Treatment of latent tuberculosis infection: An update

Prevalence and treatment outcomes of latent tuberculosis infection among older patients with chronic obstructive pulmonary disease in an area with intermediate tuberculosis burden

ABSTRACTChronic obstructive pulmonary disease (COPD) and aging both increase the risk of tuberculosis (TB), an important infectious disease in human. Exploring the burden and predictors of latent tuberculosis infection (LTBI) and treatment outcomes for older individuals with COPD is essential to guide LTBI intervention policy. We enrolled patients aged over 60 years with COPD between January 2021 and June 2023 for LTBI screening using interferon-gamma release assay (IGRA). LTBI treatment options included all WHO-recommended regimens. The final regimen was selected through shared decision-making between patients and their COPD physicians, leveraging the long-standing rapport being established. We investigated the prevalence of LTBI in this population, identified risk factors using logistic regression analysis, and evaluated treatment outcomes. A total of 810 COPD patients (mean: 72.8-years) underwent LTBI screening, with an IGRA-positive rate of 23.8%. IGRA positivity was correlated with smoking pack-years (adjusted odds ratio [aOR]: 1.02, p < 0.001), current smoking status (aOR 1.40, p = 0.030), COPD duration (aOR 1.10, p = 0.03), inhaled corticosteroid use (aOR 3.06, p < 0.001), and a cumulative equivalent dose of prednisolone exceeding 210 mg over 2 years (aOR 3.13, p < 0.001). Treatment was initiated in 150 patients (77.7%), predominantly with weekly rifapentine plus isoniazid (3HP) (60.7%). The overall completion rate was 82.0%, with adverse reactions being the primary reason for discontinuation. Our findings support that the LTBI intervention is recommended for older patients with COPD, especially those at higher risk, as nearly 25% of them have tuberculosis infection. The high treatment completion rate highlights the safety and feasibility of the WHO-recommended regimens.

Diagnosis and Treatment of Latent Tuberculosis Infection in Adults in South Korea

Latent tuberculosis infection (LTBI) is characterized by immune responses to Mycobacterium tuberculosis antigens without clinical symptoms or evidence of active tuberculosis. Effective LTBI management is crucial for tuberculosis elimination, requiring accurate diagnosis and treatment. In South Korea, LTBI guidelines have been updated periodically, the latest being in 2024. This review discusses the recent changes in the Korean guideline for the diagnosis and treatment of LTBI in adults.

Levofloxacin for the Prevention of Multidrug-Resistant Tuberculosis in Vietnam

BACKGROUND

Prevention of drug-resistant tuberculosis is a global health priority. However, trials evaluating the effectiveness of treating Mycobacterium tuberculosis infection among contacts of persons with drug-resistant tuberculosis are lacking.

METHODS

We conducted a double-blind, randomized, controlled trial comparing 6 months of daily levofloxacin (weight-based doses) with placebo to treat M. tuberculosis infection. The trial population comprised household contacts of persons with bacteriologically confirmed rifampicin-resistant or multidrug-resistant (MDR) tuberculosis in Vietnam. Contacts of any age with a positive tuberculin skin test or immunologic impairment were eligible. The primary end point was bacteriologically confirmed tuberculosis within 30 months. Secondary end points included grade 3 or 4 adverse events, death from any cause, and acquired drug resistance.

RESULTS

Of 3948 persons screened for eligibility, 61 (1.5%) had coprevalent tuberculosis (defined as active tuberculosis disease diagnosed before randomization) and 2041 underwent randomization. Of these 2041 participants, 1995 (97.7%) completed 30 months of follow-up, had a primary end-point event, or died. Confirmed tuberculosis occurred in 6 participants (0.6%) in the levofloxacin group and 11 (1.1%) in the placebo group (incidence rate ratio, 0.55; 95% confidence interval [CI], 0.19 to 1.62); this difference was not significant. There was little difference in grade 3 or 4 adverse events between the two groups (risk difference, 1.0 percentage point; 95% CI, -0.3 to 2.4). Adverse events of any grade were reported in 306 participants (31.9%) taking levofloxacin and 125 (13.0%) taking placebo (risk difference, 18.9 percentage points; 95% CI, 14.2 to 23.6). No acquired fluoroquinolone resistance was observed.

CONCLUSIONS

Although the incidence of tuberculosis was lower in the levofloxacin group than in the placebo group at 30 months, the difference was not significant. (Funded by the National Health and Medical Research Council of Australia; VQUIN MDR Australia New Zealand Clinical Trials Registry number, ACTRN12616000215426.).

Prevalence of tuberculosis infection among contacts of drug-resistant tuberculosis patients: A systematic review and meta-analysis

INTRODUCTION

Contact investigations with drug-susceptible tuberculosis (DS-TB) patients have demonstrated a high prevalence of tuberculosis infection (TBI). However, the prevalence of TBI among individuals in close contact with drug-resistant tuberculosis (DR-TB) patients is poorly understood. This systematic review and meta-analysis aimed to determine the prevalence of TBI among household and non-household contacts of DR-TB patients.

METHOD AND ANALYSIS

We searched five databases (Medline, Embase, Scopus, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL)) from inception to 2 June 2023. All studies that reported the prevalence of TBI among DR-TB contacts were included in the study. A random-effects meta-analysis was conducted to estimate the pooled prevalence of TBI with a 95% confidence interval (CI). Sub-group analyses were conducted using study characteristics as covariates.

RESULTS

Thirty studies involving 7659 study participants from 19 countries were included. The pooled prevalence of TBI among DR-TB contacts was 36.52% (95% CI: 30.27-42.77). The sub-group analysis showed considerable heterogeneity in the estimates, with the highest prevalence reported in Southeast Asia (80.74%; 95% CI: 74.09-87.39), household contacts (38.60%; 95% CI: 30.07-47.14), lower-middle-income countries (LMICs) (54.72; 95% CI: 35.90, 73.55), children (43.27%; 95% CI: 25.50, 61.04), and studies conducted between 2004 and 2012 (45.10; 95% CI: 32.44, 57.76).

CONCLUSION

The prevalence of TBI among DR-TB contacts was high, with substantial regional variations. Further research is needed to determine the drug susceptibility status of TBI in DR-TB contacts.

PROTOCOL REGISTRATION

The protocol is registered in PROSPERO (CRD42023390339).

Metabolic Rewiring of Mycobacterium tuberculosis upon Drug Treatment and Antibiotics Resistance

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge, further compounded by the issue of antimicrobial resistance (AMR). AMR is a result of several system-level molecular rearrangements enabling bacteria to evolve with better survival capacities: metabolic rewiring is one of them. In this review, we present a detailed analysis of the metabolic rewiring of Mtb in response to anti-TB drugs and elucidate the dynamic mechanisms of bacterial metabolism contributing to drug efficacy and resistance. We have discussed the current state of AMR, its role in the prevalence of the disease, and the limitations of current anti-TB drug regimens. Further, the concept of metabolic rewiring is defined, underscoring its relevance in understanding drug resistance and the biotransformation of drugs by Mtb. The review proceeds to discuss the metabolic adaptations of Mtb to drug treatment, and the pleiotropic effects of anti-TB drugs on Mtb metabolism. Next, the association between metabolic changes and antimycobacterial resistance, including intrinsic and acquired drug resistance, is discussed. The review concludes by summarizing the challenges of anti-TB treatment from a metabolic viewpoint, justifying the need for this discussion in the context of novel drug discovery, repositioning, and repurposing to control AMR in TB.

Efficacy and Safety of Different Drug Regimens for Tuberculosis Preventive Treatment: A Systematic Review and Meta-Analysis

Tuberculosis prevention treatment (TPT) is crucial to the eradication of tuberculosis (TB). Through a comprehensive review and meta-analysis, we compared the efficacy and safety of different TPT regimens. We searched PubMed, Google Scholar, and medrxiv.org with search terms Tuberculosis Preventive Treatment, TPT, efficacy, safety, and drug regimens for TPT and all RCT, irrespective of age, setting, or co-morbidities, comparing at least one TPT regimen to placebo, no therapy, or other TPT regimens were screened and those reporting either efficacy or safety or both were included. The meta-analysis data were synthesized with Review Manager and the risk ratio (RR) was calculated. Out of 4465 search items, 15 RCTs (randomized-controlled trials) were included. The TB infection rate was 82/6308 patients in the rifamycin plus isoniazid group (HR) as compared to 90/6049 in the isoniazid monotherapy (H) group (RR: 0.89 (95% CI: 0.66, 1.19; p=0.43). A total of 965/6478 vs 1065/6219 adverse drug reactions (ADRs) occurred in HR and H groups respectively (RR: 0.86 (95%CI: 0.80 0.93); P<0.0001). Efficacy analysis of the rifampicin plus pyrazinamide (RZ) vs H showed that the risk ratio of infection rate was not considerably varied (RR: 0.97 (95% CI: 0.47, 2.03); P=0.94). Safety analysis showed in 229/572 patients developed ADRs in rifampicin plus pyrazinamide as compared to 129/600 ADRs in the isoniazid group. (RR: 1.87 (95% CI: 1.44, 2.43)). Safety analysis of only rifamycin (R) vs H group showed 23/718 ADRs in R vs 57/718 ADRs in H group (RR: 0.40 (95% CI: 0.25 0.65); P=0.0002). Rifamycin plus isoniazid (3HP/R) has no edge over other regimens in terms of efficacy but this regimen was found significantly safer as compared to any other regimens used for TPT. Rifampicin plus pyrazinamide (RZ) was found equally efficacious but less safe as compared to other regimens.

Latent Tuberculosis in India: An Overview

Treatment of latent tuberculosis infection (LTBI) is essential for tuberculosis (TB) eradication. LTBI patients serve as a reservoir for active TB cases. The WHO's End TB Strategy now prioritises the detection and treatment of LTBI. A comprehensive approach focused on integrated LTBI control is required to accomplish this goal. This review aims to summarise what we know about LTBI in the existing literature, its prominence, diagnostic strategies, and new interventions to alert people of its occurrence and symptoms. We used Medical Subject Heading (MeSH) phrases to search for published publications on the English language in PubMed, Scopus, and Google Scholar. To provide clarity and impact, we examined several government websites to identify the most effective and current treatment regimens. LTBI is a spectrum of infections, such as intermittent, transitory, or progressive, with early, subclinical, and ultimately active TB cases. The global burden of LTBI cannot be firmly established because no "gold-standard" test exists. Screening is advised for high-risk individuals, such as immigrants, occupants and staff members of congregate living facilities, and those who are HIV-positive. The most reliable form of LTBI screening is still the targeted tuberculin skin test (TST). Although LTBI therapy is challenging, for India to become TB-free, it must first focus on testing and treating LTBI. The government should focus on generalising the new diagnostic criteria and adopting a more specific treatment known to all to eliminate TB once and for all.

Management of Tuberculosis Infection: Current Situation, Recent Developments and Operational Challenges

Tuberculosis infection (TBI) is defined as a state of infection in which individuals host live Mycobacterium tuberculosis with or without clinical signs of active TB. It is now understood as a dynamic process covering a spectrum of responses to infection resulting from the interaction between the TB bacilli and the host immune system. The global burden of TBI is about one-quarter of the world’s population, representing a reservoir of approximately 2 billion people. On average, 5–10% of people who are infected will develop TB disease over the course of their lives, but this risk is enhanced in a series of conditions, such as co-infection with HIV. The End-TB strategy promotes the programmatic management of TBI as a crucial endeavor to achieving global targets to end the TB epidemic. The current development of new diagnostic tests capable of discriminating between simple TBI and active TB, combined with novel short-course preventive treatments, will help achieve this goal. In this paper, we present the current situation and recent developments of management of TBI and the operational challenges.

Anti-tuberculosis treatment strategies and drug development: challenges and priorities

Despite two decades of intensified research to understand and cure tuberculosis disease, biological uncertainties remain and hamper progress. However, owing to collaborative initiatives including academia, the pharmaceutical industry and non-for-profit organizations, the drug candidate pipeline is promising. This exceptional success comes with the inherent challenge of prioritizing multidrug regimens for clinical trials and revamping trial designs to accelerate regimen development and capitalize on drug discovery breakthroughs. Most wanted are markers of progression from latent infection to active pulmonary disease, markers of drug response and predictors of relapse, in vitro tools to uncover synergies that translate clinically and animal models to reliably assess the treatment shortening potential of new regimens. In this Review, we highlight the benefits and challenges of 'one-size-fits-all' regimens and treatment duration versus individualized therapy based on disease severity and host and pathogen characteristics, considering scientific and operational perspectives.

Four months of rifampicin monotherapy for latent tuberculosis infection in children

Diagnosing and treating latent tuberculosis infection (LTBI) is an important part of efforts to combat tuberculosis (TB). The Korean guidelines for TB published in 2020 recommend 2 LTBI regimens for children and adolescents: 9 months of daily isoniazid (9H) and 3 months of daily isoniazid plus rifampicin. Isoniazid for 6-12 months has been used to effectively treat LTBI in children for over 50 years. However, a long treatment period results in poor patient compliance. This review summarizes pediatric data on the treatment completion rate, safety, and efficacy of 4 months of daily rifampicin (4R) and evaluates the pharmacokinetics and pharmacodynamics of rifampicin in children. The 4R regimen has a higher treatment completion rate than the 9H regimen and equivalent safety in children. The efficacy of preventing TB is also consistent with that of 9H when summarizing reports published to date. A shorter treatment period could increase patient compliance and, therefore, prevent TB in more patients. By using an effective, safe, and highly compliant regimen for the treatment of children with LTBI, we would become one step closer to our goal of eradicating TB.

Latent tuberculosis: Risk factors, screening and treatment in liver transplantation recipients from an endemic area

BACKGROUND

Patients undergoing solid organ transplantation, particularly those who live or have lived in tuberculosis (TB) endemic areas, are at a high risk of developing TB. The majority of post-transplantation TB cases are associated with reactivation of latent TB infection (LTBI). Brazil is in a single position with overlapping areas of high TB endemicity and high transplant activity. In liver transplant (LT), one should be aware of the potential hepatotoxicity associated with the treatment regimens for LTBI.

AIM

To evaluate the frequency of LTBI in LT patients and treatment-related issues.

METHODS

This was a retrospective analysis of a cohort of cirrhotic patients aged ≥ 18 years, who underwent LT at a high-complexity teaching hospital from January 2005 to December 2012.

RESULTS

Overall, 429 patients underwent LT during the study period. Of these, 213 (49.7%) underwent the tuberculin skin test (TST) during the pre-transplant period, and 35 (16.4%) of them had a positive result. The treatment for LTBI was initiated after LT in 12 (34.3%) of the TST-positive patients; in 3 (25.0%), treatment was maintained for at least 6 mo.

CONCLUSION

The prevalence of LTBI was lower than expected. Initiation and completion of LTBI treatment was limited by difficulties in the management of these special patients.

Factors influencing the initiation and adherence of LTBI treatment in healthcare workers: a systematic review

Despite the importance of latent tuberculosis infection (LTBI) treatment and management in healthcare workers (HCWs), only a few studies have provided a comprehensive review of factors associated with the success rate of each stage of the LTBI treatment, as well as strategies to improve treatment adherence. This study investigated factors and determinants of patient losses at each stage of the entire cascade of LTBI in HCWs. Studies were extracted from PubMed, EBSCOhost, EMBASE, Cochrane Library, and ScienceDirect. Our study found poor completion rates of LTBI treatment in HCWs. The main reason for not visiting the outpatient clinic or not accepting treatment was related to the demographic characteristics, whereas adverse drug effects were the main reason for treatment discontinuation. These findings suggest that tailored interventions must be developed to improve the success rate at each stage of the LTBI treatment in HCWs.

Tuberculosis risk with biologics by screening-guided preventive strategy in rheumatoid arthritis under intermediate tuberculosis burden

OBJECTIVES

We aimed to compare tuberculosis (TB) risk during biologics treatment between patients with RA who did (prophylaxis) and did not (non-prophylaxis) undergo chemoprophylaxis following pre-biologic latent TB screening in Korea of an intermediate TB burden.

METHODS

Using the 2002-16 Korea National Health Insurance database, we conducted a cohort study examining TB risk, defined by International Classification of Diseases Tenth Revision codes plus anti-TB drugs, among RA patients initiating a biologic drug with and without chemoprophylaxis after screening triage for latent TB. To control baseline confounding, we used propensity score-based fine stratification (PSS) and weighting. Cox proportional hazards models estimated hazard ratios and 95% CIs comparing TB risk between the prophylaxis vs non-prophylaxis groups.

RESULTS

The PSS-weighted study cohort (mean age 57.0 years; 81.3% female) included 2249 and 7225 RA patients in the prophylaxis and non-prophylaxis groups, respectively. During 2.42 years of biologics treatment, 118 patients developed TB with the incidence rate per 100 person-years of 0.33 in the prophylaxis and 0.63 in the non-prophylaxis groups. The PSS-weighted hazard ratio (95% CI) for TB associated with the prophylaxis was 0.52 (0.32, 0.86). During the follow-up time, the incidence rate of TB remained consistently low in the prophylaxis group but it was highest in the first year, then time-dependently declined in the non-prophylaxis group.

CONCLUSION

This population-based cohort study warns that the current screening-based preventive strategy generates a substantially higher TB risk after biologics initiation among screening-negative patients compared with screening-positive patients receiving chemoprophylaxis, when the background TB burden is not low.

Tuberculosis prevention in patients undergoing kidney transplantation: A nurse-led program for screening and treatment

BACKGROUND

Systematic screening for, and treatment of, latent tuberculosis (TB) infection is recommended prior to kidney transplant. However, little is known about patient compliance with, or the safety profile of, preventive therapies used in clinical practice.

METHODS

This was a retrospective observational study of patients who were eligible for kidney transplant and were evaluated for TB infection between January 2013 and June 2019 at the TB clinic of a tertiary care teaching hospital. All patient data were registered prospectively as part of our nurse-led program before kidney transplant. We assessed completion rates, tolerance with therapy, development of TB, and associated workload.

RESULTS

In total, 1568 patients were referred to our TB clinic for evaluation. Preventive therapy was given to 385 patients and completed by 340 (88.3%). Of these, 89 (23.1%) experienced some intolerance, with 27 requiring full discontinuation. After a median follow-up of 45 months (1426 patient-years), 206 (53.5%) of the treated patients received a kidney transplant; only one patient, who failed to complete treatment, developed post-transplant TB (7.01 cases per 10 000 patient-years; 95% confidence interval, 0.35-34.59). Extra nurse or medical visits were required by 268 (69.6%) patients.

CONCLUSION

Despite the complexity and workload generated by patients with ESRD awaiting kidney transplant, preventive therapy for TB is effective in most cases. Our experience provides important evidence on the feasibility of preventive therapy for TB before kidney transplant when delivered as part of a comprehensive nurse-led program.

Bedaquiline: Current status and future perspectives

The development of drug-resistant tuberculosis (TB) is a major threat worldwide. Based on World Health Organization (WHO) reports, it is estimated that more than 500 000 new cases of drug-resistant TB occur annually. In addition, there are alarming reports of increasing multidrug-resistant TB (MDR-TB) and the emergence of extensively drug-resistant TB (XDR-TB) from different countries of the world. Therefore, new options for TB therapy are required. Bedaquiline (BDQ), a novel anti-TB drug, has significant minimum inhibitory concentrations (MICs) both against drug-susceptible and drug-resistant TB. Moreover, BDQ was recently approved for therapy of MDR-TB. The current narrative review summarises the available data on BDQ resistance, describes its antimicrobial properties, and provides new perspectives on clinical use of this novel anti-TB agent.

Asian Organization for Crohn's and Colitis and Asia Pacific Association of Gastroenterology practice recommendations for medical management and monitoring of inflammatory bowel disease in Asia

Inflammatory bowel disease (IBD) has increased in incidence and prevalence in Asian countries since the end of the 20th century. Moreover, differences in the cause, phenotypes, and natural history of IBD between the East and West have been recognized. Therefore, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have established recommendations on medical management of IBD in Asia. Initially, the committee members drafted 40 recommendations, which were then assessed according to Grading of Recommendations Assessment, Development and Evaluation. Eight statements were rejected as this indicated that consensus had not been reached. The recommendations encompass pretreatment evaluation; medical management of active IBD; medical management of IBD in remission; management of IBD during the periconception period and pregnancy; surveillance strategies for colitis-associated cancer; monitoring side effects of thiopurines and methotrexate; and infections in IBD.

Radical Releasing Anti-Tuberculosis Agents and the Treatment of Mycobacterial Tuberculosis Infections - An Overview

The treatment and management of tuberculosis (TB) is a major global concern. Approved drugs for the treatment of TB to date displayed various modes of action which can be grouped into radical releasing and non-radical releasing anti TB agents. Radical releasing agents are of special interest because they diffuse directly into the mycobacterium cell wall, interact with the host cell DNA causing DNA strand breakages and fatal destabilization of the DNA helix inhibiting nucleic acid synthase. As a therapeutic agent with aforementioned activity, nitroimidazoles and most especially bicyclic nitroimidazoles are currently in clinical use for the treatment of tuberculosis. However, the approved drugs, pretomanid (PR) and delamanid (DE) are limited in their nitric oxide radical (NO•) releasing abilities to cause effective bactericidity. It is believed that their bactericidal activity can be improved by harnessing alternative strategies to increase NO• release. The last decade has witness the strategic inclusion of NO-donors into native drugs to improve their activities and/or reverse resistance. The rationale behind this strategy is the targeting of NO• release at specific therapeutic sites. This review therefore aims to highlight various radical releasing agents that may be effective in the treatment of TB. The review also investigates various structural modification to PR and DE and suggests alternative strategies to improve NO• release as well as some applications where NO-donor hybrid drugs have been used with good therapeutic effect.

Behçet's disease with latent Mycobacterium tuberculosis infection

Objective

The aim of this study is to examine the clinical features of patients with Behçet's disease (BD) in the presence or absence of latent tuberculosis infection (LTBI).

Methods

This was a retrospective study of 232 consecutive patients with active BD hospitalized between October 2012 and June 2017. LTBI was diagnosed based on the positive T-SPOT.TB assay, negative clinical, and imaging examinations.

Results

Among the 232 patients, 68 (29.3%) had LTBI. The frequency, number, and scope of oral ulcers in the BD-LTBI group were significantly more serious than in the non-LTBI group (all P < 0.05). Genital ulcers and eye involvement in the LTBI group were significantly higher than in the non-LTBI group (both P < 0.01). No active TB was diagnosed during follow-up (median, 27.9 months; range, 3-58 months). The patients with LTBI had signs of liver damage compared with the non-LTBI group. In the LTBI group, the frequency of alanine transaminase >2.0, the upper limit of normal, was higher in the rifampicin subgroup compared with the non-rifampicin subgroup (P = 0.033).

Conclusion

Patients with BD and LTBI had worse clinical features than those with BD without LTBI. Rifampicin might be associated with the damage to liver in BD patients combined with latent TB.

Interferon gamma release assay tests are associated with persistence and completion of latent tuberculosis infection treatment in the United States: Evidence from commercial insurance data

Background

Risk-targeted testing and treatment of latent tuberculosis infection (LTBI) is a critical component of the United States’ (US) tuberculosis (TB) elimination strategy, but relatively low treatment completion rates remain a challenge. Both treatment persistence and completion may be facilitated by diagnosing LTBI using interferon gamma release assays (IGRA) rather than tuberculin skin tests (TST).

Methods

We used a national sample of administrative claims data to explore associations diagnostic test choice (TST, IGRA, TST with subsequent IGRA) and treatment persistence and completion in persons initiating a daily dose isoniazid LTBI treatment regimen in the US private healthcare sector between July 2011 and March 2014. Associations were analyzed with a generalized ordered logit model (completion) and a negative binomial regression model (persistence).

Results

Of 662 persons initiating treatment, 327 (49.4%) completed at least the 6-month regimen and 173 (26.1%) completed the 9-month regimen; 129 (19.5%) persisted in treatment one month or less. Six-month completion was least likely in persons receiving a TST (42.2%) relative to persons receiving an IGRA (55.0%) or TST then IGRA (67.2%; p = 0.001). Those receiving an IGRA or a TST followed by an IGRA had higher odds of completion compared to those receiving a TST (aOR = 1.59 and 2.50; p = 0.017 and 0.001, respectively). Receiving an IGRA or a TST and subsequent IGRA was associated with increased treatment persistence relative to TST (aIRR = 1.14 and 1.25; p = 0.027 and 0.009, respectively).

Conclusions

IGRA use is significantly associated with both higher levels of LTBI treatment completion and treatment persistence. These differences are apparent both when IGRAs alone were administered and when IGRAs were administered subsequent to a TST. Our results suggest that IGRAs contribute to more effective LTBI treatment and consequently individual and population protections against TB.

Tuberculosis among Newly Arrived Immigrants and Refugees in the United States

Rationale: U.S. health departments routinely conduct post-arrival evaluation of immigrants and refugees at risk for tuberculosis (TB), but this important intervention has not been thoroughly studied.Objectives: To assess outcomes of the post-arrival evaluation intervention.Methods: We categorized at-risk immigrants and refugees as having had recent completion of treatment for pulmonary TB disease overseas (including in Mexico and Canada); as having suspected TB disease (chest radiograph/clinical symptoms suggestive of TB) but negative culture results overseas; or as having latent TB infection (LTBI) diagnosed overseas. Among 2.1 million U.S.-bound immigrants and refugees screened for TB overseas during 2013-2016, 90,737 were identified as at risk for TB. We analyzed a national data set of these at-risk immigrants and refugees and calculated rates of TB disease for those who completed post-arrival evaluation.Results: Among 4,225 persons with recent completion of treatment for pulmonary TB disease overseas, 3,005 (71.1%) completed post-arrival evaluation within 1 year of arrival; of these, TB disease was diagnosed in 22 (732 cases/100,000 persons), including 4 sputum culture-positive cases (133 cases/100,000 persons), 13 sputum culture-negative cases (433 cases/100,000 persons), and 5 cases with no reported sputum-culture results (166 cases/100,000 persons). Among 55,938 with suspected TB disease but negative culture results overseas, 37,089 (66.3%) completed post-arrival evaluation; of these, TB disease was diagnosed in 597 (1,610 cases/100,000 persons), including 262 sputum culture-positive cases (706 cases/100,000 persons), 281 sputum culture-negative cases (758 cases/100,000 persons), and 54 cases with no reported sputum-culture results (146 cases/100,000 persons). Among 30,574 with LTBI diagnosed overseas, 18,466 (60.4%) completed post-arrival evaluation; of these, TB disease was diagnosed in 48 (260 cases/100,000 persons), including 11 sputum culture-positive cases (60 cases/100,000 persons), 22 sputum culture-negative cases (119 cases/100,000 persons), and 15 cases with no reported sputum-culture results (81 cases/100,000 persons). Of 21,714 persons for whom treatment for LTBI was recommended at post-arrival evaluation, 14,977 (69.0%) initiated treatment and 8,695 (40.0%) completed treatment.Conclusions: Post-arrival evaluation of at-risk immigrants and refugees can be highly effective. To optimize the yield and impact of this intervention, strategies are needed to improve completion rates of post-arrival evaluation and treatment for LTBI.

Tuberculin skin test and predictive host factors for false-negative results in patients with pulmonary and extrapulmonary tuberculosis

INTRODUCTION

Tuberculin skin test (TST) has been the standard test for screening for Mycobacterium tuberculosis infection for decades. Identifying persons with latent tuberculosis infection (LTBI) is crucial, as they constitute a reservoir that sustains the global tuberculosis (TB) epidemic. However, different factors, such as HIV infection, can lower the sensitivity of the test.

OBJECTIVES

The aim of this study was to determine the TST sensitivity in active TB patients and to ascertain risk factors that could be associated with false-negative results.

METHODS

Retrospective cohort study of all active TB notifications with a TST result (n = 8833), from 2008 to 2015. TST results were interpreted using a 5 mm and 10 mm cutoff. Bivariate and multivariate logistic regression analysis were used to evaluate the association of sociodemographic and clinical factors with false-negative TST results and to develop predictive risk models.

RESULTS

TST presented an overall sensitivity of 63.8% (5 mm) and 56.1% (10 mm). HIV infection was the risk factor with the strongest association with false-negative results (aOR 4.65-5 mm; aOR 5.05-10 mm). Other factors such as chronic renal failure (CRF) (aOR 1.55-5 mm; aOR 1.73-10 mm), alcohol abuse (aOR 1.52-5 mm; aOR 1.31-10 mm), drug abuse (aOR 1.90-5 mm; aOR 1.76-10 mm) or age ≥65 years (OR 1.69-5 mm and 10 mm) were also associated with a probability of false-negative results.

CONCLUSION

These results highlight the importance of knowing which factors influence TST results, such as HIV status, substance abuse or age, thus improving its usefulness as a screening method for LTBI.

Conversion and Reversion Rates of Tuberculosis Screening Assays in Patients With Rheumatic Diseases and Negative Baseline Screening Under Long-Term Biologic Treatment

Background:

To determine the conversion and reversion rates of tuberculosis (TB) screening tests (Tuberculin Skin Test-TST, Interferon Gamma Release Assay-IGRA: T-SPOT.TB) during biologic treatment in patients with rheumatic diseases and negative baseline screening.

Methods:

This was a long-term, longitudinal cohort study of 50 patients with rheumatic diseases and negative baseline TB screening (TST: < 5 mm, negative T-SPOT.TB) treated with tumor necrosis factor inhibitors (TNFi) or other non-TNFi biologics. Patients were rescreened at a mean time of 1.4 (first rescreening) and 6.9 (second rescreening) years from baseline, with both assays. The conversion (negative to positive) and reversion (positive to negative) rate was calculated for each TB screening test.

Results:

Fifty patients (mean age = 60 years) with various rheumatic diseases (rheumatoid arthritis: n = 24, spondyloarthropathies: n = 23, other: n = 3) were enrolled. During the first phase (baseline to first rescreening), all patients were treated with TNFi while during the second phase (first to second rescreening), TNFi (54%) and non-TNFi (46%) were used. Fifteen patients (30%) displayed conversion of at least 1 screening assay during follow-up (10 at the first and 5 at the second rescreening). This conversion rate was higher with TST (n = 11, 22% or 3.47/100 patient-years) compared to T-SPOT.TB (n = 4, 8% or 1.74/100 patient-years). Among the 10 converters at the first rescreening, 5 received isoniazid (INH) preventive therapy and 5 did not; an equal number of patients (3/5, 60%) reverted to negative with or without INH therapy. None of the patients developed active TB during follow-up (6.9 ± 1.0 years).

Conclusions:

Approximately one-third of patients with rheumatic diseases and negative baseline TB screening developed conversion of at least 1 screening test during long-term biologic treatment. This occurred most often with TST and was usually a transient event. These findings do not support routine serial TB retesting in biologic-treated patients with rheumatic diseases in the absence of TB risk factors.

Levofloxacin versus placebo for the treatment of latent tuberculosis among contacts of patients with multidrug-resistant tuberculosis (the VQUIN MDR trial): a protocol for a randomised controlled trial

INTRODUCTION

Treatment of latent tuberculosis infection (LTBI) plays a substantial role in the prevention of drug-susceptible tuberculosis (TB). However, clinical trials to evaluate the efficacy of preventive therapy for presumed multidrug-resistant (MDR) LTBI are lacking. This trial aims to evaluate the efficacy of the antibiotic levofloxacin in preventing the development of active TB among latently infected contacts of index patients with MDR-TB.

METHODS AND ANALYSIS

A double-blind placebo-controlled parallel group randomised controlled trial will be conducted in 10 provinces of Vietnam. Household contacts living with patients with bacteriologically confirmed rifampicin-resistant or MDR-TB will be eligible for recruitment if they have a positive tuberculin skin test or are known to be immunosuppressed, and do not have active TB. Participants will be randomised to receive either levofloxacin or placebo tablets once per day for 6 months. Screening for incident TB will be performed at 6 months intervals. The primary study outcome is the incidence of bacteriologically confirmed TB within 30 months after randomisation. Analysis will be by intention to treat, using Poisson regression.

ETHICS

Ethical approval from the University of Sydney Human Research Ethics Committee was obtained on 29 April 2015 (2014/929), and from the Vietnam Ministry of Health Institutional Review Board on 30 September 2015 (4040/QD-BYT).

DISSEMINATION

Findings of the study will be published in peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12616000215426.

Cross-validation of existing signatures and derivation of a novel 29-gene transcriptomic signature predictive of progression to TB in a Brazilian cohort of household contacts of pulmonary TB

The goal of this study was to identify individuals at risk of progression and reactivation among household contacts (HHC) of pulmonary TB cases in Vitoria, Brazil. We first evaluated the predictive performance of six published signatures on the transcriptional dataset obtained from peripheral blood mononuclear cell samples from HHC that either progressed to TB disease or not (non-progressors) during a five-year follow-up. The area under the curve (AUC) values for the six signatures ranged from 0.670 to 0.461, and the PPVs did not reach the WHO published target product profiles (TPPs). We therefore used as training cohort the earliest time-point samples from the African cohort of adolescents (GSE79362) and applied an ensemble feature selection pipeline to derive a novel 29-gene signature (PREDICT29). PREDICT29 was tested on 16 progressors and 21 non-progressors. PREDICT29 performed better in segregating progressors from non-progressors in the Brazil cohort with the area under the curve (AUC) value of 0.911 and PPV of 20%. This proof of concept study demonstrates that PREDICT29 can predict risk of progression/reactivation to clinical TB disease in recently exposed individuals at least 5 years prior to disease development. Upon validation in larger and geographically diverse cohorts, PREDICT29 can be used to risk-stratify recently infected for targeted therapy.

Inhaled Corticosteroids And Risk Of Tuberculosis In Patients With Obstructive Lung Diseases: A Systematic Review And Meta-Analysis Of Non-randomized Studies

Background

An association between systemic corticosteroids and tuberculosis (TB) is reported in the literature. Here within, we conducted a systematic review and meta-analysis to evaluate the effects of inhaled corticosteroids (ICS) on the risk of TB in patients with obstructive lung diseases.

Methods

The review was registered on PROSPERO (CRD42018095874). PubMed, CENTRAL, Scopus and Web of Science were searched from inception to September 2018. Papers reporting cases of incident TB in patients with obstructive lung diseases were included; studies without data on ICS use were excluded. Simultaneous use of oral corticosteroids (OCS) and population attributable fraction (PAF) for TB from ICS exposure were also assessed. Data were analyzed using a generic inverse variance method with a random-effects model. ORs with 95% CI were estimated.

Results

Out of 4044 retrieved papers, 9 articles evaluating adult patients only were included in the review. 36,351 patients were prescribed ICS, while 147,171 were not. Any ICS use was associated with an increased risk of TB versus no ICS use (OR=1.46; 95% CI 1.06 to 2.01; p=0.02; I²=96%). A similar result was also found for current ICS use versus prior/no ICS use, as well as for high, moderate and low ICS dose versus no ICS. When simultaneous OCS use was evaluated, the independent contribution of ICS was confirmed only in patients not on OCS (OR=1.63; 95% CI 1.05 to 2.52; p=0.03; I²=94%). Only 0.49% of all TB cases could be attributable to ICS exposure.

Conclusions

Despite the association between ICS and TB, the contribution of this risk factor to the epidemiology of TB seems to be limited. As a consequence, no population-based interventions are warranted. Rather, this risk should be taken into account on an individual basis, particularly in those patients with a high risk of progression from LTBI to TB.

2018 Belgian guidelines for the screening for latent tuberculosis in HIV-infected patients

Objectives: To review the current knowledge on screening for latent tuberculosis infection (LTBI) in HIV-infected adults and provide specific guidelines for Belgium. Focus is given to who to test, which testing method to use, timing of screening and choice of LTBI treatment. Methods: Expert review by the members of the Belgian LTBI group, in consultancy with the ARC College. Results: Target population, timing of screening, testing method, active TB exclusion, treatment of LTBI and guideline implementation are all reviewed. Conclusions: The principal changes include a selective approach to screen for LTBI (screening only of the HIV-infected patients at highest risk of active TB) as well as the timing of screening (testing for LTBI performed only after immune-restauration by antiretroviral therapy).

Estimating the prevalence of latent tuberculosis in a low-incidence setting: Australia

Migration is a key driver of tuberculosis (TB) in many low-incidence settings, with the majority of TB cases attributed to reactivation of latent TB (LTBI) acquired overseas. A greater understanding of LTBI risk in heterogeneous migrant populations would aid health planning. We aimed to estimate the LTBI prevalence and distribution among locally born and overseas-born Australians.

Annual risks of TB infection estimates were applied to population cohorts (by country of birth, year of arrival and age) in Australian census data in 2006, 2011 and 2016.

Both the absolute number and proportion of Australian residents with LTBI increased from 4.6% (interquartile range (IQR) 4.2–5.2%) in 2006 to 5.1% (IQR 4.7–5.5%) in 2016, due to the increasing proportion of the population born overseas (23.8% in 2006 to 28.3% in 2016). Of all residents estimated to have LTBI in 2016; 93.2% were overseas born, 21.6% were aged <35 years and 34.4% had migrated to Australia since 2007.

The overall prevalence of LTBI in Australia is low. Some residents, particularly migrants from high-incidence settings, may have considerably higher risk of LTBI, and these findings allow for tailored public health interventions to reduce the risk and impact of future TB disease.

Lessons learned from two interventions designed to increase adherence to LTBI treatment in Latino youth

Effort is required to meet the Healthy People 2020 goal of tuberculosis (TB) disease reduction to 1 new case per 100,000 in the United States (US) and reduce burden among those disparately affected. Preventing new cases by reducing conversion from latent TB infection (LTBI) to infectious disease is one approach to reducing disease burden. This paper describes the outcome of a trial designed to determine if LTBI-positive youth prescribed daily Isoniazid with peer counseling would achieve higher adherence than attention control participants. The paper also compares adherence to a previous trial. 263 students age 15.9 years (SD = 1.2), 51.7% female, 96.2% Latino, 43.7% foreign-born were randomly assigned to condition. Adherence was measured by self-report validated by metabolite analysis. Outcome analyses used number of pills taken and proportion of youth consuming 80% of medication. There was no significant difference by condition for either analysis. Thirty-seven percent of adherence participants completed treatment versus 40% of controls. Without a usual-care control group we were unable to determine whether conditions were equally effective or ineffective. The study's inability to pay for treatment resulted in the intervention being tested in the context of compromised access to care. Still to be determined is whether same-age peers can influence adherence among Latino adolescents.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT00233168.

Impact of Choice of Test for Latent Tuberculosis Infection on Treatment Acceptance and Completion

OBJECTIVE

The aim of this study is to assess whether choice of test for tuberculosis (TB) infection affects decisions to accept and complete treatment among contacts to TB cases.

METHODS

Retrospective study is conducted in which TB contacts, ⩾15 years old during 2005 and 2009, were tested for infection with either a tuberculin skin test (TST) or an interferon-gamma release assay test, the QuantiFERON-TB Gold In-Tube (QFT-GIT).

RESULTS

Of 658 persons with valid test results, 185 (28%) had positive results, including 128 of 406 (32%) who had TST and 57 of 252 (23%) who received QFT-GIT. Treatment acceptance was 43 of 57 (75%) among QFT-GIT-positive and 97 of 128 (76%) among TST-positive persons (risk ratio [RR] = 1.0, 95% confidence interval [CI], 0.83-1.2). Treatment completion was 56% among QFT-GIT-positive (32 of 57) and 59% (75 of 128) among TST-positive persons (RR = 0.96, 95% CI, 0.73-1.26).

DISCUSSION

Our study showed no difference in proportions of TB contacts ⩾15 years old with positive TST results who accepted or completed LTBI treatment compared with those with positive QFT-GIT results. Future studies should include high-risk persons with no known TB exposure, who constitute the main reservoir for TB cases in the United States.

A scoring strategy for progression risk and rates of treatment completion in subjects with latent tuberculosis

It is unknown whether patients with LTBI at high vs. low risk of developing active TB are currently adequately identified and treated in the US. In this study our objective was 1) To retrospectively apply the online calculator (tstin3d.com) to determine the probability of having LTBI and assign cumulative risk of progression. 2) Measure treatment outcomes in subjects with Low: 0-<10%, Intermediate: 10-<50% and High: 50–100% cumulative risk. We performed medical record review of tuberculin skin test and/or Interferon-γ release assay (IGRAs) positive patients with LTBI seen from 2010–2015. Of 125 subjects included, 51(41%), 46 (37%) and 28 (22%) subjects were in Low, Intermediate and High risk groups respectively. Tstin3d.com was useful in determining the probability of LTBI in tuberculin skin test positive US-born subjects. Overall treatment completion rate was 61% in 114 subjects with complete treatment information and similar completion rates were seen in the three groups (Low-60%, Intermediate-63% and High-57%). Provider assessment of important clinical risk factors was often incomplete. Logistic regression analysis showed no association of assessment of important risk factors with treatment completion. The major limitations of the calculator are the lack of an updated data on country-specific prevalence of TB disease as the global burden of TB continues to decrease as well as falsely high positive predictive values that due to “transiently” positive IGRA results in subjects from countries with low prevalence. Nonetheless, our findings suggest that tstin3d.com could be utilized in the US setting for improving providing awareness of risk stratification of patients with LTBI for short course treatment regimens based on risk.

Tuberculosis preventive treatment: the next chapter of tuberculosis elimination in India

The End TB Strategy envisions a world free of tuberculosis—zero deaths, disease and suffering due to tuberculosis by 2035. This requires reducing the global tuberculosis incidence from >1250 cases per million people to <100 cases per million people within the next two decades. Expanding testing and treatment of tuberculosis infection is critical to achieving this goal. In high-burden countries, like India, the implementation of tuberculosis preventive treatment (TPT) remains a low priority. In this analysis article, we explore potential challenges and solutions of implementing TPT in India. The next chapter in tuberculosis elimination in India will require cost-effective and sustainable interventions aimed at tuberculosis infection. This will require constant innovation, locally driven solutions to address the diverse and dynamic tuberculosis epidemiology and persistent programme monitoring and evaluation. As new tools, regimens and approaches emerge, midcourse adjustments to policy and practice must be adopted. The development and implementation of new tools and strategies will call for close collaboration between local, national and international partners—both public and private—national health authorities, non-governmental organisations, research community and the diagnostic and pharmaceutical industry. Leading by example, India can contribute to global knowledge through operational research and programmatic implementation for combating tuberculosis infection.

Outcomes of Treatment for Latent Tuberculosis Infection in Patients With Inflammatory Bowel Disease Receiving Biologic Therapy

BACKGROUND

Treatment for latent tuberculosis infection (LTBI) is of particular concern in patients with inflammatory bowel disease (IBD) initiating biologic therapies to prevent tuberculosis (TB) reactivation. This study aimed to evaluate the effectiveness of LTBI treatment in IBD patients receiving biologic therapy.

METHODS

There was a retrospective review of all IBD patients diagnosed with LTBI following a tuberculin skin test (TST) and/or interferon gamma release assay (IGRA) and who received biologic therapy between 2002 and 2016. The primary outcome was tuberculosis reactivation after completion of LTBI treatment.

RESULTS

Three-hundred twenty-nine IBD patients were identified, and 35 (27 Crohn's disease; 8 ulcerative colitis) met the study inclusion criteria. The mean age was 38.3 years, and 68.6% were male. The most common LTBI treatment regimen was isoniazid (INH) for 9 months (74%). Biologic therapies used were infliximab (40%), adalimumab (29%), vedolizumab (20%), and certolizumab pegol (11%). Combination therapy with an immunomodulator was administered in 57% of cases. The median time from initiation of LTBI treatment to biologics was 43 days. The mean duration of follow-up was 2.9 years. The estimated median annual risk of TB reactivation without treatment was 0.52% by a prediction formula. Only 1 patient taking adalimumab monotherapy developed reactivation of TB several years after completing 6 months of isoniazid therapy. The estimated TB reactivation rate was 0.98 cases per 100 patient-years of follow-up in our cohort.

CONCLUSIONS

Treatment for LTBI in patients with IBD treated with biologics is effective but does not eliminate the risk of reactivation. 10.1093/ibd/izy133_video1izy133.video15776720675001.

The usefulness of routine chest radiograph examinations in patients treated with TNF inhibitors for inflammatory arthritis in South Korea

OBJECTIVES

We aimed to investigate the usefulness of routine chest radiograph (CXR) examinations for patients with inflammatory arthritis treated with a tumor necrosis factor (TNF) inhibitor in terms of (i) the role of CXR in baseline latent tuberculosis infection (LTBI) screening and (ii) detecting asymptomatic active tuberculosis after TNF inhibitor initiation.

METHODS

From January 2011 to June 2017, 469 patients with inflammatory arthritis were enrolled in the study at a tertiary referral center in South Korea. At our institution, CXR was performed for all patients undergoing a tuberculin skin test (TST) and/or an interferon-gamma release assay (IGRA) at the LTBI screening visit. LTBI treatment was determined by (i) positive TST or IGRA or (ii) CXR findings suggestive of spontaneously healed tuberculosis. After TNF inhibitor initiation, patients were recommended to undergo CXR at a specified interval.

RESULTS

Of 469 patients, 187 were treated for LTBI. Among them, 181 patients were treated for LTBI because of a positive TST or IGRA result. TST was considered positive if induration size was ≥10 mm. The remaining six patients were considered positive on the basis of CXR findings compatible with spontaneously healed tuberculosis, such as noncalcified nodules with distinct margins and fibrotic linear opacity, despite demonstrating negative results for TST and IGRA. Thus, CXR had a diagnostic value as a baseline LTBI test in 6 (1.3%) patients. After TNF inhibitor initiation, 2 patients who had respiratory symptoms were diagnosed with active tuberculosis. For asymptomatic patients, routine CXR follow-up could not detect any case of active pulmonary tuberculosis within 1 year (n = 219) or after 1 year (n = 217).

CONCLUSIONS

CXR should be performed as one of the LTBI screening tests for patients with inflammatory arthritis in a tuberculosis-prevalent country. However, after TNF inhibitor treatment, routine CXR follow-up was not advantageous.

Effects of preventive therapy for latent tuberculosis infection and factors associated with treatment abandonment: a cross-sectional study

Background

Routine data on the use of preventive therapy (PT) for latent tuberculosis infection (LTBI) in students are scarce in high tuberculosis (TB) burden countries. This study aimed to investigate the effects of PT and identify factors related to PT abandonment during the school TB epidemic in Guangzhou, southern China.

Methods

Purified protein derivative (PPD) skin testing was performed on all staff and students in a vocational school in Guangzhou, southern China during December 2014. Subjects (n=362) with a reactive PPD induration ≥15 mm, or with papules, blisters, and a normal chest X-ray image were recommended for PT. The subjects were assigned to a PT group (n=156) and control group (n=206), respectively, on a voluntary basis. Subjects in the PT group received isoniazid (INH) combined with rifampicin (RFP) for 3 consecutive months; after which, the incidence of TB and protective rate of PT for reducing TB were observed during a 2-year follow up period. An improved questionnaire was used to identify factors that influenced treatment abandonment. All data were subjected to univariate and multivariate logistic regression analyses.

Results

Two cases in the PT group and 20 cases in the control group developed TB. The protective rate of PT for reducing TB was 86.8%. In the PT group, 69 cases finished PT, with a completion rate of 44.2%, and the incidence rates of adverse events and hepatotoxicity were 12.2% and 1.9%, respectively. Among 362 LTBI cases, a total of 293 cases abandoned PT. Discrimination (OR =7.173, 95% CI, 3.361-15.307), worry about adverse drug reactions (OR =2.752, 95% CI, 1.459-5.192), a low parental education level (OR =2.605, 95% CI, 1.420-4.777), and accepting the opinion of a non-TB specialist (OR =6.017, 95% CI, 3.077-11.765) were identified as high-risk factors for abandoning PT.

Conclusions

A PT regimen consisting of INH combined with RFP for 3 consecutive months is reasonable for use in schools. Discrimination, worry about adverse drug reactions, a low parental education level, and accepting the opinion of a non-TB specialist are all factors that may increase the risk for treatment abandonment among LTBI cases. To overcome psychological obstacles is critical for improving treatment adherence.

Latent tuberculosis infection: Opportunities and challenges

Diagnosing and treating latent tuberculosis (TB) infection (LTBI) is recognized by the World Health Organization as an important strategy to accelerate the decline in global TB and achieve TB elimination. Even among low-TB burden countries that have achieved high rates of detection and successful treatment for active TB, a number of barriers have prevented implementing or expanding LTBI treatment programmes. Of those infected with TB, relatively few will develop active disease and the current diagnostic tests have a low predictive value. LTBI treatment using isoniazid (INH) has low completion rates due to the long duration of therapy and poor tolerability. Both patients and physicians often perceive the risk of toxicity to be greater than the risk of reactivation TB. As a result, LTBI treatment has had a limited or negligible role outside of countries with high resources and low burden of disease. New tools have emerged including the interferon-gamma release assays that more accurately diagnose LTBI, particularly in people vaccinated with Bacillus Calmette-Guerin (BCG). Shorter, better tolerated treatment using rifamycins are proving safe and effective alternatives to INH. While still imperfect, TB prevention using these new diagnostic and treatment tools appear cost effective in modelling studies in the United States and have the potential to improve TB prevention efforts globally. Continued research to understand the host-organism interactions within the spectrum of LTBI is needed to develop better tools. Until then, overcoming the barriers and optimizing our current tools is essential for progressing toward TB elimination.

Preventive therapy for tuberculosis in rheumatological patients undergoing therapy with biological drugs

INTRODUCTION

Latent tuberculosis infection (LTBI) accounts for almost a quarter of the world population, and, in 5-10% of the subjects with impaired immune-response against M. tuberculosis growth, it may progress to active tuberculosis (TB). In this review, we focus on the need to propose a screening for LTBI including preventive therapy offer in rheumatic patients undergoing therapy with biological drugs. Areas covered: We report on evidence that biologics are associated with an increased risk of active TB reactivation. This effect seems to be mainly limited to treatment with anti-tumor necrosis factor (TNF) agents, while non-anti-TNF-targeted biologics are not likely associated to any increased risk. We introduce the concept that the patients' coexisting host-related risk factors, such as comorbidities, are crucial to identify those at higher risk to reactivate TB. We report that preventive TB therapy is well tolerated in patients treated with biological drugs. Expert commentary: Availability of non-anti-TNF targeted biologics, that are not associated with an increased risk of TB reactivation, offers a great opportunity to tailor a therapeutic intervention at low/absent TB risk. After proper LTBI screening investigations, preventive TB therapy has been demonstrated to be effective and well-tolerated to reduce the risk of TB reactivation in rheumatic patients requiring biological drugs.

Incorporation of Social Determinants of Health in the Peer-Reviewed Literature: A Systematic Review of Articles Authored by the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention

OBJECTIVES

Social determinants of health (SDHs) are the complex, structural, and societal factors that are responsible for most health inequities. Since 2003, the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP) has researched how SDHs place communities at risk for communicable diseases and poor adolescent health. We described the frequency and types of SDHs discussed in articles authored by NCHHSTP.

METHODS

We used the MEDLINE/PubMed search engine to systematically review the frequency and type of SDHs that appeared in peer-reviewed publications available in PubMed from January 1, 2009, through December 31, 2014, with a NCHHSTP affiliation. We chose search terms to identify articles with a focus on the following SDH categories: income and employment, housing and homelessness, education and schooling, stigma or discrimination, social or community context, health and health care, and neighborhood or built environment. We classified articles based on the depth of topic coverage as "substantial" (ie, one of ≤3 foci of the article) or "minimal" (ie, one of ≥4 foci of the article).

RESULTS

Of 862 articles authored by NCHHSTP, 366 (42%) addressed the SDH factors of interest. Some articles addressed >1 SDH factor (366 articles appeared 568 times across the 7 categories examined), and we examined them for each category that they addressed. Most articles that addressed SDHs (449/568 articles; 79%) had a minimal SDH focus. SDH categories that were most represented in the literature were health and health care (190/568 articles; 33%) and education and schooling (118/568 articles; 21%).

CONCLUSIONS

This assessment serves as a baseline measurement of inclusion of SDH topics from NCHHSTP authors in the literature and creates a methodology that can be used in future assessments of this topic.

Impact of nursing interventions on adherence to treatment with antituberculosis drugs in children and young people: A nonrandomized controlled trial

AIM

To evaluate the association of a new nursing intervention on the adherence to antituberculosis treatment in a paediatric cohort (<18 years).

BACKGROUND

Tuberculosis remains a public health problem worldwide. The risk of developing tuberculosis after primary infection and its severity are higher in children. Proper adherence to antituberculosis treatment is critical for disease control.

DESIGN

Nonrandomized controlled trial; Phase 1, retrospective (2011-2013), compared with Phase 2, prospective with intervention (2015-2016), in a referral centre for paediatric tuberculosis in Spain (NCT03230409).

METHODS

A total of 359 patients who received antituberculosis drugs after close contact with a smear-positive patient (primary chemoprophylaxis) or were treated for latent tuberculosis infection or tuberculosis disease were included, 261 in Phase 1 and 98 in Phase 2. In Phase 2, a new nurse-led intervention was implemented in all patients and included two educational steps (written information in the child's native language and follow-up telephone calls) and two monitoring steps (Eidus-Hamilton test and follow-up questionnaire) that were exclusively carried out by nurses.

RESULTS

Adherence to antituberculosis treatment increased from 74.7% in Phase 1% to 87.8% in Phase 2 (p = 0.014; Chi-square test), after the implementation of the nurse-led intervention. In Phase 2, nonadherence was only associated with being born abroad (28.6% vs. 7.8%; p = 0.019; Chi-square test) and with foreign origin families (27.3% vs. 0%; p < 0.0001; Chi-square test).

CONCLUSION

The nurse-led intervention was associated to an increase in adherence to antituberculosis treatment. Immigrant-related variables remained major risk factors for sub-optimal adherence in a low-endemic setting.

National policies on the management of latent tuberculosis infection: review of 98 countries

Objective

To review policies on management of latent tuberculosis infection in countries with low and high burdens of tuberculosis.

Methods

We divided countries reporting data to the World Health Organization (WHO) Global Tuberculosis Programme into low and high tuberculosis burden, based on WHO criteria. We identified national policy documents on management of latent tuberculosis through online searches, government websites, WHO country offices and personal communication with programme managers. We made a descriptive analysis with a focus on policy gaps and deviations from WHO policy recommendations.

Findings

We obtained documents from 68 of 113 low-burden countries and 30 of 35 countries with the highest burdens of tuberculosis or human immunodeficiency virus (HIV)-associated tuberculosis. Screening and treatment of latent tuberculosis infection in people living with HIV was recommended in guidelines of 29 (96.7%) high-burden and 54 (79.7%) low-burden countries. Screening for children aged < 5 years with household tuberculosis contact was the policy of 25 (83.3%) high- and 28 (41.2%) low-burden countries. In most high-burden countries the recommendation was symptom screening alone before treatment, whereas in all low-burden countries it was testing before treatment. Some low-burden countries' policies did not comply with WHO recommendations: nine (13.2%) recommended tuberculosis preventive treatment for travellers to high-burden countries and 10 (14.7%) for patients undergoing abdominal surgery.

Conclusion

Lack of solid evidence on certain aspects of management of latent tuberculosis infection results in national policies which vary considerably. This highlights a need to advance research and develop clear, implementable and evidence-based WHO policies.

Screening for latent and active tuberculosis infection in the elderly at admission to residential care homes: A cost-effectiveness analysis in an intermediate disease burden area

BACKGROUND

Tuberculosis (TB) in the elderly remains a challenge in intermediate disease burden areas like Hong Kong. Given a higher TB burden in the elderly and limited impact of current case-finding strategy by patient-initiated pathway, proactive screening approaches for the high-risk group could be optimal and increasingly need targeted economic evaluations. In this study, we examined whether and under what circumstance the screening strategies are cost-effective compared with no screening strategy for the elderly at admission to residential care homes.

METHODS

A decision analytic process based on Markov model was adopted to evaluate the cost-effectiveness of four strategies: (i) no screening, (ii) TB screening (CXR) and (iii) TB screening (Xpert) represent screening for TB in symptomatic elderly by chest X-ray and Xpert® MTB/RIF respectively, and (iv) LTBI/TB screening represents screening for latent and active TB infection by QuantiFERON®-TB Gold In-Tube and chest X-ray. The target population was a hypothetical cohort of 65-year-old people, using a health service provider perspective and a time horizon of 20 years. The outcomes were direct medical costs, life-years and quality-adjusted life-years (QALYs) measured by incremental cost-effectiveness ratio (ICER).

RESULTS

In the base-case analysis, no screening was the most cost-saving; TB screening (CXR) was dominated by TB screening (Xpert); LTBI/TB screening resulted in more life-years and QALYs accrued. The ICERs of LTBI/TB screening were US$19,712 and US$29,951 per QALY gained compared with no screening and TB screening (Xpert), respectively. At the willingness-to-pay threshold of US$50,000 per QALY gained, LTBI/TB screening was the most cost-effective when the probability of annual LTBI reactivation was greater than 0.155% and acceptability of LTBI/TB screening was greater than 38%. In 1,000 iterations of Monte Carlo simulation, the probabilities of no screening, TB screening (CXR), TB screening (Xpert), and LTBI/TB screening to be cost-effective were 0, 1.3%, 20.1%, and 78.6% respectively.

CONCLUSIONS

Screening for latent and active TB infection in Hong Kong elderly people at admission to residential care homes appears to be highly effective and cost-effective. The key findings may be the next key factor to bring down TB endemic in the elderly population among intermediate TB burden areas.

Implementing an isoniazid preventive therapy program for people living with HIV in Thailand

Treatment of people living with HIV (PLHIV) with latent tuberculosis (TB) infection using isoniazid preventive therapy (IPT) can reduce the risk of TB disease, however, the scale-up of IPT among PLHIV in Thailand and worldwide has been slow. To hasten the implementation of IPT in Thailand, we developed IPT implementation training curricula and tools for health care providers and implemented IPT services in seven large government hospitals. Of the 659 PLHIV enrolled, 272 (41.3%) reported symptoms of TB and 39 (14.3% of those with TB symptoms) were diagnosed with TB. A total of 346 (52.4%) participants were eligible for IPT; 318 (91.9%) of these participants opted to have a tuberculin skin test (TST) and 52 (16.3% of those who had a TST) had a positive TST result. Among the 52 participants with a positive TST, 46 (88.5%) initiated and 39 (75.0%) completed 9 months of IPT: physicians instructed three participants to stop IPT, two participants were lost to follow-up, one chose to stop therapy, and one developed TB. IPT can be implemented among PLHIV in Thailand and could reduce the burden of TB in the country.

Treatment of Latent Tuberculosis Infection

The treatment of latent tuberculosis infection (LTBI) is an essential component of tuberculosis (TB) elimination in regions that have a low incidence of TB. However, the decision to treat individuals with LTBI must consider the limitations of current diagnostic tests for LTBI, the risk of developing active TB disease, the potential adverse effects from chemoprophylactic therapy, and the importance of treatment adherence. When an individual has been diagnosed with LTBI and active TB has been ruled out, this is followed by an evaluation of the risks and benefits of LTBI treatment within the context of the regional epidemiology of TB and public health priorities. Once the decision to treat LTBI has been reached, and the infection is not suspected to be due to drug-resistant TB, the recommended regimens include isoniazid and/or rifamycin-derivatives, and the choice of regimen will depend upon the clinical considerations for that individual, such as patient preference, concomitant medications, hepatic disease, pregnancy, or immunodeficiency. As the duration of treatment of LTBI therapy is many months, therapy must be offered within a plan that monitors for adverse drug reactions and emphasizes adherence. For latent multidrug-resistant TB (MDR-TB) or extensively drug-resistant TB (XDR-TB) infection, the management is more complicated as there are few options for chemoprophylactic therapy and little evidence regarding the efficacy or risks of these regimens.

The risk of tuberculosis disease in rheumatoid arthritis patients on biologics and targeted therapy: A 15-year real world experience in Taiwan

The objective of this study is to determine the risk of tuberculosis (TB) disease in biologics users among rheumatoid arthritis (RA) patients in Taiwan from 2000 to 2015. This retrospective cohort study enrolled adult RA patients initiated on first biologics at Taichung Veterans General Hospital. TB risks were determined as hazard ratio (HR) with 95% confidence interval (CI) using cox regression. A total of 951 patients were recruited; etanercept (n = 443), adalimumab (n = 332), abatacept (n = 74), golimumab (n = 60), tocilizumab (n = 31) and tofacitinib (n = 11). Twenty-four TB cases were identified; 13 in etanercept and 11 in adalimumab group with the TB incidence rate of 889.3/ 100,000 and 1055.6/ 100,000 patient-years respectively. There was no significant difference in TB risk between adalimumab and etanercept users with an incidence rate ratio of 1.27 (p = 0.556 by Poisson model). Significant 2-year TB risk factors included elderly patient >65 year-old (HR: 2.72, 95% CI: 1.06–6.99, p = 0.037), history of TB (HR: 6.24, 95% CI: 1.77–22.00, p = 0.004) and daily glucocorticoid use ≥5mg (HR:5.01, 95% CI: 1.46–17.21, p = 0.010). Sulfasalazine treatment appeared to be protective (HR: 0.32, 95% CI: 0.11–0.97, p = 0.043). Risk management plan (RMP) for TB before initiation of biologics commenced in 2012. The 2-year TB risks after RMP was compared with that before 2012 (HR:0.67, 95% CI: 0.30–1.49, p = 0.323). Elderly RA patients with a history of previous TB infection and concomitant moderate dose glucocorticoid were at higher risk of TB disease. Concurrent sulfasalazine treatment appeared to be a protective factor against TB disease.

Latent tuberculosis infection: the final frontier of tuberculosis elimination in the USA

Since 1989, the USA has been pursuing the goal of tuberculosis elimination. After substantial progress during the past two decades, the rate of tuberculosis cases in the USA each year has now levelled off and remains well above the elimination threshold. Both epidemiological data and modelling underline the necessity of addressing latent tuberculosis infection if further progress is to be made in eliminating the disease. In this Personal View we explore next steps towards elimination. Given the estimated prevalence of latent tuberculosis infection, compared with the limited testing and treatment that currently occur, a major new effort is required. This effort should consist of a surveillance system or registry to monitor progress, scale-up of targeted testing for latent tuberculosis infection in at-risk populations, scale-up of short-course treatment regimens, engagement of affected communities and medical providers who serve those communities, and increased public health staffing for implementation and oversight. Such an effort would benefit greatly from the development of new tools, such as tests that better indicate reactivation risk, and even shorter latent tuberculosis infection treatment regimens than currently exist.

Latent Tuberculosis Infection Testing Practices in Long-Term Care Facilities, Boston, Massachusetts

OBJECTIVES

To describe latent tuberculosis infection (LTBI) testing practices in long-term care facilities (LTCFs).

DESIGN

Retrospective cohort study.

SETTING

Three Boston-area LTCFs.

PARTICIPANTS

Residents admitted between January 1 and December 31, 2011.

MEASUREMENTS

Resident demographic characteristics, comorbidities, LTCF stay, and LTBI testing and treatment.

RESULTS

Data for 291 LTCF residents admitted in 2011 were reviewed. Of the 257 without a history of LTBI and with documentation of testing, 162 (63%) were tested; 114 of 186 (61%) with a stay less than 90 days and 48 of 71 (68%) with a stay of 90 days or longer were tested. Of 196 residents with data on prior LTBI testing, 39 (19.9%) had LTBI; 12 of these (30.8%) were diagnosed at the LTCF. Hispanic participants were more likely than black participants to undergo LTBI testing (adjusted odds ratio (aOR) = 2.4, P = .003). Having a length of stay of less than 90 days (aOR = 0.7, P < .001) and history of illicit drug use (aOR = 0.7, P < .001) were associated with lower odds of LTBI testing.

CONCLUSION

One-fifth of LTCF residents had LTBI, but testing was not always performed. The high prevalence of LTBI in older adults combined with the risk of an outbreak if a case of tuberculosis occurs in a LTCF make LTBI testing and treatment an important prevention opportunity. The importance of LTBI testing in LTCFs needs to be reinforced.