Efficacy of a six-month versus a 36-month regimen for prevention of tuberculosis in HIV-infected persons in India: a randomized clinical trial

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.

Efficacy, safety, and tolerability of isoniazid preventive therapy for tuberculosis in people living with HIV

OBJECTIVE

The aim of this study was to systematically assess the efficacy, safety, and tolerability of isoniazid preventive therapy (IPT) for tuberculosis (TB) in people with HIV (PWH).

DESIGN

A systematic review and meta-analysis.

METHODS

A thorough literature search was performed using PubMed, Cochrane CENTRAL, and Google Scholar from their inception to June 30, 2021. All randomized controlled trials (RCTs) investigating the efficacy, safety, or tolerability of IPT on PWH compared with placebo or active comparators were included in the study. The heterogeneity among the studies was identified by using the I2 statistic and Cochran's Q test.

RESULTS

Out of the 924 nonduplicate RCTs identified through database searching and other sources, 26 studies comprising 38 005 patients were included. The overall effect estimate identified the reduction of active TB incidence [odds ratio (OR) 0.69; 95% confidence interval (95% CI) 0.57-0.84; P  < 0.001], but not all-cause mortality (OR 0.91; 95% CI 0.82, 1.02; P  = 0.10) with IPT compared with the control. In addition, no significant association was identified between the use of IPT and the risk of peripheral neuropathy (OR 1.50; 95% CI 0.96-2.36; P  = 0.08) and hepatotoxicity (OR 1.21; 95% CI 0.97-1.52; P  = 0.09).

CONCLUSION

This systematic review and meta-analysis identified a significant reduction in the incidence of active TB, but not all-cause mortality, among PWH who received IPT compared with the control. Lesser number of outcomes may be the reason for nonsignificant results in terms of safety outcomes of IPT. Therefore, there is a need for extensive and long-term studies to address these issues further, especially in TB/HIV endemic areas.

Annual Tuberculosis Preventive Therapy for Persons With HIV Infection : A Randomized Trial

BACKGROUND

Tuberculosis preventive therapy for persons with HIV infection is effective, but its durability is uncertain.

OBJECTIVE

To compare treatment completion rates of weekly isoniazid-rifapentine for 3 months versus daily isoniazid for 6 months as well as the effectiveness of the 3-month rifapentine-isoniazid regimen given annually for 2 years versus once.

DESIGN

Randomized trial. (ClinicalTrials.gov: NCT02980016).

SETTING

South Africa, Ethiopia, and Mozambique.

PARTICIPANTS

Persons with HIV infection who were receiving antiretroviral therapy, were aged 2 years or older, and did not have active tuberculosis.

INTERVENTION

Participants were randomly assigned to receive weekly rifapentine-isoniazid for 3 months, given either annually for 2 years or once, or daily isoniazid for 6 months. Participants were screened for tuberculosis symptoms at months 0 to 3 and 12 of each study year and at months 12 and 24 using chest radiography and sputum culture.

MEASUREMENTS

Treatment completion was assessed using pill counts. Tuberculosis incidence was measured over 24 months.

RESULTS

Between November 2016 and November 2017, 4027 participants were enrolled; 4014 were included in the analyses (median age, 41 years; 69.5% women; all using antiretroviral therapy). Treatment completion in the first year for the combined rifapentine-isoniazid groups (n = 3610) was 90.4% versus 50.5% for the isoniazid group (n = 404) (risk ratio, 1.78 [95% CI, 1.61 to 1.95]). Tuberculosis incidence among participants receiving the rifapentine-isoniazid regimen twice (n = 1808) or once (n = 1802) was similar (hazard ratio, 0.96 [CI, 0.61 to 1.50]).

LIMITATION

If rifapentine-isoniazid is effective in curing subclinical tuberculosis, then the intensive tuberculosis screening at month 12 may have reduced its effectiveness.

CONCLUSION

Treatment completion was higher with rifapentine-isoniazid for 3 months compared with isoniazid for 6 months. In settings with high tuberculosis transmission, a second round of preventive therapy did not provide additional benefit to persons receiving antiretroviral therapy.

PRIMARY FUNDING SOURCE

The U.S. Agency for International Development through the CHALLENGE TB grant to the KNCV Tuberculosis Foundation.

Tuberculosis preventive therapy for people living with HIV: A systematic review and network meta-analysis

BACKGROUND

Tuberculosis (TB) preventive therapy (TPT) is an essential component of care for people living with HIV (PLHIV). We compared efficacy, safety, completion, and drug-resistant TB risk for currently recommended TPT regimens through a systematic review and network meta-analysis (NMA) of randomized trials.

METHODS AND FINDINGS

We searched MEDLINE, Embase, and the Cochrane Library from inception through June 9, 2020 for randomized controlled trials (RCTs) comparing 2 or more TPT regimens (or placebo/no treatment) in PLHIV. Two independent reviewers evaluated eligibility, extracted data, and assessed the risk of bias. We grouped TPT strategies as follows: placebo/no treatment, 6 to 12 months of isoniazid, 24 to 72 months of isoniazid, and rifamycin-containing regimens. A frequentist NMA (using graph theory) was carried out for the outcomes of development of TB disease, all-cause mortality, and grade 3 or worse hepatotoxicity. For other outcomes, graphical descriptions or traditional pairwise meta-analyses were carried out as appropriate. The potential role of confounding variables for TB disease and all-cause mortality was assessed through stratified analyses. A total of 6,466 unique studies were screened, and 157 full texts were assessed for eligibility. Of these, 20 studies (reporting 16 randomized trials) were included. The median sample size was 616 (interquartile range [IQR], 317 to 1,892). Eight were conducted in Africa, 3 in Europe, 3 in the Americas, and 2 included sites in multiple continents. According to the NMA, 6 to 12 months of isoniazid were no more efficacious in preventing microbiologically confirmed TB than rifamycin-containing regimens (incidence rate ratio [IRR] 1.0, 95% CI 0.8 to 1.4, p = 0.8); however, 6 to 12 months of isoniazid were associated with a higher incidence of all-cause mortality (IRR 1.6, 95% CI 1.2 to 2.0, p = 0.02) and a higher risk of grade 3 or higher hepatotoxicity (risk difference [RD] 8.9, 95% CI 2.8 to 14.9, p = 0.004). Finally, shorter regimens were associated with higher completion rates relative to longer regimens, and we did not find statistically significant differences in the risk of drug-resistant TB between regimens. Study limitations include potential confounding due to differences in posttreatment follow-up time and TB incidence in the study setting on the estimates of incidence of TB or all-cause mortality, as well as an underrepresentation of pregnant women and children.

CONCLUSIONS

Rifamycin-containing regimens appear safer and at least as effective as isoniazid regimens in preventing TB and death and should be considered part of routine care in PLHIV. Knowledge gaps remain as to which specific rifamycin-containing regimen provides the optimal balance of efficacy, completion, and safety.

Pulmonary tuberculosis screening in anti-retroviral treated adults living with HIV in Kenya

Background

People living with HIV (PLHIV) who reside in high tuberculosis burden settings remain at risk for tuberculosis disease despite treatment with anti-retroviral therapy and isoniazid preventive therapy (IPT). The performance of the World Health Organization (WHO) symptom screen for tuberculosis in PLHIV receiving anti-retroviral therapy is sub-optimal and alternative screening strategies are needed.

Methods

We enrolled HIV-positive adults into a prospective study in western Kenya. Individuals who were IPT-naïve or had completed IPT > 6 months prior to enrollment were eligible. We evaluated tuberculosis prevalence overall and by IPT status. We assessed the accuracy of the WHO symptom screen, GeneXpert MTB/RIF (Xpert), and candidate biomarkers including C-reactive protein (CRP), hemoglobin, erythrocyte sedimentation rate (ESR), and monocyte-to-lymphocyte ratio for identifying pulmonary tuberculosis. Some participants were evaluated at 6 months post-enrollment for tuberculosis.

Results

The study included 383 PLHIV, of whom > 99% were on antiretrovirals and 88% had received IPT, completed a median of 1.1 years (IQR 0.8–1.55) prior to enrollment. The prevalence of pulmonary tuberculosis at enrollment was 1.3% (n = 5, 95% CI 0.4–3.0%): 4.3% (0.5–14.5%) among IPT-naïve and 0.9% (0.2–2.6%) among IPT-treated participants. The sensitivity of the WHO symptom screen was 0% (0–52%) and specificity 87% (83–90%). Xpert and candidate biomarkers had poor to moderate sensitivity; the most accurate biomarker was CRP ≥ 3.3 mg/L (sensitivity 80% (28–100) and specificity 72% (67–77)). Six months after enrollment, the incidence rate of pulmonary tuberculosis following IPT completion was 0.84 per 100 person-years (95% CI, 0.31–2.23).

Conclusions

In Kenyan PLHIV treated with IPT, tuberculosis prevalence was low at a median of 1.4 years after IPT completion. WHO symptoms screening, Xpert, and candidate biomarkers were insensitive for identifying pulmonary tuberculosis in antiretroviral-treated PLHIV.

Tuberculosis research conducted over the years at the ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT)

This review article highlights some of the key research conducted at the ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT) over the years since its inception in 1956 till the present. The research carried out in the field of tuberculosis at ICMR-NIRT has been a joint effort between the ICMR, NIRT, the TB control program in India with assistance from World Health Organization (WHO) and the National Institutes of Health (NIH), USA. The research carried out at ICMR-NIRT has helped to formulate the national guidelines for the control and the management of tuberculosis in India. The major highlights of the research carried out at ICMR-NIRT are provided in this manuscript.

Guidelines for the Treatment of Latent Tuberculosis Infection: Recommendations from the National Tuberculosis Controllers Association and CDC, 2020

Comprehensive guidelines for treatment of latent tuberculosis infection (LTBI) among persons living in the United States were last published in 2000 (American Thoracic Society. CDC targeted tuberculin testing and treatment of latent tuberculosis infection. Am J Respir Crit Care Med 2000;161:S221–47). Since then, several new regimens have been evaluated in clinical trials. To update previous guidelines, the National Tuberculosis Controllers Association (NTCA) and CDC convened a committee to conduct a systematic literature review and make new recommendations for the most effective and least toxic regimens for treatment of LTBI among persons who live in the United States.

The systematic literature review included clinical trials of regimens to treat LTBI. Quality of evidence (high, moderate, low, or very low) from clinical trial comparisons was appraised using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. In addition, a network meta-analysis evaluated regimens that had not been compared directly in clinical trials. The effectiveness outcome was tuberculosis disease; the toxicity outcome was hepatotoxicity. Strong GRADE recommendations required at least moderate evidence of effectiveness and that the desirable consequences outweighed the undesirable consequences in the majority of patients. Conditional GRADE recommendations were made when determination of whether desirable consequences outweighed undesirable consequences was uncertain (e.g., with low-quality evidence).

These updated 2020 LTBI treatment guidelines include the NTCA- and CDC-recommended treatment regimens that comprise three preferred rifamycin-based regimens and two alternative monotherapy regimens with daily isoniazid. All recommended treatment regimens are intended for persons infected with Mycobacterium tuberculosis that is presumed to be susceptible to isoniazid or rifampin. These updated guidelines do not apply when evidence is available that the infecting M. tuberculosis strain is resistant to both isoniazid and rifampin; recommendations for treating contacts exposed to multidrug-resistant tuberculosis were published in 2019 (Nahid P, Mase SR Migliori GB, et al. Treatment of drug-resistant tuberculosis. An official ATS/CDC/ERS/IDSA clinical practice guideline. Am J Respir Crit Care Med 2019;200:e93–e142). The three rifamycin-based preferred regimens are 3 months of once-weekly isoniazid plus rifapentine, 4 months of daily rifampin, or 3 months of daily isoniazid plus rifampin. Prescribing providers or pharmacists who are unfamiliar with rifampin and rifapentine might confuse the two drugs. They are not interchangeable, and caution should be taken to ensure that patients receive the correct medication for the intended regimen. Preference for these rifamycin-based regimens was made on the basis of effectiveness, safety, and high treatment completion rates. The two alternative treatment regimens are daily isoniazid for 6 or 9 months; isoniazid monotherapy is efficacious but has higher toxicity risk and lower treatment completion rates than shorter rifamycin-based regimens.

In summary, short-course (3- to 4-month) rifamycin-based treatment regimens are preferred over longer-course (6–9 month) isoniazid monotherapy for treatment of LTBI. These updated guidelines can be used by clinicians, public health officials, policymakers, health care organizations, and other state and local stakeholders who might need to adapt them to fit individual clinical circumstances.

Incidence of tuberculosis among HIV infected individuals on long term antiretroviral therapy in private healthcare sector in Pune, Western India

Background

Despite rapid scale up of antiretroviral therapy (ART), Tuberculosis (TB) remains the commonest opportunistic infection and cause of death among HIV infected individuals in resource limited settings like India. Incidence of TB in individuals on ART in private healthcare sector in India is infrequently studied.

Methods

This retrospective cohort study conducted between 1st March 2009 and 1st March 2017 aimed to evaluate rate of incident TB in individuals initiated on ART at 3 private sector ART clinics in Pune, India. Individuals more than 12 years of age with ART duration of atleast 6 months were included. Patients were classified as having prevalent TB if they had a TB episode within the year prior to ART initiation or if they developed TB within 6 months of starting ART. Individuals who were diagnosed with TB after 6 months of starting ART were classified as incident TB cases. A recurrent episode of TB after treatment completion or cure of prevalent TB was also regarded as incident TB. Patients were classified as definitive TB if Mycobacterium tuberculosis was grown in culture from a biological sample or a positive rapid molecular test. Patients were classified as probable TB if there was radiologic evidence of TB in absence of confirmatory culture or PCR.

Results

1904 patients with a median duration of follow up on ART of 57 (IQR = 32.0, 84.0) months were included. Of these, 182 developed incident TB (22% definitive TB, 38% recurrent cases). TB incidence at 6–12 months, 13–24 months, 25–60 months and > 60 months of ART was 24.32, 5.46, 2.54 and 0.75 cases per 100 person years respectively. Current time updated CD4 count < 500 cells/mm³ (p < 0.0001), virologic failure on ART (adjusted Hazard Ratio (aHR): 3.05 (95% CI: 2.094, 4.454), p < 0.0001) and receipt of ART without IPT (aHR: 8.24 (95% CI, 3.358, 20.204), p < 0.0001) were associated with higher risk of incident TB.

Conclusion

Starting ART early in treatment naïve individuals, prompt detection of virologic failure on ART and providing IPT along with ART will be useful in reducing incident TB. Efforts from private sector are crucial in achieving Sustainable Development Goals set by Government of India and attaining the vision of a TB free India.

TB preventive therapy for people living with HIV: key considerations for scale-up in resource-limited settings

Tuberculosis (TB) is the leading cause of death for persons living with the human immunodeficiency virus (PLHIV). TB preventive therapy (TPT) works synergistically with, and independently of, antiretroviral therapy to reduce TB morbidity, mortality and incidence among PLHIV. However, although TPT is a crucial and cost-effective component of HIV care for adults and children and has been recommended as an international standard of care for over a decade, it remains highly underutilized. If we are to end the global TB epidemic, we must address the significant reservoir of tuberculous infection, especially in those, such as PLHIV, who are most likely to progress to TB disease. To do so, we must confront the pervasive perception that barriers to TPT scale-up are insurmountable in resource-limited settings. Here we review available evidence to address several commonly stated obstacles to TPT scale-up, including the need for the tuberculin skin test, limited diagnostic capacity to reliably exclude TB disease, concerns about creating drug resistance, suboptimal patient adherence to therapy, inability to monitor for and prevent adverse events, a 'one size fits all' option for TPT regimen and duration, and uncertainty about TPT use in children, adolescents, and pregnant women. We also discuss TPT delivery in the era of differentiated care for PLHIV, how best to tackle advanced planning for drug procurement and supply chain management, and how to create an enabling environment for TPT scale-up success.

Preventive therapy for HIV-associated tuberculosis

PURPOSE OF REVIEW

Tuberculosis (TB) remains the leading cause of death in people living with HIV (PLHIV) despite the achievements in antiretroviral therapy coverage. TB preventive therapy (TPT) has proved efficacy but has been neglected and poorly implemented. We reviewed recent publications and guidelines about TPT in PLHIV.

RECENT FINDINGS

High-quality studies showed that TPT has a durable effect, over 5 years, preventing TB and all-cause mortality. There is new evidence showing the noninferiority of shorter, rifamycin-based regimens of TPT increasing the options for treatment. Recent studies describing robust implementation in different settings showed promising results for feasibility, tolerance, retention, and cost-effectiveness. New WHO recommendations, unifying previous versions, have been released to guide countries implementation.

SUMMARY

New evidence support the scale up of TPT for PLHIV globally, further studies are needed to bring more evidence for specific populations, like pregnant women and for drug-drug interactions with antiretroviral agents.

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

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

Addressing knowledge gaps and prevention for tuberculosis-infected Indian adults: a vital part of elimination

BACKGROUND

India plans to eliminate tuberculosis (TB) by 2025, and has identified screening and prevention as key activities. Household contacts (HHCs) of index TB cases are a high-risk population that would benefit from rapid implementation of these strategies. However, best practices for TB prevention and knowledge gaps among HHCs have not been studied. We evaluated TB knowledge and understanding of prevention among tuberculin skin-test (TST) positive HHCs. While extensive information is available in other high-burden settings regarding TB knowledge gaps, identifying how Indian adult contacts view their transmission risk and prevention options may inform novel screening algorithms and education efforts that will be part of the new elimination plan.

METHODS

We approached adult HHC to administer a questionnaire on TB knowledge and understanding of infection. Over 1 year, 100 HHC were enrolled at a tertiary hospital in Pune, India.

RESULTS

The study population was 61% (n = 61) female, with a mean age of 36.6 years (range 18-67, SD = 12). Education levels were high, with 78 (78%) having at least a high school education, and 23 (24%) had at least some college education. Four (4%) of our participants were HIV-infected. General TB knowledge among HHC was low, with a majority of participants believing that you can get TB from sharing dishes (70%) or touching something that has been coughed on (52%). Understanding of infection was also low, with 42% believing that being skin-test positive means you have disease. To assess readiness for preventive therapy, we asked participants whether they are at a higher risk of progressing to active disease because of their LTBI status. Fifty-four (55%) felt that they are at higher risk. Only 8% had heard of preventive therapy.

CONCLUSION

Our TB knowledge survey among HHCs with evidence of recent exposure found that knowledge is poor and families are confused about transmission in the household. It is imperative that the Indian program develop tools and incentives that can be used to educate TB cases and their families on what infected HHCs can do to prevent disease, including preventive therapy.

IPT during HIV treatment in Myanmar: high rates of coverage, completion and drug adherence

Setting: A southern Myanmar district providing isoniazid preventive therapy (IPT) in one of the last countries to formally recommend it as part of human immunodeficiency virus (HIV) care. Objective: To assess coverage and adherence and the feasibility of IPT scale-up in a routine care setting in Myanmar. Design: A retrospective analysis of people living with HIV (PLHIV) screened for tuberculosis (TB) and enrolled in IPT over a 3-year period (July 2011-June 2014) using clinical databases. Results: Among 3377 patients under HIV care and screened for TB, 2740 (81.1%) initiated IPT, with 2651 (96.8%) completing a 6- or 9-month course of IPT; 83 (3.1%) interrupted treatment for different reasons, including loss to follow-up (n = 41), side effects (n = 15) or drug adherence issues (n = 9); 6 (0.2%) died. Among the IPT patients, 33 (1.2%) were diagnosed with TB, including 9 (0.3%) while on IPT and 24 (0.9%) within 1 year of completion of therapy. Among the PLHIV who completed IPT, one case of isoniazid resistance was detected. Conclusion: Scaling up IPT in Myanmar HIV settings is feasible with high rates of drug adherence and completion, and a low rate of discontinuation due to side effects. IPT scale-up should be prioritised in HIV clinical settings in Myanmar.

Effect of isoniazid preventive therapy on risk of death in west African, HIV-infected adults with high CD4 cell counts: long-term follow-up of the Temprano ANRS 12136 trial

BACKGROUND

Temprano ANRS 12136 was a factorial 2 × 2 trial that assessed the benefits of early antiretroviral therapy (ART; ie, in patients who had not reached the CD4 cell count threshold used to recommend starting ART, as per the WHO guidelines that were the standard during the study period) and 6-month isoniazid preventive therapy (IPT) in HIV-infected adults in Côte d'Ivoire. Early ART and IPT were shown to independently reduce the risk of severe morbidity at 30 months. Here, we present the efficacy of IPT in reducing mortality from the long-term follow-up of Temprano.

METHODS

For Temprano, participants were randomly assigned to four groups (deferred ART, deferred ART plus IPT, early ART, or early ART plus IPT). Participants who completed the trial follow-up were invited to participate in a post-trial phase. The primary post-trial phase endpoint was death, as analysed by the intention-to-treat principle. We used Cox proportional models to compare all-cause mortality between the IPT and no IPT strategies from inclusion in Temprano to the end of the follow-up period.

FINDINGS

Between March 18, 2008, and Jan 5, 2015, 2056 patients (mean baseline CD4 count 477 cells per μL) were followed up for 9404 patient-years (Temprano 4757; post-trial phase 4647). The median follow-up time was 4·9 years (IQR 3·3-5·8). 86 deaths were recorded (Temprano 47 deaths; post-trial phase 39 deaths), of which 34 were in patients randomly assigned IPT (6-year probability 4·1%, 95% CI 2·9-5·7) and 52 were in those randomly assigned no IPT (6·9%, 5·1-9·2). The hazard ratio of death in patients who had IPT compared with those who did not have IPT was 0·63 (95% CI, 0·41 to 0·97) after adjusting for the ART strategy (early vs deferred), and 0·61 (0·39-0·94) after adjustment for the ART strategy, baseline CD4 cell count, and other key characteristics. There was no evidence for statistical interaction between IPT and ART (p_interaction=0·77) or between IPT and time (p_interaction=0·94) on mortality.

INTERPRETATION

In Côte d'Ivoire, where the incidence of tuberculosis was last reported as 159 per 100 000 people, 6 months of IPT has a durable protective effect in reducing mortality in HIV-infected people, even in people with high CD4 cell counts and who have started ART.

FUNDING

National Research Agency on AIDS and Viral Hepatitis (ANRS).

Tuberculosis Associated with HIV Infection

Tuberculosis (TB) has recently surpassed HIV as the primary infectious disease killer worldwide, but the two diseases continue to display lethal synergy. The burden of TB is disproportionately borne by people living with HIV, particularly where HIV and poverty coexist. The impact of these diseases on one another is bidirectional, with HIV increasing risk of TB infection and disease progression and TB slowing CD4 recovery and increasing progression to AIDS and death among the HIV infected. Both antiretroviral therapy (ART) and latent TB infection (LTBI) treatment mitigate the impact of coinfection, and ART is now recommended for HIV-infected patients independent of CD4 count. LTBI screening should be performed for all HIV-positive people at the time of diagnosis, when their CD4 count rises above 200, and yearly if there is repeated exposure. Tuberculin skin tests (TSTs) may perform better with serial testing than interferon gamma release assays (IGRAs). Any patient with HIV and a TST induration of ≥5 mm should be evaluated for active TB disease and treated for LTBI if active disease is ruled out. Because HIV impairs multiple aspects of immune function, progressive HIV is associated with lower rates of cavitary pulmonary TB and higher rates of disseminated and extrapulmonary disease, so a high index of suspicion is important, and sputum should be obtained for evaluation even if chest radiographs are negative. TB diagnosis is similar in patients with and without TB, relying on smear, culture, and nucleic acid amplification tests, which are the initial tests of choice. TSTs and IGRAs should not be used in the evaluation of active TB disease since these tests are often negative with active disease. Though not always performed in resource-limited settings, drug susceptibility testing should be performed on all TB isolates from HIV-positive patients. Urine lipoarabinomannan testing may also be helpful in HIV-positive patients with disseminated disease. Treatment of TB in HIV-infected patients is similar to that of TB in HIV-negative patients except that daily therapy is required for all coinfected patients, vitamin B6 supplementation should be given to all coinfected patients receiving isoniazid to reduce peripheral neuropathy, and specific attention needs to be paid to drug-drug interactions between rifamycins and many classes of antiretrovirals. In patients requiring ART that contains ritonavir or cobicistat, this can be managed by the use of rifabutin at 150 mg daily in place of rifampin. For newly diagnosed coinfected patients, mortality is lower if treatment is provided in parallel, rather than serially, with treatment initiation within 2 weeks preferred for those with CD4 counts of <50 and within 8 to 12 weeks for those with higher CD4 counts. When TB immune reconstitution inflammatory syndrome occurs, patients can often be treated symptomatically with nonsteroidal anti-inflammatory drugs, but a minority will benefit from steroids. Generally, patients who do not have space-occupying lesions such as occurs in TB meningitis do not require cessation of therapy.

Current trends and intricacies in the management of HIV-associated pulmonary tuberculosis

Human immunodeficiency virus (HIV) epidemic has undoubtedly increased the incidence of tuberculosis (TB) globally, posing a formidable global health challenge affecting 1.2 million cases. Pulmonary TB assumes utmost significance in the programmatic perspective as it is readily transmissible as well as easily diagnosable. HIV complicates every aspect of pulmonary tuberculosis from diagnosis to treatment, demanding a different approach to effectively tackle both the diseases. In order to control these converging epidemics, it is important to diagnose early, initiate appropriate therapy for both infections, prevent transmission and administer preventive therapy. Liquid culture methods and nucleic acid amplification tests for TB confirmation have replaced conventional solid media, enabling quicker and simultaneous detection of mycobacterium and its drug sensitivity profile Unique problems posed by the syndemic include Acquired rifampicin resistance, drug-drug interactions, malabsorption of drugs and immune reconstitution inflammatory syndrome or paradoxical reaction that complicate dual and concomitant therapy. While the antiretroviral therapy armamentarium is constantly reinforced by discovery of newer and safer drugs every year, only a few drugs for anti tuberculosis treatment have successfully emerged. These include bedaquiline, delamanid and pretomanid which have entered phase III B trials and are also available through conditional access national programmes. The current guidelines by WHO to start Antiretroviral therapy irrespective of CD4+ cell count based on benefits cited by recent trials could go a long way in preventing various complications caused by the deadly duo. This review provides a consolidated gist of the advancements, concepts and updates that have emerged in the management of HIV-associated pulmonary TB for maximizing efficacy, offering latest solutions for tackling drug-drug interactions and remedial measures for immune reconstitution inflammatory syndrome.

Reactivation tuberculosis: role of surveillance

The incidence and death rates from tuberculosis (TB) have declined through concerted efforts in the diagnosis and treatment of active disease. Despite this, 9.6 million new cases and 1.1 million deaths in 2014 are unacceptably high. To decrease the rates of TB further, the huge number of persons with latent TB infection (LTBI) from whom new cases will arise has to be addressed with a sense of priority. Identifying the highest risk groups and providing effective treatment has been shown to decrease active TB. Further research to refine the predictors of reactivation and shorter effective treatments are urgently needed. Implementing intensified case finding, testing and treatment for LTBI will require continued investment in health care capacity at multiple levels.

Continuous isoniazid for the treatment of latent tuberculosis infection in people living with HIV

OBJECTIVE

This systematic review was carried out to determine the effectiveness of continuous isoniazid (given for at least 36 months) for the treatment of latent tuberculosis infection (LTBI) in people living with HIV (PLHIV).

METHODS

Six databases and HIV and tuberculosis (TB) conference abstract books were searched for randomized controlled trials that compared the effectiveness of continuous isoniazid with 6 months of isoniazid. Outcomes of interest were TB incidence, mortality, adverse events and risk of drug resistance. Data were pooled using fixed-effects meta-analysis.

RESULTS

Three studies were included, from Botswana, South Africa and India. The risk of active TB was 38% lower among patients receiving continuous isoniazid compared with isoniazid regimen for 6 months [relative risk (RR) 0.62, 95% confidence interval (CI): 0.42-0.89; I = 0%], and 49% lower for those with a positive tuberculin skin test (TST) (RR 0.51, 95% CI: 0.30-0.86; I = 7%). Similarly, individuals with positive TST had a 50% lower chance of death (RR 0.50, 95% CI: 0.27-0.91; I = 3%). Two studies found no evidence of an increase in adverse events in the continuous isoniazid group, whereas a third study, that used a different definition for adverse events, found strong evidence of increase. There was no evidence of increased drug resistance when continuous isoniazid was given.

CONCLUSION

For PLHIV in settings with high TB and HIV prevalence and transmission, continuous isoniazid for at least 36 months is beneficial and probably outweighs the risk of increased adverse events compared with an isoniazid regimen for 6 months.

Emerging drugs and alternative possibilities in the treatment of tuberculosis

INTRODUCTION

Tuberculosis (TB) remains a global health problem. Drug resistance, treatment duration, complexity, and adverse drug reactions associated with anti-TB regimens are associated with treatment failure, prolonged infectiousness and relapse. With the current set of anti-TB drugs the goal to end TB has not been met. New drugs and new treatment regimens are needed to eradicate TB.

AREAS COVERED

Literature was explored to select publications on drugs currently in phase II and phase III trials. These include new chemical entities, immunotherapy, established drugs in new treatment regimens and vaccines for the prophylaxis of TB.

EXPERT OPINION

Well designed trials, with detailed pharmacokinetic/pharmacodynamic analysis, in which information on drug exposure and drug susceptibility of the entire anti-TB regimen is included, in combination with long-term follow-up will provide relevant data to optimize TB treatment. The new multi arm multistage trial design could be used to test new combinations of compounds, immunotherapy and therapeutic vaccines. This new approach will both reduce the number of patients exposed to inferior treatment and the financial burden. Moreover, it will speed up drug evaluation. Considering the investments involved in development of new drugs it is worthwhile to thoroughly investigate existing, non-TB drugs in new regimens.

Implementation of isoniazid preventive therapy in an HIV clinic in Cambodia: high rates of discontinuation when combined with antiretroviral therapy

OBJECTIVE

Data on feasibility and completion rates of isoniazid preventive therapy (IPT) in HIV-infected patient in Asia are limited. Within a hospital-based HIV programme in Phnom Penh, Cambodia, we determined the proportion completing IPT and reasons for non-completion.

METHODS

Retrospective cohort study using HIV/IPT programme data, including all adults starting IPT (300 mg/day self-administered for 24 weeks) from February 2011 to March 2013. All patients underwent symptom screening and further investigations as indicated. After ruling out tuberculosis (TB), IPT was started, with monthly follow-up visits. As per national guideline, IPT was only prescribed for ART-naïve patients. IPT completion was defined as taking IPT for at least 22 of the planned 24 weeks. Stavudine/lamivudine/nevirapine was the preferential first-line ART regimen.

RESULTS

Among 445 ART-naïve patients starting IPT (median age: 35 years (IQR: 31-43), median CD4 count 354 cells/μl (IQR 215-545) and 288 (65%) were female), 214 (48%) started ART after a median of 4 weeks (IQR 2-6) on IPT ('concurrent ART'). Overall, 348 (78%) completed IPT. Among individuals with concurrent ART, the completion rate was 73% (157/214). Those without concurrent ART had a higher completion rate (83%; 191/231; P 0.017). The main reason for non-completion with concurrent ART was drug toxicity (mainly hepatotoxicity/rash), occurring in 22% (48/214). Without concurrent ART, the main reason for non-completion was loss to follow-up (16/231; 7%). Fourteen (3%) patients were diagnosed with TB while on IPT, of whom three had a positive TB culture at baseline. An additional 14 TB cases were diagnosed after IPT completion; four were bacteriologically confirmed.

CONCLUSION

Although overall completion rates were acceptable, IPT discontinuation due to drug toxicity was common in patients subsequently initiating ART. Future studies should evaluate whether this relates to IPT, ARVs or both, and whether the increased toxicity would justify delaying IPT initiation until stabilisation on ART.

Isoniazid-associated hepatitis in adults infected with HIV receiving 36 months of isoniazid prophylaxis in Botswana

BACKGROUND

The World Health Organization recommends 36 months of isoniazid preventive therapy (36IPT) for adults infected with HIV living in TB-endemic countries. We determined the rates and risk factors for isoniazid-associated hepatitis with the use of 36IPT.

METHODS

One thousand six adults infected with HIV received 36IPT during a pragmatic randomized trial set in Botswana public health clinics providing HIV care. Enrollment exclusion criteria included jaundice or elevations of serum transaminases (ESTs) > 2.5-fold the upper limit of normal (ULN). Participants with any CD4+ lymphocyte count were eligible and received antiretroviral therapy (ART) when CD4+ < 200 cells/μL. 36IPT was stopped for severe hepatitis (more than fivefold ULN EST) but not for moderate hepatitis (2.5-fold to fivefold ULN EST).

RESULTS

Pharmacy refill records showed 2,237 person-years of isoniazid receipt; 48% of participants initiated ART by 36 months. A total of 1.9% (19 of 1,006) of participants were diagnosed with severe hepatitis; three had jaundice and two of these developed hepatic encephalopathy. Another 3.1% (31 of 1,006) of participants experienced moderate hepatitis. Thirty-eight percent (19 of 50) of participants with moderate to severe hepatitis concomitantly received ART. Forty percent (20 of 50) of moderate to severe cases occurred within the first 2 months of IPT and during this period were not associated with receipt of ART at baseline (hazard ratio, 1.49; 95% CI, 0.20-11.1; P = .70).

CONCLUSIONS

Adults infected with HIV receiving 36IPT did not have an increased incidence of moderate to severe hepatitis or hepatic encephalopathy compared with published reports among people infected with HIV, people not infected with HIV in trials or public health programs. Compared with participants not receiving ART, the risk of moderate to severe hepatitis was not increased by ART.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00164281; URL: www.clinicaltrials.gov.

Use of isoniazid preventive therapy for tuberculosis prophylaxis among people living with HIV/AIDS: a review of the literature

BACKGROUND

Tuberculosis (TB) is the leading preventable cause of death in persons living with HIV (PLHIV), accounting for over a quarter of all HIV-associated deaths in 2012. Isoniazid preventive therapy (IPT) has the potential to decrease TB-related cases and deaths in PLHIV; however, implementation of this has been slow in many high HIV- and TB-burden settings.

METHODOLOGY

We performed an assessment of the evidence for the use of IPT in adults living with HIV based on a review of the literature published from 1995 to 2013. Eligible articles included data on mortality, morbidity, or retention in care related to the provision of IPT to adults with HIV in low- or middle-income countries. Cost-effectiveness information was also abstracted.

RESULTS

We identified 41 articles involving over 45,000 PLHIV. While there was little evidence to demonstrate that IPT reduced mortality in PLHIV, there was substantial evidence that IPT reduced TB incidence. While these findings were consistent irrespective of CD4 or antiretroviral therapy status, studies frequently demonstrated a greater benefit among patients with a positive TB skin test (TST). Duration of effectiveness and benefits of prolonged therapy varied across settings.

CONCLUSIONS

This analysis supports World Health Organization recommendations for the provision of IPT to PLHIV to reduce TB-associated morbidity and serves to highlight the need to strengthen IPT implementation. While there appears to be a greater benefit of IPT among PLHIV who are TST positive, IPT should be provided to all PLHIV without presumptive TB when TST is not available.

Debunking the myths perpetuating low implementation of isoniazid preventive therapy amongst human immunodeficiency virus-infected persons

Isoniazid preventive therapy (IPT) is the administration of isoniazid (INH) to people with latent tuberculosis (TB) infection (LTBI) to prevent progression to active TB disease. Despite being life-saving for human immunodeficiency virus (HIV)-infected persons who do not have active TB, IPT is poorly implemented globally due to misconceptions shared by healthcare providers and policy makers. However, amongst HIV-infected patients especially those living in resource-limited settings with a high burden of TB, available evidence speaks for IPT: Among HIV-infected persons, active TB- the major contraindication to IPT, can be excluded with symptom screening; chest X-ray and tuberculin skin testing are unreliable and often lead to logistic delays resulting in increased numbers of people with LTBI progressing to active TB; the use of IPT has not been found to increase the risk of the development of INH mono-resistance; IPT is cost-effective and cheaper than the cost of treating cases of active TB that would develop without IPT; ART and IPT have an additive effect on the prevention of TB, and both are safe and beneficial even in children. In order to sustain the recorded gains from ART scale-up and to further reduce TB-related morbidity and mortality, more efforts are needed to scale-up IPT implementation globally.

Accuracy of the Berger-Exner test for detecting third-order selection bias in randomised controlled trials: a simulation-based investigation

BACKGROUND

Randomised controlled trials (RCT) are highly influential upon medical decisions. Thus RCTs must not distort the truth. One threat to internal trial validity is the correct prediction of future allocations (selection bias). The Berger-Exner test detects such bias but has not been widely utilized in practice. One reason for this non-utilisation may be a lack of information regarding its test accuracy. The objective of this study is to assess the accuracy of the Berger-Exner test on the basis of relevant simulations for RCTs with dichotomous outcomes.

METHODS

Simulated RCTs with various parameter settings were generated, using R software, and subjected to bias-free and selection bias scenarios. The effect size inflation due to bias was quantified. The test was applied in both scenarios and the pooled sensitivity and specificity, with 95% confidence intervals for alpha levels of 1%, 5%, and 20%, were computed. Summary ROC curves were generated and the relationships of parameters with test accuracy were explored.

RESULTS

An effect size inflation of 71% - 99% was established. Test sensitivity was 1.00 (95% CI: 0.99 - 1.00) for alpha level 1%, 5%, and 20%; test specificity was 0.94 (95% CI: 0.93 - 0.96); 0.82 (95% CI: 0.80 - 0.84), and 0.56 (95% CI: 0.54 - 0.58) for alpha 1%, 5%, and 20%, respectively. Test accuracy was best with the maximal procedure used with a maximum tolerated imbalance (MTI) = 2 as the randomisation method at alpha 1%.

CONCLUSIONS

The results of this simulation study suggest that the Berger-Exner test is generally accurate for identifying third-order selection bias.

Isoniazid plus antiretroviral therapy to prevent tuberculosis: a randomised double-blind, placebo-controlled trial

BACKGROUND

Antiretroviral therapy reduces the risk of tuberculosis, but tuberculosis is more common in people with HIV than in people without HIV. We aimed to assess the effect of isoniazid preventive therapy on the risk of tuberculosis in people infected with HIV-1 concurrently receiving antiretroviral therapy.

METHODS

For this pragmatic randomised double-blind, placebo-controlled trial in Khayelitsha, South Africa, we randomly assigned (1:1) patients to receive either isoniazid preventive therapy or a placebo for 12 months (could be completed during 15 months). Randomisation was done with random number generator software. Participants, physicians, and pharmacy staff were masked to group assignment. The primary endpoint was time to development of incident tuberculosis (definite, probable, or possible). We excluded tuberculosis at screening by sputum culture. We did a modified intention-to-treat analysis and excluded all patients randomly assigned to groups who withdrew before receiving study drug or whose baseline sputum culture results suggested prevalent tuberculosis. This study is registered with ClinicalTrials.gov, number NCT00463086.

FINDINGS

1329 participants were randomly assigned to receive isoniazid preventive therapy (n=662) or placebo (n=667) between Jan 31, 2008, and Sept 31, 2011, and contributed 3227 person-years of follow-up to the analysis. We recorded 95 incident cases of tuberculosis; 37 were in the isoniazid preventive therapy group (2·3 per 100 person-years, 95% CI 1·6-3·1), and 58 in the placebo group (3·6 per 100 person-years, 2·8-4·7; hazard ratio [HR] 0·63, 95% CI 0·41-0·94). Study drug was discontinued because of grade 3 or 4 raised alanine transaminase concentrations in 19 of 662 individuals in the isoniazid preventive therapy group and ten of the 667 individuals in the placebo group (risk ratio 1·9, 95% CI 0·90-4·09). We noted no evidence that the effect of isoniazid preventive therapy was restricted to patients who were positive on tuberculin skin test or interferon gamma release assay (adjusted HR for patients with negative tests 0·43 [0·21-0·86] and 0·43 [0·20-0·96]; for positive tests 0·86 [0·37-2·00] and 0·55 [0·26-1·24], respectively).

INTERPRETATION

Without a more predictive test or a multivariate algorithm that predicts benefit, isoniazid preventive therapy should be recommended to all patients receiving antiretroviral therapy in moderate or high incidence areas irrespective of tuberculin skin test or interferon gamma release assay status.

FUNDING

Department of Health of South Africa, the Wellcome Trust, Médecins Sans Frontières, European and Developing Countries Clinical Trials Partnership, Foundation for Innovation and New Diagnostics, the European Union, and Hasso Plattner (Institute of Infectious Diseases and Molecular Medicine, University of Cape Town).

Eligibility for isoniazid preventive therapy in South African gold mines

SETTING

The "Thibela TB" cluster randomised trial of community-wide isoniazid preventive therapy (IPT) to reduce tuberculosis incidence in the South African gold mines.

OBJECTIVES

To determine the proportion of participants eligible for IPT and the reasons and risk factors for ineligibility, to inform the scale-up of IPT.

DESIGN

Cross-sectional survey of participants in intervention clusters (mine shafts) consenting to tuberculosis screening and assessment for eligibility to start IPT.

RESULTS

Among 27,126 consenting participants, 94.7% were male, the median age was 41 years, 12.2% reported previous tuberculosis, 0.6% reported ever taking IPT and 2.5% reported currently taking antiretroviral therapy. There were 24,430 (90.1%) assessed as eligible to start IPT, of whom 23,659 started IPT. The most common reasons for ineligibility were having suspected tuberculosis that was subsequently confirmed by a positive smear and/or culture (n=705), excessive alcohol consumption (n=427) and being on tuberculosis treatment at time of initial screen (n=241). Ineligibility was associated with factors including older age, female gender, prior history of tuberculosis and being in "HIV care". However, at least 78% were eligible for IPT in all of these sub-groups.

CONCLUSIONS

The vast majority of participants in this community-wide intervention were eligible for IPT.

Diagnosis & treatment of tuberculosis in HIV co-infected patients

Human immunodeficiency virus (HIV) associated tuberculosis (TB) remains a major global public health challenge, with an estimated 1.4 million patients worldwide. Co-infection with HIV leads to challenges in both the diagnosis and treatment of tuberculosis. Further, there has been an increase in rates of drug resistant tuberculosis, including multi-drug (MDR-TB) and extensively drug resistant TB (XDRTB), which are difficult to treat and contribute to increased mortality. Because of the poor performance of sputum smear microscopy in HIV-infected patients, newer diagnostic tests are urgently required that are not only sensitive and specific but easy to use in remote and resource-constrained settings. The treatment of co-infected patients requires antituberculosis and antiretroviral drugs to be administered concomitantly; challenges include pill burden and patient compliance, drug interactions, overlapping toxic effects, and immune reconstitution inflammatory syndrome. Also important questions about the duration and schedule of anti-TB drug regimens and timing of antiretroviral therapy remain unanswered. From a programmatic point of view, screening of all HIV-infected persons for TB and vice-versa requires good co-ordination and communication between the TB and AIDS control programmes. Linkage of co-infected patients to antiretroviral treatment centres is critical if early mortality is to be prevented. We present here an overview of existing diagnostic strategies, new tests in the pipeline and recommendations for treatment of patients with HIV-TB dual infection.