Rapid Detection of Rifampin Resistance 江振源主任

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1 101 年度最新結核病治療指引 醫師在職繼續教育系列 Rapid Detection of Rifampin Resistance 江振源主任 主辦單位 行政院衛生署國立臺灣大學傳染病防治研究及教育中心臺大醫院內科部 聯絡方式 電話 : 網站 :

2 Rapid detection of Rifampicin Resistance CHIANG Chen Yuan MD, MPH Director, Department of Lung Health and NCDs By the end of this presentation, participants would be able to describe Rapid diagnosis of drug resistant tuberculosis Rapid testing in the context of national tuberculosis programme Sensitivity, Specificity, Positive predictive value Xpert MTB/RIF for national tuberculosis programmes Rifampicin resistance and MDR TB 1

3 Rapid diagnosis of drug resistance in tuberculosis Phenotypic methods Microscopic observation broth drug susceptibility assay (MODS) Slide DST Phage based assays Colorimatric methods: the MTT and resazurin as redox indicators Nitrate reductase assay Palomino JC. Curr Opin Pulm Med 2006, Ven Deun A. IJTLD 2010 Diagnosis of MDR TB, Damien Project, Bangladesh 1. Fluorescence microscopy 2. If positive Fluorescein diacetate (FDA) vital staining: fluoresces only after cleavage by living bacilli 3. If positive slide drug susceptibility testing 4. All suspects also have sputum culture on Löwenstein Jensen solid ldmedia 2

4 FDA vital staining Slide courtesy: Van Deun A. Slide drug susceptibility testing Damien Project, Bangladesh 3

5 Drug-free control, 4+ colonies INH 1 µg/ml: 4+, resistant EMB small colonies, 2+: susceptible RMP 1 µg/ml, negative: susceptible 民國前 / 通用格式民國前 / 通用格式民國前 / 通用格式 Diagnosis of MDR TB Rajshahi Chest Hospital Suspects FDA+ MDR 民國前 / 通用格式 民國前 / 通用格式 民國前 / 通用格式 民國前 / 通用格式 x2008 (7 m) x2009 x2010 (6 m) Courtesy: Damien Project, Bangladesh 4

6 Slide DST Slide DST on fresh smear positive sputum failed less often than LJ DST, 96% accuracy for rifampicin and MDR TB. 90% accuracy for isoniazid i id Mycobacteriophage based methods Pai M, et al. J Infection 2005;51:

7 FASTPlaque -Response R-resistant strain RIF- RIF+ FASTPlaque -Response R-susceptible strain RIF- RIF+ 6

8 Rapid diagnosis of drug resistance in M. tuberculosis Genotypic methods DNA sequencing Solid phase hybridization techniques: Line probe assay (INNO LiPA RiF TB Assay) and the GenoType MTBDR assay Microarrays Real time polymerase chain reaction techniques: TaqMan probe, fluorescence resonance energy transfer (FRET) probes, molecular beacons and bioprobes. Xpert MTB/RIF 7

9 GenoType MTBDRplus test procedure 1) DNA Extraction From NALC/NaOH Processed sputum 3) Hybridization Reverse hybridization of amplified nucleic acids to specific DNA probes bound on strips 2) Amplification by PCR 4) Evaluation Line Probe Assay 8

10 Use of Genotype MTBDR Assay for Molecular Detection of Rifampin and Isoniazid Resistance in Mycobacterium tuberculosis Clinical Strains Isolated in Italy 206 isolates from the Italian drug resistance surveillance system Results were compared to conventional drug susceptibility test and verified by genome sequencing rate of concordance 91.5% (130 of 142) for rifampin i 67.1% (116 of 173) for isoniazid Miotto P, et al. J Clin Microbiol 2006;44:

11 Rapid Molecular Screening for MDR TB in a High Volume Public Health Laboratory in South Africa the Genotype MTBDRplus assay: detects mutations directly from smear positive sputum in the rpob gene (RIF resistance), the katg gene (high level INH resistance), the inha gene (low level INH resistance). Sensitivity, specificity, and positive and negative predictive values 98.9, 99.4, 97.9, and 99.7%, for rifampicin resistance; 94.2, 99.7, 99.1, and 97.9%, for isoniazid resistance; 98.8, 100, 100, and 99.7%,for MDR TB Barnard M, et al. Am J Respir Crit Care Med 2008;177: tested with 125 clinical isolates and directly with 72 smear tested with 125 clinical isolates and directly with 72 smearpositive sputum specimens identify RMP resistance correctly in 74 of 75 strains (98.7%) and 30 of 31 specimens (96.8%) the new GenoType MTBDRplus assay enhanced the rate of detection of INH resistance from 66 (88.0%) to 69 (92.0%) among the 75 INH resistant strains 36 (87.8%) to 37 (90.2%) among the 41 specimens containing INH resistant strains. 10

12 Diagnosis of drug resistant tuberculosis Susceptibility testing Depends on resource and the epidemic of drug resistant it ttuberculosis Comprehensive drug susceptibility testing Selective drug susceptibility testing Programmatic requirements infrastructure development acquisition and maintenance of equipment quality assurance and biosafety External Quality Assessment of DST in Global DRS Network Sensitivity Ability to detect resistance Specificity Ability to detect susceptibility Efficiency/Accuracy Ratio between correct and total number of results Reproducibility (duplicate set of 10 strains and 10 non duplicate strains= 30) Intra laboratory agreement Predictive value for resistance Proportion of true resistance to total resistance Predictive value for susceptibility Proportion of true susceptibility to total susceptibility 11

13 Drug susceptibility testing proficiency in the network of supranational tuberculosis reference laboratories, Rounds 6 14 Efficiency Int J Tuberc Lung Dis 2011;15: Performance of the 16 supranational reference laboratories that participated in all rounds Int J Tuberc Lung Dis 2011;15:

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15 Diagnosis of Drug Resistant TB: Reliability and Rapidity of Detection For the choices of methods, appropriateness and sustainability should be considered in conjunction with the prospects of complete population coverage. Excellent coverage will only be feasible through decentralization of simple, low requirement methods or alternatively by centralized genotypic DST with, in principle, easy specimen referral. The small differences in DST turnaround time are relatively unimportant, provided primary culture isolation is not required. Conventional slow DST will still be needed for confirmation and for epidemiological monitoring. Ven Deun A. Int J Tuberc Lung Dis

16 Sensitivity = 95%, Specificity = 98%, Positive Predictive Value? True resistance True susceptible Total Test resistance Test susceptible Total True resistance True susceptible Total Test resistance Test susceptible Total Sensitivity = 95%, Specificity = 98%, Positive Predictive Value (PPV)? True resistance True susceptible Total Test resistance PPV Test susceptible Total /479 = 59.5% True resistance True susceptible Total Test resistance Test susceptible Total PPV 950/1130 = 84.1% 15

17 Resistance Predictive Values of Rifampicin Susceptibility Tests based on 14 th Round PT data (2007) of SNRL network (data from Armand Van Deun) predictive values (%) Resistance Sensitivity= 99.6% Specificity= 97.9% Resistance prevalence Resistance among New and Previously Treated Cases 7 6 New Previously treated HRS E RES HES HRS HRE ES RS RE HS HE HR S E R H WHO/CDS/TB/ :

18 Weighted Mean of MDR TB % (95% CI, ) among all TB cases. 2.9% (95% CI, ) among new cases, 15.3% (95% CI, ) among previously treated cases Anti-Tuberculosis Drug Resistance in the World. Fourth Global Report WHO/HTM/TB/ Previously treated tuberculosis cases Relapse Treatment after default Treatment after failure Chronic case 17

19 Failure of retreatment in Peru Cat I Regimen: 2HREZ/4H2R2 Cat II Regimen: 2HRZES/HREZ/5HRE 344 failure of retreatment patients 298 (87%) had MDR tuberculosis Suárez PG, et al. Lancet 2002; 359: MDR TB among retreatment failure in Nicaragua Regimen for new patients: 2SHRZ/6TH or 2EHRZ/6TH Retreatment regimen: 2SHRZE/1HRZE/5H3R3E3 Susceptibility testing results were available for 38 retreatment failure patients 34 (89%) were MDR TB Heldal E, et al. Int J Tuberc Lung Dis 2001; 5:

20 Infection and disease among household contacts of patients with MDR TB Among 133 close contacts of patients with MDR TB, 44% were PPD positive Six (4%) were found to have active TB at the time of initial evaluation or during follow up Five (83.3%) were MDR TB. Teixeira L, et al. Int J Tuberc Lung Dis 2001;5: Retreatment Tuberculosis Cases in Brazil First line Regimen: 2HRZ/4HR Time and site of study: From March h1986 to March 1990, at Instituto de Tisiologia e Pneumologia da Universidade do Rio de Janeiro 91 patients who fail to respond to the first line regimen 29 (33%) MDR TB Kritski AL, et al. Chest 1997; 111:

21 Prevalence of MDR TB among previously treated patients in Taipei Regimen: 2HERZ/4HER Prevalence of MDR TB 13% among relapse (n=93) 19% among treatment after default (n=57) 67% among treatment t tafter fil failure (n=33) Chiang C-Y, et al. J Formos Med Assoc 2004;103:411-5 Prevalence of primary and acquired resistance of M. tuberculosis to antituberculosis drugs in Benin Cat I regimen: 2SRHZ/6TH Sample size: 333 new patients and 57 previously treated patients MDR among new : 1/333 (0.3%) MDR among previously treated: 6/57 (11%) Relapse: 1/24 (4%) Treatment after default: 3/25 (12%) Treatment after failure: 2/9 (22%) Trébucq A, et al. Int J Tuberc Lung Dis 1999; 3:

22 High risk group of MDR TB Failure of retreatment (2SHRZE/1HRZE/5HRE) Close contacts of MDR TB Fil Failures of a 6 month rifampicin throughout i i h t regimen for new patient Relapses and defaulters of retreatment regimen Failure of anti tuberculosis treatment in the private sector Relapses and defaulters of regimens for new patient Patients who remain sputum smear positive at month 2 or 3 Examinations of patients with suspected MDR TB in a program Type of case Examined N= Pos Culture results Neg Not available DST MDR Results of DST Not MDR Not available New Relapse Treatment after default Treatment after Cat I fil failure Treatment after Cat II failure Smear+ at 3 months, New

23 Assay Procedure for the MTB/RIF Test N Engl J Med 2010;363: Assay Procedure for the MTB/RIF Test Among culture positive patients, a single, direct MTB/RIF test identified 551 (98.2%) of 561 patients with smear positive tuberculosis 124 (72.5%) of 171 with smear negative tuberculosis. A second MTB/RIF test increased sensitivity by 12.6% points and a third by 5.1% points, to a total of 90.2%. As compared with phenotypic drug susceptibility testing, MTB/RIF testing correctlyidentified 97.6% rifampin resistant bacteria and 98.1% rifampin sensitive bacteria. N Engl J Med 2010;363:

24 Feasibility, diagnostic accuracy, and effectiveness of decentralised use of the Xpert MTB/RIF test for diagnosis of tuberculosis and multidrug resistance One off MTB/RIF testing detected 933 (90.3%) of 1033 culture confirmed confirmed cases of tuberculosis, compared with 699 (67.1%) of 1041 for microscopy. MTB/RIF in smear negative, culture positive patients sensitivity 76.9% (296 of 385 samples), specificity 99.0% (846 of 2876 non tuberculosis samples). MTB/RIF test for rifampicin resistance sensitivity 94.4% (236 of 250) specificity 98.3% (796 of 810). Lancet 2011; 377: Feasibility, diagnostic accuracy, and effectiveness of decentralised use of the Xpert MTB/RIF test for diagnosis of tuberculosis and multidrug resistance Median time to detection of tuberculosis MTB/RIF test was 0 days (IQR 0 1), microscopy 1 day (0 1), solid culture 30 days (23 43), liquid culture 16 days (13 21). Median time to detection of resistance line probe assay 20 days (10 26) conventional drug susceptibility testing 106 days (30 124). The indeterminate rate of MTB/RIF testing was 2.4% (126 of 5321 samples) compared with 4.6% (441 of 9690) for cultures. Lancet 2011; 377:

25 Rapid Implementation of the Xpert MTB/RIF diagnostic test WHO March 2011 Policy recommendations 1. Xpert MTB/RIF should be used as the initial diagnostic test in individuals suspected of having MDR TB or HIV associated TB. (Strong recommendation) 2. Xpert MTB/RIF may be considered as a follow on test to microscopy in settings where MDR TB or HIV is of lesser concern, especially in further testing of smear negative specimens. (Conditional recommendation acknowledging major resource implications) WHO/HTM/TB/

26 WHO Global Tuberculosis Control 2011 Courtesy: Matteo Zignol 25

27 Feasibility at peripheral health facilities in resource limited settings? WHO/HTM/TB/

28 100% 90% 80% 70% 60% 50% 40% 30% 20% PPV NPV Predictive value of rifampicin resistance 10% Rifampicin resistance prevalence 0% 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% Rapid Implementation of the Xpert MTB/RIF diagnostic test WHO March 2011 Xpert MTB/RIF for national tuberculosis programmes in low income countries: when, where and how? In all low income countries, the prevalence of RMP resistance is less than 5% among patients who have never previously been treated for TB (with two exceptions) and, for the most part, even less than 2%. For these naive TB patients, any MTB/RIF test result requires an alternative confirmatory test for a definitive diagnosis of RMP resistance. Low income countries: less than US$995 per capita of Gross National Income, World bank, ( classifications/country and lending groups) Trebucq A, et al, Int J Tuberc Lung Dis 2011; 15:

29 Conventional susceptibility testing and Xpert Conventional DST Xpert Rifampicin resistance Rifampicin Susceptible Rifampicin resistance a b Rifampicin Susceptible c d False positive rifampicin resistance on Xpert MTB/RIF A false positive result was most likely, given the wild type rpobgene sequence and exclusion of both mixed infection and mixture of drug susceptible and drug resistant populations. the manufacturer performed a root cause analysis, which identified the bead manufacturing scale up and annealing temperature requirements of probe B as potential causes Int J Tuberc Lung Dis 2012;16:

30 Conventional susceptibility testing and Xpert Conventional DST MDR TB Non MDR TB Xpert Rifampicin resistance a b Rifampicin Susceptible c d Global INH resistance patterns given resistance to RMP, by MDR TB prevalence tertiles based on WHO/The Union Global DRS data Int J Tuberc Lung Dis 2012;16:

31 Global INH resistance patterns given resistance to RMP, by MDR TB prevalence tertiles based on WHO/The Union Global DRS data Int J Tuberc Lung Dis 2012;16:203-5 Courtesy: Matteo Zignol 30