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Akalu TY, Clements ACA, Gebreyohannes EA, Wolde HF, Shiferaw FW, Alene KA. Burden of drug-resistant tuberculosis among contacts of index cases: a protocol for a systematic review. BMJ Open 2024; 14:e074364. [PMID: 38195168 PMCID: PMC10806946 DOI: 10.1136/bmjopen-2023-074364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 11/07/2023] [Indexed: 01/11/2024] Open
Abstract
INTRODUCTION People having close contact with drug-resistant tuberculosis (DR-TB) patients are at increased risk of contracting and developing the disease. However, no comprehensive review has been undertaken to estimate the burden of DR-TB among contacts of DR-TB patients. Therefore, the current systematic review will quantify the prevalence and incidence of DR-TB among contacts of DR-TB patients. METHOD AND ANALYSIS Systematic searches will be conducted in Medline, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled trials (CENTRAL) and Cumulative Index to Nursing and Allied Health Literature (CINHAL) databases. The search will be conducted without restrictions on time, language and geography. A random-effects meta-analysis will be conducted for effect estimates. The pooled prevalence and incidence of DR-TB will be compared between people with and without contact with DR-TB patients. The presence of heterogeneity between studies will be assessed by Higgins I2 statistics. Subgroup analysis will be conducted to determine the source of heterogeneity. The risk of bias will be assessed using a visual inspection of the funnel plot and Egger's regression test statistics. Trim and fill analysis will be done in the presence of publication bias. A sensitivity analysis will be conducted by trimming low-quality studies. The systematic review will be reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines. ETHICS AND DISSEMINATION Ethical approval will not be required for this study as it will be a systematic review and meta-analysis based on previously published evidence. The findings of the systematic review will be presented at scientific conferences and published in scientific journals. PROTOCOL REGISTRATION The protocol is published in PROSPERO with registration number CRD42023390339.
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Affiliation(s)
- Temesgen Yihunie Akalu
- Epidemiology and Biostatistics, University of Gondar, Gondar, Ethiopia
- Curtin University Faculty of Health Sciences, Perth, Western Australia, Australia
- Telethon Kids Institute, Nedlands, Western Australia, Australia
| | - Archie C A Clements
- Telethon Kids Institute, Nedlands, Western Australia, Australia
- Peninsula Medical School, University of Plymouth, Plymouth, UK
| | - Eyob Alemayehu Gebreyohannes
- Telethon Kids Institute, Nedlands, Western Australia, Australia
- School of Allied Health, University of Western Australia, Perth, Western Australia, Australia
| | - Haileab Fekadu Wolde
- Epidemiology and Biostatistics, University of Gondar, Gondar, Ethiopia
- Curtin University Faculty of Health Sciences, Perth, Western Australia, Australia
- Telethon Kids Institute, Nedlands, Western Australia, Australia
| | | | - Kefyalew Addis Alene
- Curtin University Faculty of Health Sciences, Perth, Western Australia, Australia
- Telethon Kids Institute, Nedlands, Western Australia, Australia
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Fan J, An J, Shu W, Tang K, Shang Y, Xue Y, Qin S, Pang Y. Impact of Xpert MTB/RIF on Outcomes of Adults Hospitalized With Spinal Tuberculosis: Findings From a Comparative Cohort in Beijing, China. Front Public Health 2022; 10:901504. [PMID: 35784201 PMCID: PMC9247639 DOI: 10.3389/fpubh.2022.901504] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundSpinal tuberculosis (TB) is one of the most common forms of extrapulmonary tuberculosis, causing increased morbidity and lifelong disabilities. Here, we conducted a retrospective study to determine the impact on patient outcomes of the Xpert MTB/RIF test vs. phenotypical drug susceptibility testing for spinal TB.MethodsIn-patients with spinal TB were enrolled in 2013 and 2017 at Beijing Chest Hospital. Data were collected from an electronic patient record system that documented demographic and clinical characteristics. All the patients were routinely followed-up at 1, 3, 6, 9, and 12 months after surgery during outpatient treatment.ResultsA total of 361 patients affected by spinal TB were enrolled in our analysis, including 178 patients in 2013 and 183 patients in 2017. In 2013, the cumulative postoperative recurrence rate of patients with spinal TB was 23% (41/178), which was significantly higher than that in 2017 (8.2%, 15/183, P < 0.001). Additionally, the patients with spinal TB diagnosed in 2013 relapsed significantly sooner than those in 2017 (P < 0.001). In the multivariate analysis, rifampicin (RIF) resistance was associated with the recurrence of spinal TB. The turnaround time of Xpert ranged from 1 to 3 days, with a median of 1 day (IQR: 1–2). For the phenotypic drug susceptibility test (pDST)-based algorithm, the median turnaround time was 67 days, considerably longer than that of the Xpert-based algorithm (P < 0.001).ConclusionThe RIF resistance is an independent risk factor for postoperative recurrence in patients with spinal TB. Early detection of RIF resistance due to the application of Xpert is an effective strategy to reduce spinal TB recurrence.
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Affiliation(s)
- Jun Fan
- Orthopaedics Department, Beijing Chest Hospital, Capital Medical University/ Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Jun An
- Medical Records Department, Beijing Chest Hospital, Capital Medical University/ Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Wei Shu
- Clinical Center on TB Control, Beijing Chest Hospital, Capital Medical University/ Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Kai Tang
- Orthopaedics Department, Beijing Chest Hospital, Capital Medical University/ Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Yuanyuan Shang
- Department of Bacteriology and Immunology, Beijing Key Laboratory on Drug-Resistant Tuberculosis Research, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Yi Xue
- Department of Bacteriology and Immunology, Beijing Key Laboratory on Drug-Resistant Tuberculosis Research, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Shibing Qin
- Orthopaedics Department, Beijing Chest Hospital, Capital Medical University/ Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
| | - Yu Pang
- Department of Bacteriology and Immunology, Beijing Key Laboratory on Drug-Resistant Tuberculosis Research, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing, China
- *Correspondence: Yu Pang
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Nair D, Navneethapandian PD, Tripathy JP, Harries AD, Klinton JS, Watson B, Sivaramakrishnan GN, Reddy DS, Murali L, Natrajan M, Swaminathan S. Impact of rapid molecular diagnostic tests on time to treatment initiation and outcomes in patients with multidrug-resistant tuberculosis, Tamil Nadu, India. Trans R Soc Trop Med Hyg 2016; 110:534-541. [DOI: 10.1093/trstmh/trw060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/09/2016] [Indexed: 11/13/2022] Open
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Pang Y, Dong H, Tan Y, Deng Y, Cai X, Jing H, Xia H, Li Q, Ou X, Su B, Li X, Zhang Z, Li J, Zhang J, Huan S, Zhao Y. Rapid diagnosis of MDR and XDR tuberculosis with the MeltPro TB assay in China. Sci Rep 2016; 6:25330. [PMID: 27149911 PMCID: PMC4858717 DOI: 10.1038/srep25330] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/15/2016] [Indexed: 11/09/2022] Open
Abstract
New diagnostic methods have provided a promising solution for rapid and reliable detection of drug-resistant TB strains. The aim of this study was to evaluate the performance of the MeltPro TB assay in identifying multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) patients from sputum samples. The MeltPro TB assay was evaluated using sputum samples from 2057 smear-positive TB patients. Phenotypic Mycobacterial Growth Indicator Tube (MGIT) 960 drug susceptibility testing served as a reference standard. The sensitivity of the MeltPro TB assay was 94.2% for detecting resistance to rifampicin and 84.9% for detecting resistance to isoniazid. For second-line drugs, the assay showed a sensitivity of 83.3% for ofloxacin resistance, 75.0% for amikacin resistance, and 63.5% for kanamycin resistance. However, there was a significant difference for detecting kanamycin resistance between the two pilot sites in sensitivity, which was 53.2% in Guangdong and 81.5% in Shandong (P = 0.015). Overall, the MeltPro TB assay demonstrated good performance for the detection of MDR- and XDR-TB, with a sensitivity of 86.7% and 71.4%, respectively. The MeltPro TB assay is an excellent alternative for the detection of MDR- and XDR-TB cases in China, with high accuracy, short testing turn-around time, and low unit price compared with other tests.
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Affiliation(s)
- Yu Pang
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | | | - Yaoju Tan
- Department of Clinical Laboratory, Guangzhou Chest Hospital, Guangdong Province, Guangzhou, China
| | - Yunfeng Deng
- Katharine Hsu International Research Center of Human Infectious Diseases, Shandong Provincial Chest Hospital, Jinan, China
| | - Xingshan Cai
- Department of Clinical Laboratory, Guangzhou Chest Hospital, Guangdong Province, Guangzhou, China
| | - Hui Jing
- Katharine Hsu International Research Center of Human Infectious Diseases, Shandong Provincial Chest Hospital, Jinan, China
| | - Hui Xia
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qiang Li
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xichao Ou
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Biyi Su
- Department of Clinical Laboratory, Guangzhou Chest Hospital, Guangdong Province, Guangzhou, China
| | - Xuezheng Li
- Katharine Hsu International Research Center of Human Infectious Diseases, Shandong Provincial Chest Hospital, Jinan, China
| | | | | | | | - Shitong Huan
- Bill and Melinda Gates Foundation, China Office, Beijing, China
| | - Yanlin Zhao
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Tomasicchio M, Theron G, Pietersen E, Streicher E, Stanley-Josephs D, van Helden P, Warren R, Dheda K. The diagnostic accuracy of the MTBDRplus and MTBDRsl assays for drug-resistant TB detection when performed on sputum and culture isolates. Sci Rep 2016; 6:17850. [PMID: 26860462 PMCID: PMC4748215 DOI: 10.1038/srep17850] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 11/04/2015] [Indexed: 11/23/2022] Open
Abstract
Although molecular tests for drug-resistant TB perform well on culture isolates, their accuracy using clinical samples, particularly from TB and HIV-endemic settings, requires clarification. The MTBDRplus and MTBDRsl line probe assays were evaluated in 181 sputum samples and 270 isolates from patients with culture-confirmed drug-sensitive-TB, MDR-TB, or XDR-TB. Phenotypic culture-based testing was the reference standard. Using sputum, the sensitivities for resistance was 97.7%, 95.4%, 58.9%, 61.6% for rifampicin, isoniazid, ofloxacin, and amikacin, respectively, whereas the specificities were 91.8%, 89%, 100%, and 100%, respectively. MTBDRsl sensitivity differed in smear-positive vs. smear-negative samples (79.2% vs. 20%, p < 0.0001 for ofloxacin; 72.9% vs. 37%, p = 0.0023 for amikacin) but not by HIV status. If used sequentially, MTBDRplus and MTBDRsl could rule-in XDR-TB in 78.5% (22/28) and 10.5% (2/19) of smear-positive and smear-negative samples, respectively. On culture isolates, the sensitivity for resistance to rifampicin, isoniazid, ofloxacin, and amikacin was 95.1%, 96.1%, 72.3% and 76.6%, respectively, whereas the specificities exceeded 96%. Using a sequential testing approach, rapid sputum-based diagnosis of fluoroquinolone or aminoglycoside-resistant TB is feasible only in smear-positive samples, where rule-in value is good. Further investigation is required in samples that test susceptible in order to rule-out second-line drug resistance.
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Affiliation(s)
- Michele Tomasicchio
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Grant Theron
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town, Cape Town, South Africa
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Elize Pietersen
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Elizabeth Streicher
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Danielle Stanley-Josephs
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Paul van Helden
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Rob Warren
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Keertan Dheda
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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MTBDRplus and MTBDRsl Assays: Absence of Wild-Type Probe Hybridization and Implications for Detection of Drug-Resistant Tuberculosis. J Clin Microbiol 2016; 54:912-8. [PMID: 26763971 DOI: 10.1128/jcm.02505-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 01/06/2016] [Indexed: 01/24/2023] Open
Abstract
Accurate identification of drug-resistantMycobacterium tuberculosisis imperative for effective treatment and subsequent reduction in disease transmission. Line probe assays rapidly detect mutations associated with resistance and wild-type sequences associated with susceptibility. Examination of molecular-level performance is necessary for improved assay result interpretation and for continued diagnostic development. Using data collected from a large, multisite diagnostic study, probe hybridization results from line probe assays, MTBDRplusand MTBDRsl, were compared to those of sequencing, and the diagnostic performance of each individual mutation and wild-type probe was assessed. Line probe assay results classified as resistant due to the absence of wild-type probe hybridization were compared to those of sequencing to determine if novel mutations were inhibiting wild-type probe hybridization. The contribution of absent wild-type probe hybridization to the detection of drug resistance was assessed via comparison to a phenotypic reference standard. In our study, mutation probes demonstrated significantly higher specificities than wild-type probes and wild-type probes demonstrated marginally higher sensitivities than mutation probes, an ideal combination for detecting the presence of resistance conferring mutations while yielding the fewest number of false-positive results. The absence of wild-type probe hybridization without mutation probe hybridization was determined to be primarily the result of failure of mutation probe hybridization and not the result of novel or rare mutations. Compared to phenotypic culture-based drug susceptibility testing, the absence of wild-type probe hybridization without mutation probe hybridization significantly contributed to the detection of phenotypic rifampin and fluoroquinolone resistance with negligible increases in false-positive results.
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Zhao Y, Li G, Sun C, Li C, Wang X, Liu H, Zhang P, Zhao X, Wang X, Jiang Y, Yang R, Wan K, Zhou L. Locked Nucleic Acid Probe-Based Real-Time PCR Assay for the Rapid Detection of Rifampin-Resistant Mycobacterium tuberculosis. PLoS One 2015; 10:e0143444. [PMID: 26599667 PMCID: PMC4657947 DOI: 10.1371/journal.pone.0143444] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/04/2015] [Indexed: 02/07/2023] Open
Abstract
Drug-resistant Mycobacterium tuberculosis can be rapidly diagnosed through nucleic acid amplification techniques by analyzing the variations in the associated gene sequences. In the present study, a locked nucleic acid (LNA) probe-based real-time PCR assay was developed to identify the mutations in the rpoB gene associated with rifampin (RFP) resistance in M. tuberculosis. Six LNA probes with the discrimination capability of one-base mismatch were designed to monitor the 23 most frequent rpoB mutations. The target mutations were identified using the probes in a “probe dropout” manner (quantification cycle = 0); thus, the proposed technique exhibited superiority in mutation detection. The LNA probe-based real-time PCR assay was developed in a two-tube format with three LNA probes and one internal amplification control probe in each tube. The assay showed excellent specificity to M. tuberculosis with or without RFP resistance by evaluating 12 strains of common non-tuberculosis mycobacteria. The limit of detection of M. tuberculosis was 10 genomic equivalents (GE)/reaction by further introducing a nested PCR method. In a blind validation of 154 clinical mycobacterium isolates, 142/142 (100%) were correctly detected through the assay. Of these isolates, 88/88 (100%) were determined as RFP susceptible and 52/54 (96.3%) were characterized as RFP resistant. Two unrecognized RFP-resistant strains were sequenced and were found to contain mutations outside the range of the 23 mutation targets. In conclusion, this study established a sensitive, accurate, and low-cost LNA probe-based assay suitable for a four-multiplexing real-time PCR instrument. The proposed method can be used to diagnose RFP-resistant tuberculosis in clinical laboratories.
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Affiliation(s)
- Yong Zhao
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
| | - Guilian Li
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China
| | - Chongyun Sun
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
- Department of Clinical Laboratory, Chinese People’s Liberation Army General Hospital, Beijing 100853, P. R. China
| | - Chao Li
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China
| | - Xiaochen Wang
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, P. R. China
| | - Haican Liu
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China
| | - Pingping Zhang
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
| | - Xiuqin Zhao
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China
| | - Xinrui Wang
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
- Institute for Plague Prevention and Control of Hebei Province, Zhangjiakou 075000, P. R. China
| | - Yi Jiang
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China
| | - Ruifu Yang
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
| | - Kanglin Wan
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China
- * E-mail: (LZ); (KW)
| | - Lei Zhou
- Laboratory of Analytical Microbiology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, P. R. China
- Beijing Key Laboratory of POCT for Bioemergency and Clinic (No. BZ0329), Beijing 100071, P. R. China
- * E-mail: (LZ); (KW)
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Nardell EA. Transmission and Institutional Infection Control of Tuberculosis. Cold Spring Harb Perspect Med 2015; 6:a018192. [PMID: 26292985 DOI: 10.1101/cshperspect.a018192] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Tuberculosis (TB) transmission control in institutions is evolving with increased awareness of the rapid impact of treatment on transmission, the importance of the unsuspected, untreated case of transmission, and the advent of rapid molecular diagnostics. With active case finding based on cough surveillance and rapid drug susceptibility testing, in theory, it is possible to be reasonably sure that no patient enters a facility with undiagnosed TB or drug resistance. Droplet nuclei transmission of TB is reviewed with an emphasis on risk factors relevant to control. Among environmental controls, natural ventilation and upper-room ultraviolet germicidal ultraviolet air disinfection are the most cost-effective choices, although high-volume mechanical ventilation can also be used. Room air cleaners are generally not recommended. Maintenance is required for all engineering solutions. Finally, personal protection with fit-tested respirators is used in many situations where administrative and engineering methods cannot assure protection.
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Affiliation(s)
- Edward A Nardell
- Division of Global Health Equity, Brigham & Women's Hospital, Boston, Massachusetts 02115
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9
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Ballif M, Nhandu V, Wood R, Dusingize JC, Carter EJ, Cortes CP, McGowan CC, Diero L, Graber C, Renner L, Hawerlander D, Kiertiburanakul S, Du QT, Sterling TR, Egger M, Fenner L. Detection and management of drug-resistant tuberculosis in HIV-infected patients in lower-income countries. Int J Tuberc Lung Dis 2015; 18:1327-36. [PMID: 25299866 DOI: 10.5588/ijtld.14.0106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
SETTING Drug resistance threatens tuberculosis (TB) control, particularly among human immunodeficiency virus (HIV) infected persons. OBJECTIVE To describe practices in the prevention and management of drug-resistant TB under antiretroviral therapy (ART) programs in lower-income countries. DESIGN We used online questionnaires to collect program-level data on 47 ART programs in Southern Africa (n = 14), East Africa (n = 8), West Africa (n = 7), Central Africa (n = 5), Latin America (n = 7) and the Asia-Pacific (n = 6 programs) in 2012. Patient-level data were collected on 1002 adult TB patients seen at 40 of the participating ART programs. RESULTS Phenotypic drug susceptibility testing (DST) was available in 36 (77%) ART programs, but was only used for 22% of all TB patients. Molecular DST was available in 33 (70%) programs and was used in 23% of all TB patients. Twenty ART programs (43%) provided directly observed therapy (DOT) during the entire course of treatment, 16 (34%) during the intensive phase only, and 11 (23%) did not follow DOT. Fourteen (30%) ART programs reported no access to second-line anti-tuberculosis regimens; 18 (38%) reported TB drug shortages. CONCLUSIONS Capacity to diagnose and treat drug-resistant TB was limited across ART programs in lower-income countries. DOT was not always implemented and drug supplies were regularly interrupted, which may contribute to the global emergence of drug resistance.
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Affiliation(s)
- M Ballif
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - V Nhandu
- Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - R Wood
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - J C Dusingize
- Women's Equity in Access to Care & Treatment, Kigali, Rwanda
| | - E J Carter
- United States Agency for International Development Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - C P Cortes
- University of Chile School of Medicine, Santiago, Chile
| | - C C McGowan
- Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - L Diero
- United States Agency for International Development Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - C Graber
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - L Renner
- University of Ghana Medical School, Accra, Ghana
| | - D Hawerlander
- Centre Intégré de Recherches Biocliniques, Abidjan, Côte d'Ivoire
| | - S Kiertiburanakul
- Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; Children's Hospital, Ho Chi Minh City, Viet Nam
| | - Q T Du
- Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - T R Sterling
- Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - M Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - L Fenner
- Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
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10
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Seifert M, Catanzaro D, Catanzaro A, Rodwell TC. Genetic mutations associated with isoniazid resistance in Mycobacterium tuberculosis: a systematic review. PLoS One 2015; 10:e0119628. [PMID: 25799046 PMCID: PMC4370653 DOI: 10.1371/journal.pone.0119628] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 01/14/2015] [Indexed: 01/12/2023] Open
Abstract
Background Tuberculosis (TB) incidence and mortality are declining worldwide; however, poor detection of drug-resistant disease threatens to reverse current progress toward global TB control. Multiple, rapid molecular diagnostic tests have recently been developed to detect genetic mutations in Mycobacterium tuberculosis (Mtb) genes known to confer first-line drug resistance. Their utility, though, depends on the frequency and distribution of the resistance associated mutations in the pathogen population. Mutations associated with rifampicin resistance, one of the two first-line drugs, are well understood and appear to occur in a single gene region in >95% of phenotypically resistant isolates. Mutations associated with isoniazid, the other first-line drug, are more complex and occur in multiple Mtb genes. Objectives/Methodology A systematic review of all published studies from January 2000 through August 2013 was conducted to quantify the frequency of the most common mutations associated with isoniazid resistance, to describe the frequency at which these mutations co-occur, and to identify the regional differences in the distribution of these mutations. Mutation data from 118 publications were extracted and analyzed for 11,411 Mtb isolates from 49 countries. Principal Findings/Conclusions Globally, 64% of all observed phenotypic isoniazid resistance was associated with the katG315 mutation. The second most frequently observed mutation, inhA-15, was reported among 19% of phenotypically resistant isolates. These two mutations, katG315 and inhA-15, combined with ten of the most commonly occurring mutations in the inhA promoter and the ahpC-oxyR intergenic region explain 84% of global phenotypic isoniazid resistance. Regional variation in the frequency of individual mutations may limit the sensitivity of molecular diagnostic tests. Well-designed systematic surveys and whole genome sequencing are needed to identify mutation frequencies in geographic regions where rapid molecular tests are currently being deployed, providing a context for interpretation of test results and the opportunity for improving the next generation of diagnostics.
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Affiliation(s)
- Marva Seifert
- University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - Donald Catanzaro
- University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - Antonino Catanzaro
- University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - Timothy C. Rodwell
- University of California San Diego, School of Medicine, La Jolla, California, United States of America
- * E-mail:
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Naidoo P, du Toit E, Dunbar R, Lombard C, Caldwell J, Detjen A, Squire SB, Enarson DA, Beyers N. A comparison of multidrug-resistant tuberculosis treatment commencement times in MDRTBPlus line probe assay and Xpert® MTB/RIF-based algorithms in a routine operational setting in Cape Town. PLoS One 2014; 9:e103328. [PMID: 25079599 PMCID: PMC4117508 DOI: 10.1371/journal.pone.0103328] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 07/01/2014] [Indexed: 01/28/2023] Open
Abstract
Background Xpert MTB/RIF was introduced as a screening test for all presumptive tuberculosis cases in primary health services in Cape Town, South Africa. Study Aim To compare multidrug-resistant tuberculosis (MDR-TB) treatment commencement times in MDRTBPlus Line Probe Assay and Xpert MTB/RIF-based algorithms in a routine operational setting. Methods The study was undertaken in 10 of 29 high tuberculosis burden primary health facilities, selected through stratified random sampling. An observational study was undertaken as facilities transitioned to the Xpert MTB/RIF-based algorithm. MDR-TB diagnostic data were collected from electronic laboratory records and treatment data from clinical records and registers. Kaplan Meier time-to-event analysis was used to compare treatment commencement time, laboratory turnaround time and action delay between algorithms. A facility-level paired analysis was done: the median time-to-event was estimated per facility in each algorithm and mean differences between algorithms compared using a paired t-test. Cox proportional hazards regression was used to assess the effect of patient-level variables on treatment commencement time. The difference between algorithms was compared using the hazard ratio. Results The median treatment commencement time in the Xpert MTB/RIF-based algorithm was 17 days (95% CI 13 to 22 days), with a median laboratory turnaround time (to result available in the laboratory) of <1 day (95% CI<1 to 1 day). There was a decrease of 25 days (95% CI 17 to 32 days, p<0.001) in median MDR-TB treatment commencement time in the Xpert MTB/RIF-based algorithm. We found no significant effect on treatment commencement times for the patient-level variables assessed. Conclusion MDR-TB treatment commencement time was significantly reduced in the Xpert MTB/RIF-based algorithm. Changes in the health system may have contributed. However, an unacceptable level of delay remains. Health system and patient factors contributing to delay need to be evaluated and addressed to optimise test benefits.
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Affiliation(s)
- Pren Naidoo
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- * E-mail:
| | - Elizabeth du Toit
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Rory Dunbar
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Carl Lombard
- Medical Research Council, Cape Town, South Africa
| | - Judy Caldwell
- Cape Town Health Directorate, Cape Town, South Africa
| | - Anne Detjen
- The International Union Against TB and Lung Disease, Paris, France
| | - S. Bertel Squire
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Nulda Beyers
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Impact of introducing the line probe assay on time to treatment initiation of MDR-TB in Delhi, India. PLoS One 2014; 9:e102989. [PMID: 25058124 PMCID: PMC4109962 DOI: 10.1371/journal.pone.0102989] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 06/26/2014] [Indexed: 11/19/2022] Open
Abstract
SETTING National Institute of Tuberculosis and Respiratory Diseases (erstwhile Lala Ram Sarup Institute) in Delhi, India. OBJECTIVES To evaluate before and after the introduction of the line Probe Assay (LPA) a) the overall time to MDR-TB diagnosis and treatment initiation; b) the step-by-step time lapse at each stage of patient management; and c) the lost to follow-up rates. METHODS A retrospective cohort analysis was done using data on MDR-TB patients diagnosed during 2009-2012 under Revised National Tuberculosis Control Programme at the institute. RESULTS Following the introduction of the LPA in 2011, the overall median time from identification of patients suspected for MDR-TB to the initiation of treatment was reduced from 157 days (IQR 127-200) to 38 days (IQR 30-79). This reduction was attributed mainly to a lower diagnosis time at the laboratory. Lost to follow-up rates were also significantly reduced after introduction of the LPA (12% versus 39% pre-PLA). CONCLUSION Introduction of the LPA was associated with a major reduction in the delay between identification of patients suspected for MDR-TB and initiation of treatment, attributed mainly to a reduction in diagnostic time in the laboratory.
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13
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Steingart KR, Schiller I, Horne DJ, Pai M, Boehme CC, Dendukuri N. Xpert® MTB/RIF assay for pulmonary tuberculosis and rifampicin resistance in adults. Cochrane Database Syst Rev 2014; 2014:CD009593. [PMID: 24448973 PMCID: PMC4470349 DOI: 10.1002/14651858.cd009593.pub3] [Citation(s) in RCA: 427] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Accurate, rapid detection of tuberculosis (TB) and TB drug resistance is critical for improving patient care and decreasing TB transmission. Xpert® MTB/RIF assay is an automated test that can detect both TB and rifampicin resistance, generally within two hours after starting the test, with minimal hands-on technical time. The World Health Organization (WHO) issued initial recommendations on Xpert® MTB/RIF in early 2011. A Cochrane Review on the diagnostic accuracy of Xpert® MTB/RIF for pulmonary TB and rifampicin resistance was published January 2013. We performed this updated Cochrane Review as part of a WHO process to develop updated guidelines on the use of the test. OBJECTIVES To assess the diagnostic accuracy of Xpert® MTB/RIF for pulmonary TB (TB detection), where Xpert® MTB/RIF was used as both an initial test replacing microscopy and an add-on test following a negative smear microscopy result.To assess the diagnostic accuracy of Xpert® MTB/RIF for rifampicin resistance detection, where Xpert® MTB/RIF was used as the initial test replacing culture-based drug susceptibility testing (DST).The populations of interest were adults presumed to have pulmonary, rifampicin-resistant or multidrug-resistant TB (MDR-TB), with or without HIV infection. The settings of interest were intermediate- and peripheral-level laboratories. The latter may be associated with primary health care facilities. SEARCH METHODS We searched for publications in any language up to 7 February 2013 in the following databases: Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; ISI Web of Knowledge; MEDION; LILACS; BIOSIS; and SCOPUS. We also searched the metaRegister of Controlled Trials (mRCT) and the search portal of the WHO International Clinical Trials Registry Platform to identify ongoing trials. SELECTION CRITERIA We included randomized controlled trials, cross-sectional studies, and cohort studies using respiratory specimens that allowed for extraction of data evaluating Xpert® MTB/RIF against the reference standard. We excluded gastric fluid specimens. The reference standard for TB was culture and for rifampicin resistance was phenotypic culture-based DST. DATA COLLECTION AND ANALYSIS For each study, two review authors independently extracted data using a standardized form. When possible, we extracted data for subgroups by smear and HIV status. We assessed the quality of studies using QUADAS-2 and carried out meta-analyses to estimate pooled sensitivity and specificity of Xpert® MTB/RIF separately for TB detection and rifampicin resistance detection. For TB detection, we performed the majority of analyses using a bivariate random-effects model and compared the sensitivity of Xpert® MTB/RIF and smear microscopy against culture as reference standard. For rifampicin resistance detection, we undertook univariate meta-analyses for sensitivity and specificity separately to include studies in which no rifampicin resistance was detected. MAIN RESULTS We included 27 unique studies (integrating nine new studies) involving 9557 participants. Sixteen studies (59%) were performed in low- or middle-income countries. For all QUADAS-2 domains, most studies were at low risk of bias and low concern regarding applicability.As an initial test replacing smear microscopy, Xpert® MTB/RIF pooled sensitivity was 89% [95% Credible Interval (CrI) 85% to 92%] and pooled specificity 99% (95% CrI 98% to 99%), (22 studies, 8998 participants: 2953 confirmed TB, 6045 non-TB).As an add-on test following a negative smear microscopy result, Xpert®MTB/RIF pooled sensitivity was 67% (95% CrI 60% to 74%) and pooled specificity 99% (95% CrI 98% to 99%; 21 studies, 6950 participants).For smear-positive, culture-positive TB, Xpert® MTB/RIF pooled sensitivity was 98% (95% CrI 97% to 99%; 21 studies, 1936 participants).For people with HIV infection, Xpert® MTB/RIF pooled sensitivity was 79% (95% CrI 70% to 86%; 7 studies, 1789 participants), and for people without HIV infection, it was 86% (95% CrI 76% to 92%; 7 studies, 1470 participants). Comparison with smear microscopy In comparison with smear microscopy, Xpert® MTB/RIF increased TB detection among culture-confirmed cases by 23% (95% CrI 15% to 32%; 21 studies, 8880 participants).For TB detection, if pooled sensitivity estimates for Xpert® MTB/RIF and smear microscopy are applied to a hypothetical cohort of 1000 patients where 10% of those with symptoms have TB, Xpert® MTB/RIF will diagnose 88 cases and miss 12 cases, whereas sputum microscopy will diagnose 65 cases and miss 35 cases. Rifampicin resistance For rifampicin resistance detection, Xpert® MTB/RIF pooled sensitivity was 95% (95% CrI 90% to 97%; 17 studies, 555 rifampicin resistance positives) and pooled specificity was 98% (95% CrI 97% to 99%; 24 studies, 2411 rifampicin resistance negatives). Among 180 specimens with nontuberculous mycobacteria (NTM), Xpert® MTB/RIF was positive in only one specimen that grew NTM (14 studies, 2626 participants).For rifampicin resistance detection, if the pooled accuracy estimates for Xpert® MTB/RIF are applied to a hypothetical cohort of 1000 individuals where 15% of those with symptoms are rifampicin resistant, Xpert® MTB/RIF would correctly identify 143 individuals as rifampicin resistant and miss eight cases, and correctly identify 833 individuals as rifampicin susceptible and misclassify 17 individuals as resistant. Where 5% of those with symptoms are rifampicin resistant, Xpert® MTB/RIF would correctly identify 48 individuals as rifampicin resistant and miss three cases and correctly identify 931 individuals as rifampicin susceptible and misclassify 19 individuals as resistant. AUTHORS' CONCLUSIONS In adults thought to have TB, with or without HIV infection, Xpert® MTB/RIF is sensitive and specific. Compared with smear microscopy, Xpert® MTB/RIF substantially increases TB detection among culture-confirmed cases. Xpert® MTB/RIF has higher sensitivity for TB detection in smear-positive than smear-negative patients. Nonetheless, this test may be valuable as an add-on test following smear microscopy in patients previously found to be smear-negative. For rifampicin resistance detection, Xpert® MTB/RIF provides accurate results and can allow rapid initiation of MDR-TB treatment, pending results from conventional culture and DST. The tests are expensive, so current research evaluating the use of Xpert® MTB/RIF in TB programmes in high TB burden settings will help evaluate how this investment may help start treatment promptly and improve outcomes.
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Affiliation(s)
- Karen R Steingart
- Liverpool School of Tropical MedicineCochrane Infectious Diseases GroupPembroke PlaceLiverpoolUK
| | - Ian Schiller
- McGill University Health CentreDepartment of Clinical EpidemiologyMcGill UniversityMontrealCanada
| | - David J Horne
- University of WashingtonDivision of Pulmonary and Critical Care MedicineSeattleUSA
| | - Madhukar Pai
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthPurvis Hall, Room 501020 Pine Avenue WestMontrealCanadaH3A 1A2
| | - Catharina C Boehme
- Foundation for Innovative New Diagnostics (FIND)16, Av de BudéGenevaSwitzerland
| | - Nandini Dendukuri
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthPurvis Hall, Room 501020 Pine Avenue WestMontrealCanadaH3A 1A2
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Evaluation of a diagnostic algorithm for sputum smear-negative pulmonary tuberculosis in HIV-infected adults. J Acquir Immune Defic Syndr 2013; 63:331-8. [PMID: 23599010 DOI: 10.1097/qai.0b013e31829341af] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The Revised National TB Control Program bases diagnosis of tuberculosis (TB) on sputum smear examination and response to a course of antibiotics, whereas World Health Organization recommends early chest radiography [chest x-ray (CXR)] for HIV-infected symptomatic patients. We evaluated the utility of initial CXR in the diagnostic algorithm for symptomatic HIV-infected patients with negative sputum smears. METHODS HIV-infected ambulatory patients with cough or fever of ≥2 weeks and 3 sputum smears negative for acid-fast bacilli were enrolled in Chennai and Pune, India, between 2007 and 2009. After a CXR and 2 sputum cultures, a course of broad-spectrum antibiotics was given and patients were reviewed after 14 days. Sensitivity, specificity, positive and negative predictive values of symptoms, CXR, and various combinations for diagnosing pulmonary tuberculosis (PTB) were determined, using sputum culture as gold standard. RESULTS Five hundred four patients (330 males; mean age: 35 years; median CD4: 175 cells per cubic millimeter) were enrolled. CXR had a sensitivity and specificity of 72% and 57%, respectively, with positive predictive value (PPV) of 21% and negative predictive value (NPV) of 93% to diagnose PTB. TB culture was positive in 49 of 235 patients (21%) with an abnormal initial CXR and 19 of 269 patients (7%) with a normal CXR (P < 0.001). Sensitivity and specificity of cough ≥2 weeks for predicting PTB was 97% and 6%, with PPV and NPV of 14% and 94%, respectively. CONCLUSIONS Although moderately sensitive, basing a diagnosis of TB on initial CXR leads to overdiagnosis. An absence of weight loss had a high NPV, whereas none of the combinations had a good PPV. A rapid and accurate diagnostic test is required for HIV-infected chest symptomatic.
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Multicenter evaluation of genechip for detection of multidrug-resistant Mycobacterium tuberculosis. J Clin Microbiol 2013; 51:1707-13. [PMID: 23515537 DOI: 10.1128/jcm.03436-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drug-resistant tuberculosis (TB), especially multidrug-resistant TB (MDR-TB), is still one of the most serious threats to TB control worldwide. Early diagnosis of MDR-TB is important for effectively blocking transmission and establishing an effective protocol for chemotherapy. Genechip is a rapid diagnostic method based on molecular biology that overcomes the poor biosafety, time consumption, and other drawbacks of traditional drug sensitivity testing (DST) that can detect MDR-TB. However, the Genechip approach has not been effectively evaluated, especially in limited-resource laboratories. In this study, we evaluated the performance of Genechip for MDR-TB in 1,814 patients in four prefectural or municipal laboratories and compared its performance with that of traditional DST. The results showed that the sensitivity and specificity of Genechip were 87.56% and 97.95% for rifampin resistance and 80.34% and 95.82% for isoniazid resistance, respectively. In addition, we found that the positive grade of the sputum smears influenced the judgment of results by Genechip. The test judged only 75% of the specimens of "scanty" positive grade. However, the positive grade of the specimens showed no influence on the accuracy of Genechip. Overall, the study suggests that, in limited-resource laboratories, Genechip showed high sensitivity and specificity for rifampin and isoniazid resistance, making it a more effective, rapid, safe, and cost-beneficial method worthy of broader use in limited-resource laboratories in China.
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Barnard M, Warren R, Gey Van Pittius N, van Helden P, Bosman M, Streicher E, Coetzee G, O'Brien R. Genotype MTBDRsl line probe assay shortens time to diagnosis of extensively drug-resistant tuberculosis in a high-throughput diagnostic laboratory. Am J Respir Crit Care Med 2012; 186:1298-305. [PMID: 23087027 DOI: 10.1164/rccm.201205-0960oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Conventional culture-based drug susceptibility testing (DST) for the second-line antituberculosis drugs is slow, leading to diagnostic delay with associated exacerbation of transmission, amplification of resistance, and increased mortality. OBJECTIVES To assess the diagnostic performance of the GenoType MTBDRsl line probe assay (LPA) for the rapid detection of mutations conferring resistance to ofloxacin (OFX), amikacin (AMK), and ethambutol and to determine the impact of implementation on the turnaround time in a high-throughput diagnostic laboratory. METHODS Six hundred and fifty-seven direct patient acid-fast bacilli smear-positive specimens resistant to isoniazid, rifampin, or both according to the GenoType MTBDRplus assay were consecutively tested, using the GenoType MTBDRsl LPA. The diagnostic performance was assessed relative to the "gold standard" culture-based method, and the laboratory turnaround times for both methods were determined. MEASUREMENTS AND MAIN RESULTS A total of 516 of 657 patient specimens had valid results for both tests. The sensitivity for detecting OFX, AMK, and extensive drug resistance, using the GenoType MTBDRsl LPA, was 90.7% (95% confidence interval [CI], 80.1-96.0%), 100% (95% CI, 91.8-100%), and 92.3% (95% CI, 75.9-97.9%), respectively, and the specificity for detection was 98.1% (95% CI, 96.3-99.0%), 99.4% (95% CI, 98.2-99.8%), and 99.6% (95% CI, 98.5-99.9%), respectively. Implementation of this test significantly reduced the turnaround time by 93.3% (P < 0.001), calculated from the date that the specimen was received at the laboratory to reporting second-line results. In addition, a significant increase in diagnostic yield of 20.1% and 19.3% (P < 0.001) for OFX and AMK resistance, respectively, was obtained for isolates that were either contaminated or had lost viability. CONCLUSIONS The GenoType MTBDRsl LPA is a rapid and reliable DST that can be easily incorporated into the diagnostic algorithm. This assay significantly improved diagnostic yield (P < 0.001) while simultaneously decreasing diagnostic delay for reporting second-line DST. The rapid dissemination of second-line DST results will guide initiation of appropriate treatment, thereby reducing transmission and improving treatment outcome.
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Affiliation(s)
- Marinus Barnard
- National Health Laboratory Service (NHLS), Tuberculosis Reference Laboratory, Green Point, Cape Town, South Africa
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Rapid, high-throughput detection of rifampin resistance and heteroresistance in Mycobacterium tuberculosis by use of sloppy molecular beacon melting temperature coding. J Clin Microbiol 2012; 50:2194-202. [PMID: 22535987 DOI: 10.1128/jcm.00143-12] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Rifampin resistance in Mycobacterium tuberculosis is largely determined by mutations in an 80-bp rifampin resistance determining region (RRDR) of the rpoB gene. We developed a rapid single-well PCR assay to identify RRDR mutations. The assay uses sloppy molecular beacons to probe an asymmetric PCR of the M. tuberculosis RRDR by melting temperature (T(m)) analysis. A three-point T(m) code is generated which distinguishes wild-type from mutant RRDR DNA sequences in approximately 2 h. The assay was validated on synthetic oligonucleotide targets containing the 44 most common RRDR mutations. It was then tested on a panel of DNA extracted from 589 geographically diverse clinical M. tuberculosis cultures, including isolates with wild-type RRDR sequences and 25 different RRDR mutations. The assay detected 236/236 RRDR mutant sequences as mutant (sensitivity, 100%; 95% confidence interval [CI], 98 to 100%) and 353/353 RRDR wild-type sequences as wild type (specificity, 100%; 95% CI, 98.7 to 100%). The assay identified 222/225 rifampin-resistant isolates as rifampin resistant (sensitivity, 98.7%; 95% CI, 95.8 to 99.6%) and 335/336 rifampin-susceptible isolates as rifampin susceptible (specificity, 99.7%; 95% CI, 95.8 to 99.6%). All mutations were either individually identified or clustered into small mutation groups using the triple T(m) code. The assay accurately identified mixed (heteroresistant) samples and was shown analytically to detect RRDR mutations when present in at least 40% of the total M. tuberculosis DNA. This was at least as accurate as Sanger DNA sequencing. The assay was easy to use and well suited for high-throughput applications. This new sloppy molecular beacon assay should greatly simplify rifampin resistance testing in clinical laboratories.
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Jenkins SG, Schuetz AN. Current concepts in laboratory testing to guide antimicrobial therapy. Mayo Clin Proc 2012; 87:290-308. [PMID: 22386185 PMCID: PMC3496983 DOI: 10.1016/j.mayocp.2012.01.007] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 01/17/2012] [Accepted: 01/23/2012] [Indexed: 02/08/2023]
Abstract
Antimicrobial susceptibility testing (AST) is indicated for pathogens contributing to an infectious process that warrants antimicrobial therapy if susceptibility to antimicrobials cannot be predicted reliably based on knowledge of their identity. Such tests are most frequently used when the etiologic agents are members of species capable of demonstrating resistance to commonly prescribed antibiotics. Some organisms have predictable susceptibility to antimicrobial agents (ie, Streptococcus pyogenes to penicillin), and empirical therapy for these organisms is typically used. Therefore, AST for such pathogens is seldom required or performed. In addition, AST is valuable in evaluating the activity of new and experimental compounds and investigating the epidemiology of antimicrobial resistant pathogens. Several laboratory methods are available to characterize the in vitro susceptibility of bacteria to antimicrobial agents. When the nature of the infection is unclear and the culture yields mixed growth or usual microbiota (wherein the isolates usually bear little relationship to the actual infectious process), AST is usually unnecessary and results may, in fact, be dangerously misleading. Phenotypic methods for detection of specific antimicrobial resistance mechanisms are increasingly being used to complement AST (ie, inducible clindamycin resistance among several gram-positive bacteria) and to provide clinicians with preliminary direction for antibiotic selection pending results generated from standardized AST (ie, β-lactamase tests). In addition, molecular methods are being developed and incorporated by microbiology laboratories into resistance detection algorithms for rapid, sensitive assessment of carriage states of epidemiologically and clinically important pathogens, often directly from clinical specimens (ie, presence of vancomycin-resistant enterococci in fecal specimens).
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Affiliation(s)
- Stephen G Jenkins
- Department of Pathology, Weill Cornell Medical College, East 68th Street, New York, NY 10065, USA.
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