New regimens to prevent tuberculosis in adults with HIV infection

Commit, Invest and Deliver: Towards Achieving End Tuberculosis Strategy Goals Through Active Case Finding and Preventive Treatment in China

This paper addresses the World Tuberculosis (TB) Day 2025 theme, "Yes! We can end TB! Commit, Invest, Deliver". Through comprehensive analysis of China's TB epidemic landscape and associated challenges, we align with the "National TB Prevention and Control Plan (2024-2030)" which emphasizes that building Zero-TB communities through the integration of "active case finding" and "TB preventive treatment (TPT)" represents a viable pathway toward ending the TB epidemic. Active case finding serves as a critical intervention for early detection and transmission reduction, while TPT constitutes an essential strategy for decreasing latent TB infection incidence. By facilitating the rapid expansion of Zero-TB communities through governmental commitment, strategic resource allocation, and coordinated implementation, we anticipate achieving the ultimate goal of TB epidemic elimination.

Predicted choice and acceptability of regimens for tuberculosis preventive treatment among people living with HIV in Uganda - a discrete choice experiment

Introduction

Little is known about how people living with HIV would choose if offered different tuberculosis preventive treatment (TPT) regimens, and under which conditions they would accept treatment. Actionable evidence regarding preference for TPT is needed to inform policy and the development of novel TPT regimens.

Methods

Adults engaged in care at an HIV clinic in Kampala, Uganda, completed a discrete choice experiment survey with nine random choice tasks. In each task, participants first chose between two hypothetical TPT regimens with differing treatment features (number of pills, frequency, duration, adjusted antiretroviral dosage, and side effects). Second, they answered if they would accept the selected treatment, versus taking no treatment. We simulated predicted TPT regimen choice based on hierarchical Bayesian estimation of individual preference weights.

Results

Among 400 participants, 394 gave high-quality answers and were included (median age 44, 71.8% female, 91.4% previously received TPT). Across nine tasks, 60.2% (237/394) accepted all selected TPT regimens, 39.3% (155/394) accepted some regimens, and 0.5% (2/394) accepted none. Regimens requiring antiretroviral dosage adjustment were more likely to be unacceptable (adjusted odds ratio, aOR 27.4, 95% confidence interval [CI] 18.5 - 40.7), as were regimens requiring more pills per dose (aOR 24.5 [95% CI 16.6 - 36.3] for 10 pills compared to 1 or 5 pills per dose). Choice simulations showed that if only 6 months of daily isoniazid (6H) was available, 11.9% would prefer no TPT. However, offering a 4-pill, fixed-dose combination 3HP regimen in addition to 6H increased the acceptability from 88.1% to 98.8% (predicted choice of 3HP 94.5%, 6H 4.4%, no TPT 1.2%).

Conclusions

While adults living with HIV in Uganda demonstrate a high willingness to accept different TPT regimens, offering regimens with preferred features, such as 3HP as a fixed-dose combination, could drive TPT acceptance and uptake from high to nearly universal.

A Situational Analysis and an Untapped Opportunity for Tackling Challenges Associated with Coverage of Tuberculosis Preventive Treatment: A Multi-Centric Study in India

OBJECTIVES

To assesses the coverage, adherence, reasons for non-initiation and non-completion of tuberculosis preventive treatment (TPT) among household child contacts (HHCC) of pulmonary tuberculosis (TB).

METHODS

This cross-sectional study was conducted across eight sites in India. Estimated sample size was 200 per site. Information was collected through record review and house-to-house visits of HHCCs of notified pulmonary TB cases during January to March 2022. Coverage and adherence was assessed by proportion of eligible HHCC initiated and completed TPT, respectively.

RESULTS

Of 2554 HHCCs eligible for TPT, initiation and completion rate was 34% and 22%, respectively. Across the sites the median time to conduct home visit was 14 d (IQR 9, 22) and TPT initiation was 7 d (IQR 1, 21). Reasons for the non-initiation were no information provided by paramedical workers (82%), information provided by paramedical workers but TPT was not given (19%), parents felt it's not important (9%), and fear of side-effects (3%). Reasons for non-completion were: TPT received for less than six months (from healthcare providers) (54%), advised for the lesser duration TPT by the doctors (4%), parents felt completion was not important (32%), parents' fear of side-effects or myth (5%), and HHCC complained of side-effect (0.7%).

CONCLUSIONS

Inadequate emphasis on home visits leads to TPT initiation in only one-third and completion in less than one-fourth of eligible HHCCs. This poor coverage was primarily due to the health system related issues. Rarely reported TPT side-effects highlighted its safety.

Tuberculosis Preventive Treatment in High TB-Burden Settings: A State-of-the-Art Review

Tuberculosis (TB) is the leading cause of death from a single infectious agent. The burden is highest in some low- and middle-income countries. One-quarter of the world's population is estimated to have been infected with TB, which is the seedbed for progressing from TB infection to the deadly and contagious disease itself. Although some individuals may clear their infections through innate and acquired immunity, many do not. People living with HIV, TB-exposed household contacts, other individuals recently infected, and immunosuppressed individuals are at especially high risk of progressing to TB disease. There have been major advances in recent years to support the programmatic management of TB infection. New tests of infection, including those that predict progression to TB disease, have become available. Numerous World Health Organization-recommended TB preventive treatment (TPT) regimens are available for all ages and for both drug-susceptible and drug-resistant TB infection. All regimens are generally safe, efficacious, and cost effective and have a low risk of generating resistance. TPT is recommended for pregnant women who are at risk for developing TB, but some regimens are associated with an increased likelihood of poor obstetric and fetal outcomes, and newer regimens have not yet been tested in pregnancy. New formulations of rifapentine-based TPT have been developed, and the cost has been radically reduced. Innovative models of delivery to support the scale up of TPT have been developed. Modeling suggests that scaling up TPT, especially regimens with optimal target product profile characteristics, can contribute substantially to ending the TB epidemic. The global uptake of TPT has increased substantially, especially for people living with HIV. Implementation gaps remain, particularly for children, pregnant women, and other household contacts. Further innovation is required to support the continued scale up of TPT and to contribute to ending the TB epidemic.

A Meta-Analysis of Levofloxacin for Contacts of Multidrug-Resistant Tuberculosis

BACKGROUND

Data from randomized trials evaluating the effectiveness of tuberculosis (TB) preventive treatment for contacts of multidrug-resistant (MDR)-TB are lacking. Two recently published randomized trials that did not achieve statistical significance provide the opportunity for a meta-analysis.

METHODS

We conducted combined analyses of two phase 3 trials of levofloxacin MDR-TB preventive treatment - Levofloxacin for the Prevention of Multidrug-Resistant Tuberculosis (VQUIN) trial and the Levofloxacin preventive treatment in children exposed to MDR-TB (TB-CHAMP) trial. Following MDR-TB household exposure, VQUIN enrolled mainly adults in Vietnam; TB-CHAMP enrolled mainly young children in South Africa. Random assignment in both trials was 1:1 at the household level to daily levofloxacin or placebo for 6 months. The primary outcome was incident TB by 54 weeks. We estimated the treatment effect overall using individual participant data meta-analysis.

RESULTS

The VQUIN trial (n=2041) randomly assigned 1023 participants to levofloxacin and 1018 participants to placebo; TB-CHAMP (n=922) assigned 453 participants to levofloxacin and 469 participants to placebo. Median age was 40 years (interquartile range 28 to 52 years) in VQUIN and 2.8 years (interquartile range 1.3 to 4.2 years) in TB-CHAMP. Overall, 8 levofloxacin-group participants developed TB by 54 weeks versus 21 placebo-group participants; the relative difference in cumulative incidence was 0.41 (95% confidence interval [CI] 0.18 to 0.92; P=0.03). No association was observed between levofloxacin and grade 3 or above adverse events (risk ratio 1.07, 95% CI 0.70 to 1.65). Musculoskeletal events of any grade occurred more frequently in the levofloxacin group (risk ratio 6.36, 95% CI 4.30 to 9.42), but not among children under 10 years of age. Overall, four levofloxacin-group participants and three placebo-group participants had grade 3 events.

CONCLUSIONS

In this meta-analysis of two randomized trials, levofloxacin was associated with a 60% relative reduction in TB incidence among adult and child household MDR-TB contacts, but with an increased risk of musculoskeletal adverse events. (Funded by the Australian National Health and Medical Research Council, UNITAID, and others.).

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.

Transcriptomic Signatures of Progression to Tuberculosis Disease Among Close Contacts in Brazil

BACKGROUND

Approximately 5% of people infected with Mycobacterium tuberculosis progress to tuberculosis (TB) disease without preventive therapy. There is a need for a prognostic test to identify those at highest risk of incident TB so that therapy can be targeted. We evaluated host blood transcriptomic signatures for progression to TB disease.

METHODS

Close contacts (≥4 hours of exposure per week) of adult patients with culture-confirmed pulmonary TB were enrolled in Brazil. Investigation for incident, microbiologically confirmed, or clinically diagnosed pulmonary or extrapulmonary TB disease through 24 months of follow-up was symptom triggered. Twenty previously validated blood TB transcriptomic signatures were measured at baseline by real-time quantitative polymerase chain reaction. Prognostic performance for incident TB was tested by receiver operating characteristic curve analysis at 6, 9, 12, and 24 months of follow-up.

RESULTS

Between June 2015 and June 2019, 1854 close contacts were enrolled. Twenty-five progressed to incident TB, of whom 13 had microbiologically confirmed disease. Baseline transcriptomic signature scores were measured in 1789 close contacts. Prognostic performance for all signatures was best within 6 months of diagnosis. Seven signatures (Gliddon4, Suliman4, Roe3, Roe1, Penn-Nicholson6, Francisco2, and Rajan5) met the minimum World Health Organization target product profile for a prognostic test through 6 months and 3 signatures (Gliddon4, Rajan5, and Duffy9) through 9 months. None met the target product profile threshold through ≥12 months of follow-up.

CONCLUSIONS

Blood transcriptomic signatures may be useful for predicting TB risk within 9 months of measurement among TB-exposed contacts to target preventive therapy administration.

The 3 HP regimen for tuberculosis preventive treatment: safety, dosage and related concerns during its large-scale implementation in countries like India

The 3-month once-weekly isoniazid-rifapentine (3 HP) regimen for tuberculosis preventive treatment recommended by WHO is being rolled in countries including India. It has higher completion rates and lower risk of hepatotoxicity than isoniazid preventive treatment, but trials also showed higher frequency of systemic drug reactions (SDRs) including flu-like syndromes and dizziness, and also uncommon Grade 3 or 4 adverse events like hypotension, syncope, bronchospasm. Low BMI is a risk factor for SDRs. Available data on safety of 3 HP in the Asian region is limited, heterogeneous, but points to a higher frequency of SDRs suggesting a need for caution in its large-scale implementation. 19% (118/614) of household contacts initiated on 3 HP in Delhi reported dizziness. Multiple lines of evidence including pharmacokinetic data suggest that the SDRs may be related to isoniazid and its plasma concentration. WHO and national guidelines for the 3 HP regimen currently recommend a fixed dose of once-weekly 900 mg isoniazid in adults regardless of body weight that poses a risk of SDRs for lower weight adults, amplified by the acetylator status and the lack of co-administration of pyridoxine. Weight based dosing, co-administration of pyridoxine and pharmacovigilance studies should accompany the roll out of 3 HP to ensure its safe and successful implementation.

Evaluating the implementation of weekly rifapentine-isoniazid (3HP) for tuberculosis prevention among people living with HIV in Uganda: A qualitative evaluation of the 3HP Options Trial

Three months of isoniazid-rifapentine (3HP) is being scaled up for tuberculosis (TB) preventive treatment (TPT) among people living with HIV (PLHIV) in high-burden settings. More evidence is needed to identify factors influencing successful 3HP delivery. We conducted a qualitative assessment of 3HP delivery nested within the 3HP Options Trial, which compared three optimized strategies for delivering 3HP: facilitated directly observed therapy (DOT), facilitated self-administered therapy (SAT), and patient choice between facilitated DOT and facilitated SAT at the Mulago HIV/AIDS clinic in Kampala, Uganda. We conducted 72 in-depth interviews among PLHIV purposively selected to investigate factors influencing 3HP acceptance and completion. We conducted ten key informant interviews with healthcare providers (HCPs) involved in 3HP delivery to identify facilitators and barriers at the clinic level. We used post-trial 3HP delivery data to assess sustainability. We used thematic analysis (inductive and deductive) to align the emergent themes with the RE-AIM framework dimensions to report implementation outcomes. Understanding the need for TPT, once-weekly dosing, shorter duration, and perceived 3HP safety enhanced acceptance overall. Treatment monitoring by HCPs and reduced risk of HIV status disclosure enabled DOT acceptance. Dosing autonomy enabled SAT acceptance. Switching between DOT and SAT as needed enabled acceptance of patient choice. Dosing reminders, reimbursement for clinical visits, and social support enabled 3HP completion; pill burden, side effects, and COVID-19-related treatment restrictions hindered completion. All HCPs were trained and participated in 3HP delivery with high fidelity. Training, care integration, prior TPT experience with daily isoniazid, and few 3HP-related serious adverse events enabled adoption, whereas initial concerns about 3HP safety among HCPs, and COVID-19 treatment disruptions delayed 3HP adoption. Refresher training and collaboration among HCPs enabled implementation whereas limited diagnostic facilities for adverse events at the clinic hindered implementation. SAT was modified post-trial; DOT was discontinued due to inadequate ongoing financial support beyond the study period. Facilitated delivery strategies made 3HP treatment convenient for PLHIV and were feasible and implemented with high fidelity by HCPs. However, the costs of 3HP facilitation may limit wider scale-up. Trial registration: ClinicalTrials.gov (NCT03934931); Registered 2nd May 2019; https://clinicaltrials.gov/study/NCT03934931?id = NCT03934931&rank = 1.

Tuberculosis prevention: current strategies and future directions

BACKGROUND

An estimated one fourth of the world's population is infected with Mycobacterium tuberculosis, and 5-10% of those infected develop tuberculosis in their lifetime. Preventing tuberculosis is one of the most underutilized but essential components of curtailing the tuberculosis epidemic. Moreover, current evidence illustrates that tuberculosis manifestations occur along a dynamic spectrum from infection to disease rather than a binary state as historically conceptualized. Elucidating determinants of transition between these states is crucial to decreasing the tuberculosis burden and reaching the END-TB Strategy goals as defined by the WHO. Vaccination, detection of infection, and provision of preventive treatment are key elements of tuberculosis prevention.

OBJECTIVES

This review provides a comprehensive summary of recent evidence and state-of-the-art updates on advancements to prevent tuberculosis in various settings and high-risk populations.

SOURCES

We identified relevant studies in the literature and synthesized the findings to provide an overview of the current state of tuberculosis prevention strategies and latest research developments.

CONTENT

We present the current knowledge and recommendations regarding tuberculosis prevention, with a focus on M. bovis Bacille-Calmette-Guérin vaccination and novel vaccine candidates, tests for latent infection with M. tuberculosis, regimens available for tuberculosis preventive treatment and recommendations in low- and high-burden settings.

IMPLICATIONS

Effective tuberculosis prevention worldwide requires a multipronged approach that addresses social determinants, and improves access to tuberculosis detection and to new short tuberculosis preventive treatment regimens. Robust collaboration and innovative research are needed to reduce the global burden of tuberculosis and develop new detection tools, vaccines, and preventive treatments that serve all populations and ages.

Concurrent TB and HIV therapies effectively control clinical reactivation of TB during co-infection but fail to eliminate chronic immune activation

The majority of Human Immunodeficiency Virus (HIV) negative individuals exposed to Mycobacterium tuberculosis (Mtb) control the bacillary infection as latent TB infection (LTBI). Co-infection with HIV, however, drastically increases the risk to progression to tuberculosis (TB) disease. TB is therefore the leading cause of death in people living with HIV (PLWH) globally. Combinatorial antiretroviral therapy (cART) is the cornerstone of HIV care in humans and reduces the risk of reactivation of LTBI. However, the immune control of Mtb infection is not fully restored by cART as indicated by higher incidence of TB in PLWH despite cART. In the macaque model of co-infection, skewed pulmonary CD4+ TEM responses persist, and new TB lesions form despite cART treatment. We hypothesized that regimens that concurrently administer anti-TB therapy and cART would significantly reduce TB in co-infected macaques than cART alone, resulting in superior bacterial control, mitigation of persistent inflammation and lasting protective immunity. We studied components of TB immunity that remain impaired after cART in the lung compartment, versus those that are restored by concurrent 3 months of once weekly isoniazid and rifapentine (3HP) and cART in the rhesus macaque (RM) model of LTBI and Simian Immunodeficiency Virus (SIV) co-infection. Concurrent administration of cART + 3HP did improve clinical and microbiological attributes of Mtb/SIV co-infection compared to cART-naïve or -untreated RMs. While RMs in the cART + 3HP group exhibited significantly lower granuloma volumes after treatment, they, however, continued to harbor caseous granulomas with increased FDG uptake. cART only partially restores the constitution of CD4 + T cells to the lung compartment in co-infected macaques. Concurrent therapy did not further enhance the frequency of reconstituted CD4+ T cells in BAL and lung of Mtb/SIV co-infected RMs compared to cART, and treated animals continued to display incomplete reconstitution to the lung. Furthermore, the reconstituted CD4+ T cells in BAL and lung of cART + 3HP treated RMs exhibited an increased frequencies of activated, exhausted and inflamed phenotype compared to LTBI RMs. cART + 3HP failed to restore the effector memory CD4+ T cell population that was significantly reduced in pulmonary compartment post SIV co-infection. Concurrent therapy was associated with the induction of Type I IFN transcriptional signatures and led to increased Mtb-specific TH1/TH17 responses correlated with protection, but decreased Mtb-specific TNFa responses, which could have a detrimental impact on long term protection. Our results suggest the mechanisms by which Mtb/HIV co-infected individuals remain at risk for progression due to subsequent infections or reactivation due of persisting defects in pulmonary T cell responses. By identifying lung-specific immune components in this model, it is possible to pinpoint the pathways that can be targeted for host-directed adjunctive therapies for TB/HIV co-infection.

Evaluating the implementation of weekly rifapentine-isoniazid (3HP) for tuberculosis prevention among people living with HIV in Uganda: A qualitative evaluation of the 3HP Options Trial

Three months of isoniazid-rifapentine (3HP) is being scaled up for tuberculosis (TB) preventive treatment (TPT) among people living with HIV (PLHIV) in high-burden settings. More evidence is needed to identify factors influencing successful 3HP delivery. We conducted a qualitative assessment of 3HP delivery nested within the 3HP Options Trial, which compared three optimized strategies for delivering 3HP: facilitated directly observed therapy (DOT), facilitated self-administered therapy (SAT), and patient choice between facilitated DOT and facilitated SAT at the Mulago HIV/AIDS clinic in Kampala, Uganda. We conducted 72 in-depth interviews among PLHIV purposively selected to investigate factors influencing 3HP acceptance and completion. We conducted ten key informant interviews with healthcare providers (HCPs) involved in 3HP delivery to identify facilitators and barriers at the clinic level. We used post-trial 3HP delivery data to assess sustainability. We conducted an inductive thematic analysis and aligned the emergent themes with the RE-AIM framework dimensions to report implementation outcomes. Understanding the need for TPT, once-weekly dosing, shorter duration, and perceived 3HP safety enhanced acceptance overall. Treatment monitoring by HCPs and reduced risk of HIV status disclosure enabled DOT acceptance. Dosing autonomy enabled SAT acceptance. Switching between DOT and SAT as required enabled acceptance for patient choice. Dosing reminders, reimbursement for clinical visits, and social support enabled 3HP completion; pill burden, side effects, and COVID-19-related treatment restrictions hindered completion. All HCPs were trained and participated in 3HP delivery with high fidelity. Training, care integration, and collaboration among HCPs enabled, whereas initial concerns about 3HP safety among HCPs delayed 3HP adoption and implementation. SAT was maintained post-trial; DOT was discontinued due to inadequate ongoing financial support beyond the study period. Facilitated delivery strategies made 3HP treatment convenient for PLHIV and were feasible and implemented with high fidelity by HCPs. However, the costs of 3HP facilitation may limit wider scale-up.

Long-Term Protective Effect of Tuberculosis Preventive Therapy in a Medium/High Tuberculosis Incidence Setting

BACKGROUND

The duration of the protective effect of tuberculosis preventive therapy (TPT) is controversial. Some studies have found that the protective effect of TPT is lost after cessation of therapy among people with human immunodeficiency virus (HIV) in settings with very high tuberculosis incidence, but others have found long-term protection in low-incidence settings.

METHODS

We estimated the incidence rate (IR) of new tuberculosis disease for up to 12 years after randomization to 4 months of rifampin or 9 months of isoniazid, among 991 Brazilian participants in a TPT trial in the state of Rio de Janeiro, with an incidence of 68.6/100 000 population in 2022. The adjusted hazard ratios (aHRs) of independent variables for incident tuberculosis were calculated.

RESULTS

The overall tuberculosis IR was 1.7 (95% confidence interval [CI], 1.01- 2.7) per 1000 person-years (PY). The tuberculosis IR was higher among those who did not complete TPT than in those who did (2.9 [95% CI, 1.3-5.6] vs 1.1 [.4-2.3] per 1000 PY; IR ratio, 2.7 [1.0-7.2]). The tuberculosis IR was higher within 28 months after randomization (IR, 3.5 [95% CI, 1.6-6.6] vs 1.1 [.5-2.1] per 1000 PY between 28 and 143 months; IR ratio, 3.1 [1.2-8.2]). Treatment noncompletion was the only variable associated with incident tuberculosis (aHR, 3.2 [95% CI, 1.1-9.7]).

CONCLUSIONS

In a mostly HIV-noninfected population, a complete course of TPT conferred long-term protection against tuberculosis.

US Guidelines Fall Short on Short-Course Tuberculosis-Preventive Therapy

The provision of tuberculosis-preventive therapy (TPT) to vulnerable populations is critical for global control. Shorter-course TPT regimens are highly effective and improve completion rates. Despite incorporation of 1 month of rifapentine and isoniazid into global guidelines, current US TPT guidelines do not include this as a recommended regimen, but should.

Preference for daily (1HP) vs. weekly (3HP) isoniazid-rifapentine among people living with HIV in Uganda

BACKGROUND

Both 1 month of daily (1HP) and 3 months of weekly (3HP) isoniazid-rifapentine are recommended as short-course regimens for TB prevention among people living with HIV (PLHIV). We aimed to assess acceptability and preferences for 1HP vs. 3HP among PLHIV.

METHODS

In a cross-sectional survey among PLHIV at an HIV clinic in Kampala, Uganda, participants were randomly assigned to a hypothetical scenario of receiving 1HP or 3HP. Participants rated their level of perceived intention and confidence to complete treatment using a 0-10 Likert scale, and chose between 1HP and 3HP.

RESULTS

Among 429 respondents (median age: 43 years, 71% female, median time on ART: 10 years), intention and confidence were rated high for both regimens. Intention to complete treatment was rated at least 7/10 by 92% (189/206 randomized to 1HP) and 93% (207/223 randomized to 3HP). Respectively 86% (178/206) and 93% (208/223) expressed high confidence to complete treatment. Overall, 81% (348/429) preferred 3HP over 1HP.

CONCLUSIONS

Both 1HP and 3HP were highly acceptable regimens, with 3HP preferred by most PLHIV. Weekly, rather than daily, dosing appears preferable to shorter duration of treatment, which should inform scale-up and further development of short-course regimens for TB prevention.

Uptake and Completion of Tuberculosis Preventive Treatment Using 12-Dose, Weekly Isoniazid-Rifapentine Regimen in Bangladesh: A Community-Based Implementation Study

BACKGROUND

The United Nations high-level meeting (UNHLM) pledged to enroll 30 million in tuberculosis preventive treatment (TPT) by 2022, necessitating TPT expansion to all at tuberculosis (TB) risk. We assessed the uptake and completion of a 12-dose, weekly isoniazid-rifapentine (3HP) TPT regimen.

METHODS

Between February 2018 and March 2019 in Dhaka, community-based TPT using 3HP targeted household contacts of 883 confirmed drug-sensitive pulmonary TB patients. Adhering to World Health Organization guidelines, contacts underwent active TB screening before TPT initiation.

RESULTS

Of 3193 contacts who were advised health facility visits for screening, 67% (n = 2149) complied. Among these, 1804 (84%) received chest X-rays. Active TB was diagnosed in 39 (2%) contacts; they commenced TB treatment. Over 97% of 1216 contacts began TPT, with completion rates higher among females, those with more education and income, non-slum residents, and those without 3HP-related adverse events. Adverse events, mainly mild, occurred in 5% of participants.

CONCLUSIONS

The 3HP regimen, with its short duration, self-administered option, and minimal side effects, achieved satisfactory completion rates. A community-focused TPT approach is feasible, scalable nationally, and aligns with UNHLM targets.

Pharmacokinetics, Safety, and Tolerability of Once-Daily Darunavir With Cobicistat and Weekly Isoniazid/Rifapentine

BACKGROUND

Once-weekly isoniazid with rifapentine (HP) for 3 months is a recommended treatment for latent tuberculosis infection in persons with HIV. HP reduces exposures of certain antiretroviral medications, resulting in limited options for the concomitant use of these therapies. Here, we examined the pharmacokinetics (PK), safety, and tolerability of darunavir/cobicistat with HP.

METHODS

This was an open-label, fixed sequence, two-period crossover study in persons without HIV. Participants received darunavir 800 mg/cobicistat 150 mg once-daily alone for 4 days, then continued darunavir/cobicistat once-daily for days 5-19 with HP coadministration on days 5, 12, and 19. Intensive PK assessments were performed on days 4, 14, and 19. PK parameters were determined using noncompartmental methods. Geometric mean ratios with 90% confidence intervals (CIs) were calculated and compared between phases using mixed-effects models.

RESULTS

Thirteen participants were enrolled. Two withdrew after day 4, and one withdrew after day 14. Of the 3 withdrawals, 2 were attributed to drug-related adverse events. Darunavir area under the concentration-time curve, maximum concentrations (Cmax), and concentrations at 24 hours postdose (C24h) were reduced by 71%, 41%, and 96% ∼48-72 hours after HP administration (day 14), respectively, and 36%, 17%, and 89% with simultaneous HP administration (day 19), respectively. On day 14, 45% of the predose and 73% of C24h concentrations were below the darunavir EC50 (0.055 µg/mL).

CONCLUSIONS

Darunavir exposures were significantly decreased with HP coadministration. Temporal relationships between HP coadministration and the extent of induction or mixed inhibition/induction of darunavir metabolism were apparent. Coadministration of darunavir/cobicistat with 3HP should be avoided.

Prioritizing persons deprived of liberty in global guidelines for tuberculosis preventive treatment

In this Policy Forum piece, Aditya Narayan and colleagues discuss the challenges and opportunities for tuberculosis preventive treatment in carceral settings.

Efficacy of anti-tuberculosis drugs for the treatment of latent tuberculosis infection: a systematic review and network meta-analysis

Despite the availability of three network meta-analyses (NMA) examining the efficacy, treatment completion, and adverse events associated with all latent tuberculosis infection (LTBI) treatments, there is currently no evidence to support the notion that the benefits of these treatments outweigh the potential risks. This NMA aimed to conduct a comprehensive comparison and update of the efficacy, treatment completion rates and adverse events associated with recommended treatment options for LTBI for individuals with confirmed LTBI, as outlined in the 2020 World Health Organization (WHO) Consolidated Guidelines for TB preventive treatment. A comprehensive search of the MEDLINE and Scopus databases was conducted until April 2023. The NMA was applied to estimate the risk difference and corresponding 95% confidence interval (CI) using a combination of direct and indirect evidence. The risk-benefit assessment was employed to evaluate the feasibility of the extra benefits in relation to the extra risks. The primary outcomes of interest in this study were active TB disease, completion rates, and adverse events. The meta-analysis incorporated data from 15 studies, which collectively demonstrated that the administration of a placebo resulted in a significant increase in the risk of developing TB disease by 1.279%, compared to the daily intake of isoniazid for 6 months (6H). Furthermore, treatment completion rates were significantly higher when using isoniazid plus rifapentine weekly for 3 months (3HP) and rifampicin daily for 4 months (4R), as compared to 6H. Considering adverse events, the combination of 3HP, 4R, and isoniazid administered daily for 9 months (referred to as 9H) significantly decreased adverse events by 4.53% in comparison to 6H. The risk-benefit assessment showed that alternative treatment regimens (9H, 4R, 3HR and 3HP) had a lower incidence of adverse events, while demonstrating a higher efficacy in preventing TB, as compared to 6H. This review indicates that there were no significant differences observed among various active treatment options in terms of their efficacy in preventing active TB. Moreover, completion rates were higher in 3HP and 4R, and a reduction in adverse events was observed in 3HP, 4R, and 9H.

Completion, safety, and efficacy of tuberculosis preventive treatment regimens containing rifampicin or rifapentine: an individual patient data network meta-analysis

BACKGROUND

3 months of weekly rifapentine plus isoniazid (3HP) and 4 months of daily rifampicin (4R) are recommended for tuberculosis preventive treatment. As these regimens have not been compared directly, we used individual patient data and network meta-analysis methods to compare completion, safety, and efficacy between 3HP and 4R.

METHODS

We conducted a network meta-analysis of individual patient data by searching PubMed for randomised controlled trials (RCTs) published between Jan 1, 2000, and Mar 1, 2019. Eligible studies compared 3HP or 4R to 6 months or 9 months of isoniazid and reported treatment completion, adverse events, or incidence of tuberculosis disease. Deidentified individual patient data from eligible studies were provided by study investigators and outcomes were harmonised. Methods for network meta-analysis were used to generate indirect adjusted risk ratios (aRRs) and risk differences (aRDs) with their 95% CIs.

FINDINGS

We included 17 572 participants from 14 countries in six trials. In the network meta-analysis, treatment completion was higher for people on 3HP than for those on 4R (aRR 1·06 [95% CI 1·02-1·10]; aRD 0·05 [95% CI 0·02-0·07]). For treatment-related adverse events leading to drug discontinuation, risks were higher for 3HP than for 4R for adverse events of any severity (aRR 2·86 [2·12-4·21]; aRD 0·03 [0·02-0·05]) and for grade 3-4 adverse events (aRR 3·46 [2·09-6·17]; aRD 0·02 [0·01-0·03]). Similar increased risks with 3HP were observed with other definitions of adverse events and were consistent across age groups. No difference in the incidence of tuberculosis disease between 3HP and 4R was found.

INTERPRETATION

In the absence of RCTs, our individual patient data network meta-analysis indicates that 3HP provided an increase in treatment completion over 4R, but was associated with a higher risk of adverse events. Although findings should be confirmed, the trade-off between completion and safety must be considered when selecting a regimen for tuberculosis preventive treatment.

FUNDING

None.

TRANSLATIONS

For the French and Spanish translations of the abstract see Supplementary Materials section.

Understanding patient-level costs of weekly isoniazid-rifapentine (3HP) among people living with HIV in Uganda

BACKGROUND: Twelve weeks of weekly isoniazid and rifapentine (3HP) prevents TB disease among people with HIV (PWH), but the costs to people of taking TB preventive treatment is not well described.METHODS: We surveyed PWH who initiated 3HP at a large urban HIV/AIDS clinic in Kampala, Uganda, as part of a larger trial. We estimated the cost of one 3HP visit from the patient perspective, including both out-of-pocket costs and estimated lost wages. Costs were reported in 2021 Ugandan shillings (UGX) and US dollars (USD; USD1 = UGX3,587)RESULTS: The survey included 1,655 PWH. The median participant cost of one clinic visit was UGX19,200 (USD5.36), or 38.5% of the median weekly income. Per visit, the cost of transportation was the largest component (median: UGX10,000/USD2.79), followed by lost income (median: UGX4,200/USD1.16) and food (median: UGX2,000/USD0.56). Men reported greater income loss than women (median: UGX6,400/USD1.79 vs. UGX3,300/USD0.93), and participants who lived further than a 30-minute drive to the clinic had higher transportation costs than others (median: UGX14,000/USD3.90 vs. UGX8,000/USD2.23).CONCLUSION: Patient-level costs to receive 3HP accounted for over one-third of weekly income. Patient-centered approaches to averting or defraying these costs are needed.

Updated considerations in the diagnosis and management of tuberculosis infection and disease: integrating the latest evidence-based strategies

INTRODUCTION

Tuberculosis (TB) is a leading infectious cause of global morbidity and mortality, affecting nearly a quarter of the human population and accounting for over 10 million deaths each year. Over the past several decades, TB incidence and mortality have gradually declined, but 2021 marked a threatening reversal of this trend highlighting the importance of accurate diagnosis and effective treatment of all forms of TB.

AREAS COVERED

This review summarizes advances in TB diagnostics, addresses the treatment of people with TB infection and TB disease including recent evidence for treatment regimens for drug-susceptible and drug-resistant TB, and draws attention to special considerations in children and during pregnancy.

EXPERT OPINION

Improvements in diagnosis and management of TB have expanded the available options for TB control. Molecular testing has enhanced the detection of TB disease, but better diagnostics are still needed, particularly for certain populations such as children. Novel treatment regimens have shortened treatment and improved outcomes for people with TB. However, important questions remain regarding the optimal management of TB. Work must continue to ensure the potential of the latest developments is realized for all people affected by TB.

Viral suppression among adults with HIV receiving routine dolutegravir-based antiretroviral therapy and 3 months weekly isoniazid-rifapentine

OBJECTIVE

We aimed to evaluate safety of 3 months weekly isoniazid-rifapentine (3HP) for tuberculosis (TB) prevention when co-administered with dolutegravir-based antiretroviral therapy (TLD), and compare viral suppression among those initiating TLD + 3HP vs. TLD alone.

DESIGN/METHODS

We analyzed data from an ongoing Phase 3 randomized trial comparing TB screening strategies among adults with CD4 + ≤350 cells/μl initiating routine antiretroviral therapy (ART) in Kampala, Uganda. TB screen-negative participants without contraindications are referred for self-administered 3HP. HIV viral load is routinely measured at 6 and 12 months. Here, we included TB-negative participants who initiated TLD with or without 3HP. We determined the number who discontinued 3HP due to drug toxicity. In addition, we assessed viral suppression at 6 and 12 months and used log-binomial regression to assess risk of viremia at 6 months for participants who initiated TLD + 3HP vs. TLD alone.

RESULTS

Of 453 participants initiating TLD (287 [63.4%] female, median age 30 years [interquartile range (IQR) 25-37], median pre-ART CD4 + cell count 188 cells/μl [IQR 86-271]), 163 (36.0%) initiated 3HP. Of these, 154 (94.5%) completed 3HP and one (0.6%) had treatment permanently discontinued due to a possible 3HP-related adverse event. At 6 months, for participants who received TLD + 3HP, risk of viremia >50 copies/ml was 1.51 [95% confidence interval (CI) 1.07-2.14] times that of participants who received TLD alone. There was no difference in viral suppression between those who received TLD + 3HP vs. TLD alone at 12 months.

CONCLUSIONS

Co-administration of TLD + 3HP was well tolerated. However, those who received TLD + 3HP were less likely to achieve viral suppression within six-months compared to those who received TLD alone.

Efficacy and safety of different regimens in the treatment of patients with latent tuberculosis infection: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Treatment of latent tuberculosis infection (LTBI) is effective in preventing progression to TB disease. This study aimed to synthesize available evidence on the efficacy, adherence, and safety of LTBI treatment in order to assist policymakers to design appropriate national treatment policies and treatment protocols.

METHOD

The PRISMA-NMA was used to review and report this research. Randomized controlled trials which compared the efficacy and safety of LTBI treatments were included. A systematic literature search was done to identify relevant articles from online databases PubMed/ MEDLINE, Embase, and Cochrane Center for Clinical Trial database (CENTRAL). The network meta-analysis was done using R- studio Version 1.4.1103.

RESULT

In this review, 42 studies were included, which enrolled 46,022 people who had recent contact with patients with active tuberculosis, evidence radiological of previous tuberculosis, tuberculin test equal or greater than 5 mm, radiographs that indicated inactive fibrotic or calcified parenchymal and/or lymph node lesions, had conversion to positive results on a tuberculin skin test, participants living with HIV, chronic Silicosis, immigrants, prisoners, old people, and pregnant women who were at risk for latent TB were included. The incidence of TB among people living with HIV who have taken 3RH as TPT was lower, followed by 48%,followed by 6H (41%). However, 3HP has also the potential to reduce the incidence of TB by 36% among HIV negative patients who had TB contact history. Patients' adherence to TPT was higher among patients who have taken 4R (RR 1.38 95% CI 1.0,1.89) followed by 3RH (34%). The proportion of subjects who permanently discontinued a study drug because of an adverse event were three times higher in the 3RH treatment group. Furthermore, the risk of grade 3 and 4 liver toxicity was significantly higher in 9H followed by 1HP, and 6H.

CONCLUSION

From this review, it can be concluded 3RH and 6H has a significant impact on the reduction of TB incidence among PLWH and 3HP among HIV negative people who had TB contact history. However, combinations of rifampicin either with isoniazid were significantly associated with adverse events which resulted in permanent discontinuation among adult patients. Furthermore, grade 3 and 4 liver toxicity was more common in patents who have taken 9H, 1HP, and 6H. This may support the current recommended TPT regimen of 3HP, 3RH, and 6H.

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.

A Multistage Antigen Complex Epera013 Promotes Efficient and Comprehensive Immune Responses in BALB/c Mice

Tuberculosis (TB) remains a serious global health problem. Despite the widespread use of the Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine, the primary factor for the TB pandemic and deaths is adult TB, which mainly result from endogenous reactivation of latent Mycobacterium tuberculosis (MTB) infection. Improved new TB vaccines with eligible safety and long-lasting protective efficacy remains a crucial step toward the prevention and control of TB. In this study, five immunodominant antigens, including three early secreted antigens and two latency associated antigens, were used to construct a single recombinant fusion protein (Epera013f) and a protein mixture (Epera013m). When formulated with aluminum adjuvant, the two subunit vaccines Epera013m and Epera013f were administered to BALB/c mice. The humoral immune responses, cellular responses and MTB growth inhibiting capacity elicited after Epera013m and Epera013f immunization were analyzed. In the present study, we demonstrated that both the Epera013f and Epera013m were capable of inducing a considerable immune response and protective efficacy against H37Rv infection compared with BCG groups. In addition, Epera013f generated a more comprehensive and balanced immune status, including Th1, Th2 and innate immune response, over Epera013f and BCG. The multistage antigen complex Epera013f possesses considerable immunogenicity and protective efficacy against MTB infection ex vivo indicating its potential and promising applications in further TB vaccine development.

New and Repurposed Drugs for the Treatment of Active Tuberculosis: An Update for Clinicians

Although tuberculosis (TB) is preventable and curable, the lengthy treatment (generally 6 months), poor patient adherence, high inter-individual variability in pharmacokinetics (PK), emergence of drug resistance, presence of comorbidities, and adverse drug reactions complicate TB therapy and drive the need for new drugs and/or regimens. Hence, new compounds are being developed, available drugs are repurposed, and the dosing of existing drugs is optimized, resulting in the largest drug development portfolio in TB history. This review highlights a selection of clinically available drug candidates that could be part of future TB regimens, including bedaquiline, delamanid, pretomanid, linezolid, clofazimine, optimized (high dose) rifampicin, rifapentine, and para-aminosalicylic acid. The review covers drug development history, preclinical data, PK, and current clinical development.

Contextualizing and optimizing novel strategies to improve the latent TB continuum of care: Insights from people living with HIV and health care providers in Brazil

Tuberculosis (TB) causes 1 in 3 deaths among people living with HIV (PLHIV). Diagnosing and treating latent tuberculosis infection (LTBI) is critical to reducing TB incidence and mortality. Blood-based screening tests (e.g., QuantiFERON-TB Gold Plus (QFT+)) and shorter-course TB preventive therapy (TPT) regimens such as 3HP (3 months weekly isoniazid-rifapentine) hold significant promise to improve TB outcomes. We qualitatively explored barriers and solutions to optimizing QFT+ and 3HP among PLHIV in three cities in Brazil. We conducted 110 in-depth interviews with PLHIV, health care providers (HCP) and key informants (KI). Content analysis was conducted including the use of case summaries and comparison of themes across populations and contexts. LTBI screening and treatment practices were dependent on HCP's perceptions of whether they were critical to improving TB outcomes. Many HCP lacked a strong understanding of LTBI and perceived the current TPT regimen as complicated. HCP reported that LTBI screening and treatment were constrained by clinic staffing challenges. While PLHIV generally expressed willingness to consider any test or treatment that doctors recommended, they indicated HCP rarely discussed LTBI and TPT. TB testing and treatment requests were constrained by structural factors including financial and food insecurity, difficulties leaving work for appointments, stigma and family responsibilities. QFT+ and 3HP were viewed by all participants as tools that could significantly improve the LTBI cascade by avoiding complexities of TB skin tests and longer LTBI treatment courses. QFT+ and 3HP were perceived to have challenges, including the potential to increase workload on over-burdened health systems if not implemented alongside improved supply chains, staffing, and training, and follow-up initiatives. Multi-level interventions that increase understanding of the importance of LTBI and TPT among HCP, improve patient-provider communication, and streamline clinic-level operations related to QFT+ and 3HP are needed to optimize their impact among PLHIV and reduce TB mortality.

Landscape of TB Infection and Prevention among People Living with HIV

Tuberculosis (TB) is one of the leading causes of mortality in people living with HIV (PLHIV) and contributes to up to a third of deaths in this population. The World Health Organization guidelines aim to target early detection and treatment of TB among PLHIV, particularly in high-prevalence and low-resource settings. Prevention plays a key role in the fight against TB among PLHIV. This review explores TB screening tools available for PLHIV, including symptom-based screening, chest radiography, tuberculin skin tests, interferon gamma release assays, and serum biomarkers. We then review TB Preventive Treatment (TPT), shown to reduce the progression to active TB and mortality among PLHIV, and available TPT regimens. Last, we highlight policy-practice gaps and barriers to implementation as well as ongoing research needs to lower the burden of TB and HIV coinfection through preventive activities, innovative diagnostic tests, and cost-effectiveness studies.

Tuberculosis Infection in Pregnant People: Current Practices and Research Priorities

Women are significantly more likely to develop tuberculosis (TB) disease within the first 90 days after pregnancy than any other time in their lives. Whether pregnancy increases risk of progression from TB infection (TBI) to TB disease is unknown and is an active area of investigation. In this review, we discuss the epidemiology of TB and TBI in pregnancy, TBI diagnostics, and prevalence in pregnancy. We also review TBI treatment and highlight research priorities, such as short-course TB prevention regimens, drug-resistant TB prevention, and additional considerations for safety, tolerability, and pharmacokinetics that are unique to pregnant and postpartum people.

Pregnancy in Women With HIV in a Tuberculosis Preventive Therapy Trial

BACKGROUND

Tuberculosis preventive therapy (TPT) is recommended for people with HIV infection, including during pregnancy. The effect of TPT exposure at conception and during pregnancy is poorly documented.

METHODS

We report pregnancy outcomes among South African women with HIV enrolled in a randomized trial of 4 TPT regimens (two 3-month regimens, rifapentine/isoniazid [3HP] or rifampin/isoniazid [3HR], isoniazid for 6 months, or isoniazid continuously). Descriptive statistics and risk ratios were assessed to examine relationships between study regimens and outcomes.

RESULTS

216/896 women (24%) conceived during the study. Women who conceived were younger (27.9 vs 31.3 years) and had higher mean CD4 counts (589.1 vs 536.7). The odds of pregnancy were higher in women in the rifamycin-isoniazid arms than those in the isoniazid arms (3HP: relative risk [RR] 1.73, P = 0.001; 3HR:RR 1.55, P = 0.017) despite increased contraceptive use compared with the standard 6H therapy. Thirty-four women became pregnant while taking preventive treatment (8 rifamycin and 26 isoniazid monotherapy). Pregnancy outcomes in these women were as follows: 17 (50%) mother/baby healthy, 3 (9%) spontaneous abortions, 6 (18%) elective abortions, 1 (3%) premature delivery, 2 (6%) neonatal deaths [1 rifamycin-isoniazid and 1 isoniazid], and 5 (15%) unknown.

CONCLUSIONS

Pregnancy was common in women who had received TPT and more frequent in women who had received rifamycin-isoniazid-based regimens.

Evidence for Implementation: Management of TB in HIV and Pregnancy

PURPOSE OF REVIEW

Pregnant people living with HIV (PLWH) are at especially high risk for progression from latent tuberculosis infection (LTBI) to active tuberculosis (TB) disease. Among pregnant PLWH, concurrent TB increases the risk of complications such as preeclampsia, intrauterine fetal-growth restriction, low birth weight, preterm-delivery, perinatal transmission of HIV, and admission to the neonatal intensive care unit. The grave impact of superimposed TB disease on maternal morbidity and mortality among PLWH necessitates clear guidelines for concomitant therapy and an understanding of the pharmacokinetics (PK) and potential drug-drug interactions (DDIs) between antitubercular (anti-TB) agents and antiretroviral therapy (ART) in pregnancy.

RECENT FINDINGS

This review discusses the currently available evidence on the use of anti-TB agents in pregnant PLWH on ART. Pharmacokinetic and safety studies of anti-TB agents during pregnancy and postpartum are limited, and available data on second-line and newer anti-TB agents used in pregnancy suggest that several research gaps exist. DDIs between ART and anti-TB agents can decrease plasma concentration of ART, with the potential for perinatal transmission of HIV. Current recommendations for the treatment of LTBI, drug-susceptible TB, and multidrug-resistant TB (MDR-TB) are derived from observational studies and case reports in pregnant PLWH. While the use of isoniazid, rifamycins, and ethambutol in pregnancy and their DDIs with various ARTs are well-characterized, there is limited data on the use of pyrazinamide and several new and second-line antitubercular drugs in pregnant PLWH. Further research into treatment outcomes, PK, and safety data for anti-TB agent use during pregnancy and postpartum is urgently needed.

Testing and Treating Mycobacterium tuberculosis Infection

After infection with Mycobacterium tuberculosis, a minority of individuals will progress to tuberculosis disease (TB). The risk is higher among persons with well-established risk factors and within the first year after infection. Testing and treating individuals at high risk of progression maximizes the benefits of TB preventive therapy; avoiding testing of low-risk persons will limit potential harms. Several treatment options are available; rifamycin-based regimens offer the best efficacy-safety balance. In this review, we present an overview of the diagnosis and treatment of TB infection, and summarize common clinical scenarios.

Developing tuberculosis vaccines for people with HIV: consensus statements from an international expert panel

New tuberculosis vaccine candidates that are in the development pipeline need to be studied in people with HIV, who are at high risk of acquiring Mycobacterium tuberculosis infection and tuberculosis disease and tend to develop less robust vaccine-induced immune responses. To address the gaps in developing tuberculosis vaccines for people with HIV, a series of symposia was held that posed six framing questions to a panel of international experts: What is the use case or rationale for developing tuberculosis vaccines? What is the landscape of tuberculosis vaccines? Which vaccine candidates should be prioritised? What are the tuberculosis vaccine trial design considerations? What is the role of immunological correlates of protection? What are the gaps in preclinical models for studying tuberculosis vaccines? The international expert panel formulated consensus statements to each of the framing questions, with the intention of informing tuberculosis vaccine development and the prioritisation of clinical trials for inclusion of people with HIV.

Preventive Treatment for Household Contacts of Drug-Susceptible Tuberculosis Patients

People who live in the household of someone with infectious pulmonary tuberculosis are at a high risk of tuberculosis infection and subsequent progression to tuberculosis disease. These individuals are prioritized for contact investigation and tuberculosis preventive treatment (TPT). The treatment of TB infection is critical to prevent the progression of infection to disease and is prioritized in household contacts. Despite the availability of TPT, uptake in household contacts is poor. Multiple barriers prevent the optimal implementation of these policies. This manuscript lays out potential next steps for closing the policy-to-implementation gap in household contacts of all ages.

Evaluating the effect of short-course rifapentine-based regimens with or without enhanced behaviour-targeted treatment support on adherence and completion of treatment for latent tuberculosis infection among adults in the UK (RID-TB: Treat): protocol for an open-label, multicentre, randomised controlled trial

INTRODUCTION

The successful scale-up of a latent tuberculosis (TB) infection testing and treatment programme is essential to achieve TB elimination. However, poor adherence compromises its therapeutic effectiveness. Novel rifapentine-based regimens and treatment support based on behavioural science theory may improve treatment adherence and completion.

METHODS AND ANALYSIS

A pragmatic multicentre, open-label, randomised controlled trial assessing the effect of novel short-course rifapentine-based regimens for TB prevention and additional theory-based treatment support on treatment adherence against standard-of-care. Participants aged between 16 and 65 who are eligible to start TB preventive therapy will be recruited in England. 920 participants will be randomised to one of six arms with allocation ratio of 5:5:6:6:6:6: daily isoniazid +rifampicin for 3 months (3HR), routine treatment support (control); 3HR, additional treatment support; weekly isoniazid +rifapentine for 3 months (3HP), routine treatment support; weekly 3HP, additional treatment support ; daily isoniazid +rifapentine for 1 month (1HP), routine treatment support; daily 1HP, additional treatment support. Additional treatment support comprises reminders using an electronic pillbox, a short animation, and leaflets based on the perceptions and practicalities approach. The primary outcome is adequate treatment adherence, defined as taking ≥90% of allocated doses within the pre-specified treatment period, measured by electronic pillboxes. Secondary outcomes include safety and TB incidence within 12 months. We will conduct process evaluation of the trial interventions and assess intervention acceptability and fidelity and mechanisms for effect and estimate the cost-effectiveness of novel regimens. The protocol was developed with patient and public involvement, which will continue throughout the trial.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from The National Health Service Health Research Authority (20/LO/1097). All participants will be required to provide written informed consent. We will share the results in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

EudraCT 2020-004444-29.

Evaluation of TB elimination strategies in Canadian Inuit populations: Nunavut as a case study

Tuberculosis (TB) continues to disproportionately affect Inuit populations in Canada with some communities having over 300 times higher rate of active TB than Canadian-born, non-Indigenous people. Inuit Tuberculosis Elimination Framework has set the goal of reducing active TB incidence by at least 50% by 2025, aiming to eliminate it by 2030. Whether these goals are achievable with available resources and treatment regimens currently in practice has not been evaluated. We developed an agent-based model of TB transmission to evaluate timelines and milestones attainable in Nunavut, Canada by including case findings, contact-tracing and testing, treatment of latent TB infection (LTBI), and the government investment on housing infrastructure to reduce the average household size. The model was calibrated to ten years of TB incidence data, and simulated for 20 years to project program outcomes. We found that, under a range of plausible scenarios with tracing and testing of 25%–100% of frequent contacts of detected active cases, the goal of 50% reduction in annual incidence by 2025 is not achievable. If active TB cases are identified rapidly within one week of becoming symptomatic, then the annual incidence would reduce below 100 per 100,000 population, with 50% reduction being met between 2025 and 2030. Eliminating TB from Inuit populations would require high rates of contact-tracing and would extend beyond 2030. The findings indicate that time-to-identification of active TB is a critical factor determining program effectiveness, suggesting that investment in resources for rapid case detection is fundamental to controlling TB.

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TB elimination in Inuit populations would likely extend beyond timelines outlined in action plans.

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Rapid case findings combined with testing of frequent contacts are fundamental to TB control.

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Reducing average household size has minimal effect on rates of TB incidence.

Knowledge and Attitudes of Indonesian General Practitioners Towards the Isoniazid Preventive Therapy Program in Indonesia

OBJECTIVES

The Indonesian Ministry of Health launched isoniazid preventive therapy (IPT) in 2016, with general practitioners (GPs) at the frontline of this program. However, the extent to which GPs have internalized this program remains uncertain. The aim of this study was to identify the knowledge and attitudes of GPs towards the IPT program in Indonesia.

METHODS

This study used an online, self-administered questionnaire distributed via e-mail and social messaging services. A logistic regression model was employed to identify the explanatory variables influencing the level of knowledge and attitudes toward IPT among GPs in Indonesia. An empirical analysis was conducted separately for each response variable (knowledge and attitudes).

RESULTS

Of the 418 respondents, 128 (30.6%) had a good knowledge of IPT. Working at a public hospital was the only variable associated with good knowledge, with an adjusted odds ratio (aOR) of 1.69 (95% confidence interval [CI], 1.02 to 2.81). Furthermore, 279 respondents (66.7%) had favorable attitudes toward IPT. In the adjusted logistic regression analysis, good knowledge (aOR, 0.55; 95% CI, 0.34 to 0.89), 1-5 years of work experience (aOR, 2.09; 95% CI, 1.21 to 3.60), and having experienced IPT training (aOR, 0.48; 95% CI, 0.25 to 0.93), were significantly associated with favorable attitudes.

CONCLUSIONS

In general, GPs in Indonesia had favorable attitudes toward IPT. However, their knowledge of IPT was limited. GPs are an essential element of the IPT program in the country, and therefore, adequate information dissemination to improve their understanding is critical for the long-term viability and quality of the IPT program in Indonesia.

Isoniazid preventive therapy and tuberculosis transcriptional signatures in people with HIV

OBJECTIVES

To examine the association between isoniazid preventive therapy (IPT) or nontuberculous mycobacteria (NTM) sputum culture positivity and tuberculosis (TB) transcriptional signatures in people with HIV.

DESIGN

Cross-sectional study.

METHODS

We enrolled adults living with HIV who were IPT-naive or had completed IPT more than 6 months prior at HIV care clinics in western Kenya. We calculated TB signatures using gene expression data from qRT-PCR. We used multivariable linear regression to analyze the association between prior receipt of IPT or NTM sputum culture positivity with a transcriptional TB risk score, RISK6 (range 0-1). In secondary analyses, we explored the association between IPT or NTM positivity and four other TB transcriptional signatures.

RESULTS

Among 381 participants, 99.7% were receiving antiretroviral therapy and 86.6% had received IPT (completed median of 1.1 years prior). RISK6 scores were lower (mean difference 0.10; 95% confidence interval (CI): 0.06-0.15; P  < 0.001) among participants who received IPT than those who did not. In a model that adjusted for age, sex, duration of ART, and plasma HIV RNA, the RISK6 score was 52.8% lower in those with a history of IPT ( P  < 0.001). No significant association between year of IPT receipt and RISK6 scores was detected. There was no association between NTM sputum culture positivity and RISK6 scores.

CONCLUSION

In people with HIV, IPT was associated with significantly lower RISK6 scores compared with persons who did not receive IPT. These data support investigations of its performance as a TB preventive therapy response biomarker.

Isoniazid adherence reduces mortality and incident tuberculosis at 96 weeks among adults initiating antiretroviral therapy with advanced HIV in multiple high burden settings

Background

People with human immunodeficiency virus (HIV) and advanced immunosuppression initiating antiretroviral therapy (ART) remain vulnerable to tuberculosis (TB) and early mortality. To improve early survival, isoniazid preventive therapy (IPT) or empiric TB treatment have been evaluated; however, their benefit on longer-term outcomes warrants investigation.

Methods

We present a 96-week preplanned secondary analysis among 850 ART-naive outpatients (≥13 years) enrolled in a multicountry, randomized trial of efavirenz-containing ART plus either 6-month IPT (n = 426) or empiric 4-drug TB treatment (n = 424). Inclusion criteria were CD4 count <50 cells/mm³ and no confirmed or probable TB. Death and incident TB were compared by strategy arm using the Kaplan-Meier method. The impact of self-reported adherence (calculated as the proportion of 100% adherence) was assessed using Cox-proportional hazards models.

Results

By 96 weeks, 85 deaths and 63 TB events occurred. Kaplan-Meier estimated mortality (10.1% vs 10.5%; P = .86) and time-to-death (P = .77) did not differ by arm. Empiric had higher TB risk (6.1% vs 2.7%; risk difference, −3.4% [95% confidence interval, −6.2% to −0.6%]; P = .02) and shorter time to TB (P = .02) than IPT. Tuberculosis medication adherence lowered the hazards of death by ≥23% (P < .0001) in empiric and ≥20% (P < .035) in IPT and incident TB by ≥17% (P ≤ .0324) only in IPT.

Conclusions

Empiric TB treatment offered no longer-term advantage over IPT in our population with advanced immunosuppression initiating ART. High IPT adherence significantly lowered death and TB incidence through 96 weeks, emphasizing the benefit of ART plus IPT initiation and completion, in persons with advanced HIV living in high TB-burden, resource-limited settings.

Effect of different interventions for latent tuberculosis infections in China: a model-based study

BACKGROUND

Tuberculosis (TB) has a serious impact on people's health. China is one of 30 countries that has a high TB burden. As the currently decreasing speed of the incidence of TB, the WHO's goal of "End TB Strategy" is hard to achieve by 2035. As a result, a SEIR model that determines the impact of different tuberculosis preventive treatments (TPTs) in different age groups, and the effect of different interventions on latent TB infections (LTBIs) in China is developed.

METHODS

A Susceptible-Exposed-Infectious-Recovered (SEIR) model was established. Goodness-of-fit tests were used to assess model performance. Predictive analysis was used to assess the effect of different interventions on LTBIs and achieving the goals of the "End TB Strategy".

RESULTS

The Chi-square test indicated the model provided a good statistical fit to previous data on the incidence of TB (χ² = 0.3085, p > 0.999). The 1HP treatment regimen (daily rifapentine + isoniazid for 4 weeks) was most effective in reducing the number of TB cases by 2035. The model indicated that several strategies could achieve the 2035 target of the "End TB Strategy": completion of active case finding (ACF) for LTBI and TPT nation-wide within 5 years; completion of ACF for LTBIs and TPT within 2 years in high-incidence areas; completion of TPT in the elderly within 2 years; or introduction of a new vaccine in which the product of annual doses and vaccine efficiency in the three age groups above 14 years old reached 10.5 million.

CONCLUSION

The incidence of TB in China declined gradually from 2005 to 2019. Implementation of ACF for LTBIs and TPT nation-wide or in areas with high incidence, in the elderly, or administration of a new and effective vaccine could greatly reduce the number of TB cases and achieve the 2035 target of the "End TB Strategy" in China.

WHO target product profiles for TB preventive treatment

BACKGROUND: The WHO has developed target product profiles (TPPs) describing the most appropriate qualities for future TPT regimens to assist developers in aligning the characteristics of new treatments with programmatic requirements.METHODS: A technical consultation group was convened by the WHO to determine regimen attributes with greatest potential impact for patients (i.e., improved risk/benefit profile) and populations (i.e., reduction in transmission and TB prevalence). The group categorised regimen attributes as 'priority´ or 'desirable´; and defined for each attribute the minimum requirements and optimal targets.RESULTS: Nine priority attributes were defined, including efficacy, treatment duration, safety, drug-drug interactions, barrier to emergence of drug resistance, target population, formulation, dosage, frequency and route of administration, stability and shelf life. Regimens meeting optimal targets were characterised, for example, as having superior efficacy, treatment duration of ≤2 weeks, and improved tolerability and safety profile compared with current regimens. The four desirable attributes included regimen cost, safety in special populations, treatment adherence and need for drug susceptibility testing in the index patient.DISCUSSION: It may be difficult for a single regimen to satisfy all characteristics so regimen developers may have to consider trade-offs. Additional operational aspects may be relevant to the feasibility and public health impact of new TPT regimens.

Clinical standards for the diagnosis, treatment and prevention of TB infection

BACKGROUND: Tuberculosis (TB) preventive therapy (TPT) decreases the risk of developing TB disease and its associated morbidity and mortality. The aim of these clinical standards is to guide the assessment, management of TB infection (TBI) and implementation of TPT.METHODS: A panel of global experts in the field of TB care was identified; 41 participated in a Delphi process. A 5-point Likert scale was used to score the initial standards. After rounds of revision, the document was approved with 100% agreement.RESULTS: Eight clinical standards were defined: Standard 1, all individuals belonging to at-risk groups for TB should undergo testing for TBI; Standard 2, all individual candidates for TPT (including caregivers of children) should undergo a counselling/health education session; Standard 3, testing for TBI: timing and test of choice should be optimised; Standard 4, TB disease should be excluded prior to initiation of TPT; Standard 5, all candidates for TPT should undergo a set of baseline examinations; Standard 6, all individuals initiating TPT should receive one of the recommended regimens; Standard 7, all individuals who have started TPT should be monitored; Standard 8, a TBI screening and testing register should be kept to inform the cascade of care.CONCLUSION: This is the first consensus-based set of Clinical Standards for TBI. This document guides clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage TBI.

Implementing the 4R and 9H regimens for TB preventive treatment in Indonesia

BACK GROUND:

The implementation of tuberculosis preventive treatment (TPT) is challenging especially in resource-limited settings. As part of a Phase 3 trial on TPT, we described our experience with the use of rifampicin for 4 months (4R) and isoniazid for 9 months (9H) in Indonesia.

METHODS:

In 2011–2017, children and adults with latent TB infection were randomised to either 4R or 9H and followed until 16 months after randomisation for children and 28 months for adults. The primary outcome was the treatment completion rate. Secondary outcomes were Grade 3–5 adverse events (AEs), active TB occurrence, and health costs.

RESULTS:

A total of 157 children and 860 adults were enrolled. The 4R treatment completion rate was significantly higher than that of 9H (78.7% vs. 65.5%), for a rate difference of 13.2% (95% CI 7.1–19.2). No Grade 3–5 AEs were reported in children; in adults, it was lower in 4R (0.4%) compared to 9H (2.8%). The incidence of active TB was lower with 4R than with 9H (0.09/100 person-year vs. 0.36/100 person-year) (rate difference: −0.36/100 person-year). The total cost per patient was lower for the 4R regimen than for the 9H regimen (USD151.9 vs. USD179.4 in adults and USD152.9 vs. USD206.5 in children)

CONCLUSIONS:

Completion and efficacy rates for 4R were better than for 9H. Compared to 9H, 4R was cheaper in all age groups, safer in adults and equally safe in children. The Indonesian TB program could benefit from these benefits of the 4R regimen.