Rifampin and pyrazinamide vs isoniazid for prevention of tuberculosis in HIV-infected persons: an international randomized trial. Terry Beirn Community Programs for Clinical Research on AIDS, the Adult AIDS Clinical Trials Group, the Pan American Health Organization, and the Centers for Disease Control and Prevention Study Group

Safety and Tolerability of Six Months of Isoniazid Plus Pyridoxine or Three Months of Rifampicin for Tuberculosis among Subjects with Diabetes Mellitus: A Randomized Trial

Tuberculosis (TB) associated with diabetes mellitus (DM) is a growing problem, particularly in low- and medium-resource countries. We conducted an open-label, parallel-group, randomized, and controlled trial in a tertiary care center in Mexico City to assess TB preventive treatment (TPT) with isoniazid (INH) or rifampicin (RIF) in people with type 2 DM. Participants were assigned six months of INH 300 mg/day plus pyridoxine 75 mg or three months of RIF 600 mg/day. The primary outcomes were adverse events resulting in permanent treatment cessation and considered possibly or probably related to study drugs. We included 130 subjects, 68 randomized to INH and 62 to RIF. We prematurely halted the study based on recommendations of the Adverse Event Safety Panel. There was no difference between arms in the overall frequency of adverse events. However, the INH group had significantly more permanent treatment interruptions due to grade 2 recurrent or grade 3 or 4 hepatoxicity. In comparison, the RIF arm had more treatment interruptions due to grade 3 or 4 gastrointestinal intolerance. TPT using INH or RIF is not safe enough to be considered a universal indication to patients with type 2 DM and TB infection. These results underline the need to search for alternative TB preventions with better safety profiles for type 2 DM patients.

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.

Landscape of TB Infection and Prevention among People Living with HIV

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

Practices and attitudes towards tuberculosis and latent tuberculosis infection screening in people living with HIV/AIDS among HIV physicians in Japan

Background

Tuberculosis (TB) continues to be the leading cause of death for people living with HIV/AIDS (PLHIV), and HIV is the strongest known risk factor for progression to active TB disease for persons with latent TB infection (LTBI). Screening for active TB and LTBI, and TB preventive therapy (TPT) is recommended, however, clinical practices regarding LTBI screening for HIV positive population have not been uniform, resulting in low rates of LTBI screening and TPT uptake, in both low and high TB-burden countries. We sought to explore the practices and attitudes towards TB and LTBI screening in PLHIV among HIV physicians in Japan.

Methods

We conducted a cross-sectional survey whereby an on-line questionnaire was administered to physicians who are currently, or have the experience of, providing care and treatment for PLHIV in Japan.

Results

The questionnaire was sent to a total of 83 physicians, of which 59 responded (response rate; 71.1%). 52.5% (31/59) conducted routine screening and 44.0% (26/59) conducted selectively screening for active TB among HIV/AIDS patients. As for LTBI, 54.2% (32/59) conducted routine screening and 35.6% (21/59) conducted selective screening for LTBI among PLHIV. “T-SPOT only” was the most frequently used method of screening (n = 33), followed by “QFT only” (n = 11). Criteria for LTBI screening included TB burden in the country of birth of the patient, previous contact with a TB patient, and CD4+ cell count. 83.1% (49/59) either “always” or “selectively” offered TPT to PLHIV diagnosed with LTBI, and among the 49 respondents who did provide TPT, 77.6% (38/49) chose 9-months isoniazid as their first choice. None chose regimen including rifampicin.

Conclusions

Our study revealed that practices regarding TB and LTBI screening and treatment for PLHIV among HIV physicians were mixed and not necessarily in accordance with the various published guidelines. Building and disseminating scientific evidence that takes into consideration the local epidemiology of TB and HIV in Japan is urgently needed to assist physicians make decisions.

Mycobacterial infections in solid organ transplant recipients

Mycobacterium tuberculosis (MTB) infection in solid organ transplant (SOT) recipients remains a major challenge for physicians and surgeons. Active tuberculosis (TB) is associated with increased morbidity and mortality in SOT recipients. MTB usually develops after transplantation in a recipient with latent TB infection (LTBI) before transplantation and may also be transmitted from the donor or acquired from the community. Therefore, screening for LTBI in donors and recipients before transplantation is very important in preventing active disease after transplantation. This review article is based on recently published data, case series, and expert recommendations. We reviewed updated information about the epidemiology, diagnosis, and treatment of latent and active TB before and after transplantation. We also reviewed recent treatments for multidrug-resistant TB.

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.

Infectious Diseases Learning Unit: Understanding Advances in the Treatment of Latent Tuberculosis Infection Among People With Human Immunodeficiency Virus

Tuberculosis (TB) remains the leading cause of death among people with human immunodeficiency virus (PWH). The diagnosis of latent TB infection (LTBI) and treatment with TB preventative therapy (TPT) can reduce morbidity and mortality in this population. Historically, isoniazid has been recommended for TPT in PWH due to the absence of drug-drug interactions with most antiretroviral therapy (ART). However, newer rifamycin-based regimens are safer, shorter in duration, associated with improved adherence, and may be as or more effective than isoniazid TPT. Current guidelines have significant heterogeneity in their recommendations for TPT regimens and acceptability of drug interactions with modern ART. In this Infectious Diseases learning unit, we review common questions on diagnosis, treatment, and drug interactions related to the management of LTBI among PWH.

Are We There Yet? Short-Course Regimens in TB and HIV: From Prevention to Treatment of Latent to XDR TB

PURPOSE OF REVIEW

Despite broad uptake of antiretroviral therapy (ART), tuberculosis (TB) incidence and mortality among people with HIV remain unacceptably high. Short-course regimens for TB, incorporating both novel and established drugs, offer the potential to enhance adherence and completion rates, thereby reducing the global TB burden. This review will outline short-course regimens for TB among patients with HIV.

RECENT FINDINGS

After many years without new agents, there is now active testing of many novel drugs to treat TB, both for latent infection and active disease. Though not all studies have included patients with HIV, many have, and there are ongoing trials to address key implementation challenges such as potent drug-drug interactions with ART. The goal of short-course regimens for TB is to enhance treatment completion without compromising efficacy. Particularly among patients with HIV, studying these shortened regimens and integrating them into clinical care are of urgent importance. There are now multiple short-course regimens for latent infection and active disease that are safe and effective among patients with HIV.

Treatment of latent M. tuberculosis infection and use of antiretroviral therapy to prevent tuberculosis

Even with treatment of HIV with antiretroviral therapy (ART), the risk of tuberculosis (TB) reactivation remains higher in HIV-infected than HIV-uninfected persons. In this issue of the JCI, Ganatra et al. explored TB reactivation in the context of ART using TB and simian immunodeficiency virus-coinfected (TB/SIV-coinfected) nonhuman primates. The authors found that treating rhesus macaques with ART restored CD4+ T cells in whole blood, spleen, and bronchoalveolar lavage (BAL) fluid, but not in the lung interstitium. TB risk was not decreased in the coinfected macaques treated with ART for 14-63 days, suggesting that ART does not decrease the short-term risk of reactivation. Reactivation occurred as CD4+ T cells were increasing, which is consistent with observations made in humans. This study provides a potential model for systematic evaluation of TB/SIV coinfection and different treatment regimens and strategies to prevent TB reactivation.

Latent Tuberculosis and HIV Infection

Purpose of Review

Tuberculosis is the number one infectious killer of people with HIV worldwide, but it can be both prevented and treated. Prevention of tuberculosis by screening for and treating latent tuberculosis infection (LTBI), along with the initiation of antiretroviral therapy (ART), is the key component of HIV care.

Recent Findings

While access to ART has increased worldwide, uptake and completion of LTBI treatment regimens among people living with HIV (PWH) are very poor. Concomitant TB-preventive therapy and ART are complex because of drug–drug interactions, but these can be managed. Recent clinical trials of shorter preventive regimens have demonstrated safety and efficacy in PWH with higher completion rates. More research is needed to guide TB-preventive therapy in children and in pregnant women, and for drug-resistant TB (DR-TB).

Summary

Antiretroviral therapy and tuberculosis-preventive treatment regimens can be optimized to avoid drug–drug interactions, decrease pill burden and duration, and minimize side effects in order to increase adherence and treatment completion rates among PWH and LTBI.

Once-weekly rifapentine and isoniazid for tuberculosis prevention in patients with HIV taking dolutegravir-based antiretroviral therapy: a phase 1/2 trial

BACKGROUND

Short-course preventive therapy with 12 doses of once-weekly rifapentine (900 mg) plus isoniazid (900 mg) could greatly improve tuberculosis control, especially in areas with high co-endemicity with HIV. However, a small previous trial of such therapy with dolutegravir in healthy, HIV-negative adults was halted early after two of the four patients developed serious adverse events. Because of the potential use of this therapy, and variable safety outcomes of tuberculosis drugs seen in patients with and without HIV, we aimed to characterise safety, pharmacokinetics, and virological suppression in adults who are HIV positive.

METHODS

DOLPHIN was a phase 1/2, single-arm trial done at The Aurum Institute (Tembisa Clinical Research Site, Tembisa, South Africa), with pharmacokinetic visits done at VxPharma (Pretoria, South Africa). Adults (≥18 years) with HIV infection and undetectable viral load (<40 copies per mL) after at least 8 weeks of efavirenz-based or dolutegravir-based regimens were recruited in three consecutive groups, subject to approval by the independent safety monitoring committee. Participants received 50 mg of daily dolutegravir in place of efavirenz for 8 weeks, then began once-weekly rifapentine (900 mg)-isoniazid (900 mg) for 12 weeks. Groups 1A (n=12) and 1B (n=18) had intensive dolutegravir pharmacokinetic sampling at week 8 (before rifapentine-isoniazid), at week 11 (after the third dose of rifapentine)-isoniazid and at week 16 after the eighth dose. Group 2 (n=30) were treated with the same schedule and had sparse dolutegravir pharmacokinetic sampling at weeks 8, 11, and 16. Participants were followed 4 weeks after completion of prophylactic tuberculosis treatment. HIV viral loads were measured at baseline and at weeks 11 and 24. Primary endpoints were adverse events (grade 3 or higher) and dolutegravir population pharmacokinetics, assessed in participants who began rifapentine-isoniazid. This trial was registered at ClinicalTrials.gov, NCT03435146.

FINDINGS

Between Jan 24, 2018, and Nov 25, 2018, 61 participants were enrolled into three groups; one participant withdrew (from group 1A). 43 (70%) of 60 participants were women and all participants were black African. Median age was 40 years (IQR 35-48), CD4 cell count was 683 cells per μL (447-935), and body-mass index was 28·9 kg/m² (24·0-32·9). Three grade 3 adverse events occurred; two elevated creatinine and one hypertension. Rifapentine-isoniazid increased dolutegravir clearance by 36% (relative standard error 13%) resulting in a 26% decrease in dolutegravir area under the curve. Overall geometric mean ratio of trough concentrations with versus without rifapentine-isoniazid was 0·53 (90% CI 0·49-0·56) though this ratio varied by day after rifapentine-isoniazid dose. All but one trough value was above the 90% maximal inhibitory concentration for dolutegravir and HIV viral loads were less than 40 copies per mL in all patients.

INTERPRETATION

Our results suggest 12 doses of once-weekly rifapentine-isoniazid can be given for tuberculosis prophylaxis to patients with HIV taking dolutegravir-based antiretroviral therapy, without dose adjustments. Further exploration of the pharmacokinetics, safety, and efficacy in children and pharmacodynamics in individuals naive to antiretroviral therapy is needed.

FUNDING

UNITAID.

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.

Seventy Years of Tuberculosis Prevention: Efficacy, Effectiveness, Toxicity, Durability, and Duration

Tuberculosis (TB) has been a leading infectious cause of death worldwide for much of human history, with 1.6 million deaths estimated in 2017. The Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health has played an important role in understanding and responding to TB, and it has made particularly substantial contributions to prevention of TB with chemoprophylaxis. TB preventive therapy is highly efficacious in the prevention of TB disease, yet it remains underutilized by TB programs worldwide despite strong evidence to support its use in high-risk groups, such as people living with HIV and household contacts, including those under 5 years of age. We review the evidence for TB preventive therapy and discuss the future of TB prevention.

Treatment for latent tuberculosis infection in low- and middle-income countries: progress and challenges with implementation and scale-up

Introduction: Treatment of latent tuberculosis infection (LTBI) is a crucial but neglected component of global tuberculosis control. The 2018 United Nations High-Level Meeting committed world leaders to provide LTBI treatment to at least 30 million people, including 4 million children<5 years, 20 million other household contacts and 6 million HIV-infected people by 2022.Areas covered: This review searched MEDLINE between 1990 and 2019 and discussed: i) high-risk groups to be prioritized for diagnosis and treatment of LTBI; ii) challenges with diagnosing LTBI in programmatic settings; iii) LTBI treatment options including isoniazid monotherapy, shorter regimens (rifampicin-monotherapy, rifampicin-isoniazid and rifapentine-isoniazid) and treatments for contacts of drug-resistant patients; iv) issues with programmatic scale-up of treatment including policy considerations, ruling out active TB, time to start treatment, safety, uninterrupted drug supplies and treatment adherence; and v) recording and reporting.Expert opinion: In 2017, <1.5 million persons were reported to be treated for LTBI. This must rapidly increase to 6 million persons annually. If HIV programs focus on HIV-infected people already accessing or about to start antiretroviral therapy and TB programs focus on household contacts, these targets could be achieved. Isoniazid remains the current treatment of choice although shorter courses of rifapentine-isoniazid are possible alternatives.

One Month of Rifapentine plus Isoniazid to Prevent HIV-Related Tuberculosis

BACKGROUND

Tuberculosis is the leading killer of patients with human immunodeficiency virus (HIV) infection. Preventive therapy is effective, but current regimens are limited by poor implementation and low completion rates.

METHODS

We conducted a randomized, open-label, phase 3 noninferiority trial comparing the efficacy and safety of a 1-month regimen of daily rifapentine plus isoniazid (1-month group) with 9 months of isoniazid alone (9-month group) in HIV-infected patients who were living in areas of high tuberculosis prevalence or who had evidence of latent tuberculosis infection. The primary end point was the first diagnosis of tuberculosis or death from tuberculosis or an unknown cause. Noninferiority would be shown if the upper limit of the 95% confidence interval for the between-group difference in the number of events per 100 person-years was less than 1.25.

RESULTS

A total of 3000 patients were enrolled and followed for a median of 3.3 years. Of these patients, 54% were women; the median CD4+ count was 470 cells per cubic millimeter, and half the patients were receiving antiretroviral therapy. The primary end point was reported in 32 of 1488 patients (2%) in the 1-month group and in 33 of 1498 (2%) in the 9-month group, for an incidence rate of 0.65 per 100 person-years and 0.67 per 100 person-years, respectively (rate difference in the 1-month group, -0.02 per 100 person-years; upper limit of the 95% confidence interval, 0.30). Serious adverse events occurred in 6% of the patients in the 1-month group and in 7% of those in the 9-month group (P = 0.07). The percentage of treatment completion was significantly higher in the 1-month group than in the 9-month group (97% vs. 90%, P<0.001).

CONCLUSIONS

A 1-month regimen of rifapentine plus isoniazid was noninferior to 9 months of isoniazid alone for preventing tuberculosis in HIV-infected patients. The percentage of patients who completed treatment was significantly higher in the 1-month group. (Funded by the National Institute of Allergy and Infectious Diseases; BRIEF TB/A5279 ClinicalTrials.gov number, NCT01404312.).

The Global Landscape of Tuberculosis Therapeutics

Tuberculosis (TB) is one of the oldest infections afflicting humans yet remains the number one infectious disease killer worldwide. Despite decades of experience treating this disease, TB regimens require months of multidrug therapy, even for latent infections. There have been important recent advances in treatment options across the spectrum of TB, from latent infection to extensively drug-resistant (XDR) TB disease. In addition, new, potent drugs are emerging out of the development pipeline and are being tested in novel regimens in multiple currently enrolling trials. Shorter, safer regimens for many forms of TB are now available or are in our near-term vision. We review recent advances in TB therapeutics and provide an overview of the upcoming clinical trials landscape that will help define the future of worldwide TB treatment.

Treatment of tuberculosis infection in children

INTRODUCTION

Identifying and treating children with tuberculosis (TB) infection in both low and high-TB burden settings will decrease the incidence of TB disease worldwide. Areas covered: This review covers each of the available TB infection treatment options for children based on effectiveness, safety, tolerability and treatment completion rates. Six to 9 months of daily administered isoniazid is no longer the treatment of choice for many children with TB infection. Shorter, rifamycin based, TB infection treatment regimens are effective, safe and easier for children to complete. Fluroquinolone-based regimens are recommended for the treatment of children infected by a source case with drug-resistant TB. Directly observed therapy (DOT) programs improve childhood TB infection treatment completion rates. Expert commentary: As shorter, rifamycin-based, TB infection treatment regimens offer superior treatment success rate in both adults and children; the widespread use of these regimens has huge potential to decrease the burden of TB disease worldwide. The implementation of these programs will involve improving patient access to the medications, decreasing their cost to the patient, and the use of novel electronic methods to document patient treatment completion.

Rifampicin resistance after treatment for latent tuberculous infection: a systematic review and meta-analysis

SETTING

Treatment for latent tuberculous infection (LTBI) reduces the risk of tuberculosis (TB) disease. Shorter, rifamycin-containing regimens have been shown to be as effective as 6 months of isoniazid and superior with regard to safety and completion rate. It is unknown whether preventive therapy with rifamycins increases resistance to the drugs used.

OBJECTIVE

To determine whether treatment for LTBI with rifamycin-containing regimens leads to significant development of resistance against rifamycins.

DESIGN

Systematic review and meta-analysis.

RESULTS

We included six randomised-controlled trials of rifamycin-containing regimens for LTBI treatment that reported drug resistance. There was no statistically significant increased risk of rifamycin resistance after LTBI treatment with rifamycin-containing regimens compared to non-rifamycin-containing regimens (RR 3.45, 95%CI 0.72-16.56; P = 0.12) or placebo (RR 0.20, 95%CI 0.02-1.66; P = 0.13).

CONCLUSION

Preventive treatment with rifamycin-containing regimens does not significantly increase rifamycin resistance. Programmatic management of LTBI requires the creation of sound surveillance systems to monitor drug resistance.

Preclinical Efficacy Testing of New Drug Candidates

This is a review of the preclinical efficacy testing of new antituberculosis drug candidates. It describes existing dynamic in vitro and in vivo models of antituberculosis chemotherapy and their utility in preclinical evaluations of promising new drugs and combination regimens, with an effort to highlight recent developments. Emphasis is given to the integration of quantitative pharmacokinetic/pharmacodynamic analyses and the impact of lesion pathology on drug efficacy. Discussion also includes in vivo models of chemotherapy of latent tuberculosis infection.

Enhanced Prophylaxis plus Antiretroviral Therapy for Advanced HIV Infection in Africa

BACKGROUND

In sub-Saharan Africa, among patients with advanced human immunodeficiency virus (HIV) infection, the rate of death from infection (including tuberculosis and cryptococcus) shortly after the initiation of antiretroviral therapy (ART) is approximately 10%.

METHODS

In this factorial open-label trial conducted in Uganda, Zimbabwe, Malawi, and Kenya, we enrolled HIV-infected adults and children 5 years of age or older who had not received previous ART and were starting ART with a CD4+ count of fewer than 100 cells per cubic millimeter. They underwent simultaneous randomization to receive enhanced antimicrobial prophylaxis or standard prophylaxis, adjunctive raltegravir or no raltegravir, and supplementary food or no supplementary food. Here, we report on the effects of enhanced antimicrobial prophylaxis, which consisted of continuous trimethoprim-sulfamethoxazole plus at least 12 weeks of isoniazid-pyridoxine (coformulated with trimethoprim-sulfamethoxazole in a single fixed-dose combination tablet), 12 weeks of fluconazole, 5 days of azithromycin, and a single dose of albendazole, as compared with standard prophylaxis (trimethoprim-sulfamethoxazole alone). The primary end point was 24-week mortality.

RESULTS

A total of 1805 patients (1733 adults and 72 children or adolescents) underwent randomization to receive either enhanced prophylaxis (906 patients) or standard prophylaxis (899 patients) and were followed for 48 weeks (loss to follow-up, 3.1%). The median baseline CD4+ count was 37 cells per cubic millimeter, but 854 patients (47.3%) were asymptomatic or mildly symptomatic. In the Kaplan-Meier analysis at 24 weeks, the rate of death with enhanced prophylaxis was lower than that with standard prophylaxis (80 patients [8.9% vs. 108 [12.2%]; hazard ratio, 0.73; 95% confidence interval [CI], 0.55 to 0.98; P=0.03); 98 patients (11.0%) and 127 (14.4%), respectively, had died by 48 weeks (hazard ratio, 0.76; 95% CI, 0.58 to 0.99; P=0.04). Patients in the enhanced-prophylaxis group had significantly lower rates of tuberculosis (P=0.02), cryptococcal infection (P=0.01), oral or esophageal candidiasis (P=0.02), death of unknown cause (P=0.03), and new hospitalization (P=0.03). However, there was no significant between-group difference in the rate of severe bacterial infection (P=0.32). There were nonsignificantly lower rates of serious adverse events and grade 4 adverse events in the enhanced-prophylaxis group (P=0.08 and P=0.09, respectively). Rates of HIV viral suppression and adherence to ART were similar in the two groups.

CONCLUSIONS

Among HIV-infected patients with advanced immunosuppression, enhanced antimicrobial prophylaxis combined with ART resulted in reduced rates of death at both 24 weeks and 48 weeks without compromising viral suppression or increasing toxic effects. (Funded by the Medical Research Council and others; REALITY Current Controlled Trials number, ISRCTN43622374 .).

Efficacy and completion rates of rifapentine and isoniazid (3HP) compared to other treatment regimens for latent tuberculosis infection: a systematic review with network meta-analyses

BACKGROUND

We conducted a systematic review and network meta-analysis (NMA) to examine the efficacy and completion rates of treatments for latent tuberculosis infection (LTBI). While a previous review found newer, short-duration regimens to be effective, several included studies did not confirm LTBI, and analyses did not account for variable follow-up or assess completion.

METHODS

We searched MEDLINE, Embase, CENTRAL, PubMed, and additional sources to identify RCTs in patients with confirmed LTBI that involved a regimen of interest and reported on efficacy or completion. Regimens of interest included isoniazid (INH) with rifapentine once weekly for 12 weeks (INH/RPT-3), 6 and 9 months of daily INH (INH-6; INH-9), 3-4 months daily INH plus rifampicin (INH/RFMP 3-4), and 4 months daily rifampicin alone (RFMP-4). NMAs were performed to compare regimens for both endpoints.

RESULTS

Sixteen RCTs (n = 44,149) and 14 RCTs (n = 44,128) were included in analyses of efficacy and completion. Studies were published between 1968 and 2015, and there was diversity in patient age and comorbidities. All regimens of interest except INH-9 showed significant benefits in preventing active TB compared to placebo. Comparisons between active regimens did not reveal significant differences. While definitions of regimen completion varied across studies, regimens of 3-4 months were associated with a greater likelihood of adequate completion.

CONCLUSIONS

Most of the active regimens showed an ability to reduce the risk of active TB relative to no treatment, however important differences between active regimens were not found. Shorter rifamycin-based regimens may offer comparable benefits to longer INH regimens. Regimens of 3-4 months duration are more likely to be completed than longer regimens.

Preventive therapy for latent tuberculosis infection-the promise and the challenges

Around one third of the world's population may harbour latent tuberculosis infection (LTBI), an asymptomatic immunological state that confers a heightened risk of subsequently developing tuberculosis (TB). Effectively treating LTBI will be essential if the End TB Strategy is to be realized. This review evaluates the evidence in relation to the effectiveness of preventive antibiotic therapy to treat LTBI due to both drug-susceptible and drug-resistant bacteria. Current national and international preventive therapy guidelines are summarized, as well as ongoing randomized trials evaluating regimens to prevent drug-resistant TB. Populations that may benefit most from screening and treatment for LTBI include close contacts of patients with TB (particularly children under 5 years of age) and individuals with substantial immunological impairment. The risks and benefits of treatment must be carefully balanced for each individual. Electronic decision support tools offer one way in which clinicians can help patients to make informed decisions. Modelling studies indicate that the expanded use of preventive therapy will be essential to achieving substantial reductions in the global TB burden. However, the widespread scale-up of screening and treatment will require careful consideration of cost-effectiveness, while ensuring the drivers of ongoing disease transmission are also addressed.

Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis

The American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America jointly sponsored the development of this guideline for the treatment of drug-susceptible tuberculosis, which is also endorsed by the European Respiratory Society and the US National Tuberculosis Controllers Association. Representatives from the American Academy of Pediatrics, the Canadian Thoracic Society, the International Union Against Tuberculosis and Lung Disease, and the World Health Organization also participated in the development of the guideline. This guideline provides recommendations on the clinical and public health management of tuberculosis in children and adults in settings in which mycobacterial cultures, molecular and phenotypic drug susceptibility tests, and radiographic studies, among other diagnostic tools, are available on a routine basis. For all recommendations, literature reviews were performed, followed by discussion by an expert committee according to the Grading of Recommendations, Assessment, Development and Evaluation methodology. Given the public health implications of prompt diagnosis and effective management of tuberculosis, empiric multidrug treatment is initiated in almost all situations in which active tuberculosis is suspected. Additional characteristics such as presence of comorbidities, severity of disease, and response to treatment influence management decisions. Specific recommendations on the use of case management strategies (including directly observed therapy), regimen and dosing selection in adults and children (daily vs intermittent), treatment of tuberculosis in the presence of HIV infection (duration of tuberculosis treatment and timing of initiation of antiretroviral therapy), as well as treatment of extrapulmonary disease (central nervous system, pericardial among other sites) are provided. The development of more potent and better-tolerated drug regimens, optimization of drug exposure for the component drugs, optimal management of tuberculosis in special populations, identification of accurate biomarkers of treatment effect, and the assessment of new strategies for implementing regimens in the field remain key priority areas for research. See the full-text online version of the document for detailed discussion of the management of tuberculosis and recommendations for practice.

Tuberculosis elimination in the post Millennium Development Goals era

The Millennium Development Goal for tuberculosis (TB) is to stop the increase in incidence and halve the mortality of TB between 1990 and 2015. This goal has now been reached on a global scale, although not in the most affected region of Africa. The new target is TB elimination, defined as one case of active TB per one million population per year, which is to be reached before 2050. This review will discuss the main tools in play, namely case-finding and new diagnostics, increased access and effectiveness of anti-TB therapy (directly observed therapy, short course (DOTS)), preventive therapy for latent infection, and vaccination. Each approach is discussed and a way forward in research and management is suggested.

Updates on the risk factors for latent tuberculosis reactivation and their managements

The preventive treatment of latent tuberculosis infection (LTBI) is of great importance for the elimination and control of tuberculosis (TB) worldwide, but existing screening methods for LTBI are still limited in predicting the onset of TB. Previous studies have found that some high-risk factors (including human immunodeficiency virus (HIV), organ transplantation, silicosis, tumor necrosis factor-alpha blockers, close contacts and kidney dialysis) contribute to a significantly increased TB reactivation rate. This article reviews each risk factor's association with TB and approaches to address those factors. Five regimens are currently recommended by the World Health Organization, and no regimen has shown superiority over others. In recent years, studies have gradually narrowed down to the preventive treatment of LTBI for high-risk target groups, such as silicosis patients, organ-transplantation recipients and HIV-infected patients. This review discusses regimens for each target group and compares the efficacy of different regimens. For HIV patients and transplant recipients, isoniazid monotherapy is effective in treating LTBI, but for others, little evidence is available at present.

Isoniazid Prophylactic Therapy for the Prevention of Tuberculosis in HIV Infected Adults: A Systematic Review and Meta-Analysis of Randomized Trials

Background

Infection with Human Immunodeficiency virus (HIV) is an important risk factor for Tuberculosis (TB). Anti-Retroviral Therapy (ART) has improved the prognosis of HIV and reduced the risk of TB infected patients. Isoniazid Preventive Therapy (IPT) aims to reduce the development of active TB in patients with latent TB.

Objective

Systematically review and synthesize effect estimates of IPT for TB prevention in adult HIV patients. Secondary objectives were to assess the effect of IPT on HIV disease progression, all-cause mortality and adverse drug reaction (ADR).

Search Strategy

Electronic databases were searched to identify relevant articles in English available by September 11^th 2015.

Selection Criteria

Research articles comparing IPT to placebo or no treatment in HIV infected adults using randomized clinical trials.

Data Analysis

A qualitative review included study-level information on randomization and treatment allocation. Effect estimates were pooled using random-effects models to account for between-study heterogeneity.

Main Results

This review assessed ten randomized clinical trials that assigned 7619 HIV patients to IPT or placebo. An overall 35% of TB risk reduction (RR = 0.65, 95% CI (0.51, 0.84)) was found in all participants, however, larger benefit of IPT was observed in Tuberculin Skin Test (TST) positive participants, with pooled relative risk reduction of 52% [RR = 0.48; 95% CI (0.29, 0.82)] and with a prediction interval ranging from 0.13 to 1.81. There was no statistically significant effect of IPT on TB occurrence in TST negative or unknown participants. IPT also reduced the risk of HIV disease progression in all participants (RR = 0.69; 95% CI (0.48, 0.99)) despite no benefits observed in TST strata. All-cause mortality was not affected by IPT although participants who had 12 months of IPT tend to have a reduced risk (RR = 0.65; 95% CI(0.47, 0.90)). IPT had an elevated, yet statistically non-significant, risk of adverse drug reaction [RR = 1.20; 95% CI (1.20, 1.71)]. Only a single study assessed the effect of IPT in combination with ART in preventing TB and occurrence of multi-drug resistant tuberculosis.

Conclusions

IPT use substantially contributes in preventing TB in persons with HIV in general and in TST positive individuals in particular. More evidence is needed to explain discrepancies in the protective effect of IPT in these individuals.

Management of latent tuberculous infection in Norway in 2009: a descriptive cross-sectional study

SETTING

Despite a steep increase in the number of individuals treated for latent tuberculous infection (LTBI), few data are available on how treatment is implemented.

OBJECTIVE

To obtain baseline information on initiation and completion of treatment for LTBI in Norway in 2009.

DESIGN

A descriptive cross-sectional study.

RESULTS

All 721 patients treated for LTBI in 2009 in Norway were included, of whom 607 (84%) completed treatment. The treatment regimen generally consisted of 3 months of rifampicin and isoniazid. The three main reasons for starting treatment were: 1) countries of origin with high tuberculosis (TB) prevalence, 2) a positive tuberculin skin test, and 3) a positive interferon gamma release assay. The use of directly observed treatment varied by health region and age. The majority of the 34 medical specialists interviewed saw a need for new national guidelines to improve the selection of high-risk patients with LTBI.

CONCLUSIONS

Management of LTBI is in accordance with current guidelines, with a high completion rate. More targeted selection of which patients should be offered preventive treatment is required, and new guidelines and tools to enhance risk assessment are necessary.

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.

Sensitization of Gram-negative bacteria to rifampin and OAK combinations

While individually inefficient against Gram-negative bacteria, in-vitro combinations of rifampin and OAK were mutually synergistic since sub-minimal inhibitory concentrations of one compound have potentiated the other by 2–4 orders of magnitude. Synergy persisted in-vivo as single-dose systemic treatment of Klebsiella infected mice resulted in 10–20% versus 60% survival, respectively accomplished by individual and combined compounds. This outcome was achieved without drug formulation, rather, pharmacokinetic considerations have inspired the therapeutic regimen.

Tuberculosis incidence after 36 months' isoniazid prophylaxis in HIV-infected adults in Botswana: a posttrial observational analysis

OBJECTIVE

Thirty-six months of isoniazid preventive therapy (36IPT) was superior to 6 months of IPT (6IPT) in preventing tuberculosis (TB) among HIV-infected adults in Botswana. We assessed the posttrial durability of this benefit.

DESIGN

A 36-month double-blind placebo controlled trial (1 : 1 randomization) with recruitment between November 2004 and July 2006 and observation until June 2011.

METHODS

One thousand, nine hundred and ninety-five participants were followed in eight public health clinics. Twenty-four percent had a tuberculin skin test ≥5 mm (TST-positive). A minimum CD4 lymphocyte count was not required for enrolment. Antiretroviral therapy (ART) was provided in accordance with Botswana guidelines; 72% of participants retained by June 2011 had initiated ART. Multivariable analysis using Cox regression analysis included treatment arm, TST status, ART as a time-dependent variable and CD4 cell count at baseline and updated at 36 months.

RESULTS

In the posttrial period, 2.13 and 2.14 per 100 person-years accumulated, whereas 0.93 and 1.13% TB incidence rates were observed in the 36IPT and 6IPT arms, respectively (P = 0.52). The crude hazard ratio of TB during the trial and posttrial was 0.57 [95% confidence intervals (CI) 0.33, 0.99] and 0.82 (95% CI 0.46, 1.49), and when restricted to TST-positive participants was 0.26 (95% CI 0.08, 0.80) and 0.40 (95% CI 0.15, 1.08), respectively. Multivariable analysis showed that ART use was associated with reduced death (adjusted hazard ratio 0.36, 95% CI 0.17-0.75) but not TB (0.92, 95% CI 0.55-1.53) in the posttrial period.

CONCLUSION

The benefit of 36IPT for TB prevention declined posttrial in this cohort. Adjunctive measures are warranted to prevent TB among HIV-infected persons receiving long-term ART in TB-endemic settings.

Delivery of rifampicin-chitin nanoparticles into the intracellular compartment of polymorphonuclear leukocytes

Polymorphonuclear leukocytes (PMNs) provide the primary host defence against invading pathogens by producing reactive oxygen species (ROS) and microbicidal products. However, few pathogens can survive for a prolonged period of time within the PMNs. Additionally their intracellular lifestyle within the PMNs protect themselves from the additional lethal action of host immune systems such as antibodies and complements. Antibiotic delivery into the intracellular compartments of PMNs is a major challenge in the field of infectious diseases. In order to deliver antibiotics within the PMNs and for the better treatment of intracellular bacterial infections we synthesized rifampicin (RIF) loaded amorphous chitin nanoparticles (RIF-ACNPs) of 350±50 nm in diameter. RIF-ACNPs nanoparticles are found to be non-hemolytic and non-toxic against a variety of host cells. The release of rifampicin from the prepared nanoparticles was ∼60% in 24 h, followed by a sustained pattern till 72 h. The RIF-ACNPs nanoparticles showed 5-6 fold enhanced delivery of RIF into the intracellular compartments of PMNs. The RIF-ACNPs showed anti-microbial activity against Escherichia coli, Staphylococcus aureus and a variety of other bacteria. In summary, our results suggest that RIF-ACNPs could be used to treat a variety of intracellular bacterial infections.

Quantiferon-TB Gold: performance for ruling out active tuberculosis in HIV-infected adults with high CD4 count in Côte d'Ivoire, West Africa

Objective

To assess the performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) test for active tuberculosis (TB) in HIV adults, and its variation over time in patients on antiretroviral therapy (ART) and/or isoniazide preventive therapy (IPT).

Methods

Transversal study and cohort nested in the Temprano ANRS 12136 randomized controlled trial assessing benefits of initiating ART earlier than currently recommended by World Health Organization, with or without a 6-month IPT. Performance of QFT-GIT for detecting active TB at baseline in the first 50% participants, and 12-month incidence of conversion/reversion in the first 25% participants were assessed. QFT-GIT threshold for positivity was 0.35 IU/ml.

Results

Among the 975 first participants (median baseline CD4 count 383/mm³, positive QFT-GIT test 35%), 2.7% had active TB at baseline. QFT-GIT sensitivity, specificity, positive and negative predictive value for active TB were 88.0%, 66.6%, 6.5% and 99.5%. For the 444 patients with a second test at 12 months, rates for conversion and reversion were 9.3% and 14%. Reversion was more frequent in patients without ART and younger patients. IPT and early ART were not associated with reversion/conversion.

Conclusion

A negative QFT-GIT could rule out active TB in HIV-infected adults not severely immunosuppressed, thus avoiding repeated TB testing and accelerating diagnosis and care for other diseases.

Trial Registration

ClinicalTrials.gov NCT00495651.

Tuberculosis in pregnancy: current recommendations for screening and treatment in the USA

The main focus of this review is the management of active and latent tuberculosis in pregnancy in industrialized countries. The review is geared towards the healthcare professional taking care of the obstetric patient. The epidemiology of active and latent tuberculosis in the USA and recommendations for the screening of tuberculosis in pregnancy are considered. The history of treatment methodology and its relationship to the current treatment of active and latent tuberculosis in pregnancy is reviewed, and finally, a discussion of the best time to treat latent tuberculosis in a pregnant patient is undertaken, along with thoughts on future changes and advances in this field.

Prevention of HIV-associated opportunistic infections and diseases in the age of highly active antiretroviral therapy

Since the introduction of highly active antiretroviral therapy (HAART), the rates of opportunistic infections have decreased markedly as has overall morbidity and mortality from HIV infection in developed countries. However, opportunistic infections remain the most important cause of death in HIV-infected people due to both late presentation of HIV infections and failure of HAART to adequately restore cell-mediated immunity in all individuals. While prophylaxis may be discontinued in patients who have responded to HAART with sustained increases of their CD4 counts above risk thresholds, for those patients who fail HAART, those who are unable to tolerate it, or whose treatments are interrupted, opportunistic-infection prophylaxis remains essential. Some HIV-associated diseases, such as anogenital human papilloma virus-induced neoplasia and hepatitis C infection, have not decreased in frequency with the advent of HAART. For these conditions, effective screening and treatment programs will be necessary to prevent ongoing morbidity. This review will provide an update on HIV-associated opportunistic infections and their prevention in the age of HAART, as well as discuss novel presentations of opportunistic illnesses, such as immune restoration syndromes.

Treatment of latent tuberculosis infection

Treatment of latent tuberculosis (TB) infection is an important component of TB control programs in both high- and low-prevalence countries. Clinical trials of treatment of latent TB conducted over several decades have demonstrated that preventive treatment can reduce the risk of developing active TB up to 90%. Although 9 months of daily, self-administered isoniazid has been the most widely used and recommended regimen for the treatment of latent infection, other regimens such as 3 months of daily isoniazid and rifampin, or 4 months of daily rifampin alone have also been recommended and used. Most recently, a 12-dose regimen of once-weekly isoniazid and rifapentine has been shown to be noninferior to 9 months of daily isoniazid in a large and well conducted clinical trial. Adoption of such a regimen on a large scale could have significant implications for TB elimination efforts.

Treatment of Latent Tuberculosis Infection in Children

Treatment of latent tuberculosis infection (LTBI) is an effective way of preventing future cases of tuberculosis disease. We review pediatric and adult studies of LTBI treatment (isoniazid and rifampin monotherapy, isoniazid plus rifampin, isoniazid plus rifapentine, and rifampin plus pyrazinamide). Based upon this review and our pediatric experience, we can offer recommendations for routine (isoniazid) and alternative courses of therapy.

Outcome and determinants of mortality in 269 patients with combination anti-tuberculosis drug-induced liver injury

BACKGROUND AND AIM

Worldwide anti-tuberculosis (TB) drug-induced liver disease (DILI) is an important cause of hepatotoxicity, and drug-induced acute liver failure (ALF). Reported series on anti-TB DILI are limited by a mix of cases with mild transaminase elevation or adaptation. Our aim was to analyze the clinical features, laboratory characteristics, outcome, and determine predictors of 90-day mortality.

METHODS

Single center analysis of consecutive cases of anti-TB DILI following combination anti-TB drugs exposure from 1997-2011.

RESULTS

Of the 269 patients, 191 (71%) experienced jaundice and 69 (25.7%) accounted for ALF. The mean age and treatment duration was 41.3 years and 1.9 months, respectively; males constituted 55.7%. DILI occurred throughout the course of treatment; three-quarters occurred within the first 2 months. HIV infection was present in 21 (7.8%). The 90-day mortality was 22.7%. DILI accompanied by jaundice (n = 191), encephalopathy (n = 69) or ascites (n = 69) resulted in mortality in 30%, 69.6% and 50.7%, respectively (P < 0.001). Age, gender, transaminase levels, HIV or hepatitis B surface antigen (HBsAg) status did not influence survival. Treatment duration, encephalopathy, ascites, bilirubin, serum albumin, international normalized ratio (INR), serum creatinine and leukocyte count were associated with mortality (P < 0.001). Multivariate logistic regression model for mortality, incorporating encephalopathy, albumin, bilirubin, INR, and creatinine yielded a C-statistic of 97%.

CONCLUSIONS

Anti-TB DILI occurs throughout treatment duration progressing to ALF in a quarter of patients. The overall mortality is 22.7%, which is higher when accompanied by jaundice, ascites or encephalopathy. An anti-TB DILI model, incorporating bilirubin, INR, encephalopathy, serum creatinine and albumin predicted mortality with C-statistic of 97%.

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

Background

The optimal duration of preventive therapy for tuberculosis (TB) among HIV-infected persons in TB-endemic countries is unknown.

Methods

An open-label randomized clinical trial was performed and analyzed for equivalence. Seven hundred and twelve HIV-infected, ART-naïve patients without active TB were randomized to receive either ethambutol 800 mg and isoniazid 300 mg daily for six-months (6EH) or isoniazid 300 mg daily for 36-months (36H). Drugs were dispensed fortnightly and adherence checked by home visits. Patients had chest radiograph, sputum smear and culture performed every six months, in addition to investigations if they developed symptoms. The primary endpoint was incident TB while secondary endpoints were all-cause mortality and adverse events. Survival analysis was performed on the modified intent to treat population (m-ITT) and rates compared.

Findings

Tuberculosis developed in 22 (6.4%) of 344 subjects in the 6EH arm and 13 (3.8%) of 339 subjects in the 36H arm with incidence rates of 2.4/100py (95%CI- 1.4–3.5) and 1.6/100py (95% CI-0.8–3.0) with an adjusted rate ratio (aIRR) of 1.6 (0.8–3.2). Among TST-positive subjects, the aIRR of 6EH was 1.7 (0.6–4.3) compared to 36H, p = 0.8. All-cause mortality and toxicity were similar in the two arms. Among 15 patients with confirmed TB, 4 isolates were resistant to isoniazid and 2 were multidrug-resistant.

Interpretation

Both regimens were similarly effective in preventing TB, when compared to historical incidence rates. However, there was a trend to lower TB incidence with 36H. There was no increase in isoniazid resistance compared to the expected rate in HIV-infected patients.

The trial is registered at ClinicalTrials.gov, NCT00351702.

Current management options for latent tuberculosis: a review

Tuberculosis remains the world's second leading infectious cause of death, with nearly one-third of the global population latently infected. Treatment of latent tuberculosis infection is a mainstay of tuberculosis-control efforts in low-to medium-incidence countries. Isoniazid monotherapy has been the standard of care for decades, but its utility is impaired by poor completion rates. However, new, shorter-course regimens using rifamycins improve completion rates and are cost-saving compared with standard isoniazid monotherapy. We review the currently available therapies for latent tuberculosis infection and their toxicities and include a brief economic comparison of the different regimens.

Predictors of latent tuberculosis treatment initiation and completion at a U.S. public health clinic: a prospective cohort study

Background

Treatment of latent tuberculosis infection (LTBI) is a key component in U.S. tuberculosis control, assisted by recent improvements in LTBI diagnostics and therapeutic regimens. Effectiveness of LTBI therapy, however, is limited by patients’ willingness to both initiate and complete treatment. We aimed to evaluate the demographic, medical, behavioral, attitude-based, and geographic factors associated with LTBI treatment initiation and completion of persons presenting with LTBI to a public health tuberculosis clinic.

Methods

Data for this prospective cohort study were collected from structured patient interviews, self-administered questionnaires, clinic intake forms, and U.S. census data. All adults (>17 years) who met CDC guidelines for LTBI treatment between January 11, 2008 and May 6, 2009 at Wake County Health and Human Services Tuberculosis Clinic in Raleigh, North Carolina were included in the study. In addition to traditional social and behavioral factors, a three-level medical risk variable (low, moderate, high), based on risk factors for both progression to and transmission of active tuberculosis, was included for analysis. Clinic distance and neighborhood poverty level, based on percent residents living below poverty level in a person’s zip code, were also analyzed. Variables with a significance level <0.10 by univariate analysis were included in log binomial models with backward elimination. Models were used to estimate risk ratios for two primary outcomes: (1) LTBI therapy initiation (picking up one month’s medication) and (2) therapy completion (picking up nine months INH therapy or four months rifampin monthly).

Results

496 persons completed medical interviews and questionnaires addressing social factors and attitudes toward LTBI treatment. 26% persons initiated LTBI therapy and 53% of those initiating completed therapy. Treatment initiation predictors included: a non-employment reason for screening (RR 1.6, 95% CI 1.0-2.5), close contact to an infectious TB case (RR 2.5, 95% CI 1.8-3.6), regular primary care(RR 1.4, 95% CI 1.0-2.0), and history of incarceration (RR 1.7, 95% CI 1.0-2.8). Persons in the “high” risk category for progression/transmission of TB disease had higher likelihood of treatment initiation (p < 0.01), but not completion, than those with lower risk.

Conclusions

Investment in social support and access to regular primary care may lead to increased LTBI therapy adherence in high-risk populations.

Latent and subclinical tuberculosis in HIV infected patients: a cross-sectional study

BACKGROUND

HIV and tuberculosis (TB) are commonly associated. Identifying latent and asymptomatic tuberculosis infection in HIV-positive patients is important in preventing death and morbidity associated with active TB.

METHODS

Cross-sectional study of one time use of an interferon-gamma release assay (T-SPOT.TB - immunospot) to detect tuberculosis infection in patients in a UK inner city HIV clinic with a large sub-Saharan population.

RESULTS

542 patient samples from 520 patients who disclosed their symptoms of TB were tested. Median follow-up was 35 months (range 27-69). More than half (55%) originated from countries with medium or high tuberculosis burden and 57% were women. Antiretroviral therapy was used by 67%; median CD4 count at test was 458 cells/μl. A negative test was found in 452 samples and an indeterminate results in 40 (7.4%) but neither were associated with a low CD4 count. A positive test was found in 10% (50/502) individuals. All patients with positive tests were referred to the TB specialist, 47 (94%) had a chest radiograph and 46 (92%) attended the TB clinic. Two had culture-positive TB and a third individual with features of active TB was treated. 40 started and 38 completed preventive treatment. One patient who completed preventive treatment with isoniazid monotherapy subsequently developed isoniazid-resistant pulmonary tuberculosis. No patient with a negative test has developed TB.

CONCLUSIONS

We found an overall prevalence of latent TB infection of 10% through screening for TB in those with HIV infection and without symptoms, and a further 1% with active disease, a yield greater than typically found in contact tracing. Acceptability of preventive treatment was high with 85% of those with latent TB infection eventually completing their TB chemotherapy regimens. IGRA-based TB screening among HIV-infected individuals was feasible in the clinical setting and assisted with appropriate management (including preventive treatment and therapy for active disease). Follow-up of TB incidence in this group is needed to assess the long-term effects of preventive treatment.