Expert views on screening for tuberculosis infection in patients commencing treatment with a biologic agent.

OBJECTIVE: Many biologic agents cause some degree of immunosuppression, which can increase the risk of reactivation of tuberculosis infection (TBI). This risk is variable between individual biologics. We aimed to assess current (and recommended) clinical practice of TBI screening and treatment among patients initiating treatment with biologic agents. METHODS: An online questionnaire was distributed via email to members of the Global Tuberculosis Network and associated professional organisations to seek insights into the screening for and treatment of TBI in patients treated with biologics. RESULTS: A total of 163 respondents in 27 countries answered at least one question. For all biologics described in the questionnaire, respondents advised increasing screening relative to current practice. Observed and supported TBI screening rates in patients treated with TNF-a inhibitors were high, especially for older TNF-a inhibitors. Most participants supported TBI screening in patients treated with B- or T-cell inhibitors but not in those treated with interleukin inhibitors. Guideline awareness was higher for TNF-a inhibitors than for other biologic classes (79% vs. 34%). CONCLUSIONS: Although respondents stated that TBI screening rates are lower than what they consider ideal, there was a tendency to recommend TBI screening in patients treated with biologics not known to be associated with an increased risk of TBI. As a result, there is a potential risk of over-screening and over-treatment of TBI, potentially causing harm, in patients treated with biologics other than TNF-a inhibitors. There is a need to research the risk of TBI associated with biologics and for guidelines to address the spectrum of TBI risk across all types of biologics.

Characteristics of isoniazid-induced psychosis: a systematic review of case reports and case series.

PURPOSE: Isoniazid, a first-line antitubercular drug, is associated with nervous system adverse drug reactions such as seizures, peripheral neuropathy, and psychosis. This systematic review of case reports and case series aimed to characterize the demographic, social, and clinical factors associated with isoniazid-induced psychosis in patients with active tuberculosis (TB) and those who received isoniazid for latent TB infection (LTBI). METHODS: We comprehensively searched the Embase, PubMed, and Scopus databases to identify relevant studies published between the date of inception of the database and June 2024. RESULTS: A total of 28 studies, including 21 case reports and 7 case series involved 37 patients who developed isoniazid-induced psychosis. A higher frequency of isoniazid-induced psychosis was observed during the first 2 months of treatment, with a relatively early onset observed among patients aged 18 years or less. Delusions and/or hallucinations are the common symptoms of isoniazid-induced psychosis. Psychomotor disturbances, disorganized speech or formal thought disorder, disorganized or abnormal behaviour, and neuropsychiatric symptoms (sleep disturbances, hostility or aggression, confusion, affective symptoms, anxiety symptoms, and cognitive difficulties) were the other symptoms observed in the included studies. More than 80% of cases rechallenged with isoniazid resulted in the recurrence of psychotic symptoms. CONCLUSION: Patients with TB and LTBI should be assessed for psychotic and neuropsychiatric symptoms during isoniazid therapy, mainly in the first 2 months. Further research is required to understand the impact of underlying risk factors, such as genetic predisposition and isoniazid pharmacokinetics, as well as the clinical utility and dosage recommendations of pyridoxine for managing isoniazid-induced psychosis.

Factors associated with incomplete tuberculosis preventive treatment: a retrospective analysis of six-years programmatic data in Cambodia.

Tuberculosis (TB) preventive treatment (TPT) effectively prevents the progression from TB infection to TB disease. This study explores factors associated with TPT non-completion in Cambodia using 6-years programmatic data (2018-2023) retrieved from the TB Management Information System (TB-MIS). Out of 14,262 individuals with latent TB infection (LTBI) initiated with TPT, 299 (2.1%) did not complete the treatment. Individuals aged between 15-24 and 25-34 years old were more likely to not complete the treatment compared to those aged < 5 years old, with aOR = 1.7, p = 0.034 and aOR = 2.1, p = 0.003, respectively. Individuals initiated with 3-month daily Rifampicin and Isoniazid (3RH) or with 6-month daily Isoniazid (6H) were more likely to not complete the treatment compared to those initiated with 3-month weekly Isoniazid and Rifapentine (3HP), with aOR = 2.6, p < 0.001 and aOR = 7, p < 0.001, respectively. Those who began TPT at referral hospitals were nearly twice as likely to not complete the treatment compared to those who started the treatment at health centers (aOR = 1.95, p = 0.003). To improve TPT completion, strengthen the treatment follow-up among those aged between 15 and 34 years old and initiated TPT at referral hospitals should be prioritized. The national TB program should consider 3HP the first choice of treatment.

Intention to receive Latent Tuberculosis Infection (LTBI) treatment and its associated factors among healthcare workers in a Malaysian teaching university hospital.

The acceptability of latent tuberculosis infection (LTBI) therapy remains low among healthcare workers (HCWs). Up to 10% of LTBI cases can reactivate into active tuberculosis, posing risks to HCWs and patients. Understanding HCWs' intention to undergo LTBI treatment is crucial for designing effective management policies, especially where no LTBI policy exists. This cross-sectional study investigated the intention to receive LTBI therapy and its associated factors among HCWs in a Malaysian teaching hospital. The study was conducted from 5th to 30th May 2023, in a hospital without an LTBI screening program. Stratified random sampling was used to select HCWs, excluding those undergoing TB or LTBI therapy. Respondents completed a questionnaire measuring intention to receive LTBI treatment, LTBI knowledge, attitude, perceived norm, and perceived behavioral control. Of the 256 respondents, the majority were female (63.7%), under 35 years old (64.45%), had no comorbidities (82.0%), and worked in clinical settings (70.3%). However, 60.5% of respondents had low LTBI knowledge and 60.5% held unfavorable attitudes toward LTBI treatment. Despite this, 53.5% of respondents intended to undergo LTBI therapy if diagnosed. Factors positively associated with this intention included being female [aOR: 2.033, 95% CI: 1.080-3.823], having high LTBI knowledge [aOR 1.926, 95% CI: 1.093-3.397], had favorable attitude [aOR 3.771, 95% CI: 1.759-8.084], and strongly perceiving social norms supportive of LTBI treatment [aOR 4.593, 95% CI: 2.104-10.023]. These findings emphasize the need for an LTBI management policy in the teaching hospital. To boost HCWs' intention and acceptance of LTBI treatment, a focused program improving knowledge, attitude, and perception of social norms could be introduced.

Adherence to preventive treatment for latent tuberculosis infection in close contacts of pulmonary tuberculosis patients: A cluster-randomized controlled trial in China.

OBJECTIVES: This study examined adherence rates to tuberculosis preventive treatment (TPT) among close contacts of individuals with pulmonary tuberculosis (PTB) and identified factors associated with TPT adherence in China. METHODS: A multicenter, cluster-randomized, open-label control trial was carried out across three sites involving 34 counties in China. Close contacts of bacteriologically confirmed rifampin and isoniazid-susceptible PTB cases were identified and screened for latent tuberculosis infection (LTBI). Eligible participants were randomly assigned to either the 3H2P2 group, which consisted of a 3-month, twice-weekly regimen of rifapentine and isoniazid, or the 6H group, which entailed a 6-month daily regimen of isoniazid. To assess the factors influencing adherence, a two-level logistic regression model was utilized. RESULTS: Out of the 2434 close contacts who initiated TPT, 2121 (87.1%) completed the regimen. Of the 313 individuals who did not complete TPT, 60.1% refused to continue, and 27.8% discontinued due to adverse effects. The two-level logistic regression model revealed several factors associated with enhanced TPT adherence: enrollment in the 3H2P2 group (odds ratio [OR] = 2.09), management by a TB dispensary responsible for TPT (OR = 2.55), supervision by healthcare workers (OR = 6.40), and clinician incentives (OR = 2.49). Conversely, the occurrence of any adverse effects (OR = 0.08) was identified as a risk factor for nonadherence. CONCLUSION: Administering TPT to individuals with LTBI is feasible among close contacts. Adherence to TPT can be enhanced through shorter, safer treatment regimens and supportive interventions, such as directly supervised therapy for TPT recipients and incentives for healthcare providers managing TPT.

Strategies for isoniazid preventive therapy in HIV-positive patients who consume alcohol.

WHO guidance to defer isoniazid preventive therapy (IPT) among those with regular alcohol use because of hepatotoxicity concerns may exclude many people living with HIV (PLWH) at high TB risk in these settings.To evaluate hepatotoxicity during TB preventive therapy (TPT) in PLWH who report alcohol use in Uganda over 10 years.We developed a Markov model of latent TB infection, isoniazid preventive therapy (IPT - a type of TPT), and TB disease using data from the Alcohol Drinkers' Exposure to Preventive Therapy for TB (ADEPTT) study. We modeled several treatment scenarios, including no IPT, IPT with liver enzyme monitoring (AST/ALT) during treatment, and IPT with pre-screening using the tuberculin skin test (TST).The no IPT scenario had 230 TB deaths/100,000 population over 10 years, which is more than that seen in any IPT scenario. IPT, even with no monitoring, was preferred over no IPT when population TB disease incidence was >50 in 100,000.For PLWH who report alcohol use in high TB burden settings, IPT should be offered, ideally with regular AST/ALT monitoring. However, even if regular monitoring is not possible, IPT is still preferable to no IPT in almost every modeled scenario..

Progress Toward Tuberculosis Elimination and Tuberculosis Program Performance - National Tuberculosis Indicators Project, 2016-2022.

Problem/Condition: Elimination of tuberculosis (TB) is defined as reducing TB disease incidence in the United States to less than 1 case per million persons per year. In 2022, TB incidence in the United States was 2.5 TB cases per 100,000 persons. CDC's TB program developed a set of national TB indicators to evaluate progress toward TB elimination through monitoring performance of state and city TB program activities. Examining TB indicator data enables state- and city-level TB programs to identify areas for program evaluation and improvement activities. These data also help CDC identify states and cities that might benefit from technical assistance. Period Covered: The 5-year period for which the most recent data were available for each of five indicators: 1) overall TB incidence (2018-2022), 2) TB incidence among non-U.S.-born persons (2018-2022), 3) percentage of persons with drug susceptibility results reported (2018-2022), 4) percentage of contacts to sputum acid-fast bacillus (AFB) smear-positive TB patients with newly diagnosed latent TB infection (LTBI) who completed treatment (2017-2021), and 5) percentage of patients with completion of TB therapy within 12 months (2016-2020). Description of System: The National TB Indicators Project (NTIP) is a web-based performance monitoring tool that uses national TB surveillance data reported through the National TB Surveillance System and the Aggregate Reports for TB Program Evaluation. NTIP was developed to facilitate the use of existing data to help TB program staff members prioritize activities, monitor progress, and focus program improvement efforts. The following five indicators were selected for this report because of their importance in Federal TB funding allocation and in accelerating the decline in TB cases: 1) overall TB incidence in the United States, 2) TB incidence among non-U.S.-born persons, 3) percentage of persons with drug susceptibility results reported, 4) percentage of contacts to sputum AFB smear-positive TB cases who completed treatment for LTBI, and 5) percentage of patients with completion of TB therapy within 12 months. For this report, 52 TB programs (50 states, the District of Columbia, and New York City) were categorized into terciles based on the 5-year average number of TB cases reported to National TB Surveillance System. This grouping allows comparison of TB programs that have similar numbers of TB cases and allocates a similar number of TB programs to each category. The following formula was used to calculate the relative change by TB program for each indicator: [(% from year 5 - % from year 1 ÷ % from year 1) × 100]. Results: During the 5-year period for which the most recent data were available, most TB programs had improvements in reducing overall TB incidence (71.2%) and increasing the percentage of contacts receiving a diagnosis of LTBI who completed LTBI treatment (55.8%); the majority of programs (51.0%) also had improvements in reducing incidence among non-U.S.-born persons. The average percentage of persons with drug susceptibility results reported in most jurisdictions (28 of 52, [53.9%]) met or exceeded the 5-year national average of 97% (2018-2022). The percentage of contacts to sputum acid-fast bacillus (AFB) smear-positive TB patients with newly diagnosed latent TB infection (LTBI) who completed treatment increased in 29 of 52 (55.8%) jurisdictions from 2017 to 2021, signifying that, for most jurisdictions, steps have been taken to enhance performance in this area. The average percentage of patients with completion of TB therapy within 12 months was at or above the national average of 89.7% in approximately two-thirds (32 of 52 [61.5%]) of jurisdictions. Interpretation: This report is the first to describe a 5-year relative change for TB program performance. These results suggest that TB programs are making improvements in activities that help identify persons with TB and LTBI and ensure patients complete treatment in a timely manner. Public Health Action: Use of NTIP data from individual TB programs enables a more detailed examination of trends in program performance and identification of areas for program improvement. Assessing indicator trends by TB program provides an opportunity to gain a better understanding of program performance in comparison to other programs. It can also facilitate communication between programs regarding successes and challenges in program improvement. This information is valuable for TB programs to allocate resources effectively and provide additional context on TB control for public health policymakers.

Mycobacterium dormancy and antibiotic tolerance within the retinal pigment epithelium of ocular tuberculosis.

Tuberculosis (TB) is a leading cause of death among infectious diseases worldwide due to latent TB infection, which is the critical step for the successful pathogenic cycle. In this stage, Mycobacterium tuberculosis resides inside the host in a dormant and antibiotic-tolerant state. Latent TB infection can also lead to multisystemic diseases because M. tuberculosis invades virtually all organs, including ocular tissues. Ocular tuberculosis (OTB) occurs when the dormant bacilli within the ocular tissues reactivate, originally seeded by hematogenous spread from pulmonary TB. Histological evidence suggests that retinal pigment epithelium (RPE) cells play a central role in immune privilege and in protection from antibiotic effects, making them an anatomical niche for invading M. tuberculosis. RPE cells exhibit high tolerance to environmental redox stresses, allowing phagocytosed M. tuberculosis bacilli to maintain viability in a dormant state. However, the microbiological and metabolic mechanisms determining the interaction between the RPE intracellular environment and phagocytosed M. tuberculosis are largely unknown. Here, liquid chromatography-mass spectrometry metabolomics were used to illuminate the metabolic state within RPE cells reprogrammed to harbor dormant M. tuberculosis bacilli and enhance antibiotic tolerance. Timely and accurate diagnosis as well as efficient chemotherapies are crucial in preventing the poor visual outcomes of OTB patients. Unfortunately, the efficacy of current methods is highly limited. Thus, the results will lead to propose a novel therapeutic option to synthetically kill the dormant M. tuberculosis inside the RPE cells by modulating the phenotypic state of M. tuberculosis and laying the foundation for a new, innovative regimen for treating OTB. IMPORTANCE: Understanding the metabolic environment within the retinal pigment epithelium (RPE) cells altered by infection with Mycobacterium tuberculosis and mycobacterial dormancy is crucial to identify new therapeutic methods to cure ocular tuberculosis. The present study showed that RPE cellular metabolism is altered to foster intracellular M. tuberculosis to enter into the dormant and drug-tolerant state, thereby blunting the efficacy of anti-tuberculosis chemotherapy. RPE cells serve as an anatomical niche as the cells protect invading bacilli from antibiotic treatment. LC-MS metabolomics of RPE cells after co-treatment with H2O2 and M. tuberculosis infection showed that the intracellular environment within RPE cells is enriched with a greater level of oxidative stress. The antibiotic tolerance of intracellular M. tuberculosis within RPE cells can be restored by a metabolic manipulation strategy such as co-treatment of antibiotic with the most downstream glycolysis metabolite, phosphoenolpyruvate.

A Mathematical Model for the Impact of 3HP and Social Programme Implementation on the Incidence and Mortality of Tuberculosis: Study in Brazil.

In this paper, we presented a mathematical model for tuberculosis with treatment for latent tuberculosis cases and incorporated social implementations based on the impact they will have on tuberculosis incidence, cure, and recovery. We incorporated two variables containing the accumulated deaths and active cases into the model in order to study the incidence and mortality rate per year with the data reported by the model. Our objective is to study the impact of social program implementations and therapies on latent tuberculosis in particular the use of once-weekly isoniazid-rifapentine for 12 weeks (3HP). The computational experimentation was performed with data from Brazil and for model calibration, we used the Markov Chain Monte Carlo method (MCMC) with a Bayesian approach. We studied the effect of increasing the coverage of social programs, the Bolsa Familia Programme (BFP) and the Family Health Strategy (FHS) and the implementation of the 3HP as a substitution therapy for two rates of diagnosis and treatment of latent at 1% and 5%. Based of the data obtained by the model in the period 2023-2035, the FHS reported better results than BFP in the case of social implementations and 3HP with a higher rate of diagnosis and treatment of latent in the reduction of incidence and mortality rate and in cases and deaths avoided. With the objective of linking the social and biomedical implementations, we constructed two different scenarios with the rate of diagnosis and treatment. We verified with results reported by the model that with the social implementations studied and the 3HP with the highest rate of diagnosis and treatment of latent, the best results were obtained in comparison with the other independent and joint implementations. A reduction of the incidence by 36.54% with respect to the model with the current strategies and coverage was achieved, and a greater number of cases and deaths from tuberculosis was avoided.

Tuberculosis in pregnancy and assisted reproductive technology.

Tuberculosis is a chronic infectious disease caused by mycobacterium tuberculosis infection. In the world, tuberculosis is an important factor affecting women's reproductive health, which can cause reproductive tract anatomy abnormalities, embryo implantation obstacles, ovarian reserve and ovulation dysfunction, leading to female infertility. This group of women usually need to seek assisted reproductive technology to conceive. Latent tuberculosis infection during pregnancy has no clinical manifestation, but may develop into active tuberculosis, leading to adverse pregnancy outcomes. Most pregnant women do not need to be treated for latent tuberculosis infection, unless they are combined with high-risk factors for tuberculosis progress, but they need close follow-up. Early diagnosis and treatment of active tuberculosis in pregnancy can reduce the incidence rate and mortality of pregnant women and newborns, and treatment needs multidisciplinary cooperation.

Interpreter usage and associations with latent tuberculosis infection treatment acceptance and completion in the USA among non-U.S.-born persons, 2012-2017.

BACKGROUND: Latent tuberculosis infection (LTBI) screening and treatment interventions that are tailored to optimize acceptance among the non-U.S.-born population are essential for U.S. tuberculosis elimination. We investigated the impact of medical interpreter use on LTBI treatment acceptance and completion among non-U.S.-born persons in a multisite study. METHODS: The Tuberculosis Epidemiologic Studies Consortium was a prospective cohort study that enrolled participants at high risk for LTBI at ten U.S. sites with 18 affiliated clinics from 2012 to 2017. Non-U.S.-born participants with at least one positive tuberculosis infection test result were included in analyses. Characteristics associated with LTBI treatment offer, acceptance, and completion were evaluated using multivariable logistic regression with random intercepts to account for clustering by enrollment site. Our primary outcomes were whether use of an interpreter was associated with LTBI treatment acceptance and completion. We also evaluated whether interpreter usage was associated treatment offer and whether interpreter type was associated with treatment offer, acceptance, or completion. RESULTS: Among 8,761 non-U.S.-born participants, those who used an interpreter during the initial interview had a significantly greater odds of accepting LTBI treatment than those who did not use an interpreter. There was no association between use of an interpreter and a clinician's decision to offer treatment or treatment completion once accepted. Characteristics associated with lower odds of treatment being offered included experiencing homelessness and identifying as Pacific Islander persons. Lower treatment acceptance was observed in Black and Latino persons and lower treatment completion by participants experiencing homelessness. Successful treatment completion was associated with use of shorter rifamycin-based regimens. Interpreter type was not associated with LTBI treatment offer, acceptance, or completion. CONCLUSIONS: We found greater LTBI treatment acceptance was associated with interpreter use among non-U.S.-born individuals.

Screening for latent tuberculosis in migrants-status quo and future challenges.

OBJECTIVES: To review the evidence that migrants from tuberculosis (TB) high-incidence countries migrating to TB low-incidence countries significantly contribute to active TB cases in the counties of destination, primarily through reactivation of latent TB. METHODS: This is a narrative review. The different screening programs in the countries of destination are reviewed either based on screening and preventive treatment of latent TB pre or more commonly - post arrival. RESULTS: Screening can be performed using interferon-gamma release assays (IGRA) or tuberculin skin tests (TST). Preventive treatment of latent TB is using either monotherapy with isoniazid, or in combination with rifampicin or rifapentine. We discuss the ethical issues of preventive treatment in asymptomatic individuals and how these are addressed in different screening programs. CONCLUSION: Screening migrants from TB high endemic countries to TB low endemic countries is beneficial. There is a lack of standardization and agreement on screening protocols, follow up and treatment.

Isoniazid use, effectiveness, and safety for treatment of latent tuberculosis infection: a systematic review.

BACKGROUND: The treatment strategy for latent tuberculosis infection is to reduce the number of tuberculosis cases and consequently reduce the transmission of pathogenic bacteria. This study aimed to determine the safety, effectiveness, and adherence of isoniazid use for latent tuberculosis infection treatment. METHODS: To identify studies on isoniazid use for latent tuberculosis infection, five electronic databases were searched. The methods and results are presented in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Most studies (53) used isoniazid for 9 months. The prevalence of use and adherence to treatment varied considerably (18% to 100%), and were evaluated by participant completion of isoniazid treatment for latent tuberculosis infection. The adverse events most frequently reported were hepatotoxicity, gastric intolerance, and neuropathy; the rates of occurrence ranged from < 1% to 48%. In the studies that evaluated the effectiveness of isoniazid for latent tuberculosis infection, the rate varied from 0 to 19.7% for patients who did not have active tuberculosis after the follow-up period. CONCLUSIONS: The importance of maintaining follow up for patients using isoniazid should be emphasized due to the risk of developing adverse events. Despite the treatment challenges, the rates of patients who used isoniazid and developed active tuberculosis during the follow-up period were low. We believe that isoniazid continues to contribute to tuberculosis control worldwide, and better care strategies are required.

Cost-effectiveness of latent tuberculosis infection testing and treatment with 6-week regimen among key population in rural communities in China: a decision analysis study.

PURPOSE: Several model studies suggested the implementation of latent tuberculosis infection (LTBI) testing and treatment could greatly reduce the incidence of tuberculosis (TB) and achieve the 2035 target of the "End TB" Strategy in China. The present study aimed to evaluate the cost-effectiveness of LTBI testing and TB preventive treatment among key population (≥ 50 years old) susceptible to TB at community level in China. METHODS: A Markov model was developed to investigate the cost-effectiveness of LTBI testing using interferon gamma release assay (IGRA) and subsequent treatment with 6-month daily isoniazid regimen (6H) (as a standard regimen for comparison) or 6-week twice-weekly rifapentine and isoniazid regimen (6-week H2P2) in a cohort of 10,000 adults with an average initial age of 50 years. RESULTS: In the base-case analysis, LTBI testing and treatment with 6H was dominated (i.e., more expensive with a lower quality-adjusted life year (QALY)) by LTBI testing and treatment with 6-week H2P2. LTBI testing and treatment with 6-week H2P2 was more effective than no intervention at a cost of $20,943.81 per QALY gained, which was below the willingness-to-pay (WTP) threshold of $24,211.84 per QALY gained in China. The one-way sensitivity analysis showed the change of LTBI prevalence was the parameter that most influenced the results of the incremental cost-effectiveness ratios (ICERs). CONCLUSION: As estimated by a Markov model, LTBI testing and treatment with 6-week H2P2 was cost-saving compared with LTBI testing and treatment with 6H, and it was considered to be a cost-effective option for TB control in rural China.

Incidence of tuberculosis disease in individuals diagnosed with tuberculosis infection after screening: A population-based cohort study in South Korea.

OBJECTIVES: Limited evidence exists regarding the impact of adherence to diverse tuberculosis (TB) preventive therapy (TPT) regimens on TB risk in individuals with TB infections (TBIs). This study aimed to examine the association between adherence to three TPT regimens and TB incidence. METHODS: This population-based retrospective cohort study used South Korean national health insurance data to identify individuals who were newly diagnosed with TBI between 2015 and 2020. TB incidence was compared among the different TPT regimens used. Treatment adherence was evaluated using the medication possession ratio (MPR). RESULTS: The study involved 220,483 individuals with TBI, with half undergoing TPT. Over a mean 3.17-year follow-up, 2,430 cases of active TB were observed. TPT was associated with a 14% reduction in TB incidence risk in the entire study population with varying levels of TB risk. Non-adherence (MPR <80%) rates were 36% for 9 months of treatment with isoniazid, 22% for 4 months of treatment with rifampicin, and 18% for 3 months of treatment with isoniazid and rifampicin. Non-adherence to TPT did not lead to a decrease in the risk of TB incidence, whereas adherence to TPT (MPR ≥80%) reduced the risk of TB incidence by up to 72%. CONCLUSIONS: This study reveals increased adherence with shorter TPT regimens in a national TBI cohort, emphasizing the pivotal role of medication adherence in preventing TB.