[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).

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.

Vitamin D Supplements for Prevention of Tuberculosis Infection and Disease.

BACKGROUND: Vitamin D metabolites support innate immune responses to Mycobacterium tuberculosis. Data from phase 3, randomized, controlled trials of vitamin D supplementation to prevent tuberculosis infection are lacking. METHODS: We randomly assigned children who had negative results for M. tuberculosis infection according to the QuantiFERON-TB Gold In-Tube assay (QFT) to receive a weekly oral dose of either 14,000 IU of vitamin D3 or placebo for 3 years. The primary outcome was a positive QFT result at the 3-year follow-up, expressed as a proportion of children. Secondary outcomes included the serum 25-hydroxyvitamin D (25[OH]D) level at the end of the trial and the incidence of tuberculosis disease, acute respiratory infection, and adverse events. RESULTS: A total of 8851 children underwent randomization: 4418 were assigned to the vitamin D group, and 4433 to the placebo group; 95.6% of children had a baseline serum 25(OH)D level of less than 20 ng per milliliter. Among children with a valid QFT result at the end of the trial, the percentage with a positive result was 3.6% (147 of 4074 children) in the vitamin D group and 3.3% (134 of 4043) in the placebo group (adjusted risk ratio, 1.10; 95% confidence interval [CI], 0.87 to 1.38; P = 0.42). The mean 25(OH)D level at the end of the trial was 31.0 ng per milliliter in the vitamin D group and 10.7 ng per milliliter in the placebo group (mean between-group difference, 20.3 ng per milliliter; 95% CI, 19.9 to 20.6). Tuberculosis disease was diagnosed in 21 children in the vitamin D group and in 25 children in the placebo group (adjusted risk ratio, 0.87; 95% CI, 0.49 to 1.55). A total of 29 children in the vitamin D group and 34 in the placebo group were hospitalized for treatment of acute respiratory infection (adjusted risk ratio, 0.86; 95% CI, 0.52 to 1.40). The incidence of adverse events did not differ significantly between the two groups. CONCLUSIONS: Vitamin D supplementation did not result in a lower risk of tuberculosis infection, tuberculosis disease, or acute respiratory infection than placebo among vitamin D-deficient schoolchildren in Mongolia. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT02276755.).

Isoniazid level and flu-like symptoms during rifapentine-based tuberculosis preventive therapy: A population pharmacokinetic analysis.

AIM: A population pharmacokinetic (PPK) study of the correlation of adverse drug reactions (ADRs) with the 3HP regimen (weekly high-dose rifapentine plus isoniazid for 12 doses) for latent tuberculosis infection (LTBI) remains lacking. The purpose of this study is to determine the association of rifapentine or isoniazid concentration and ADRs. METHODS: This prospective, multicentre, observational study enrolled LTBI contacts receiving 3HP treatment between January 2017 and August 2020. The concentrations of rifapentine, isoniazid and their metabolites (25-desacetyl-rifapentine and acetyl-isoniazid) in plasma samples collected monthly after 3HP treatment were determined. A PPK model was constructed to predict the maximum concentration (Cmax ) and area under the concentration-time curve from 0 to 24 h (AUC). Their association with ADRs was evaluated by applying three multivariate logistic regression models with adjustment for various covariates. RESULTS: A total of 415 LTBI cases were ultimately enrolled; 355 (85.5%) completed the 3HP treatment. Among them, 47 (11.3%) experienced systemic drug reactions and 291 (70.0%) experienced one or more flu-like symptom. The plasma concentration-time profiles of isoniazid, rifapentine and their metabolites were adequately described by the developed models. A higher Cmax of isoniazid was significantly correlated with a higher risk of any ADR (adjusted odds ratio and 95% confidence interval: 3.04 [1.07-8.65]) and any or at least two flu-like symptoms (all severity grades) (2.76 [1.06-7.17]). CONCLUSIONS: Isoniazid may be responsible for ADRs, especially flu-like symptoms, during 3HP treatment.

Factors associated with refusal of preventive therapy after initial willingness to accept treatment among college students with latent tuberculosis infection in Shandong, China.

BACKGROUND: Preventive therapy of latent tuberculosis infection (LTBI) is an important component of tuberculosis (TB) control. Research on acceptance of TB preventive therapy (TPT) is an important topic. Current studies focus on acceptability and compliance. However, it is unclear whether LTBI patients will start TPT after accepting treatment. The study assessed the factors associated with TPT refusal after initial willingness to accept treatment. METHODS: Data were derived from a baseline survey of prospective study of LTBI treatment among college students in Shandong Province, China. A total of 723 students initially willing to accept TPT were included in the analysis. Stepwise logistic regression was used to explore the individual- and family-level characteristic variables that factors associated with TPT refusal after initial willingness to accept treatment. RESULTS: Of the 723 LTBI college students who initially had acceptance willingness, 436 (60.3%) finally refused TPT. At the individual level, non-medical students were more likely to refuse TPT [odds ratio (OR) = 4.87, 95% confidence interval (CI): 3.10-7.67)], as were students with moderate physical activity (OR = 1.45, 95% CI: 1.04-2.04). Students with boarding experience (OR = 0.49, 95% CI: 0.31-0.78) and a high level of knowledge about TB (OR = 0.97, 95% CI: 0.95-0.99) were less likely to refuse TPT. At the family level, those with high father's educational level (OR = 1.50, 95% CI: 1.07-2.10) or high household income (OR = 1.80, 95% CI: 1.20-2.71) were more likely to refuse TPT after initially accepting treatment. CONCLUSIONS: Factors associated with TPT refusal after initial willingness to accept treatment, such as personal (type of students, physical activity, boarding experiences, knowledge of TB) and family characteristics (father's education level, household income) among college student with LTBI, might help identify persons for whom tailored interventions could improve the start of LTBI treatment.

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.

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.

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.

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.

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.

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.

Potential Impact of Long-Acting Products on the Control of Tuberculosis: Preclinical Advancements and Translational Tools in Preventive Treatment.

A key component of global tuberculosis (TB) control is the treatment of latent TB infection. The use of long-acting technologies to administer TB preventive treatment has the potential to significantly improve the delivery and impact of this important public health intervention. For example, an ideal long-acting treatment could consist of a single dose that could be administered in the clinic (ie, a "1-shot cure" for latent TB). Interest in long-acting formulations for TB preventive therapy has gained considerable traction in recent years. This article presents an overview of the specific considerations and current preclinical advancements relevant for the development of long-acting technologies of TB drugs for treatment of latent infection, including attributes of target product profiles, suitability of drugs for long-acting formulations, ongoing research efforts, and translation to clinical studies.

Whole-Blood 3-Gene Signature as a Decision Aid for Rifapentine-based Tuberculosis Preventive Therapy.

BACKGROUND: Systemic drug reaction (SDR) is a major safety concern with weekly rifapentine plus isoniazid for 12 doses (3HP) for latent tuberculosis infection (LTBI). Identifying SDR predictors and at-risk participants before treatment can improve cost-effectiveness of the LTBI program. METHODS: We prospectively recruited 187 cases receiving 3HP (44 SDRs and 143 non-SDRs). A pilot cohort (8 SDRs and 12 non-SDRs) was selected for generating whole-blood transcriptomic data. By incorporating the hierarchical system biology model and therapy-biomarker pathway approach, candidate genes were selected and evaluated using reverse-transcription quantitative polymerase chain reaction (RT-qPCR). Then, interpretable machine learning models presenting as SHapley Additive exPlanations (SHAP) values were applied for SDR risk prediction. Finally, an independent cohort was used to evaluate the performance of these predictive models. RESULTS: Based on the whole-blood transcriptomic profile of the pilot cohort and the RT-qPCR results of 2 SDR and 3 non-SDR samples in the training cohort, 6 genes were selected. According to SHAP values for model construction and validation, a 3-gene model for SDR risk prediction achieved a sensitivity and specificity of 0.972 and 0.947, respectively, under a universal cutoff value for the joint of the training (28 SDRs and 104 non-SDRs) and testing (8 SDRs and 27 non-SDRs) cohorts. It also worked well across different subgroups. CONCLUSIONS: The prediction model for 3HP-related SDRs serves as a guide for establishing a safe and personalized regimen to foster the implementation of an LTBI program. Additionally, it provides a potential translational value for future studies on drug-related hypersensitivity.

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.

Isoniazid prophylaxis in liver transplant recipient with latent tuberculosis: Is it harmful for transplanted liver?

BACKGROUND: Liver transplantation (LT) is considered the only treatment for patients with end-stage liver disease and, despite its incredible impacts on the patients' health status, places them in an immunocompromised state in which opportunistic infection would find a way to present. Latent tuberculosis infection (LTBI) is the most common form of TB and can be diagnosed through tuberculin skin test (TST) or Interferon-Gamma Release Assays (IGRA). LT recipients are at significant risk of TB activation. There is no strict guideline to approaching these cases though, in most centers, Isoniazid (INH) would be prescribed prophylactically. INH is a hepatotoxic medication and can have adverse effects on the transplanted liver. There is no consensus on this issue; therefore, we aimed to survey the potential hepatotoxic effects of INH among LT recipients in Shiraz, Iran. METHODS: A retrospective cohort study was conducted among LT candidates and recipients at Abu Ali Sina Organ Transplantation Center between 1993 and 2019. All the cases underwent TST and chest X-ray to detect LTBI. All the LTBI were treated with INH from 6-9 months and followed by the level of liver enzymes for quick detection of hepatotoxicity. A control group was selected among LT recipients and matched for age, gender, MELD score, and donor age. RESULTS: Among 4895 medical records reviewed, 55 (1.12%) cases had LTBI. Neither INH-related hepatotoxicity, nor signs and symptoms that were suspicious to TB reactivation were reported. Overall, three deaths were reported, two because of myocardial infarction and one due to pneumonia. Ten patients (18.2%) experienced acute rejection as confirmed with pathology and responded to methylprednisolone. Aspartate aminotransferase (AST) was diminished from pre-LT time to the first time after transplantation; after that, it showed a steady pattern. Meanwhile, Alanine transaminase (ALT) was constant before and one stage later and decreased after that. Statistical analyses only showed significant changes in the total bilirubin titer between the case and control groups. CONCLUSION: This survey showed prophylactic management of LTBI with INH in LT candidates and recipients was associated with no hepatotoxicity or related death. It seems that INH prophylaxis is safe in LT settings and can efficiently prevent TB activation; however, careful monitoring for adverse effects and liver enzymes elevation is highly recommended.

The potential of imaging tools as correlates of infection and disease for new TB vaccine development.

The development of an improved vaccine to stimulate an effective response against Mycobacterium tuberculosis (MTB) infection and disease will be a major breakthrough in the fight against TB. A lack of tools to adequately track the progression or resolution of events in TB pathogenesis that occur at bacterial loads below the threshold for culture in human samples seriously hampers vaccine development and evaluation. In this review we discuss recent studies that use new imaging applications, modalities and analysis techniques to provide insight into the dynamic processes of MTB infection and disease that are challenging to monitor. These include early infection, the spectrum of latency and subclinical disease, the paucibacillary state induced by treatment, and events leading to recurrence, including relapse.

Genome wide approaches discover novel Mycobacterium tuberculosis antigens as correlates of infection, disease, immunity and targets for vaccination.

Every day approximately six thousand people die of Tuberculosis (TB). Its causative agent, Mycobacterium tuberculosis (Mtb), is an ancient pathogen that through its evolution developed complex mechanisms to evade immune surveillance and acquire the ability to establish persistent infection in its hosts. Currently, it is estimated that one-fourth of the human population is latently infected with Mtb and among those infected 3-10% are at risk of developing active TB disease during their lifetime. The currently available diagnostics are not able to detect this risk group for prophylactic treatment to prevent transmission. Anti-TB drugs are available but only as long regimens with considerable side effects, which could both be reduced if adequate tests were available to monitor the response of TB to treatment. New vaccines are also urgently needed to substitute or boost Bacille Calmette-Guérin (BCG), the only approved TB vaccine: although BCG prevents disseminated TB in infants, it fails to impact the incidence of pulmonary TB in adults, and therefore has little effect on TB transmission. To achieve TB eradication, the discovery of Mtb antigens that effectively correlate with the human response to infection, with the curative host response following TB treatment, and with natural as well as vaccine induced protection will be critical. Over the last decade, many new Mtb antigens have been found and proposed as TB biomarkers and vaccine candidates, but only a very small number of these is being used in commercial diagnostic tests or is being assessed as candidate TB vaccine antigens in human clinical trials, aiming to prevent infection, disease or disease recurrence following treatment. Most of these antigens were discovered decades ago, before the complete Mtb genome sequence became available, and thus did not harness the latest insights from post-genomic antigen discovery strategies and genome wide approaches. These have, for example, revealed critical phase variation in Mtb replication and accompanying gene -and therefore antigen- expression patterns. In this review, we present a brief overview of past methodologies, and subsequently focus on the most important recent Mtb antigen discovery studies which have mined the Mtb antigenome through "unbiased" genome wide approaches. We compare the results for these approaches -as far as we know for the first time-, highlight Mtb antigens that have been identified independently by different strategies and present a comprehensive overview of the Mtb antigens thus discovered.

Latent Tuberculosis Infection Testing and Treatment at a Federally Qualified Health Center in Southern California: A Quality Improvement Project.

BACKGROUND: A key strategy to eliminate tuberculosis (TB) in the United States is to increase latent tuberculosis infection (LTBI) screening, testing, and treatment among non-US-born Asian populations. PURPOSE: The purpose was to increase LTBI screening, testing, and treatment at a community clinic. METHODS: Retrospective baseline LTBI data were retrieved through electronic medical record review. Interventions included adoption of standardized TB risk assessment, training providers to use shorter LTBI treatment regimens, and use of a care coordinator. Chart abstraction to examine outcomes was conducted postintervention at 4 months. RESULTS: In 2017, only 3 patients (7%) with LTBI were started on treatment. At 4 months postintervention, 28 (72%) patients with LTBI were started on treatment, of which 27 (96%) were placed on 3- to 4-month regimens. CONCLUSIONS: Training for providers and changes to clinic workflow, including use of a care coordinator, can help increase LTBI screening, testing, and treatment in community clinics.

Cost of Delivering 12-Dose Isoniazid and Rifapentine Versus 6 Months of Isoniazid for Tuberculosis Infection in a High-Burden Setting.

BACKGROUND: Successful delivery and completion of tuberculosis preventive treatment are necessary for tuberculosis elimination. Shorter preventive treatment regimens currently have higher medication costs, but patients spend less time in care and are more likely to complete treatment. It is unknown how economic costs of successful delivery differ between longer and shorter regimens in high-tuberculosis-burden settings. METHODS: We developed survey instruments to collect costs from program and patient sources, considering costs incurred from when household contacts first entered the health system. We compared the cost per completed course of preventive treatment with either 6 months of daily isoniazid (6H) or 3 months of weekly isoniazid and rifapentine (3HP), delivered by the Indus Health Network tuberculosis program in Karachi, Pakistan, between October 2016 and February 2018. RESULTS: During this period, 459 individuals initiated 6H and 643 initiated 3HP; 39% and 61% completed treatment, respectively. Considering costs to both the program and care recipients, the cost per completed course was 394 US dollars (USD) for 6H and 333 USD for 3HP. Using a new 2020 price for rifapentine reduced the cost per completed course of 3HP to 290 USD. Under varying assumptions about drug prices and costs incurred by care recipients, the cost per completed course was lower for 3HP in all scenarios, and the largest cost drivers were the salaries of clinical staff. CONCLUSIONS: In a high-burden setting, the cost of successful delivery of 3HP was lower than that of 6H, driven by higher completion.

The latent tuberculosis cascade-of-care among people living with HIV: A systematic review and meta-analysis.

BACKGROUND: Tuberculosis preventive therapy (TPT) reduces TB-related morbidity and mortality in people living with HIV (PLHIV). Cascade-of-care analyses help identify gaps and barriers in care and develop targeted solutions. A previous latent tuberculosis infection (LTBI) cascade-of-care analysis showed only 18% of persons in at-risk populations complete TPT, but a similar analysis for TPT among PLHIV has not been completed. We conducted a meta-analysis to provide this evidence. METHODS AND FINDINGS: We first screened potential articles from a LTBI cascade-of-care systematic review published in 2016. From this study, we included cohorts that reported a minimum of 25 PLHIV. To identify new cohorts, we used a similar search strategy restricted to PLHIV. The search was conducted in Medline, Embase, Health Star, and LILACS, from January 2014 to February 2021. Two authors independently screened titles and full text and assessed risk of bias using the Newcastle-Ottawa Scale for cohorts and Cochrane Risk of Bias for cluster randomized trials. We meta-analyzed the proportion of PLHIV completing each step of the LTBI cascade-of-care and estimated the cumulative proportion retained. These results were stratified based on cascades-of-care that used or did not use LTBI testing to determine eligibility for TPT. We also performed a narrative synthesis of enablers and barriers of the cascade-of-care identified at different steps of the cascade. A total of 71 cohorts were included, and 70 were meta-analyzed, comprising 94,011 PLHIV. Among the PLHIV included, 35.3% (33,139/94,011) were from the Americas and 29.2% (27,460/94,011) from Africa. Overall, 49.9% (46,903/94,011) from low- and middle-income countries, median age was 38.0 [interquartile range (IQR) 34.0;43.6], and 65.9% (46,328/70,297) were men, 43.6% (29,629/67,947) were treated with antiretroviral therapy (ART), and the median CD4 count was 390 cell/mm3 (IQR 312;458). Among the cohorts that did not use LTBI tests, the cumulative proportion of PLHIV starting and completing TPT were 40.9% (95% CI: 39.3% to 42.7%) and 33.2% (95% CI: 31.6% to 34.9%). Among cohorts that used LTBI tests, the cumulative proportions of PLHIV starting and completing TPT were 60.4% (95% CI: 58.1% to 62.6%) and 41.9% (95% CI:39.6% to 44.2%), respectively. Completion of TPT was not significantly different in high- compared to low- and middle-income countries. Regardless of LTBI test use, substantial losses in the cascade-of-care occurred before treatment initiation. The integration of HIV and TB care was considered an enabler of the cascade-of-care in multiple cohorts. Key limitations of this systematic review are the observational nature of the included studies, potential selection bias in the population selection, only 14 cohorts reported all steps of the cascade-of-care, and barriers/facilitators were not systematically reported in all cohorts. CONCLUSIONS: Although substantial losses were seen in multiple stages of the cascade-of-care, the cumulative proportion of PLHIV completing TPT was higher than previously reported among other at-risk populations. The use of LTBI testing in PLHIV in low- and middle-income countries was associated with higher proportion of the cohorts initiating TPT and with similar rates of completion of TPT.