Nanoparticles as an Alternative Strategy for the Rapid Detection of Mycobacterium tuberculosis Complex (MTBC): A Systematic Literature Review of In Vitro Studies

To identify and evaluate a new nucleic acid amplification (NAA) test target for specific detection of Mycobacterium tuberculosis (MTB) complex (MTC). MTC-specific fragment was obtained by ISSR genotyping technology. Primer pairs were designed based on the sequences of MTC-specific fragment and tested in 211 mycobacterial strains including 107 MTC strains and 104 nontuberculous mycobacteria (NTM) strains. IS6110 element (specific identification of MTC strains) and 16s rRNA gene (specific identification of Mycobacterium) amplification were used as a control to evaluate the efficacy of the NAA test target in the detection of MTC strains. One MTC-specific fragment with the length of 588 bp, located in 315947 - 316534 of the genome from MTB reference strain H(37) Rv, were obtained, cloned and sequenced. MTC-specific primer pairs MTCF/R were designed based on these sequences. All 211 mycobacterial strains accurately produced the genus-specific 16s rRNA amplicon. All MTC strains were positive in the MTCF/R PCR amplification while 99% MTC strains (106/107) were positive in the amplification of IS6110 sequences. All NTM strains were negative in both IS6110 and MTCF/R PCR amplification. The MTC-specific fragment developed in this study can be used as a new NAA test target to correctly distinguish MTC from NTM.

Evaluation of Multiplex loop-mediated isothermal amplification assay for the detection of Mycobacterium tuberculosis complex from clinically suspected cases of pulmonary tuberculosis

Background: Tuberculosis (TB) remains one of the deadliest communicable diseases. Tuberculosis is caused by Mycobacterium tuberculosis and classified as Pulmonary Tuberculosis (PTB) and Extra Pulmonary Tuberculosis (EPTB). EPTB account for 15-20 % cases of tuberculosis. EPTB diagnosis is challenging due to inadequate sample volume, pauci-bacillary nature and unusual clinical presentation. There are number of tests available for the diagnosis of EPTB but conventional microscopy has low sensitivity and although culture is gold standard method, it takes longer time for yielding positive result. On the other side, GeneXpert due to its rapidity and sensitivity help in early diagnosis and management of tuberculosis. Culture of Mycobacterium Tuberculosis Complex (MTBC) is the accepted reference standard for confirmation of tuberculosis infection and is necessary for Drug Susceptibility Testing (DST). Although solid media has been used for over 100 years, liquid culture media is increasingly being introduced in low and middle income countries for rapid detection of MTBC. To compare the efficacy of solid culture method using Lowenstein Jensen (LJ) media with GeneXpert and liquid culture method using Mycobacterium Growth Indicator Tube (MGIT) 960 for detection of Mycobacterium tuberculosis. Materials and methods: In this cross sectional study 118 suspected EPTB samples including CSF, lymphatic aspirate, pleural fluid, ascitic fluid, synovial fluid, pus were collected. Smear microscopy, culture both in solid media and liquid media using MGIT 960 method and GeneXpert machine were done. Moreover antitubercular drug sensitivity test was done by proportion method in L-J media. Results: Out of 118 samples, GeneXpert detetcs 26 (22.03%) where as the liquid MGIT 960 method detects 27 (22.88%) and solid culture detects 26 (22.03%) positive samples for Mycobacterium tuberculosis. 01 (1.8%) case was detected as multidrug resistant TB. Conclusion: GeneXpert have significant role in diagnosing EPTB patient within shorter period of time. But GeneXpert can detect only rifampicin resistance where as DST in L-J media detects other first line drugs sensitivity too. Liquid culture method using MGIT 960 yields more positive result than solid culture, also liquid culture shows rapid identification of Mycobacterium tuberculosis. Chatt Maa Shi Hosp Med Coll J; Vol.23 (2); July 2024; Page 65-68

With the incidence of culture-positive tuberculosis (TB) cases at 25.3 per 100,000 and a 25% rate of TB/HIV coinfection, the TB incidence in French Guiana is the highest of all French regions (3, 5). In this context, there is an urgent need for simple, automated systems for molecular diagnosis of TB that can be adapted to small laboratories. Introduction of a nuclear amplification test in a routine clinical laboratory is an additional expense, and its cost-effectiveness and clinical utility need to be evaluated and seem to be optimized when used for diagnosis in patients with an intermediate-to-high likelihood of TB (8, 14). With these objectives, our study aimed to evaluate a molecular assay developed for the detection of Mycobacterium tuberculosis complex (MTC) on the robotic workstation easyMAG/easyQ (EMEQ; bioMerieux, France), in comparison with culture, the gold standard. Following extraction based on the method described by Boom et al. (1), nucleic acid sequence-based amplification (NASBA) with real-time molecular beacon detection was performed on the extract (9, 12). The specificity of the EMEQ assay was initially evaluated with 33 mycobacterial isolates (16 M. tuberculosis, 2 Mycobacterium bovis, and 15 nontuberculous mycobacterium isolates). Subsequently, detection of MTC was performed on request by specialized physicians during a 1-year prospective study of hospitalized patients (90 clinical specimens split into 25 respiratory and 65 nonrespiratory samples). Samples were processed for acid-fast bacillus (AFB) smear microscopy and cultured, and isolates were identified using biochemical tests in conjunction with restriction fragment length polymorphism of the hsp65 gene (7) and the GenoType mycobacterium assay (Hain Lifescience GmbH, Germany). A total of 52 specimens were culture positive, and 44 were identified as MTC and detected by EMEQ. The 8 remaining culture-positive specimens were atypical mycobacteria (6 Mycobacterium avium and 2 Mycobacterium fortuitum specimens) and found to be negative with EMEQ. No inhibition in the specimens included was detected. Out of 38 specimens that did not grow, 35 were found to be negative with EMEQ (Table 1). Analysis of culture-negative but EMEQ-positive samples resolved 2 out of 3 discrepancies, as follows: (i) for a gastric aspirate specimen, a second aspirate specimen received the same day cultured positive for M. tuberculosis, and (ii) for a urine specimen, another urinary specimen collected 1 month later cultured positive for M. tuberculosis using the Bactec MGIT 960 liquid culture system in another laboratory. Nonetheless, for the single remaining specimen of ascitic fluid, which tested positive by the EMEQ assay in 2 different runs, no further samples could be collected. The patient who provided the remaining specimen, whose ascites was first clinically labeled as being of pancreatic origin, remained “out of sight” despite subsequent calls for specimen collection. Table 1. Results of AFB staining, culture, identification of MTC, and EMEQ for clinical specimens testeda In spite of the reported lack of sensitivity of molecular methods for nonrespiratory and paucibacillary specimens (2, 11, 13), the sensitivity in our study was 100% (Table 2); it was affected by neither the type of specimen nor the AFB counts (9 AFB-negative specimens were EMEQ positive). No false-negative result was observed. The specificity was 100% for laboratory isolates as well as respiratory clinical specimens and 97.1% for nonrespiratory specimens. Table 2. Correlation of EMEQ and MTC by culturea The negative predictive value (NPV) of a diagnostic test for tuberculosis is of great importance in deciding isolation release (6, 14), but predictive values have to be adjusted to the prevalence of the infection in the population tested (4). With a positive predictive value of 97.9% and a NPV of 100% (Table 2), EMEQ appears to be useful as a diagnostic test and to rule out TB in the group studied for intermediate-to-high clinical suspicion. In addition, with 160 min needed for automatic extraction and amplification, incorporation of an internal control enabling the detection of samples inhibitors without duplicate testing of a seeded tube (10), and risk of contamination being minimized by amplification in closed tubes, the EMEQ assay seems to be a reliable method for use in routine clinical laboratories. These preliminary results will need to be confirmed by further studies.

Papua New Guinea (PNG) is a country of great diversity. The landscape and geography ranges from volcanic and mountainous highlands to coastal and floodplain lowlands, as well as more than 600 islands. There are more than 800 cultural and language groups countrywide, with more than 80% of the population living in rural areas (National Research Institute 2010). In 2016, tuberculosis (TB) in PNG was estimated to have caused more than 30,000 cases countrywide (World Health Organization 2017a), with control challenged by the emergence of drug resistance, and complicated by a resource-limited health system. The situation faced by PNG due to TB and drug-resistant TB (DR-TB) has been described as an emergency (Eccles 2016; IRIN 2010). Research from regional settings in PNG has described a TB burden much higher than the national average, including in Western Province where this study was based (Aia et al. 2018; Cross et al. 2014; McBryde 2012). However, there is limited epidemiological data from areas outside the South Fly and provincial capital of Daru, despite evidence of a heavy TB and drug-resistant TB (DR-TB) burden (Aia et al. 2016; Furin & Cox 2016; Kase et al. 2016; McBryde 2012). The research presented in this thesis describes and characterises the distribution and determinants of TB in the rural Balimo region of Western Province. It is hoped that this study will provide epidemiological data about TB in the region that can inform local TB control strategies. This study used retrospective data analysis and laboratory techniques to describe TB in the Balimo region. The Balimo District Hospital (BDH) TB patient register was analysed, and laboratory diagnostic results were examined. A molecular assay was used to describe genetic evidence of DR-TB, and an interferon (IFN)-ɣ release assay (IGRA) was used to investigate the population-level latent TB burden and Mycobacterium tuberculosis complex (MTBC) infection in TB patients. A very high burden of TB was identified, with an estimated incidence of 727 TB cases per 100,000 people per year. Approximately 25% of TB patients were children, and more than 75% of all patients had extrapulmonary TB. Spatial analysis of TB across the region identifed a high TB burden in the area immediately surrounding Balimo. Lower rates of TB were identified in more remote areas, likely due to the challenges faced by people from rural regions in accessing health facilities. However, the spatial analysis also provided evidence of potential under-diagnosis of TB in more remote areas. DR-TB was described in the region, based on molecular evidence of rifampicin (RIF) resistance. In addition, the challenges of diagnosing TB in this region, where laboratory facilities are limited, are highlighted based on validation of the smear microscopy method used at the BDH laboratory. In combination, these results emphasise the importance of implementing a molecular method of TB diagnosis and detection of drug resistance in the Balimo region. Given the high burden of TB described in the Balimo region, an unexpectedly low proportion of latent TB was identified. Analysis of the IGRA results provided support for the accuracy of extrapulmonary TB diagnoses at BDH, which is important given more than 90% of the extrapulmonary TB diagnoses in the TB register analysis were made clinically based only on presenting signs and symptoms. Overall, this study emphasises the very high burden of TB present in the Balimo region. The results highlight the critical importance of investing in the hospital at Balimo, and ensuring that resources and facilities at the hospital are of a high standard adequate for accurate diagnosis and effective management of TB in the region. This need is especially important in the context of a region where other infectious diseases are also endemic. As a broad epidemiological study of TB in the Balimo region, the results presented in this thesis contribute important contextual information and baseline data on which future TB control efforts can be based.

Tuberculosis (TB), caused by members of the Mycobacterium tuberculosis complex (MTC), is the leading cause of infectious disease-related mortality worldwide. The standard method for TB diagnosis usually requires long periods of mycobacteria cultivation, leading to delayed diagnosis, inefficient treatment and widespread occurrence of the disease. Therefore, a rapid method for the detection and differentiation of MTC from other mycobacteria is essential for disease diagnosis. Here, we describe the potential of using the type I signal peptidase (lepB) gene as a novel target for TB diagnosis, based on confronting two-pair primers PCR (PCRCTPP) that can detect MTC and simultaneously differentiate M. bovis. The limit of detection of the developed technique was equivalent to 12–120 bacilli. PCR-CTPP was highly specific to only MTC and M. bovis, and no cross-reaction was detected in 27 DNA of the non-tuberculous mycobacterial and bacterial strains tested. Thirty-nine blinded clinical isolates and 72 sputum samples were used to validate the PCR-CTPP in comparison with the standard mycobacterial culture method. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PCR-CTPP were equal to 95, 100, 100 and 95 %, respectively, when tested with clinical isolates. Furthermore, upon testing with the sputum samples, the sensitivity, specificity, PPV and NPV were observed to be 84, 76, 90 and 67 %, respectively. Hence, this highly sensitive novel technique, which is rapid, easy to conduct and cost-effective, is a potential method for TB diagnosis and epidemiological studies, especially in resource-limited countries with a high TB burden.

To determine the treatment success rate among TB patients and associated factors in Anambra and Oyo, the two states with the largest burden of tuberculosis in Nigeria. A health facility record review for 2016 was conducted in the two states (Anambra and Oyo). A checklist was used to extract relevant information from the records kept in each of the selected DOTS facilities to determine TB treatment success rates. Treatment success rate was defined as the proportion of new smear-positive TB cases registered under DOTS in a given year that successfully completed treatment, whether with bacteriologic evidence of success ('cured') or without ('treatment completed'). Treatment success rate was classified into good (≥85%) and poor (<85%) success rates using the 85% national target for TB treatment outcome. Data were analysed using descriptive statistics and chi-square at P<0.05. There were 1281TB treatment enrollees in 2016 in Anambra and 3809 in Oyo (total=4835). An overall treatment success rate of 75.8% was achieved (Anambra-57.5%; Oyo-82.0%). The percentage cure rates were 61.5% for Anambra and 85.2% for Oyo. Overall, only 28.6% of the facilities in both states (Anambra-0.0%; Oyo-60.0%) had a good treatment success rate. More facilities in Anambra (100.0%) than Oyo (40.0%) had a poor treatment success rate (p<0.001), as did more private/FBO (100.0%) than public health facilities (60.0%) (p=0.009). All tertiary facilities had a poor treatment success rate followed by 87.5% of secondary health facilities and 56.5% of primary healthcare facilities (P=0.035). Treatment success and cure rates in Anambra state were below the 85.0% of the recommended target set by the WHO. Geographical location, and level/tier and type of facility were factors associated with this. Interventions are recommended to address these problems.

Background: Tuberculosis (TB) is now the leading cause of death from infectious disease. Rapid screening and diagnostic methods for TB are urgently required. Rapid development of metagenomics next-generation sequencing (mNGS) in recent years showed promising and satisfying application of mNGS in several kinds of infectious diseases. However, research directly evaluating the ability of mNGS in TB infection is still scarce.Methods: We conducted an adult prospective study in mainland China to evaluate the diagnostic performance of mNGS for detection of Mycobacterium tuberculosis complex (MTB) in multiple forms of direct clinical samples compared with GeneXpert MTB/RIF assay (Xpert), traditional diagnostic methods, and the clinical final diagnosis.Results: Of 123 patients presenting with suspected active TB infection between June 1, 2017, and May 21, 2018, 105 patients underwent synchronous tuberculous testing with culture, Xpert, and mNGS on direct clinical samples including sputum, cerebrospinal fluids, pus, etc. During follow-up, 45 of 105 participants had clinical final diagnosis of active TB infection, including 13 pulmonary TB cases and 32 extrapulmonary TB cases. Compared to clinical final diagnosis, mNGS produced a sensitivity of 44% for all active TB cases, which was similar to Xpert (42%) but much higher than conventional methods (29%). With only one false-positive result, mNGS had a specificity of 98% in our study. mNGS yielded significantly much higher sensitivity in pre-treatment samples (76%) than post-treatment ones (31%) (P = 0.005), which was also true for Xpert and conventional methods. Combining Xpert and mNGS together, the study identified 27 of 45 active TB cases (60%), including all 13 conventional method-identified cases, and the result reached statistical significance compared to conventional methods (McNemar-test P < 0.001).Conclusions: mNGS had a similar diagnostic ability of MTB compared with Xpert and showed potential for a variety of clinical samples. Combined mNGS and Xpert showed an overall superior advantage over conventional methods and significantly improved the etiology diagnosis of both MTB and other pathogens. The result that anti-TB treatment significantly reduced diagnostic efficacy of culture, Xpert, and mNGS highlighted the importance of collecting samples before empirical treatment.

Tuberculosis (TB) is a significant global health problem. In low-prevalence areas and low clinical suspicion, nucleic acid amplification tests (NAAT) for direct detection of Mycobacterium tuberculosis complex (MTBC) can speed therapy initiation and infection control. An NAAT assay (TBPCR) targeting MTBC IS6110 is used for detecting MTBC in our low-prevalence population. Fifteen-year review of patient records identified 146 patients with culture-positive pulmonary tuberculosis (PTB) or extrapulmonary tuberculosis (EPTB). Laboratory-developed TBPCR was retrospectively compared with standard stain and cultures for PTB and EPTB diagnoses. TBPCR assay was used in 57% of patients with PTB and 33% of patients with EPTB. TBPCR detected 88.4% of all TB (smear-positive, 97%; smear-negative, 79%) with 100% specificity. Low bacterial load was indicated in TBPCR-negative PTB (P = .002) and EPTB (P < .008). TBPCR performance was optimum but significantly underused. Guidelines are proposed for mandated use of TBPCR that capture patients with clinically suspected PTB. Focused TBPCR use in low prevalence populations will benefit patient care, infection prevention, and public health.

Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis complex (MTC), remains one of the leading causes of death in the world. In Korea, the current prevalence of multidrug-resistant TB (MDR-TB) poses a major problem. The most common method for diagnosing TB in developing countries is sputum smear microscopy; however, the sensitivity of this test is relatively low and it usually requires well-trained laboratory staff. Cultures of MTC require up to several weeks in sophisticated facilities, such as Biosafety Level 3. Effective diagnostic techniques are necessary to control TB. In Korea, we evaluated a loop-mediated isothermal amplification (LAMP) assay targeting the hspX gene (TB-hspX-LAMP) of MTC. For clinical evaluation, culture confirmation, smear microscopy and TB-hspX-LAMP were performed on 303 sputum specimens obtained from suspected TB patients in Korea. The sensitivity, specificity, positive predictive value and negative predictive value of TB-hspX-LAMP were 71.1, 98.8, 91.4 and 95.1%, respectively, compared with TB culture, which is the gold standard for diagnosis of TB. In contrast, the comparable values of smear microscopy were 24.4, 98.1, 68.8 and 88.2%, respectively. Therefore, we concluded that TB-hspX-LAMP was superior to the use of smear microscopy for the detection of MTC in sputum specimens in clinical settings in Korea.

ABSTRACTIntroduction: Tuberculosis (TB) is a leading killer worldwide. End TB strategy aims at ending the TB epidemic by 2030. Early, accurate, and affordable diagnosis represents a cornerstone to achieve this goal. Innovative strategies for TB diagnostics have been introduced. However, the ideal assay is yet unavailable and conventional methods remain necessary for diagnosis. Unique properties of nanoparticles (NPs) have allowed their utilization in TB detection via targeting disease biomarkers.Area covered: Until now, around thirty-five TB NP-based assays have been partially or fully characterized. Accuracy, low-cost, and short time-to-result represent the common properties of proposed platforms. TB nanodiagnostics now encompass almost all clinical aspects of the disease including active TB, non-tuberculous mycobacteria, rifampicin resistant TB, TB/HIV co-infection, latent TB, and extra-pulmonary TB. This review summarizes state-of-the-art knowledge of TB nanodiagnostics for the last 10 years. Special consideration is given for fabrication concepts, detection strategies, and clinical performance using various clinical specimens. The potential of TB nanodiagnostics to fulfill the need for ideal MTB testing is assessed.Expert commentary: TB nanodiagnostics show promise to be ideal detection tools that can meet the rigorous demands to end the TB epidemic by 2030.

The steadily growing epidemic of diabetes mellitus poses a threat for global tuberculosis (TB) control. Previous studies have identified an important association between diabetes mellitus and TB. However, these studies have limitations: very few were carried out in low-income countries, with none in Africa, raising uncertainty about the strength of the diabetes mellitus-TB association in these settings, and many critical questions remain unanswered. An expert meeting was held in November 2009 to discuss where there was sufficient evidence to make firm recommendations about joint management of both diseases, to address research gaps and to develop a research agenda. Ten key research questions were identified, of which 4 were selected as high priority: (i) whether, when and how to screen for TB in patients with diabetes mellitus and vice versa; (ii) the impact of diabetes mellitus and non-diabetes mellitus hyperglycaemia on TB treatment outcomes and deaths, and the development of strategies to improve outcomes; (iii) implementation and evaluation of the tuberculosis 'DOTS' model for diabetes mellitus management; and (iv) the development and evaluation of better point-of-care diagnostic and monitoring tests, including measurements of blood glucose and glycated haemoglobin A(1c) (HbA(1c)) for patients with diabetes mellitus. Implementation of this research agenda will benefit the control of both diseases.

Current Concepts in the Management of Tuberculosis

Introduction The HIV/AIDS pandemic has led to a rise in the incidence of tuberculosis and an epidemic of co-infection in many developing countries. Treatment of Mycobacterium tuberculosis in persons with HIV infection presents several challenges to the clinician, particularly in resource-poor countries. As will be discussed in this paper, diagnosis of latent tuberculosis relies on tuberculin skin testing, which has poor sensitivity and reproducibility in immunocompromised patients. The World Health Organization (WHO) recommends treatment of active tuberculosis as the primary means of global tuberculosis control. In practice, treatment of active tuberculosis typically requires that a symptomatic patient self-report to a health service for evaluation and management. Even if this approach to tuberculosis control were sufficient, many logistic and clinical problems remain involving tuberculosis diagnosis and therapy in the patient with HIV/AIDS. Recognizing the significant clinical and public health challenges surrounding the treatment of tuberculosis in patients with HIV infection, this paper will address a number of issues relevant to the care of co-infected patients. These include current guidelines for the treatment of active tuberculosis, as well as the diagnosis and treatment of latent tuberculosis in HIV-positive patients. The paper concludes with a discussion of promising new drugs for tuberculosis treatment. Epidemiology of tuberculosis and HIV co-infection It is estimated that one-third of the world population is infected with M. tuberculosis, the large majority of whom live in the developing world. The HIV pandemic of the past two decades has led to a rise in the incidence of tuberculosis, particularly in sub-Saharan Africa. There is now an emerging pandemic of patients with HIV infection who are co-infected with tuberculosis. As of December 2000, the WHO estimated that approximately 36.1 million persons worldwide are living with HIV and nearly one-third of these persons are co-infected with M. tuberculosis[1]. Approximately 68% of persons co-infected with HIV and tuberculosis live in sub-Saharan Africa, while 22% live in Southeast Asia. In the United States, the Centers for Disease Control and Prevention (CDC) estimates that approximately 40% of new tuberculosis cases among persons aged 15-44 years occur among individuals with HIV infection or AIDS. Tuberculosis rates among HIV-infected individuals in the United States, however, vary significantly among different groups, with highest rates among intravenous drug users and those who are foreign-born. Today, the burden of tuberculosis and HIV infections largely impacts the developing world, as well as the minority and low socio-economic individuals within industrialized countries. This paper will discuss issues in the treatment of M. tuberculosis in patients with HIV/AIDS; however, it is important to recognize that many patients co-infected with HIV and M. tuberculosis have limited or no access to essential diagnostic and therapeutic strategies. Escalating tuberculosis case rates over the past decade are largely attributable to HIV. Immunity to M. tuberculosis is partly under the control of the MHC class II restricted CD4 cells. With the progressive loss of CD4 cells, patients with HIV infection are at increased risk of reactivation of latent tuberculosis, as well as primary tuberculosis infection [2]. In turn, active tuberculosis infection appears to upregulate HIV replication, resulting in further immune compromise and accelerated HIV disease progression [3,4]. As a result, patients with HIV infection and active tuberculosis are at increased risk of opportunistic infections and associated mortality. The case fatality rate by the end of tuberculosis treatment is approximately 20% for new sputum smear-positive cases and up to 50% for new smear-negative cases [5]. Tuberculosis is the leading cause of death among persons with HIV/AIDS worldwide [6]. Guidelines for the treatment of active tuberculosis This section will review recent guidelines for the treatment of tuberculosis published by the Tuberculosis Committee of the Infectious Disease Society of America (IDSA) in conjunction with the American Thoracic Society (ATS) and the CDC [7,8]. In addition, we will review the Directly Observed Treatment Short-course (DOTS) strategy of the WHO for tuberculosis control worldwide. These published guidelines pertain to the treatment of tuberculosis without respect to the patient's HIV status. Modified recommendations for the treatment of tuberculosis in HIV-seropositive patients will be discussed in the following section. In April 2000, the IDSA published practice guidelines for the treatment of tuberculosis [7]. Table 1, adapted from the IDSA publication, lists the 10 essential recommendations for the treatment of patients with tuberculosis. Readers are referred to the original publication for detailed comments pertaining to these recommendations, as well as performance indicators. It should be noted that the IDSA recommendations were developed for use in industrialized nations such as the United States and are currently not feasible in many countries of the world. In Table 1, therefore, we have juxtaposed the WHO DOTS strategy guidelines for management of patients with tuberculosis.Table 1: Infectious Disease Society of America (IDSA) recommendations and World Health Organization Directly Observed Treatment Shortcourse (WHO DOTS) strategy for the management of patients with tuberculosis (TB).In geographic areas where ≥ 4% of the M. tuberculosis isolates are resistant to isoniazid, the IDSA, ATS, and CDC recommend that the usual three-drug regimen of isoniazid, rifampin and pyrazinamide be augmented with a fourth drug, either ethambutol or streptomycin. Clinicians will therefore need to be aware of the susceptibility patterns in their geographic area. In 1997, approximately 84% of the US population lived in states that had ≥ 4% of tuberculosis isolates resistant to isoniazid. Therefore, most patients in the United States should be started on an initial four-drug regimen. This is followed by isoniazid and rifampin for 18 weeks. Although a 6-month course of treatment is recommended, this should be extended to 9 months if there is a delay in AFB, culture conversion or clinical improvement for 8 weeks. The WHO Global Tuberculosis Programme (WHO/GTP) assists over 60 countries with national tuberculosis control and prevention. The priority of the WHO program has been active case finding and cure of infectious tuberculosis cases. In 1993, the WHO/GTP declared tuberculosis a global emergency and began promoting the DOTS strategy. The DOTS strategy consists of five key components: "1) Government commitment to sustained TB control activities; 2) Case detection by sputum smear microscopy among symptomatic patients self-reporting to health services; 3) Standardized treatment regimen of six to eight months for at least all confirmed sputum smear positive cases, with directly observed treatment (DOT) for at least the initial two months; 4) A regular, uninterrupted supply of all essential anti-tuberculosis drugs; and 5) A standardized recording and reporting system that allows assessment of treatment results for each patient and of the TB control programme performance overall" [9] (see Table 1). According to the WHO/GTP, as of 1999, 127 countries had accepted the DOTS strategy and were implementing it to varying degrees [10]. Nevertheless, the WHO/GTP estimate that, in 1999, only 45% of the world population had access to DOTS and 23% of new smear-positive cases were referred to DOTS programs. In addition, there are often a complex array of political, financial, and infrastructure problems that impede local DOTS programs. The current WHO DOTS strategy does not incorporate the diagnosis and treatment of latent tuberculosis. Some experts believe that the DOTS strategy, which focuses exclusively on the treatment of active cases, is insufficient for the control and elimination of tuberculosis, particularly in the HIV/AIDS era [11]. It has been recommended that targeted diagnosis and treatment of latent tuberculosis infection among specific populations be added to national tuberculosis control programs. At present, WHO recommends treatment of latent tuberculosis in HIV-positive patients; but only in settings where it is possible to provide HIV testing and counseling, and where it is possible to exclude cases of active tuberculosis and ensure proper follow-up. The DOTS strategy also employs empiric anti-tuberculous therapy without mycobacterial cultures and drug susceptibility testing. Without drug susceptibility information, it is impossible to identify cases of drug-resistant tuberculosis and to avoid treatment failure and further transmission of drug-resistant strains. The WHO recognizes the threat of multidrug-resistant tuberculosis (MDR-TB) and, in July 1999, convened a working group on DOTS-Plus for the treatment of MDR-TB [12]. DOTS-Plus is a pilot program to provide second-line drugs (i.e., fluoroquinolones, amikacin, kanamycin, capreomycin, cycloserine, para-aminosalicylic acid, and ethionamide) to manage MDR-TB in resource-limited countries. This strategy does not, however, address the role of mycobacterial cultures and drug susceptibility testing for individualized drug therapy and the prevention of drug-resistant tuberculosis. Finally, because DOTS relies on patients self-reporting to health services, additional tuberculosis transmission can take place before the patient is evaluated and receives appropriate therapy. Modeling of the tuberculosis epidemic in Tanzania suggests that DOTS may slow the incidence rate, but in the face of the HIV epidemic is unlikely to reverse the upward trend [13]. Again, some experts advocate targeted case finding, particularly among high-risk groups [11,14]. Diagnosis and treatment of active tuberculosis infection in patients with HIV infection This section deals specifically with the treatment of active tuberculosis in HIV-infected individuals as recommended by the CDC [15,16]. Again, many people co-infected with HIV and tuberculosis in the developing world do not have access to the relevant diagnostic tests and anti-tuberculosis and antiretroviral therapies. To impact tuberculosis-associated morbidity and mortality worldwide, developing countries will require both the skills and commodities to diagnose and treat individuals effectively. At present, tuberculosis treatment for the HIV-positive patient as recommended by the CDC is not applicable in most resource-poor countries. Treatment of active and latent tuberculosis infection in patients with HIV depends on the application of both clinical judgment and appropriate diagnostic tests. Active tuberculosis can occur at any CD4 cell count but atypical presentations are more likely with advanced HIV disease or AIDS. Clinicians should be alert to the sometimes atypical presentations of pulmonary and extrapulmonary tuberculosis in HIV-infected patients. Sputum acid fast staining, mycobacterial cultures, and drug susceptibility testing are recommended in all patients suspected of having tuberculosis. However, patients with HIV are slightly less likely to have positive sputum smears than non-HIV-infected individuals [17]. Likewise, chest radiographic findings can vary depending on the degree of immunosuppression. Patients with CD4 cell counts greater than 200 are more likely to have classic findings of upper lobe infiltrates with cavitary lesions, while those patients with AIDS may more likely have hilar adenopathy and pleural effusions without cavitations [18]. Mycobacteremia and extrapulmonary tuberculosis, especially meningitis and adenopathy, also correlate with diminishing numbers of CD4 cells and degree of immunosuppression. Thus, for patients with HIV infection, the diagnosis of active tuberculosis is more challenging. Clinical suspicion of tuberculosis in a patient known or suspected of being HIV-infected should result in prompt initiation of anti-tuberculosis therapy regardless of sputum staining or radiograph findings. The 1998 CDC recommendations for the treatment of tuberculosis among patients infected with HIV are summarized in Table 2[15]. The treatment of tuberculosis in the HIV-seropositive patient may differ from the standard treatment in the following ways: (i) choice of anti-tubercular regimen and dose adjustments; (ii) duration of treatment (ideally with directly observed therapy); (iii) promotion of antiretroviral therapy; and (iv) monitoring requirements. Due to rapid advances in the management of HIV disease, it is recommended that all patients co-infected with HIV and tuberculosis should be evaluated by a specialist to ensure optimal management.Table 2: Tuberculosis (TB) treatment recommendations for the HIV-seropositive patient.The treatment algorithm begins with establishing the patient's HIV status and whether the patient is on optimal antiretroviral therapy. All patients diagnosed with active tuberculosis should be HIV tested and, if seropositive, evaluated for antiretroviral therapy. It was previously felt that the diagnosis of active tuberculosis should result in the deferral of antiretroviral therapy. Early initiation of antiretroviral therapy is now recommended. While being treated for tuberculosis, the HIV-positive patient not receiving concurrent HIV therapy should be reassessed every 3 months for initiation of antiretroviral therapy. Known or suspected HIV-positive patients should receive prompt initiation of effective anti-tuberculosis therapy. If antiretroviral therapy is not started, the patient can typically receive standard anti-tuberculosis therapy: isoniazid, rifampin, pyrazinamide, and ethambutol. If the patient is to receive simultaneous anti-tuberculosis and antiretroviral therapy, the selected regimens and doses must account for significant drug-drug interactions between the rifamycins (rifampin, rifabutin, rifapentine) and the protease inhibitors and non-nucleoside reverse transcriptase inhibitors (NNRTI). Rifamycins, particularly rifampin, induce the hepatic cytochrome P-450 (CYP450) and reduce the serum levels of protease inhibitors, NNRTI, and other drugs metabolized by the CYP450 system. The CDC generally recommends the substitution of rifabutin, a less potent CYP450 inducer, for rifampin to allow simultaneous use of protease inhibitors and NNRTI. The use of rifampin with protease inhibitors or NNRTI is contraindicated, except in three antiretroviral combinations: (i) the NNRTI efavirenz and two nucleoside reverse transcriptase inhibitors (NRTI); (ii) the protease inhibitor ritonavir and one or more NRTI; and (iii) the combination of ritonavir and saquinavir, either hard-gel or soft-gel capsules [16]. Table 3 lists the recommended anti-tubercular drug doses, depending on frequency of administration and concurrent antiretroviral use.Table 3: Anti-tubercular drug doses.If the HIV-positive patient is already on an effective anti-retroviral regimen at the time of tuberculosis diagnosis, it is desirable to continue the patient on the same antiretroviral regimen with appropriate dose adjustments. If the patient is starting a new antiretroviral regimen, options include: (i) a rifabutin-based regimen with the necessary protease inhibitor or NNRTI dose adjustments; (ii) a non-rifamycin-containing regimen such as isoniazid, streptomycin, pyrazinamide, ethambutol for 2 months, then isoniazid, streptomycin, ethambutol for 7 months; or (iii) a regimen that does not contain a protease inhibitor or NNRTI. Table 4 lists the recommended dose adjustments for rifabutin-based regimens. Given the complexity of these drug interactions, it is recommended that the selection of dual anti-tubercular and antiretroviral therapies be made following consultation with a specialist.Table 4: Protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) dose adjustments with rifabutin.Among the protease inhibitors, ritonavir has the highest potency in inhibiting the CYP450 pathway. With any dose of ritonavir, including low-dose ritonavir 100 mg twice a day, a reduced dose of rifabutin (150 mg two or three times per week) is recommended. According to the 2000 CDC guidelines for the use of rifabutin or rifampin among patients taking protease inhibitors or NNRTI, co-administration of ritonavir with the usual dose of rifampin (600 mg daily or two or three times per week) may be an option but pharmokinetic and clinical data are limited [16]. As previously stated, a patient taking the combination of saquinavir (either the soft-gel or hard-gel capsule) and ritonavir should take the reduced dose of rifabutin (150 mg two or three times per week). The saquinavir-ritonavir combination may possibly be given with the usual dose of rifampin but, again, limited pharmacokinetic and clinical data are available. Saquinavir, as a sole protease inhibitor, is generally not recommended in combination with rifabutin because the serum levels of saquinavir may be decreased as much as 45%. Indinavir, nelfinavir, and amprenavir should not be used in combination with rifampin, but all three protease inhibitors can be administered with a reduced daily dose of rifabutin (150 mg daily) or the usual dose of rifabutin (300 mg two or three times per week). Efavirenz induces CYP450 and accelerates rifamycin metabolism; therefore, efavirenz should be co-administered with an increased dose of rifabutin (450 or 600 mg daily, or 600 mg two or three times per week). According to the recent CDC guidelines, efavirenz may be combined with the usual dose of rifampin (600 mg daily or two or three times per week). The NNRTI nevirapine should typically be given with the usual dose of rifabutin (300 mg daily or two or three times per week). If co-administration of nevirapine with rifampin is clearly indicated, careful monitoring is recommended. The use of delavirdine is contraindicated during the treatment of tuberculosis because the drug levels are markedly decreased with both rifampin and rifabutin. HIV-infected patients have a higher incidence of drug-resistant tuberculosis isolates than non-HIV-infected patients. There have been several reports of increased risk of rifampin resistance among HIV-positive patients [19-21]. Higher rates of drug-resistant tuberculosis in HIV-infected patients may be associated with biological, behavioral, and societal factors including drug malabsorption, non-adherence, nosocomial outbreaks, and inadequate drug therapy in countries with high rates of co-infection. Directly observed therapy, regarded as the best strategy for ensuring adherence and limiting drug-resistant tuberculosis, is recommended for all patients with HIV infection [15]. In a randomized, controlled trial of anti-tuberculosis therapy among HIV-positive patients in Baltimore, Maryland, patients who received supervised therapy for tuberculosis had better survival than those who self-administered therapy [22]. Treatment of drug-resistant tuberculosis involves initiation of a multi-drug regimen tailored to the susceptibility profile of the organism. Due to the diversity of resistance patterns, it is not possible to recommend standardized protocols for therapy. Any regimen should include two or more drugs to which the isolate is susceptible. For HIV-positive patients at risk of MDR-TB, defined as resistance to both isoniazid and rifampin, initial empiric treatment should include second-line tuberculosis drugs to which resistance is uncommon. The 1999 WHO Essential Drug List was to include the following second-line tuberculosis amikacin, kanamycin, capreomycin, cycloserine, acid, and and drug susceptibility testing should be on all tuberculosis isolates and the anti-tuberculosis regimens Although MDR-TB is associated with a high mortality rate especially in resource-poor countries where the detection of drug resistance to months, if at and the second-line drugs are often months is the duration of treatment for pulmonary tuberculosis among HIV-positive patients in the United States a regimen is used [15]. treatment is for patients with a clinical or conversion of sputum cultures from positive to Some experts recommend the use of treatment regimens in all patients with HIV infection, especially among patients with advanced [17]. duration of treatment is clearly recommended in patients with slow clinical or with or HIV-positive individuals with active tuberculosis to be at increased risk of tuberculosis of a 6-month regimen. A trial of isoniazid was among HIV-positive patients in who a 6-month regimen of isoniazid decreased the risk of a of tuberculosis among HIV-positive patients. This not whether these were to M. tuberculosis or both of which have previously been The recommend of isoniazid for HIV-positive patients of tuberculosis therapy. At present, the WHO and the CDC recommend a months of directly observed tuberculosis therapy without Treatment of latent tuberculosis infection in patients with HIV infection It is estimated that 2 people worldwide are infected with latent tuberculosis. Patients with HIV infection are at increased risk of to active disease [2]. In 2000, the and the CDC new guidelines for the diagnosis and treatment of latent tuberculosis infection This public health strategy both prevention by the latent infection before it to active infection and primary prevention by further tuberculosis In addition, the use of active antiretroviral therapy has been to reduce the incidence of tuberculosis among persons with HIV infection The new guidelines recommend targeted of populations and patients at increased risk of tuberculosis infection who from treatment to active for targeted include drug health care of and all patients with HIV Diagnosis of latent tuberculosis infection is on the tuberculin skin new including detection are being developed A has with tuberculin skin testing in are to the diagnostic of this in the United States and in populations with varying degrees of risk for latent tuberculosis. There be two significant of developing tests for the detection of latent M. tuberculosis tests the need for a health service at and their be less than tuberculin skin testing. of latent tuberculosis in an HIV-infected patient can be a diagnostic It has been that the sensitivity of tuberculin skin testing may be in patients with to as well as to and can in persons with HIV infection and of the is associated with higher CD4 cell For these testing is no recommended for the diagnosis of latent tuberculosis. guidelines are to treat latent tuberculosis infection in HIV-infected persons with at high-risk of latent tuberculosis or with recent to a case of active tuberculosis should receive therapy regardless of tuberculin has been the of treatment of latent tuberculosis clinical have a in the risk of to active tuberculosis following months of isoniazid therapy. The optimal duration of isoniazid therapy has also been including the trial of the Tuberculosis and in in the and this or months of isoniazid therapy months of isoniazid therapy reduced the tuberculosis incidence by with for months and 20% for 3 months; however, with months therapy was than for of therapy A recent of isoniazid therapy in that from isoniazid therapy 9 months, with no additional associated with therapy The new and CDC guidelines recommend isoniazid therapy for 9 months (300 mg isoniazid daily mg with months of therapy as a less The to isoniazid therapy include and poor Directly observed therapy has been to adherence but is not important in the treatment of latent tuberculosis has been the of regimens that may adherence and reduce have the of regimens for the treatment of latent tuberculosis in individuals A trial that daily rifampin and pyrazinamide for 2 months was to isoniazid for months for the treatment of latent tuberculosis in HIV-infected persons the of these the new guidelines regimens for the treatment of latent tuberculosis as summarized in Table from their publication rifampin and pyrazinamide for 2 months (600 mg rifampin daily pyrazinamide daily) is the regimen for HIV-infected patients and be for suspected cases of tuberculosis. should be for rifampin in patients receiving protease inhibitors or NNRTI, further is to in the treatment of latent tuberculosis. The same drug-drug interactions and dose adjustments for antiretroviral drugs and rifamycins It is that the also recommends the regimen for individuals the the clinical for this combination have been only in HIV-positive patients. If MDR-TB is the recommended therapy is pyrazinamide and ethambutol or pyrazinamide and a (i.e., or for Treatment for suspected to MDR-TB should be extended to months for HIV-positive American Thoracic Society and Centers for Disease Control and Prevention guidelines for the treatment of latent tuberculosis the use of rifampin pyrazinamide therapy in infected patients has been associated with a rate of patients with resulting from the use of therapy have been to the five of these patients on these CDC and have their 2000 recommendations The (i) that be used with particularly in patients with disease, on or those taking drugs; and (ii) that patients who are treated with be by a health care at and for a of tests and evaluation with a at 8 to treatment therapy with the regimen should be for significant rates of have not been observed in HIV-infected patients treated with this regimen, either in clinical or to the use of the regimen in For HIV-infected patients to persons with active tuberculosis, treatment for latent tuberculosis should be a tuberculin In addition, some experts advocate HIV-infected individuals who in high-risk evaluation for latent tuberculosis treatment should include a careful and and, chest radiograph to exclude active tuberculosis. anti-tubercular drugs in treatment of tuberculosis, particularly for MDR-TB, will on the of new anti-tubercular there are several drugs under that have in M. tuberculosis. In some cases the drug has also in a of tuberculosis, and some have received and Drug for other under include and other and is a rifamycin the serum of which is three times than that of the rifampin The of M. tuberculosis is to or one to that of Given the between and other rifamycin the of over rifampin pharmokinetic In the infected with tuberculosis and in tuberculosis a regimen is less active than a daily regimen, both rifamycins being given at 10 In tuberculosis however, the regimen is significantly less active than the daily regimen In the regimens during the of tuberculosis therapy may provide increased to as well as to health care programs. is an for and other infections that has in M. tuberculosis, to that of and in in a of tuberculosis that at 100 is as as isoniazid at and more than clinical are being to the role of in combination therapy active tuberculosis. and also promising in a of tuberculosis are a class of inhibitors with and The of at 100 is with isoniazid at per an by the and Drug for the treatment of appears to be less active M. tuberculosis than It has been recommended, however, for further at higher is a new to that has been to potent in M. in were also to be to this with of In a administration of this drug at a dose of per led to of disease burden in and with that with isoniazid per and issues in the treatment of tuberculosis in patients with HIV have previously to some of the and issues that the treatment of tuberculosis in resource-poor countries. At the and there may also some important and to effective tuberculosis treatment. A among tuberculosis patients in Tanzania that only of the patients had of the disease and treatment In a recent from people were generally well HIV but tuberculosis of and were to AIDS than tuberculosis. patients with tuberculosis were often as having AIDS. Due to the associated with the that patients with tuberculosis may not or to appropriate These the important impact that the HIV epidemic may have on the public and to tuberculosis. a epidemic of tuberculosis and HIV co-infection in many of the developing world. The increased of tuberculosis and HIV/AIDS and the rise of MDR-TB a health threat to all While significant have been made in developing regimens for the treatment of active and latent tuberculosis, therapy is and second-line drugs are drug resistance is for are the anti-tuberculosis of drugs such as and and the of which may treatment. The optimal use of these drugs in combination therapy is a promising of active In addition, we advocate the of new and tuberculosis drugs that will be made to patients in developing countries.

Tuberculosis (TB) treatment success rates are high in China, but there are still a considerable number of cases who have unfavourable treatment outcomes (UTO). We aimed to determine the proportion of TB patients with UTO and to assess whether baseline characteristics that included glycaemic status [normal fasting blood glucose (FBG), transient hyperglycaemia and diabetes mellitus (DM)] and vitamin D status were associated with UTO. Prospective cohort study conducted between November 2015 and July 2016 at six clinics within routine TB services in Jilin province, where persons with TB were consecutively recruited. Data analysis was performed using the chi-squared test and multivariate logistic regression. Of the306 recruited TB patients, 96 (31.4%) had smear-positive pulmonary TB, 187 (61.1%) had smear-negative pulmonary TB and 23 (7.5%) had extrapulmonary TB (EPTB). Of these, 95 (31.1%) had normal blood glucose, 83 (27.1%) had transient hyperglycaemia and 128 (41.8%) had DM. 227 (74.2%) patients had vitamin D deficiency/severe deficiency. There were 125 (40.8%) patients with UTO of whom the majority were lost to follow-up (57.6%) or not evaluated (28.8%). UTO was significantly associated with smear-negative pulmonary TB (P=0.009), EPTB (P<0.001) and DM (P=0.007). The proportion of TB patients with UTO increased with smear-negative pulmonary TB, EPTB and DM. TB programmes need to pay more attention to these issues and ensure intensive patient support to those at risk and early detection of DM.