[Expert consensus on tuberculosis preventive treatment for individuals at high risk of developing active diseases from latent tuberculosis infection in comprehensive medical facilities].

Promoting tuberculosis preventive treatment (TPT) for individuals with latent tuberculosis infection (LTBI) who are at high risk of developing active tuberculosis (TB) is an important tool for accelerating the decline in TB incidence and achieving the global goals of the End TB strategy. As a country with a high burden of TB, China has implemented patient-centred strategies in the past, but TPT has not been systematically implemented. In the comprehensive medical facilities, there are many types of TPT target populations and their health situation is complex, which poses more challenges for TPT implementation. To improve the work of TPT in comprehensive medical institutions, experts organized by the Chinese Medical Association Respiratory Branch and the National Respiratory Medicine Center made the following evidence-based recommendations on the identification of TPT targets and the selection of TPT timing and regimen.Recommendation 1: Based on comprehensive clinical evaluation, patients in comprehensive medical facilities who are recommended to undergo LTBI testing and TPT include: HIV infections/AIDS patients (1B), patients treated with TNF-α antagonists (1C), patients receiving long-term hemodialysis/peritoneal dialysis (1D), patients planning to receive organ transplantation or bone marrow transplantation (1C), patients with silicosis (1D), patients using glucocorticoids or other immunosuppressants for a long-time (1D), infertile women receiving assisted reproduction (2D).Recommendation 2: For TPT target populations in comprehensive medical facilities, an appropriate diagnostic technology should be selected to test for MTB infection. After exclusion of active TB, TPT should be suggested to people with LTBI after comprehensive clinical evaluation (1D).Recommendation 3: In HIV infections/AIDS patients with LTBI, TPT should be started as soon as possible regardless of whether antiretroviral treatment has been initiated (1B).Recommendation 4: 6H, 9H, 3HR and 3H2P2 regimens could be used in HIV-HIV infections/AIDS patients with LTBI (1A).Recommendation 5: For HIV infections/AIDS patients at high risk of MTB exposure, it is recommended to use isoniazid alone for 36 months or longer for TPT (1B).Recommendation 6: In patients treated with TNF-α antagonists and with LTBI, 3HR and 3H2P2 regimen is recommended for TPT (1B).Recommendation 7: In patients treated with TNF-α antagonists and with LTBI, 6H regimen can be used as an alternative for those with contraindications to combined medication or drug-induced liver injury (1B). If necessary, the TPT cycle can be extended to 6 months, depending on the course of TNF-α antagonist use (1C).Recommendation 8: In patients treated with TNF-α antagonists and with LTBI, the timing of TPT should be based on clinical assessment. TNF-α antagonist treatment can be started 4 weeks after TPT in non-urgent disease states (1C), and can be given concomitantly in emergency states (1C).Recommendation 9: For patients who receive long-term hemodialysis or peritoneal dialysis and with LTBI, 6H regimen is recommended as the preferred regimen for TPT (2B).Recommendation 10: For patients who receive long-term hemodialysis or peritoneal dialysis and with LTBI, 3HR or 3H2P2 regimen can be used as alternatives based on clinical evaluation according to patient compliance (2D).Recommendation 11: The timing of TPT varies according to different dialysis methods: in patients on peritoneal dialysis, TPT is administered at regular doses and is not affected by the timing of administration; in patients on hemodialysis, it is recommended to administer after the completion of hemodialysis (1D).Recommendation 12: For recipients who are planning to receive organ transplantation or bone marrow transplantation and with LTBI, 9H regimen is recommended for TPT (1B).Recommendation 13: Prior to organ transplantation or bone marrow transplantation, it is recommended to screen the donor for LTBI. If the donor is LTBI positive, the recipient should be suggested for TPT (1D).Recommendation 14: For recipients who are planning to receive organ or bone marrow transplantation, TPT does not have to be completed before transplantation. TPT interrupted because of transplantation should be resumed as soon as possible when the condition is stable (1D).Recommendation 15: In patients who have undergone liver transplantation, if TPT is required, it is recommended to be carried out when post-transplant liver function is stable (1D).Recommendation 16: In silicosis patients with LTBI, 6H regimen is recommended for TPT (1D).Recommendation 17: For patients on long-term oral glucocorticoids (prednisone equivalent dose≥15 mg/d for more than 4 weeks) or other immunosuppressants and with LTBI, based on comprehensive clinical evaluation, 3H2P2 regimen is recommended for TPT. In patients with contraindications to combined medication, 6H or 9H can be used as an alternative (1B).Recommendation 18: In patients taking long-term oral glucocorticoids (prednisone equivalent dose≥15 mg/d for more than 4 weeks) or use other immunosuppressants and with LTBI, the timing of initiation of TPT should be determined by the status of the primary disease. If the condition permits, it is recommended to give priority to TPT for one month before initiating glucocorticoid or other immunosuppressive therapy (2D).Recommendation 19: It is recommended that infertile women undergoing assisted reproduction should undergo LTBI testing. For those with latent genital TB, TPT is recommended using regimen for active TB treatment. For those with LTBI and reproductive system samples that are negative for TB nucleic acid testing, 6H regimen is recommended for TPT (2D).

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

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

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

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

Mixed methods study on latent tuberculosis among agate stone workers and advocacy for testing silica dust exposed individuals in India.

The 2021 tuberculosis (TB) preventive treatment guidelines in India included silicosis as a screening group, yet latent TB infection (LTBI) testing for silica-dust-exposed individuals is underemphasized. Focusing on an estimated 52 million silica-dust-exposed workers, particularly agate-stone workers in Khambhat, Gujarat, our study aims to estimate LTBI prevalence, identify predictors, and gather insights from TB and silicosis experts. Employing a sequential explanatory mixed-methods approach, a cross-sectional study involved 463 agate-stone workers aged ≥ 20 years in Khambhat, using IGRA kits for LTBI testing. In-depth interviews with experts complemented quantitative findings. Among agate-stone workers, 58% tested positive for LTBI, with predictors including longer exposure, type of work, and BCG vaccination. Our findings reveal a nearly double burden of LTBI compared to the general population, particularly in occupations with higher silica dust exposure. Experts advocate for including silica-dust-exposed individuals in high-risk groups for LTBI testing, exploring cost-effective alternatives like improved skin sensitivity tests, and shorter TB preventive treatment regimens to enhance compliance. Future research should explore upfront TB preventive treatment for silica-dust-exposed individuals with high LTBI prevalence and optimal exposure duration. This study underscores the urgent need for policy changes and innovative approaches to TB prevention among silica-dust-exposed populations, impacting global occupational health strategies.

Partial recovery of tuberculosis preventive treatment in Brazil after pandemic drawback.

Brazil was heavily affected by COVID-19 both with death toll and economically, with absence of a centralized Federal Government response. Tuberculosis (TB) notifications decreased in 2020 but partial recovery was observed in 2021. We have previously shown a sharp (93%) reduction in TB preventive treatment notifications among five Brazilian cities with more than 1,000 notifications in 2021. We hypothesized TB preventive treatment would also recover. We updated the previous analysis by adding other cities that hold more than a 1,000 notifications until 2022. Data aggregated by 2-week periods were extracted from the Information System for Notifying People Undergoing Treatment for LTBI (IL-TB). Biweekly percentage change (BPC) of notifications until October 2022 and outcomes until July 2022 (in the two weeks of TB preventive treatment initiation) were analyzed using Joinpoint software. A total of 39,701 notifications in 11 cities were included, 66% from São Paulo and Rio de Janeiro, Brazil. We found a significant increase of TB preventive treatment notifications in the beginning of 2021 (BPC range 1.4-49.6), with sustained progression in seven out of the 11 cities. Overall, median completion rates were 65%. In most cities, a gradual and steady decrease of treatment completion rates was found, except for Rio de Janeiro and Manaus (Amazonas State, Brazil), where a BPC of 1.5 and 1.2, respectively, was followed by a sustained increase. Notifications and completion proportions of TB preventive treatment were heterogeneous, which partly reflects the heterogeneity in local response to the pandemic. We found that notifications were recovered, and that the sharp 2021 decrease was no longer observed, which suggests delays in notification. In conclusion, the sharp reductions in TB preventive treatment completion rates in most cities might have been caused by delays in reporting; however, the sustained and progressive decrease are a concern.

Treatment of Psoriasis Patients with Latent Tuberculosis Using IL-17 and IL-23 Inhibitors: A Retrospective, Multinational, Multicentre Study.

BACKGROUND: Tuberculosis has a major global impact. Immunocompetent hosts usually control this disease, resulting in an asymptomatic latent tuberculosis infection (LTBI). Because TNF inhibitors increase the risk of tuberculosis reactivation, current guidelines recommend tuberculosis screening before starting any biologic drug, and chemoprophylaxis if LTBI is diagnosed. Available evidence from clinical trials and real-world studies suggests that IL-17 and IL-23 inhibitors do not increase the risk of tuberculosis reactivation. OBJECTIVE: To evaluate psoriasis patients with treated or untreated newly diagnosed LTBI who received IL-17 and IL-23 inhibitors and the tolerability/safety of tuberculosis chemoprophylaxis. METHODS: This is a retrospective, observational, multinational study from a series of 14 dermatology centres based in Portugal, Spain, Italy, Greece and Brazil, which included adult patients with moderate-to-severe chronic plaque psoriasis and newly diagnosed LTBI who were treated with IL-23 or IL-17 inhibitors between January 2015 and March 2022. LTBI was diagnosed in the case of tuberculin skin test and/or interferon gamma release assay positivity, according to local guideline, prior to initiating IL-23 or IL-17 inhibitor. Patients with prior diagnosis of LTBI (treated or untreated) or treated active infection were excluded. RESULTS: A total of 405 patients were included; complete/incomplete/no chemoprophylaxis was administered in 62.2, 10.1 and 27.7% of patients, respectively. The main reason for not receiving or interrupting chemoprophylaxis was perceived heightened risk of liver toxicity and hepatotoxicity, respectively. The mean duration of biological treatment was 32.87 ± 20.95 months, and only one case of active tuberculosis infection (ATBI) was observed, after 14 months of treatment with ixekizumab. The proportion of ATBI associated with ixekizumab was 1.64% [95% confidence interval (CI): 0-5.43%] and 0% for all other agents and 0.46% (95% CI 0-1.06%) and 0% for IL-17 and IL-23 inhibitors, respectively (not statistically significant). CONCLUSIONS: The risk of tuberculosis reactivation in patients with psoriasis and LTBI does not seem to increase with IL-17 or IL-23 inhibitors. IL-17 or IL-23 inhibitors should be preferred over TNF antagonists when concerns regarding tuberculosis reactivation exists. In patients with LTBI considered at high risk for developing complications related to chemoprophylaxis, this preventive strategy may be waived before initiating treatment with IL-17 inhibitors and especially IL-23 inhibitors.

A multistage Sendai virus vaccine incorporating latency-associated antigens induces protection against acute and latent tuberculosis.

One-quarter of the world's population is infected with Mycobacterium tuberculosis (Mtb). After initial exposure, more immune-competent persons develop asymptomatic latent tuberculosis infection (LTBI) but not active diseases, creates an extensive reservoir at risk of developing active tuberculosis. Previously, we constructed a novel recombinant Sendai virus (SeV)-vectored vaccine encoding two dominant antigens of Mtb, which elicited immune protection against acute Mtb infection. In this study, nine Mtb latency-associated antigens were screened as potential supplementary vaccine candidate antigens, and three antigens (Rv2029c, Rv2028c, and Rv3126c) were selected based on their immune-therapeutic effect in mice, and their elevated immune responses in LTBI human populations. Then, a recombinant SeV-vectored vaccine, termed SeV986A, that expresses three latency-associated antigens and Ag85A was constructed. In murine models, the doses, titers, and inoculation sites of SeV986A were optimized, and its immunogenicity in BCG-primed and BCG-naive mice were determined. Enhanced immune protection against the Mtb challenge was shown in both acute-infection and latent-infection murine models. The expression levels of several T-cell exhaustion markers were significantly lower in the SeV986A-vaccinated group, suggesting that the expression of latency-associated antigens inhibited the T-cell exhaustion process in LTBI infection. Hence, the multistage quarter-antigenic SeV986A vaccine holds considerable promise as a novel post-exposure prophylaxis vaccine against tuberculosis.

Screening for tuberculosis infection and effectiveness of preventive treatment among people with HIV in low-incidence settings.

OBJECTIVE: To determine the yield of screening for latent tuberculosis infection (LTBI) among people with HIV (PWH) in low tuberculosis (TB) incidence countries (<10 TB cases per 100 000 persons). DESIGN: A systematic review and meta-analysis were performed to assess prevalence and predictive factors of LTBI, rate of TB progression, effect of TB preventive treatment (TPT), and numbers needed to screen (NNS). METHODS: PubMed and Cochrane Library were searched for studies reporting primary data, excluding studies on active or paediatric TB. We extracted LTBI cases, odds ratios, and TB incidences; pooled estimates using a random-effects model; and used the Newcastle-Ottawa scale for bias. RESULTS: In 51 studies with 65 930 PWH, 12% [95% confidence interval (CI) 10-14] had a positive LTBI test, which was strongly associated with origin from a TB-endemic country [odds ratio (OR) 4.7] and exposure to TB (OR 2.9). Without TPT (10 629 PWH), TB incidence was 28/1000 person-years (PY; 95% CI 12-45) for LTBI-test positive versus 4/1000 PY (95% CI 0-7) for LTBI-test-negative individuals. Among 625 PWH (1644 PY) receiving TPT, 15 developed TB (6/1000 PY). An estimated 20 LTBI-positive individuals would need TPT to prevent one case of TB, and numbers NNS to detect LTBI or prevent active TB varied according to a-priori risk of LTBI. CONCLUSION: The relatively high prevalence of LTBI among PWH and the strong correlation with origin from a TB-endemic country support risk-stratified LTBI screening strategies for PWH in low-incidence countries and treating those who test positive.

Analysis of Risk Factors for Developing Tuberculosis in Patients Who Received Prophylactic Latent Tuberculosis Infection Treatment with Experience of Biologic Medications.

Biologic medications have dramatically improved the treatment outcomes of immunological inflammatory diseases, but their immunosuppressive effects put patients at risk for tuberculosis (TB). We investigated the risk factors for developing TB in patients treated for latent tuberculosis infection (LTBI) who also had experience of using biologic medications. At Keio University Hospital, we retrospectively investigated patients treated with anti-mycobacterial drugs before or concurrently with biologic medications from January 2012 to August 2020. Patients in the 'follow-on cases group' who had a positive TB screening test after initiating biologic medications and subsequently started LTBI treatment were excluded. We researched and compared the patient characteristics for TB and non-TB patient groups. Of the 146 eligible patients, 5 (3.4%) developed TB. The incidence rate was 600/100000 person-years. There were no significant differences between TB and non-TB patient groups in the history of TB, interferon-gamma release assay (IGRA), duration of biologic medication therapy, LTBI treatment periods, concomitant use of calcineurin inhibitors or anti-rheumatic drugs. The percentage of patients who received prednisolone at a dose of ≥15 mg for more than 1 month was higher in those who developed TB than in those who did not (40.0 vs. 7.1%, p = 0.054); however, this difference was not statistically significant. Regular monitoring of TB is necessary for long-term concomitant use of high prednisolone doses during and after the administration of biologic medications.

Tuberculosis screening characteristics amongst freshmen in Changping District, Beijing, China.

BACKGROUND: Screening for Tuberculosis (TB) is a critical tactic for minimizing the prevalence of illness within schools. Tuberculosis Preventive Therapy (TPT), in turn, effectively staves off the development of TB from latent tuberculosis infection (LTBI). Unfortunately, there is limited research on LTBI and TPT among students. This study aimed to assess LTBI among freshmen in Changping District and advocate for the implementation of TPT. METHODS: The prospective study collected data from 12 educational institutions within the Changping District of Beijing. The Kolmogorov - Smirnov test and other statistical methods were used for statistical analysis, [Formula: see text] was obtained using the formula [Formula: see text] nΣA2/nRnC-1, df = (C-1) (R-1). We analyzed potential factors impacting the LTBI rate, and scrutinized the possible causes behind the low application of TPT and its efficacy for LTBI treatment, China. RESULTS: Among 19,872 freshmen included in this study, 18 active TB cases (91 per 10,0000) and 2236 LTBI cases (11.6% of 19,223) were identified, respectively. Furthermore, of those with LTBI, 1045 (5.4% of 19,223) showed a strong positive for purified protein derivative (PPD), but only 312 opted for TB preventive treatment. There appeared to be no significant difference in the prevalence of LTBI and TPT rate between male and female students. Concurrently, 11 (71 per 100,000) and 7 (158 per 100,000) cases of active tuberculosis were identified in 6 universities and 6 higher vocational colleges, respectively. Interestingly, almost all freshmen who underwent TPT came from universities, suggesting a statistically significant disparity in TPT rate (χ2 = 139.829, P < 0.001) between these two types of educational institutions. Meanwhile, as for the age-wise distribution of latent infection among 17-20 years old freshmen, the LTBI rate exhibited 10.5%, 11.6%, 12.1% and 13.5%, respectively. Correlation between LTBI rate, the strong positive rate was statistically significant among different ages (χ2 = 34.559, P < 0.001). Over a follow-up period of 2 years, three students were diagnosed with active tuberculosis, one of which was resistant to rifampicin. All three students manifested a strong positive for PPD and declined preventive treatment during TB screening. CONCLUSIONS: The data indicates a high rate of LTBI amongst students in areas with a heavy TB burden, potentially leading to cross-regional TB transmission due to the migration of students. Education level might contribute to the limited uptake of TPT. Therefore, improving the implementation of TB preventive treatments is crucial in controlling and preventing TB across schools.

Latent TB infection in children and adolescents: Scientific rationale and programmatic management.

As we march towards the goals of TB elimination, one area of focus is on TB preventive therapy which deals with treatment of latent TB infection, the pool from which future TB cases are generated. Children are particularly vulnerable to disseminated TB and seriously ill TB like TB meningitis, which highlights the need for addressing latent TB infection in the age group of 0-18 years. The national TB elimination program has extended it's strategy to include TB preventive therapy from treating children <5 years and PLHIV to treating children ≥5 years, adolescents and adult household contacts of TB cases and at risk immunosuppressed groups. Newer regimens including weekly INH and Rifapentine for three months (3HP) has been recommended in the program. Concerns and opportunities for operational research in this area include surveillance and monitoring for drug toxicity and resistance, strategies to ensure adherence and improve treatment completion and outcomes.

Excluding Participants With Mycobacteria Infections From Clinical Trials: A Critical Consideration in Evaluating the Efficacy of BCG Against COVID-19.

In the context of the coronavirus disease 2019 (COVID-19) pandemic, Bacillus Calmette-Guérin (BCG), a tuberculosis (TB) vaccine, has been investigated for its potential to prevent COVID-19 with conflicting outcomes. Currently, over 50 clinical trials have been conducted to assess the effectiveness of BCG in preventing COVID-19, but the results have shown considerable variations. After scrutinizing the data, it was discovered that some trials had enrolled individuals with active TB, latent TB infection, or a history of TB. This finding raises concerns about the reliability and validity of the trial outcomes. In this study, we explore the potential consequences of including these participants in clinical trials, including impaired host immunity, immune exhaustion, and the potential masking of the BCG vaccine's protective efficacy against COVID-19 by persistent mycobacterial infections. We also put forth several suggestions for future clinical trials. Our study underscores the criticality of excluding individuals with active or latent TB from clinical trials evaluating the efficacy of BCG in preventing COVID-19.

Addressing mechanism bias in model-based impact forecasts of new tuberculosis vaccines.

In tuberculosis (TB) vaccine development, multiple factors hinder the design and interpretation of the clinical trials used to estimate vaccine efficacy. The complex transmission chain of TB includes multiple routes to disease, making it hard to link the vaccine efficacy observed in a trial to specific protective mechanisms. Here, we present a Bayesian framework to evaluate the compatibility of different vaccine descriptions with clinical trial outcomes, unlocking impact forecasting from vaccines whose specific mechanisms of action are unknown. Applying our method to the analysis of the M72/AS01E vaccine trial -conducted on IGRA+ individuals- as a case study, we found that most plausible models for this vaccine needed to include protection against, at least, two over the three possible routes to active TB classically considered in the literature: namely, primary TB, latent TB reactivation and TB upon re-infection. Gathering new data regarding the impact of TB vaccines in various epidemiological settings would be instrumental to improve our model estimates of the underlying mechanisms.

Facilitators and barriers for tuberculosis preventive treatment among patients with latent tuberculosis infection: a qualitative study.

BACKGROUND: Various factors influence tuberculosis preventive treatment (TPT) decisions thus it is important to understand the health beliefs and concerns of patients before starting TPT to ensure treatment compliance. This study aims to explore facilitators and barriers for TPT among patients diagnosed with Latent Tuberculosis infection (LTBI) attending six primary healthcare clinics in Selangor, Malaysia. METHOD: In-depth interviews were conducted face-to-face or via telephone among patients with a clinical diagnosis of LTBI using a semi-structured topic guide developed based on the common-sense model of self-regulation and literature review. Audio recordings of interviews were transcribed verbatim and analysed thematically. RESULTS: We conducted 26 In-depth interviews; Good knowledge of active tuberculosis (TB) and its associated complications, including the perceived seriousness and transmissibility of active TB, facilitates treatment. LTBI is viewed as a concern when immune status is compromised, thus fostering TPT. However, optimal health is a barrier for TPT. Owing to the lack of knowledge, patients rely on healthcare practitioners (HCPs) to determine their treatment paths. HCPs possessing comprehensive knowledge play a role in facilitating TPT whereas barriers to TPT encompass misinterpretation of tuberculin skin test (TST), inadequate explanation of TST, and apprehensions about potential medication side effects. CONCLUSIONS: Knowledge of LTBI can influence TPT uptake and patients often entrust their HCPs for treatment decisions. Improving knowledge of LTBI both among patients and HCPs can lead to more effective doctor-patient consultation and consequently boost the acceptance of TPT. Quality assurance should be enhanced to ensure the effective usage of TST as a screening tool.

Using Dynamic Oral Dosing of Rifapentine and Rifabutin to Simulate Exposure Profiles of Long-Acting Formulations in a Mouse Model of Tuberculosis Preventive Therapy.

Administration of tuberculosis preventive therapy (TPT) to individuals with latent tuberculosis infection is an important facet of global tuberculosis control. The use of long-acting injectable (LAI) drug formulations may simplify and shorten regimens for this indication. Rifapentine and rifabutin have antituberculosis activity and physiochemical properties suitable for LAI formulation, but there are limited data available for determining the target exposure profiles required for efficacy in TPT regimens. The objective of this study was to determine exposure-activity profiles of rifapentine and rifabutin to inform development of LAI formulations for TPT. We used a validated paucibacillary mouse model of TPT in combination with dynamic oral dosing of both drugs to simulate and understand exposure-activity relationships to inform posology for future LAI formulations. This work identified several LAI-like exposure profiles of rifapentine and rifabutin that, if achieved by LAI formulations, could be efficacious as TPT regimens and thus can serve as experimentally determined targets for novel LAI formulations of these drugs. We present novel methodology to understand the exposure-response relationship and inform the value proposition for investment in development of LAI formulations that have utility beyond latent tuberculosis infection.

How can we improve latent tuberculosis infection management using behaviour change wheel: a systematic review.

BACKGROUND: To ensure the effective delivery of latent tuberculosis infection (LTBI) care, it is vital to overcome potential challenges in LTBI management. This systematic review aims to identify the barriers and interventions to improve LTBI management using the Capability, Opportunity, and Motivation-Behaviour (COM-B) model and Behaviour Change Wheel (BCW). METHODS: A systematic literature search was performed on five electronic databases from database inception to 3 November 2021. A two-step technique was used in the data synthesis process: (i) the barriers of LTBI management were identified using the COM-B model, followed by (ii) mapping of intervention functions from BCW to address the identified barriers. RESULTS: Forty-seven eligible articles were included in this review. The findings highlighted the need for a multifaceted approach in tackling the barriers in LTBI management across the public, provider and system levels. The barriers were summarized into suboptimal knowledge and misperception of LTBI, as well as stigma and psychosocial burden, which could be overcome with a combination of intervention functions, targeting education, environment restructuring, persuasion, modelling, training, incentivization and enablement. CONCLUSIONS: The remedial strategies using BCW to facilitate policy reforms in LTBI management could serve as a value-added initiative in the global tuberculosis control and prevention program.

Preventive effects of Mycobacterium tuberculosis DNA vaccines on the mouse model with latent tuberculosis infection.

Background: About a quarter of the world's population with latent tuberculosis infection (LTBI) are the main source of active tuberculosis. Bacillus Calmette Guerin (BCG) cannot effectively control LTBI individuals from developing diseases. Latency-related antigens can induce T lymphocytes of LTBI individuals to produce higher IFN-γ levels than tuberculosis patients and normal subjects. Herein, we firstly compared the effects of M. tuberculosis (MTB) ag85ab and 7 latent DNA vaccines on clearing latent MTB and preventing its activation in the mouse LTBI model. Methods: A mouse LTBI model was established, and then immunized respectively with PBS, pVAX1 vector, Vaccae vaccine, ag85ab DNA and 7 kinds of latent DNAs (including rv1733c, rv2660c, rv1813c, rv2029c, rv2628, rv2659c and rv3407) for three times. The mice with LTBI were injected with hydroprednisone to activate the latent MTB. Then, the mice were sacrificed for the bacterial count, histopathological examination, and immunological evaluation. Results: Using chemotherapy made the MTB latent in the infected mice, and then using hormone treatment reactivated the latent MTB, indicating that the mouse LTBI model was successfully established. After the mouse LTBI model was immunized with the vaccines, the lung colony-forming units (CFUs) and lesion degree of mice in all vaccines group were significantly decreased than those in the PBS group and vector group (P<0.0001, P<0.05). These vaccines could induce antigen-specific cellular immune responses. The number of IFN-γ effector T cells spots secreted by spleen lymphocytes in the ag85ab DNA group was significantly increased than those in the control groups (P<0.05). In the splenocyte culture supernatant, IFN-γ and IL-2 levels in the ag85ab, rv2029c, and rv2659c DNA groups significantly increased (P<0.05), and IL-17A levels in ag85ab and rv2659c DNA groups also significantly increased (P<0.05). Compared with the PBS and vector groups, the proportion of CD4+CD25+FOXP3+ regulatory T cells in spleen lymphocytes of ag85ab, rv2660c, rv2029c, and rv3407 DNA groups were significantly reduced (P<0.05). Conclusions: MTB ag85ab and 7 kinds of latent DNA vaccines showed immune preventive efficacies on a mouse model of LTBI, especially the rv2659c, and rv1733c DNA. Our findings will provide candidates for the development of new multi-stage vaccines against TB.

[Progress in research of prophylactic therapy in contacts of rifampicin-resistant tuberculosis patients].

Tuberculosis (TB) prophylactic therapy for latent infection, which can reduce the risk for the development of active TB, is an important measure in TB control. China recommends prophylactic therapy for latent tuberculosis infection (LTBI) in some key populations to reduce the risk for TB. Contacts of patients with multi-drug and rifampicin-resistant TB (MDR/RR-TB) are at high risk for the infection with drug-resistant pathogen, however, no unified prophylactic therapy regimen has been recommended for LTBI due to exposure to MDR/RR-TB patients. This paper summarizes the current MDR/RR-TB prophylactic therapy regimen and its protection effect based on the results of the retrieval of literature, guidelines, expert consensus and technical specifications to provide reference for the prevention and control of LTBI.

Impact of COVID-19 Pandemic on Tuberculosis Preventive Services and Their Post-Pandemic Recovery Strategies: A Rapid Review of Literature.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic has disrupted tuberculosis (TB) care and prevention around the world. The aim of this study is to review literature on the impact of COVID-19 on TB preventive services and discuss their policy options during and after the pandemic. METHODS: We conducted a rapid review of scientific literature on the impact of COVID-19 on TB preventive services and their recovery strategies. After conducting a line-by-line open coding, their codes were applied in the descriptive theme building process, which was guided by the End TB strategy. TB preventive measures were selected and classified into five analytical categories: 1) vaccination against TB, 2) detection and treatment of latent TB infection (LTBI), 3) screening and diagnostics, 4) active case finding and contact tracing, and 5) surveillance. RESULTS: We identified 93 articles, of which 65 were research articles. During the pandemic, we observed decrease in Bacillus Calmette-Guérin (BCG) coverage, TB diagnostic services, case finding activities, and LTBI management. TB case detection was declined, which was not resumed to the pre-pandemic level after loosening the lock-down. Several recommendations were highlighted: 1) secure BCG stocks and its supply chains, 2) consider catch-up activities of routine immunization and LTBI screening, 3) maintain minimal TB health services, infection prevention and control, and surveillance, 4) leverage laboratory capacity and contact tracing mechanisms, 5) consider simultaneous testing for TB and COVID-19, and 6) Incorporate digital health technologies. CONCLUSIONS: Our findings and lessons learnt from the pandemic can aid in the development of future national TB control program.