) were secondary and/or university students, 35 (25%) were unemployed, 24 (17%) were currently employed and 14 (8%) retired, disabled or status was unrecorded. The median time from MDR-TB diagnosis to treatment initiation was 137 days (IQR 43–218). The treatment success rate was 69%; 9% failed treatment, which may indicate extensively drug-resistant TB (XDR-TB) or pre-XDR-TB.

Conclusion:

Close to seven in 10 patients in Mongolia had a successful treatment outcome, which is encouraging. Specific problems included the high proportion of students, about half of all diagnosed patients accessed treatment and there was an unacceptable delay of 4 months to treatment. These issues need to be addressed.     

黑龙江省未治疗艾滋病患者耐药及病毒载量结果分析

目的了解黑龙江省未治疗艾滋病病毒感染者(HIV)/艾滋病患者(AIDS)耐药情况,进行病毒载量结果相关性分析,为黑龙江省艾滋病精准防控提供依据。方法对黑龙江省132例未治疗HIV/AIDS进行基因型耐药及病毒载量检测,分析耐药突变位点及耐药发生情况以及病毒载量结果相关性。结果 132例未治疗的HIV/AIDS中,11例存在原发性耐药情况,占总检测数的8. 3%(11/132)。其中,非核苷类逆转录酶抑制剂(NNRTI)耐药率为36. 4%(4/11),核苷类逆转录酶抑制剂(NRTI)耐药率为18. 2%(2/11),蛋白酶类(PI)耐药率为45. 4%(5/11)。原发性耐药患者的病毒载量平均值为3. 04×10~5拷贝/m L(最高值为8. 65×10~5拷贝/m L,最低值为1. 41×10~2拷贝/m L),未发生原发性耐药患者的病毒载量平均值为4. 59×10~5拷贝/m L(最高值为1. 00×10~7拷贝/m L,最低值为1. 31×10~2拷贝/m L)。结论证据显示耐药毒株已经开始在黑龙江省进行传播。在开展抗病毒治疗前有必要进行治疗前耐药检测,同时应将艾滋病也有耐药毒株传播情况增加到艾滋病防治宣传内容中,进一步加强黑龙江省艾滋病防控工作力度。     

Antitubercular drug resistance in four healthcare facilities in North India

Tuberculosis (TB) is a major public-health problem in India, having the highest number of incident and multidrug-resistant (MDR) TB cases. The study was carried out to appraise the prevalence of first-line anti-TB drug resistance in Mycobacterium tuberculosis (MTB) and its patterns among different types of TB patients from different settings in a province of North India. Of 3,704 clinical specimens, 345 (9.3%) were culture-positive, and drug-susceptibility testing was carried out for 301 MTB strains. A high level of primary and acquired drug resistance of MTB was observed in the region studied, with weighted mean of 10.5% and 28.08%, 12.81% and 29.72%, 17.12% and 29.94%, 11.97% and 27.84%, and 10.74% and 23.54% for rifampicin, isoniazid, streptomycin, ethambutol-resistant and MDR cases respectively. Drug resistance was significantly higher in pulmonary (p = 0.014) and acquired drug-resistant TB cases (p < 0.001). Any drug resistance (p = 0.002) and MDR TB were significantly (p = 0.009) associated with HIV-seropositive cases. An urgent plan is needed to continuously monitor the transmission trends of drug-resistant strains, especially MDR-TB strains, in the region.     

The population structure of drug-resistant Mycobacterium tuberculosis clinical isolates from Sichuan in China

China ranks second next to India among 22 high-burden countries despite decades' effort on tuberculosis (TB) control. The Sichuan province today contains the second-largest number of TB cases among Chinese provinces, where the prevalence of drug-resistant TB, especially MDR-TB, is much higher than the average level in eastern China. In this study, the population structure and the transmission characteristics of drug-resistant TB in Sichuan province were studied by spoligotyping and 24-locus Mycobacterial interspersed repetitive units-variable number tandem DNA repeats (MIRU-VNTR), applied to a total of 306 clinical isolates. Spoligotyping-based analysis showed that Beijing family represented 69.28% of all isolates and constituted the largest group (66.24%) of MDR-TB in Sichuan. The remaining isolates, accounting for 33.76% of MDR isolates, belonged to the ill-defined T family, Manu2, H3, LAM9, and other minor unassigned clades. The discriminatory power evaluated for spoligotyping was poor (HGI=0.595), but high for 24-locus MIRU-VNTRs (HGI=0.999). The number of the most discriminatory loci (h>0.6) was 12, including locus 424, 802, 960, 1644, 1955, 2163b, 2996, 3007, 3192, 3690, 4348 and 4052. It was concluded that 24-locus MIRU-VNTRs could be a more discriminatory tool for differentiating clinical isolates from Sichuan region. The small clustering size obtained from the current population structure analysis suggested that the high prevalence of drug-resistant TB in this region might be attributed partially to the acquired resistance due to inappropriate drug use rather than active transmission of drug-resistant TB (primary resistance).     

Drug resistance study of Mycobacterium tuberculosis in Canada, February 1, 1993 to January 31, 1994

OBJECTIVE: To estimate the prevalence of resistance of Mycobacterium tuberculosis to first-line antituberculosis drugs in Canada. METHODS: M. tuberculosis isolates from one third of all culture-positive tuberculosis (TB) cases diagnosed between February 1, 1993 to January 31, 1994 in Canada were collected prospectively. Proportion of drug-resistant isolates and the factors related to drug resistance were measured. RESULTS: Of 458 study cases, 40 (8.7%) had resistance to at least one first-line antituberculosis drug, of which 5.9% had mono-resistance, 0.7% had multidrug-resistance(MDR-TB)--i.e., resistance to at least isoniazid and rifampin--and 2.2% had other patterns. The overall prevalence of resistance among the foreign-born cases was 10.6% with the highest level among those who resided in Canada for less than four years (15.5%). CONCLUSIONS: Canada has a relatively low prevalence of antituberculosis drug resistance and a very low prevalence of MDR-TB. Some new immigrants to Canada may be at higher risk for drug resistance and their initial treatment needs to be tailored accordingly.