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

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

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

Tuberculosis Preventive Treatment for Pregnant People With Human Immunodeficiency Virus in South Africa: A Modeling Analysis of Clinical Benefits and Risks

BACKGROUND

Although prior studies of tuberculosis-preventive treatment (TPT) for pregnant people with human immunodeficiency virus (PPWH) report conflicting adverse pregnancy outcome (APO) risks, international guidelines recommend TPT for PPWH.

METHODS

We used a microsimulation model to evaluate 5 TPT strategies among PPWH receiving antiretroviral therapy in South Africa: No TPT; 6 months of isoniazid (6H) or 3 months of isoniazid-rifapentine (3HP) during pregnancy (Immediate 6H or Immediate 3HP) or post partum (Deferred 6H or Deferred 3HP). The primary outcomes were maternal, fetal/infant, and combined deaths from causes potentially influenced by TPT (maternal tuberculosis, maternal hepatotoxicity, stillbirth, low birth weight [LBW], and infant tuberculosis). Tuberculosis during pregnancy confers 250% and 81% higher modeled risks of stillbirth and LBW, respectively. In lower-risk or higher-risk scenarios, immediate TPT confers 38% lower or 92% higher risks of stillbirth and 16% lower or 35% higher risks of LBW.

RESULTS

Immediate TPT would minimize deaths among PPWH. When TPT confers higher stillbirth and LBW risks, immediate TPT would produce the most combined maternal and fetal/infant deaths, even with low maternal CD4 cell count and high tuberculosis incidence. If immediate TPT yields a <4% or <20% increase in stillbirth or LBW, immediate TPT would produce fewer combined deaths than deferred TPT (sensitivity analysis range, <2%-22% and <11%-120%, respectively).

CONCLUSIONS

If APO risks are below identifiable thresholds, TPT during pregnancy could decrease combined maternal and fetal/infant deaths. Given uncertainty around isoniazid's risks, and the low threshold at which APO risks could outweigh benefits from tuberculosis deaths averted, studies of newer TPT regimens among PPWH are warranted to inform guidelines.

Twice-Daily Dolutegravir-Based Antiretroviral Therapy With 1 Month of Daily Rifapentine and Isoniazid for Tuberculosis Prevention

BACKGROUND

One month of daily rifapentine + isoniazid (1HP) is an effective, ultrashort option for tuberculosis prevention in people with human immunodeficiency virus (HIV). However, rifapentine may decrease antiretroviral drug concentrations and increase the risk of virologic failure. AIDS Clinical Trials Group A5372 evaluated the effect of 1HP on the pharmacokinetics of twice-daily dolutegravir.

METHODS

A5372 was a multicenter, pharmacokinetic study in people with HIV (≥18 years) already on dolutegravir-containing antiretroviral therapy with HIV RNA <50 copies/mL. Participants received daily rifapentine/isoniazid (600 mg/300 mg) for 28 days as part of 1HP. Dolutegravir was increased to 50 mg twice daily during 1HP, and intensive pharmacokinetic sampling was performed on day 0 (before 1HP) and on the final day of 1HP treatment.

RESULTS

Thirty-two participants (41% female; 66% Black/African; median [Q1, Q3] age, 42 [34, 49] years) were included in the pharmacokinetic analysis; 31 had HIV RNA <50 copies/mL at the end of 1HP dosing. One participant had an HIV RNA of 160 copies/mL at day 28, with HIV RNA <50 copies/mL upon repeat testing on day 42. The median (Q1, Q3) dolutegravir trough concentration was 1751 ng/mL (1195, 2542) on day 0 versus 1987 ng/mL (1331, 2278) on day 28 (day 28:day 0 geometric mean ratio, 1.05 [90% confidence interval, .93-1.2]; P = .43). No serious adverse events were reported.

CONCLUSIONS

Dolutegravir trough concentrations with 50 mg twice-daily dosing during 1HP treatment were greater than those with standard-dose dolutegravir once daily without 1HP. These pharmacokinetic, virologic, and safety data provide support for twice-daily dolutegravir use in combination with 1HP for tuberculosis prevention.

CLINICAL TRIALS REGISTRATION

NCT04272242.

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

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

Preventing tuberculosis with community-based care in an HIV-endemic setting: a modelling analysis

INTRODUCTION

Antiretroviral therapy (ART) and tuberculosis preventive treatment (TPT) both prevent tuberculosis (TB) disease and deaths among people living with HIV. Differentiated care models, including community-based care, can increase the uptake of ART and TPT to prevent TB in settings with a high burden of HIV-associated TB, particularly among men.

METHODS

We developed a gender-stratified dynamic model of TB and HIV transmission and disease progression among 100,000 adults ages 15-59 in KwaZulu-Natal, South Africa. We drew model parameters from a community-based ART initiation and resupply trial in sub-Saharan Africa (Delivery Optimization for Antiretroviral Therapy, DO ART) and other scientific literature. We simulated the impacts of community-based ART and TPT care programmes during 2018-2027, assuming that community-based ART and TPT care were scaled up to similar levels as in the DO ART trial (i.e. ART coverage increasing from 49% to 82% among men and from 69% to 83% among women) and sustained for 10 years. We projected the number of TB cases, deaths and disability-adjusted life years (DALYs) averted relative to standard, clinic-based care. We calculated programme costs and incremental cost-effectiveness ratios from the provider perspective.

RESULTS

If community-based ART care could be implemented with similar effectiveness to the DO ART trial, increased ART coverage could reduce TB incidence by 27.0% (range 21.3%-34.1%) and TB mortality by 34.6% (range 24.8%-42.2%) after 10 years. Increasing both ART and TPT uptake through community-based ART with TPT care could reduce TB incidence by 29.7% (range 23.9%-36.0%) and TB mortality by 36.0% (range 26.9%-43.8%). Community-based ART with TPT care reduced gender disparities in TB mortality rates, with a projected 54 more deaths annually among men than women (range 11-103) after 10 years of community-based care versus 109 (range 41-182) in standard care. Over 10 years, the mean cost per DALY averted by community-based ART with TPT care was $846 USD (range $709-$1012).

CONCLUSIONS

By substantially increasing coverage of ART and TPT, community-based care for people living with HIV could reduce TB incidence and mortality in settings with high burdens of HIV-associated TB and reduce TB gender disparities.

Completion of isoniazid preventive therapy for latent tuberculosis infection among children and adolescents compared to adults living with HIV in Kinshasa, Democratic Republic of the Congo

BACKGROUND

Little is known about isoniazid preventive therapy (IPT) completion rates among children or adolescents compared to adults living with HIV in Kinshasa, Democratic Republic of the Congo (DRC).

METHODS

We conducted a retrospective cohort analysis including children, adolescents, and adults living with HIV who were treated at FHI360 and partners-implemented HIV care programs at six health zones in Kinshasa, DRC, from 2004 to 2020. The primary outcome was the proportion of children, adolescents versus adults who did complete 6 months of daily self-administered IPT. Log-binomial regression assessed independent predictors of IPT non-completion and Kaplan-Meier technique for survival analysis.

RESULTS

Of 11,691 eligible patients on ART who initiated IPT, 429 were children (<11 years), 804 adolescents (11-19 years), and 10,458 adults (≥20 years). The median age was 7 (IQR: 3-9) years for children, 15 (IQR: 13-17) years for adolescents, and 43 (35-51) years for adults. Among those who were initiated on IPT, 5625 out of 11,691 people living with HIV (PLHIV) had IPT completion outcome results, and an overall 3457/5625 (61.5%) completion rate was documented. Compared to adults, children and adolescents were less likely to complete IPT [104/199 (52.3%) and 268/525 (51.0%), respectively, vs. 3085/4901 (62.9%)]. After adjustment, the only independent predictors for IPT non-completion were health zone of residence and type of ART regimen. Kaplan-Meier analysis showed comparable poor survival among patients who completed IPT versus those who did not (p-value for log-rank test, 0.15).

CONCLUSIONS

The overall sub-optimal IPT completion rate in adults as well as children/adolescents in this setting is of great concern. Prospective studies are needed to elucidate the specific barriers to IPT completion among children, adolescents, and adults in DRC as well as the scale-up of evidence-informed interventions to improve IPT completion, such as adoption of shorter TB preventive regimens.

Modeling the impact of universal tuberculosis molecular testing and timing of tuberculosis preventive treatment during antiretroviral therapy initiation in South Africa

OBJECTIVES

Targeted universal tuberculosis (TB) testing can improve TB detection among people with HIV. This approach is being scaled up in South Africa through Xpert MTB/RIF Ultra testing for individuals starting antiretroviral therapy and annually thereafter. Clarity is needed on how Universal Xpert testing may affect TB preventive treatment (TPT) provision, and on whether TPT should be delayed until TB is ruled out.

DESIGN

State-transition microsimulation.

METHODS

We simulated a cohort of South African patients being screened for TB while entering HIV care. We compared clinical and cost outcomes between four TB screening algorithms: symptom-based, C-reactive protein-based, and Universal Xpert testing with either simultaneous or delayed TPT initiation.

RESULTS

Prompt TB treatment initiation among simulated patients with TB increased from 26% (24-28%) under symptom screening to 53% (50-56%) with Universal Xpert testing. Universal Xpert testing led to increased TPT uptake when TPT initiation was simultaneous, but to approximately 50% lower TPT uptake if TPT was delayed. Universal Xpert with simultaneous TPT prevented incident TB compared to either symptom screening (median 17 cases averted per 5000 patients) or Universal Xpert with delayed TPT (median 23 averted). Universal Xpert with Simultaneous TPT cost approximately $39 per incremental TPT course compared to Universal Xpert with delayed TPT.

CONCLUSIONS

Universal Xpert testing can promote timely treatment for newly diagnosed people with HIV who have active TB. Pairing universal testing with immediate TPT will improve the promptness, uptake, and preventive effects of TPT. Simultaneous improvements to TB care cascades are needed to maximize impact.

Impact of Latent M. tuberculosis Infection Treatment on Time to CD4/CD8 Recovery in Acute, Recent, and Chronic HIV Infection

INTRODUCTION

In people living with HIV, active and latent tuberculosis (TB) coinfections are associated with immune activation that correlate with HIV progression and mortality. We investigated the effect of initiating antiretroviral therapy (ART) during acute (AHI), recent (RHI), or chronic HIV infection (CHI) on CD4/CD8 ratio normalization and associated factors, the impact of latent TB infection treatment, and prior/concomitant TB diagnosis at the time of ART initiation.

METHODS

We included sex with men and transgender women individuals initiating ART with AHI, RHI and CHI between 2013 and 2019, from a prospective cohort in Brazil. We compared time from ART initiation to the first normal CD4/CD8 ratio (CD4/CD8 ≥1) using Kaplan-Meier curves and multivariable Cox proportional hazards models. Sociodemographic and clinical variables were explored. Variables with P -values <0.20 in univariable analyses were included in multivariable analyses.

RESULTS

Five hundred fifty participants were included, 11.8% classified as AHI and 6.4% as RHI, 46.7% with CHI-CD4 cell counts ≥350 cells/mm 3 and 35.1% with CHI-CD4 cell counts <350 cells/mm 3 . Time to normalization was shortest among AHI patients, followed by RHI and CHI individuals with higher baseline CD4. In the multivariable model, AHI was associated with a six-fold increased likelihood of achieving a CD4/CD8 ratio ≥1 (hazard ratio [HR]: 6.03; 95% confidence interval [CI]: 3.70 to 9.82; P < 0.001), RHI with HR: 4.47 (95% CI: 2.57 to 7.76; P < 0.001), and CHI CD4 ≥350 cells/mm 3 with HR: 1.87 (95% CI: 1.24 to 2.84; P = 0.003). Latent TB infection treatment was significantly associated with a higher likelihood of the outcome (HR: 1.79; 95% CI: 1.22 to 2.62; P = 0.003). Previous history or concomitant active TB at ART initiation was associated with a lower likelihood of the outcome (HR: 0.41; 95% CI: 0.16 to 1.02; P = 0.054).

CONCLUSIONS

Initiating ART early during AHI may offer an opportunity to mitigate immune damage. Efforts to implement HIV diagnosis and ART initiation during AHI are critical to amplify ART benefits.

The effect of antenatal isoniazid preventive therapy on birth outcomes in Western Kenya

BACKGROUND: Pregnant women living with HIV (WLHIV) are at high risk for TB. There are limited data to inform whether TB preventive therapy is safe in pregnancy.METHODS: We completed a retrospective study of antenatal and birth records of mother-infant dyads at two health care facilities in Kisumu, Kenya. Among pregnant WLHIV, we assessed the relationship of antenatal isoniazid preventive therapy (IPT) with birth outcomes (preterm birth, low birth weight [LBW], congenital anomalies, and perinatal death).RESULTS: Of 576 mother-infant pairs, most women were on antiretroviral therapy (574, 99.7%) with viral suppression (518, 89.9%) and one-quarter had IPT exposure during pregnancy (152, 26.4%). The prevalence of preterm birth was lower among women with antenatal IPT exposure (21% vs. 30%; P = 0.03). LBW, congenital anomaly and perinatal death were not associated with antenatal IPT; however, we observed a trend toward fewer composite poor birth outcomes among women taking antenatal IPT (26% vs 33%; P = 0.08). Controlling for maternal age and viral load, IPT use during pregnancy was associated with lower odds of preterm birth (aOR 0.62, 95% CI 0.40-0.98; P = 0.04).CONCLUSION: In a programmatic setting in Western Kenya, IPT use was not associated with adverse birth outcomes.

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

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

Timing of maternal isoniazid preventive therapy on tuberculosis infection among infants exposed to HIV in low-income and middle-income settings: a secondary analysis of the TB APPRISE trial

BACKGROUND

Infants born to women with HIV in settings with a high tuberculosis burden are at risk of tuberculosis infection and rapid progression to active disease. Maternal isoniazid preventive therapy might mitigate this risk, but optimal timing of therapy remains unclear. The TB APPRISE trial showed that initiation of isoniazid during pregnancy resulted in more frequent adverse pregnancy outcomes than when initiated postpartum. We aimed to determine the proportion of infants testing positive for tuberculosis infection born to mothers who initiated isoniazid therapy antepartum compared with postpartum using two commonly used tests, the test agreement, and predictors of test positivity.

METHODS

TB APPRISE was a randomised, double-blind, placebo-controlled, non-inferiority trial done at 13 study sites across eight countries (Botswana, Haiti, India, South Africa, Tanzania, Thailand, Uganda, and Zimbabwe). Pregnant women with HIV on antiretroviral therapy were randomly assigned to receive immediate isoniazid preventive therapy (28 weeks isoniazid [300 mg daily], then placebo until week 40 after delivery) or deferred treatment (placebo until week 12 after delivery, then isoniazid [300 mg daily] for 28 weeks). Mother-infant pairs were followed up until 48 weeks after delivery. We included all liveborn infants with a tuberculin skin test or interferon-γ release assay (IGRA) at 44 weeks. The outcomes assessed in this secondary analysis were tuberculosis test positivity by study group, test agreement, and predictors of test positivity. This study was registered with ClinicalTrials.gov, NCT01494038.

FINDINGS

Between Aug 19, 2014, and April 4, 2016, 956 mothers were randomly assigned, and 749 mother-child pairs were included in this secondary analysis. Of 749 infants, 694 (93%) received Bacille Calmette-Guérin (BCG) vaccination, 675 (90%) were born to mothers who had completed isoniazid treatment, 20 (3%) were exposed to tuberculosis, seven (1%) became HIV positive, and one (<1%) developed probable tuberculosis. 43 (6%; 95% CI 4-8]) of 732 infants had a positive IGRA test result and 55 (8%; 6-10) of 727 infants had a positive tuberculin skin test result. Test positivity did not differ by study group (p=0·88 for IGRA; p=0·44 for tuberculin skin test). Test agreement was poor (κ=0·107 [95% CI 0·002-0·212]). Infant tuberculin skin test positivity was associated with breastfeeding (adjusted odds ratio 6·63 [95% CI 1·57-27·9]), BCG vaccination (4·97 [1·50-16·43]), and maternal tuberculin skin test positivity at delivery (3·28 [1·70-6·33]); IGRA positivity was associated with female sex (2·09 [1·06-4·14]).

INTERPRETATION

Deferral of maternal isoniazid preventive therapy to early postpartum had no effect on infant tuberculosis acquisition in our trial population, regardless of the diagnostic test used; however, tuberculosis test agreement is poor during infancy.

FUNDING

US National Institutes of Health.

Liver Injury Following Isoniazid Preventive Therapy in HIV Patients Attending Halibet National Referral Hospital, Eritrea: A Prospective Cohort Study

INTRODUCTION

A 6-month course of isoniazid, 300 mg daily, was programmatically introduced in Eritrea in 2014 as tuberculosis preventive therapy in people living with human immunodeficiency virus (PLHIV). The rollout of isoniazid preventive therapy (IPT) in PLHIV was successful in the first 2-3 years. After 2016, rumours based on rare but real incidents of liver injuries following use of IPT spread widely across the country and created concerns amongst healthcare professionals and consumers, that ultimately caused dramatic decline in the rollout of the intervention. Decision makers have been demanding better evidence as previously conducted local studies had inherent methodological limitations. This real-world observational study was conducted to evaluate the risk of liver injury associated with IPT among PLHIV attending Halibet national referral hospital, Asmara, Eritrea.

METHODS

A prospective cohort study, that consecutively enrolled PLHIV attending Halibet hospital, was conducted between 1 March and 30 October 2021. Those exposed to anti-retroviral therapy (ART) plus IPT were considered as exposed and those taking only ART were considered as unexposed. Both groups were prospectively followed up for 4-5 months with monthly liver function tests (LFTs). A Cox proportional hazard model was used to explore whether there was increased risk of drug-induced liver injury (DILI) associated with IPT. Probability of survival without DILI was also estimated using Kaplan-Meier curves.

RESULTS

A total of 552 patients, 284 exposed and 268 unexposed, completed the study, with a mean follow-up time of 3.97 (SD 0.675) months for the exposed and 4.06 (SD 0.675) months for the unexposed. Twelve patients developed drug-induced liver injury (DILI), with a median time-to-onset of 35 days (interquartile range: 26.8, 60 days). All cases were from the exposed group and all except two cases were asymptomatic. The incidence rate of DILI in the exposed group was 10.6 cases per 1000 person-months and zero for the unexposed group (p = 0.002).

CONCLUSION

DILI in PLHIV taking IPT was common; therefore, liver function should be closely monitored to safely administer the product. Despite high levels of deranged liver enzymes, the majority had no symptoms of DILI, emphasising the importance of close laboratory monitoring, especially during the first 3 months of treatment.

Preventing tuberculosis with community-based care in an HIV-endemic setting: a modeling analysis

Introduction

Antiretroviral therapy (ART) and TB preventive treatment (TPT) both prevent tuberculosis (TB) disease and deaths among people living with HIV. Differentiated care models, including community-based care, can increase uptake of ART and TPT to prevent TB in settings with a high burden of HIV-associated TB, particularly among men.

Methods

We developed a gender-stratified dynamic model of TB and HIV transmission and disease progression among 100,000 adults ages 15-59 in KwaZulu-Natal, South Africa. We drew model parameters from a community-based ART initiation and resupply trial in sub-Saharan Africa (Delivery Optimization for Antiretroviral Therapy, DO ART) and other scientific literature. We simulated the impacts of community-based ART and TPT care programs during 2018-2027, assuming that community-based ART and TPT care were scaled up to similar levels as in the DO ART trial (i.e., ART coverage increasing from 49% to 82% among men and from 69% to 83% among women) and sustained for ten years. We projected the number of TB cases, deaths, and disability-adjusted life years (DALYs) averted relative to standard, clinic-based care. We calculated program costs and incremental cost-effectiveness ratios from the provider perspective.

Results

If community-based ART care could be implemented with similar effectiveness to the DO ART trial, increased ART coverage could reduce TB incidence by 27.0% (range 21.3% - 34.1%) and TB mortality by 36.0% (range 26.9% - 43.8%) after ten years. Increasing both ART and TPT uptake through community-based ART with TPT care could reduce TB incidence by 29.7% (range 23.9% - 36.0%) and TB mortality by 36.0% (range 26.9% - 43.8%). Community-based ART with TPT care reduced gender disparities in TB mortality rates by reducing TB mortality among men by a projected 39.8% (range 32.2% - 46.3%) and by 30.9% (range 25.3% - 36.5%) among women. Over ten years, the mean cost per DALY averted by community-based ART with TPT care was $846 USD (range $709 - $1,012).

Conclusions

By substantially increasing coverage of ART and TPT, community-based care for people living with HIV could reduce TB incidence and mortality in settings with high burdens of HIV-associated TB and reduce TB gender disparities.

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

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

Treatment of Infection as a Core Strategy to Prevent Rifampicin-Resistant/Multidrug-Resistant Tuberculosis

An estimated 19 million people are infected with rifampicin-resistant/multidrug-resistant strains of tuberculosis worldwide. There is little done to prevent these individuals from becoming sick with RR/MDR-TB, a disease that is associated with high rates of morbidity, mortality, and suffering. There are multiple phase III trials currently being conducted to assess the effectiveness of treatment of infection (i.e., "preventive therapy") for RR/MDR-TB, but their results are likely years away. In the meantime, there is sufficient evidence to support a more comprehensive management of people who have been exposed to RR/MDR-TB so that they can maintain their health. We present a patient scenario and share our experience in implementing a systematic post-exposure management program in South Africa with the goal of inspiring similar programs in other high-burden RR/MDR-TB settings.

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.

Increased uptake of tuberculosis preventive therapy (TPT) among people living with HIV following the 100-days accelerated campaign: A retrospective review of routinely collected data at six urban public health facilities in Uganda

Tuberculosis preventive therapy (TPT) effectively decreases rates of developing active tuberculosis disease in people living with HIV (PLHIV) who are at increased risk. The Uganda Ministry of Health launched a 100-day campaign to scale-up TPT in PLHIV in July 2019. We sought to examine the effect of the campaign on trends of TPT uptake and characteristics associated with TPT uptake and completion among persons in HIV care. We retrospectively reviewed routinely collected data from 2016 to 2019 at six urban public health facilities in Uganda. HIV care database and paper-based TPT registers at six public health facilities in Kampala, Uganda were retrospectively reviewed. Estimated trends of TPT (given as Isoniazid monotherapy) uptake and completion across the 4 years, among PLHIV aged 15 years and above, and factors associated, were examined using Poisson regression model with robust standard errors using generalized estimating equation (GEE) models. On average, a total of 39,774 PLHIV aged 15 years and above were eligible for TPT each calendar year at the six health facilities. Across all 4 years, more than 70% were females (range: 73.5% -74.6%) and the median age ranged from 33 to 34 years. From 2016 quarter one to 2019 quarter two, TPT uptake was consistently below 25%, but, as expected, the uptake significantly increased by about 3-folds from 22.1% to 61.2%, in 2019 quarter two (i.e. before the roll-out of the 100-day accelerated TPT intervention) and quarter three (i.e. after the roll-out of the 100-day accelerated TPT intervention) respectively. This increase remained highly significant even after adjusting for patients' baseline characteristics (adjusted prevalence ratio [aPR] = 2.58 [95%CI 2.45, 2.72], P-value<0.001). TPT completion was consistently high at above 70% at most of the time, but, it increased significantly among those initiated during 2018 quarter four and in the subsequent two quarters after the roll-out of the 100-day accelerated TPT intervention (i.e. TPT completion was: 83.2%, 95.3%, and 97.1% among individuals initiated during 2018 quarter4, and 2019 quarters 1 and 2, respectively). The increase in TPT completion during this period remained significant even after adjusting for patients' baseline characteristics (aPR [95%CI] = 1.09 [1.04, 1.14], P value<0.001, and 1.10 [1.05,1.15], P value<0.001, for individuals initiated during 2019 quarter 1, and 2, respectively compared to those initiated during 2018 quarter 4). Not on ART or newly started on ART compared to ART experienced, and pregnant at TPT initiation compared to not pregnant were associated with poor TPT completion, whereas older age (≥25 years versus 15-24 years) was associated with higher TPT completion. The targeted 100-day campaign dramatically increased TPT uptake and completion among PLHIV suggesting a viable catch up strategy to meet WHO guidelines. Future analysis with additional years of data post 100-days TPT intervention is required to evaluate the sustainability of the observed gains.

Predictive performance of interferon-gamma release assays and the tuberculin skin test for incident tuberculosis: an individual participant data meta-analysis

Background

Evidence on the comparative performance of purified protein derivative tuberculin skin tests (TST) and interferon-gamma release assays (IGRA) for predicting incident active tuberculosis (TB) remains conflicting. We conducted an individual participant data meta-analysis to directly compare the predictive performance for incident TB disease between TST and IGRA to inform policy.

Methods

We searched Medline and Embase from 1 January 2002 to 4 September 2020, and studies that were included in previous systematic reviews. We included prospective longitudinal studies in which participants received both TST and IGRA and estimated performance as hazard ratios (HR) for the development of all diagnoses of TB in participants with dichotomised positive test results compared to negative results, using different thresholds of positivity for TST. Secondary analyses included an evaluation of the impact of background TB incidence. We also estimated the sensitivity and specificity for predicting TB. We explored heterogeneity through pre-defined sub-group analyses (e.g. country-level TB incidence). Publication bias was assessed using funnel plots and Egger's test. This review is registered with PROSPERO, CRD42020205667.

Findings

We obtained data from 13 studies out of 40 that were considered eligible (N = 32,034 participants: 36% from countries with TB incidence rate ≥100 per 100,000 population). All reported data on TST and QuantiFERON Gold in-Tube (QFT-GIT). The point estimate for the TST was highest with higher cut-offs for positivity and particularly when stratified by bacillus Calmette-Guérin vaccine (BCG) status (15 mm if BCG vaccinated and 5 mm if not [TST5/15 mm]) at 2.88 (95% CI 1.69-4.90). The pooled HR for QFT-GIT was higher than for TST at 4.15 (95% CI 1.97-8.75). The difference was large in countries with TB incidence rate <100 per 100,000 population (HR 10.38, 95% CI 4.17-25.87 for QFT-GIT VS. HR 5.36, 95% CI 3.82-7.51 for TST5/15 mm) but much of this difference was driven by a single study (HR 5.13, 95% CI 3.58-7.35 for TST5/15 mm VS. 7.18, 95% CI 4.48-11.51 for QFT-GIT, when excluding the study, in which all 19 TB cases had positive QFT-GIT results). The comparative performance was similar in the higher burden countries (HR 1.61, 95% CI 1.23-2.10 for QFT-GIT VS. HR 1.72, 95% CI 0.98-3.01 for TST5/15 mm). The predictive performance of both tests was higher in countries with TB incidence rate <100 per 100,000 population. In the lower TB incidence countries, the specificity of TST (76% for TST5/15 mm) and QFT-GIT (74%) for predicting active TB approached the minimum World Health Organization target (≥75%), but the sensitivity was below the target of ≥75% (63% for TST5/15 mm and 65% for QFT-GIT). The absolute differences in positive and negative predictive values between TST15 mm and QFT-GIT were small (positive predictive values 2.74% VS. 2.46%; negative predictive values 99.42% VS. 99.52% in low-incidence countries). Egger's test did not show evidence of publication bias (0.74 for TST15 mm and p = 0.68 for QFT-GIT).

Interpretation

IGRA appears to have higher predictive performance than the TST in low TB incidence countries, but the difference was driven by a single study. Any advantage in clinical performance may be small, given the numerically similar positive and negative predictive values. Both IGRA and TST had lower performance in countries with high TB incidence. Test choice should be contextual and made considering operational and likely clinical impact of test results.

Funding

YH, IA, and MXR were supported by the National Institute for Health and Care Research (NIHR), United Kingdom (RP-PG-0217-20009). MQ was supported by the Medical Research Council [MC_UU_00004/07].

Hepatotoxicity induced by isoniazid in patients with latent tuberculosis infection: a meta-analysis

Aim

The aim of the present study was to conduct a meta-analysis of the frequency of isoniazid-induced liver injury (INH-ILI) in patients receiving isoniazid (INH) preventative therapy (IPT).

Background

The frequency of hepatotoxicity (drug-induced liver injury: DILI) of antituberculosis drugs has been studied, especially when INH, rifampin, and pyrazinamide are co-administered. However, little is known about the frequency of DILI in patients with latent tuberculosis infection (LTBI), where IPT is indicated.

Methods

We searched PubMed, Google Scholar, and the Cochrane Database of Systematic Reviews for studies reporting the frequency of INH-ILI in patients with IPT using one or more diagnostic indicators included in the criteria of the DILI Expert Working Group.

Results

Thirty-five studies comprising a total of 22,193 participants were included. The overall average frequency of INH-ILI was 2.6% (95% CI, 1.7-3.7%). The mortality associated with INH-DILI was 0.02% (4/22193). Subgroup analysis revealed no significant differences in the frequency of INH-ILI in patients older or younger than 50 years, children, patients with HIV, candidates for liver, kidney, or lung transplant, or according to the type of study design.

Conclusion

The frequency of INH-ILI in patients receiving IPT is low. Studies on INH-ILI are needed where the current DILI criteria are used.

Isoniazid Preventive Therapy for Prevention of Tuberculosis among People Living with HIV in Ethiopia: A Systematic Review of Implementation and Impacts

BACKGROUND

Tuberculosis (TB) is a major cause of morbidity and mortality in people living with HIV (PLWHIV). Isoniazid preventive therapy (IPT) prevents TB in PLWHIV, but estimates of its effects and actual implementation vary across countries. We reviewed studies that examined the impact of IPT on PLHIV and the factors influencing its implementation in Ethiopia.

METHODS

We searched PubMed/MEDLINE, Embase, and the Cochrane Central Register of Clinical Controlled Trials from their inception to 1 April 2021 for studies of any design that examined the impact of IPT on PLHIV and the factors influencing its implementation. The protocol was registered in PROSPERO, ID: CRD42021256579.

RESULT

Of the initial 546 studies identified, 13 of which enrolled 12,426 participants, 15,640 PLHIV and 62 HIV clinical care providers were included. PLHIV who were on IPT, independently or simultaneously with ART, were less likely to develop TB than those without IPT. IPT interventions had a significant association with improved CD4 count and reduced all-cause mortality. IPT was less effective in people with advanced HIV infection. The major factors influencing IPT implementation and uptake were stock-outs, fear of developing isoniazid-resistant TB, patient's refusal and non-adherence, and improper counseling and low commitment of HIV clinical care providers.

CONCLUSION

IPT alone or in combination with ART significantly reduces the incidence of TB and mortality in PLHIV in Ethiopia than those without IPT. More research on safety is needed, especially on women with HIV who receive a combination of IPT and ART. Additionally, studies need to be conducted to investigate the efficacy and safety of the new TPT (3 months combination of isoniazid and rifapentine) in children and people living with HIV.

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.

Testing and Treating Mycobacterium tuberculosis Infection

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

Tuberculosis prevalence, incidence and prevention in a south african cohort of children living with HIV

BACKGROUND

We describe tuberculosis (TB) disease among antiretroviral treatment (ART) eligible children living with HIV (CLHIV) in South Africa to highlight TB prevention opportunities.

METHODS

In our secondary analysis among 0- to 12-year-old ART-eligible CLHIV in five Eastern Cape Province health facilities from 2012 to 2015, prevalent TB occurred 90 days before or after enrollment; incident TB occurred >90 days after enrollment. Characteristics associated with TB were assessed using logistic and Cox proportional hazards regression with generalized estimating equations.

RESULTS

Of 397 enrolled children, 114 (28.7%) had prevalent TB. Higher-income proxy [adjusted odds ratio (aOR) 1.8 [95% confidence interval (CI) 1.3-2.6] for the highest, 1.6 (95% CI 1.6-1.7) for intermediate]; CD4+ cell count <350 cells/µl [aOR 1.6 (95% CI 1.1-2.2)]; and malnutrition [aOR 1.6 (95% CI 1.1-2.6)] were associated with prevalent TB. Incident TB was 5.2 per 100 person-years and was associated with delayed ART initiation [hazard ratio (HR) 4.7 (95% CI 2.3-9.4)], malnutrition [HR 1.8 (95% CI 1.1-2.7)] and absence of cotrimoxazole [HR 2.3 (95% CI 1.0-4.9)]. Among 362 children with data, 8.6% received TB preventive treatment.

CONCLUSIONS

Among these CLHIV, prevalent and incident TB were common. Early ART, cotrimoxazole and addressing malnutrition may prevent TB in these children.

Health workers' knowledge and practice of Isoniazid preventive treatment guidelines in health facilities in Ebonyi State, Nigeria

Background

Isoniazid preventive therapy is recommended as part of a comprehensive HIV and AIDS care strategy. IPT is used as prophylaxis to reduce the incidence of TB in HIV-infected persons. However, its implementation has been very slow and has been influenced by several factors. This study assessed health workers' knowledge and adherence to Isoniazid Preventive Therapy guidelines.

Methods

This was a cross-sectional study in six health facilities providing HIV care in Ebonyi State using a semi-structured, self-administered questionnaire. Data were collected from 85 health workers working in the HIV clinics. Data were also extracted from 200 patient treatment cards. Data analysis was carried out using SPSS version 20 software. Chi-square statistics and logistic regression were carried out to determine the association between socio-demographic characteristics and knowledge as well as self-reported practice of the guideline.

Result

Slightly over half of the respondents (58.8%) had good knowledge of the guideline, and the majority (75.3%) self-reported that they practiced the guideline. Only 17% of the treatment cards had isoniazid prescribed and only 11% of these had patient adherence assessed. The most common challenges to implementation of the guideline cited by health workers were unavailability of isoniazid, poor awareness, patient non-adherence, poor resources, high pill burden, and lack of training. Being a doctor and more than 3 years duration of work in the clinic were predictors of good knowledge. There was no predictor of practice.

Conclusion

There was good knowledge and practice of the guideline from health worker self-reports, however, review of treatment card showed prescription was low. Further studies to explore and understand why there is such low prescription of INH/IPT to HIV patients despite good knowledge of healthcare professionals are recommended.

Incidence of tuberculosis among PLHIV on antiretroviral therapy who initiated isoniazid preventive therapy: A multi-center retrospective cohort study

Introduction

Isoniazid preventive therapy (IPT) is effective in treating tuberculosis (TB) infection and hence limiting progression to active disease. However, the durability of protection, associated factors and cost-effectiveness of IPT remain uncertain in low-and-middle income countries, Uganda inclusive. The Uganda Ministry of health recommends a single standard-dose IPT course for eligible people living with HIV (PLHIV). In this study we determined the incidence, associated factors and median time to TB diagnosis among PLHIV on Antiretroviral therapy (ART) who initiated IPT.

Materials and methods

We conducted a retrospective cohort study at eleven The AIDS Support Organization (TASO) centers in Uganda. We reviewed medical records of 2634 PLHIV on ART who initiated IPT from 1^st January 2016 to 30^th June 2018, with 30^th June 2021 as end of follow up date. We analyzed study data using STATA v.16. Incidence rate was computed as the number of new TB cases divided by the total person months. A Frailty model was used to determine factors associated with TB incidence.

Results

The 2634 individuals were observed for 116,360.7 person months. IPT completion rate was 92.8%. Cumulative proportion of patients who developed TB in this cohort was 0.83% (22/2634), an incidence rate of 18.9 per 100,000 person months. The median time to TB diagnosis was 18.5 months (minimum– 0.47; maximum– 47.3, IQR: 10.1–32.4). World Health Organization (WHO) HIV clinical stage III (adjusted hazard ratio (aHR) 95%CI: 3.66 (1.08, 12.42) (P = 0.037) and discontinuing IPT (aHR 95%CI: 25.96(4.12, 169.48) (p = 0.001)), were associated with higher odds of TB diagnosis compared with WHO clinical stage II and IPT completion respectively.

Conclusion

Incidence rates of TB were low overtime after one course of IPT, and this was mainly attributed to high completion rates.

Tuberculosis screening improves preventive therapy uptake (TB SCRIPT) trial among people living with HIV in Uganda: a study protocol of an individual randomized controlled trial

Background

People living with HIV (PLHIV) have an increased risk of developing active tuberculosis (TB). To reduce the burden of TB among PLHIV, the World Health Organization (WHO) recommends systematic TB screening followed by (1) confirmatory TB testing for all who screen positive and (2) TB preventive therapy (TPT) for all TPT-eligible PLHIV who screen negative. Symptom-based screening remains the standard of care in most high TB burden settings, including Uganda. Despite having high sensitivity for active TB among antiretroviral-naïve PLHIV, symptom screening has poor specificity; as such, many high-risk PLHIV without active TB are not referred for TPT. C-reactive protein (CRP) is a promising alternative strategy for TB screening that has comparable sensitivity and higher specificity than symptom screening, and was endorsed by WHO in 2021. However, the impact of CRP-based TB screening on TB burden for PLHIV remains unclear.

Methods

TB SCRIPT (TB Screening Improves Preventive Therapy Uptake) is a phase 3, multi-center, single-blinded, individual (1:1) randomized controlled trial evaluating the effectiveness of CRP-based TB screening on clinical outcomes of PLHIV. The trial aims to compare the effectiveness of a TB screening strategy based on CRP levels using a point-of-care (POC) assay on 2-year TB incidence and all-cause mortality (composite primary trial endpoint) and prevalent TB case detection and uptake of TPT (intermediate outcomes), relative to symptom-based TB screening (current practice).

Discussion

This study will be critical to improving selection of eligible PLHIV for TPT and helping guide the scale-up and integration of TB screening and TPT activities. This work will enable the field to improve TB screening by removing barriers to TPT initiation among eligible PLHIV, and provide randomized evidence to inform and strengthen WHO guidelines.

Trial registration

ClinicalTrials.gov NCT04557176. Registered on September 21, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06371-0.

Incidence of active tuberculosis among people living with HIV receiving long-term antiretroviral therapy in high TB/HIV burden settings in Thailand: implication for tuberculosis preventive therapy

Introduction

Among high tuberculosis (TB) and HIV burden countries in Asia, tuberculosis preventive therapy (TPT) in people living with HIV (PLWH) has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Therefore, we determined the incidence of active TB and mortality among 9179 adult PLWH who attended and received ART from 15 tertiary care hospitals across Thailand.

Methods

A retrospective study was conducted in 2018 using follow‐up data from 1999 to 2018. The primary endpoint was incident TB disease after ART initiation. Factors associated with TB incidence were analysed using competing risk regression. The Kaplan–Meier method was used to estimate mortality after ART initiation.

Results

During a median of 5.1 years of ART (IQR 2.2–9.5 years), 442 (4.8%) PLWH developed TB (TB/HIV), giving an overall incidence of 750 (95% CI 683–823) per 100,000 persons‐year of follow up (PYFU). In multivariate analysis, lower CD4 at ART initiation (≤100 cells/mm³, adjusted sub‐distribution hazard ratio [aSHR]: 2.08, 95% CI, 1.47–2.92; 101–200 cells/mm³, aSHR: 2.21, 95% CI, 1.54–3.16; 201–350 cells/mm³, aSHR: 1.59, 95% CI, 1.11–2.28 vs. >350 cells/mm³), male sex (aSHR: 1.40, 95% CI, 1.11–1.78), lower body weight (<50 kg, aSHR: 1.52, 95% CI, 1.17–1.95) and prior TB event (aSHR: 3.50, 95% CI, 2.72–4.52) were associated with TB incidence. PLWH with HIV RNA ≥50 copies/ml had 5–9 times higher risk of active TB disease higher than those with HIV RNA <50 copies/ml at the same CD4 level. The risk for developing TB was remarkably high during the initial period of ART (175,511 per 100,000 PYFU at<3 months) and was comparable to the general population after 10 years of ART (151 per 100,000 PYFU). TB/HIV had higher mortality (10% vs. 5%) and poorer HIV treatment outcomes: HIV RNA <50 copies/ml (63.8% vs. 82.8%), CD4 cells count (317 vs. 508 cells/mm³) at the most recent visit.

Conclusions

In this high TB burden country, TB incidence was remarkably high during the first few years after ART initiation and thereafter decreased significantly. Rapid ART initiation and appropriate TPT can be potential key interventions to tackle the TB epidemic and reduce mortality among PLWH in TB/HIV high burden settings.

Acceptability of Tuberculosis Preventive Treatment Strategies Among Healthcare Workers Using an Online Survey - China, 2021

What is already known about this topic?

In the absence of effective vaccines, tuberculosis preventive treatment (TPT) is essential for the rapid decrease in incidences of tuberculosis (TB), and healthcare workers’ acceptability is vital to implementing TPT.

What is added by this report?

Overall, 86.5% of healthcare workers knew what TPT was. Most (56.3%) healthcare workers agreed to implement TPT among high-risk groups with latent tuberculosis infection. Drug resistance, adverse events, and unguaranteed efficacy were three main barriers for healthcare workers in accepting TPT.

What are the implications for public health practice?

To further promote and implement TPT in China, practical measures included policy support, high-quality training for healthcare workers, and enhanced public awareness of TB prevention and control.

Effectiveness of a 6-Month Isoniazid on Prevention of Incident Tuberculosis Among People Living with HIV in Eritrea: A Retrospective Cohort Study

Introduction

A 6-month isoniazid as tuberculosis preventive therapy (TPT) for people living with HIV (PLHIV) was nationally introduced in Eritrea in 2014. However, its effectiveness in preventing tuberculosis (TB) and duration of protection was questioned by physicians. This study was, therefore, conducted to evaluate the impact of the isoniazid preventive therapy (IPT) primarily on the prevention of TB and duration of its protection in PLHIV.

Methods

A retrospective cohort study was conducted that selected all eligible PLHIV attending HIV care clinics in all national and regional referral hospitals in Eritrea. Data was collected from patients’ clinical cards using a structured data extraction sheet. The association between use of IPT and outcomes of interest was assessed using a Cox proportional hazard regression model and Kaplan–Meier curve.

Results

A total of 6803 patients were selected, which accounted for 75% of all PLHIV-accessing HIV care clinics in Eritrea. About 76% of patients were exposed to IPT while the remaining 24% were unexposed. The mean follow-up time was 4.9 years (SD 1.4). The incidence rate of TB was 1.7 and 10 cases per 1000 person-years in the exposed and unexposed, respectively. The unexposed had a higher risk of incident TB (adjusted hazard ratio [aHR] 3.75, 95% confidence interval [CI] 2.89, 6.13) and all-cause mortality (HR 2.41, 95% CI 1.85, 3.14) compared to the exposed. A Kaplan–Meier curve showed that the exposed group had a higher TB-free follow-up probability (98.8%) compared to the unexposed (95%) at 65 months of follow-up (p < 0.001). IPT protection decreased rapidly 6 months after isoniazid completion.

Conclusion

Use of a 6-month isoniazid as TPT was found to be effective in reducing incident TB in PLHIV-accessing HIV care clinics in Eritrea. However, the protection appeared to diminish soon, namely 6 months after completion of isoniazid, which warrants immediate attention from policy makers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00589-w.

Isoniazid or rifampicin preventive therapy with and without screening for subclinical TB: a modeling analysis

BACKGROUND

Short-course, rifamycin-based regimens could facilitate scale-up of tuberculosis preventive therapy (TPT), but it is unclear how stringently tuberculosis (TB) disease should be ruled out before TPT use.

METHODS

We developed a state-transition model of a TPT intervention among two TPT-eligible cohorts: adults newly diagnosed with HIV in South Africa (PWH) and TB household contacts in Pakistan (HHCs). We modeled two TPT regimens-4 months of rifampicin [4R] or 6 months of isoniazid [6H]-comparing each to a reference of no intervention. Before initiating TPT, TB disease was excluded either through symptom-only screening or with additional radiographic screening that could detect subclinical TB but might limit access to the TPT intervention. TPT's potential curative effects on both latent and subclinical TB were modeled, as were both acquisitions of resistance and prevention of drug-resistant disease. Although all eligible individuals received the screening and/or TPT interventions, the modeled TB outcomes comprised only those with latent or subclinical TB that would have progressed to symptomatic disease if untreated.

RESULTS

When prescribed after only symptom-based TB screening (such that individuals with subclinical TB were included among TPT recipients), 4R averted 45 active (i.e., symptomatic) TB cases (95% uncertainty range 24-79 cases or 40-89% of progressions to active TB) per 1000 PWH [17 (9-29, 43-94%) per 1000 HHCs]; 6H averted 37 (19-66, 52-73%) active TB cases among PWH [13 (7-23, 53-75%) among HHCs]. With this symptom-only screening, for each net rifampicin resistance case added by 4R, 12 (3-102) active TB cases were averted among PWH (37 [9-580] among HHCs); isoniazid-resistant TB was also reduced. Similarly, 6H after symptom-only screening increased isoniazid resistance while reducing overall and rifampicin-resistant active TB. Screening for subclinical TB before TPT eliminated this net increase in resistance to the TPT drug; however, if the screening requirement reduced TPT access by more than 10% (the estimated threshold for 4R among HHCs) to 30% (for 6H among PWH), it was likely to reduce the intervention's overall TB prevention impact.

CONCLUSIONS

All modeled TPT strategies prevent TB relative to no intervention, and differences between TPT regimens or between screening approaches are small relative to uncertainty in the outcomes of any given strategy. If most TPT-eligible individuals can be screened for subclinical TB, then pairing such screening with rifamycin-based TPT maximizes active TB prevention and does not increase rifampicin resistance. Where subclinical TB cannot be routinely excluded without substantially reducing TPT access, the choice of TPT regimen requires weighing 4R's efficacy advantages (as well as its greater safety and shorter duration that we did not directly model) against the consequences of rifampicin resistance in a small fraction of recipients.

Antiretroviral therapy timing impacts latent tuberculosis infection reactivation in a tuberculosis/simian immunodeficiency virus coinfection model

Studies using the nonhuman primate model of Mycobacteriumtuberculosis/simian immunodeficiency virus coinfection have revealed protective CD4⁺ T cell–independent immune responses that suppress latent tuberculosis infection (LTBI) reactivation. In particular, chronic immune activation rather than the mere depletion of CD4⁺ T cells correlates with reactivation due to SIV coinfection. Here, we administered combinatorial antiretroviral therapy (cART) 2 weeks after SIV coinfection to study whether restoration of CD4⁺ T cell immunity occurred more broadly, and whether this prevented reactivation of LTBI compared to cART initiated 4 weeks after SIV. Earlier initiation of cART enhanced survival, led to better control of viral replication, and reduced immune activation in the periphery and lung vasculature, thereby reducing the rate of SIV-induced reactivation. We observed robust CD8⁺ T effector memory responses and significantly reduced macrophage turnover in the lung tissue. However, skewed CD4⁺ T effector memory responses persisted and new TB lesions formed after SIV coinfection. Thus, reactivation of LTBI is governed by very early events of SIV infection. Timing of cART is critical in mitigating chronic immune activation. The potential novelty of these findings mainly relates to the development of a robust animal model of human M. tuberculosis/HIV coinfection that allows the testing of underlying mechanisms.

Brief Report: Yield of Repeat Tuberculin Skin Testing for People Living With HIV in Brazil

OBJECTIVES

In Brazil, annual tuberculin skin tests (TSTs) are recommended for people living with HIV (PLWH) with CD4 >350, with tuberculosis preventive therapy provided on test conversion. We aimed to determine the yield of repeat TSTs for PLWH.

DESIGN

Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT) to prevent tuberculosis (TB).

METHODS

We analyzed data from newly registered PLWH with negative baseline TST results. We calculated the number of TST conversions after 1 and/or 2 years among patients eligible for follow-up TSTs, the proportion of converters initiating IPT, and incidence of TB/death.

RESULTS

Among 1770 PLWH with a negative baseline TST, 679 (38%) were female and median age was 36 years (IQR 29-43). Eighty-six (5%) developed TB or died within 1 year. Among 1684 eligible for a follow-up 1-year TST, 582 (35%) were tested and 53 (9%) were positive. Forty-nine converters (92%) started IPT. Of 529 patients with a negative 1-year TST, 7 (1%) developed TB or died over the following year. Of 522 patients eligible for a 2-year TST, 158 (30%) were tested and 13 (8%) were positive. Ten converters (77%) started IPT. Of 1102 patients who did not receive a 1-year TST, 33 (3%) developed TB or died. Of the 1069 patients eligible for a 2-year TST, 259 (24%) were tested and 34 (13%) were positive. Thirty converters (88%) started IPT.

CONCLUSIONS

In this cohort of PLWH in Brazil, TST conversion was high among those retested, but only 48% received a follow-up TST within 2 years.

Short-course daily isoniazid and rifapentine for latent tuberculosis infection in people living with HIV who received coformulated bictegravir/emtricitabine/tenofovir alafenamide

INTRODUCTION

Short-course preventive therapy with 1-month course of daily administration of isoniazid (300-mg) plus rifapentine (600-mg) (1HP) and 3-month course of weekly administration of isoniazid (900-mg) plus rifapentine (900-mg) (3HP) has higher completion rates than 9-month course of daily isoniazid (9H) for individuals with latent tuberculosis infection (LTBI). We aimed to evaluate the effect, safety and tolerability of 1HP in people living with HIV (PLWH) and LTBI who received coformulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF).

METHODS

PLWH testing positive by interferon-gamma release assay and having received BIC/FTC/TAF for >2 weeks with plasma HIV RNA load (PVL) <200 copies/ml were enrolled. BIC trough plasma concentrations and cytokine profiles were determined before the first dose (day 1/baseline), 24 h after the 14th (day 15) and 28th (day 29) doses of 1HP. PVL were determined on days 15 and 29 of 1HP and every 3 months subsequently after discontinuation of 1HP.

RESULTS

From November 2019 to December 2020, 48 PLWH with LTBI were enrolled. One participant (2.1%) discontinued 1HP on day 15 due to fever and generalized rashes with PVL of 72 copies/ml, which was <50 copies/ml in three subsequent determinations while on BIC/FTC/TAF over the 12 months of follow-up. The percentages of BIC trough plasma concentrations above the protein-adjusted 95% effective concentration (paEC₉₅ = 162 ng/ml) were 56.3% and 37.0% on days 15 and 29, respectively. The percentage of PVL <200 copies/ml was 91.7% on day 15, 97.8% on day 29 and 100% at both months 3 and 6. After a median observation of 52 weeks (interquartile range, 51-55), all participants continued BIC/FTC/TAF with a median PVL of 20 copies/ml (range 20-331). Except for the participant who discontinued 1HP because of allergic reactions, none of the participants had relevant symptoms or increases of the cytokine levels assessed between baseline and days 15 and 29 of 1HP.

CONCLUSIONS

BIC/FTC/TAF in combination with 1HP was well tolerated with a high completion rate. BIC trough plasma concentrations were significantly decreased with concurrent use of 1HP among PLWH with LTBI. While transient viral blips were observed during 1HP without causing subsequent treatment failure, such combination should be applied with caution.

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.

High conversion of tuberculin skin tests during the first year of antiretroviral treatment among South African adults in primary care

OBJECTIVES

Anergy reduces the sensitivity of the tuberculin skin test (TST) to detect Mycobacterium tuberculosis infection in people living with HIV. Antiretroviral treatment (ART) can reverse TST anergy, but data is scarce.

METHODS

To estimate TST conversion rates and factors associated with TST conversion, TST was placed at ART initiation, and 6 and 12 months thereafter (if TST negative at prior assessment).

RESULTS

Of 328 ART-eligible participants, 70% (231/328) had a valid TST result of whom 78% (180/231) were TST negative. At 6-month follow-up, 22% (24/109, 95% confidence interval [CI] 15%, 31%) of participants on ART, without incident tuberculosis (TB), and with a valid TST result converted to a positive TST. Of these 109 individuals, those with baseline CD4+ cell count >250 cells/μl were more likely to TST convert compared to those with baseline CD4+ cell count ≤250 cells/μl (odds ratio [OR] 3.54, 95% CI 1.29, 11.47). At 12 months post-ART initiation, an additional 12% (9/78, 95% CI 6, 20) of participants on ART, without incident TB and with a valid TST result experienced TST conversion. After 1 year on ART, TST conversion rate was 38 per 100 person-years (95% CI 26, 52), and lower in individuals with baseline CD4+ cell count ≤250 cells/μl (23/100 person-years, 95% CI 11, 41) compared to those with baseline CD4+ cell count >250 cells/μl (50/100 person-years, 95% CI 32, 73).

CONCLUSIONS

TST conversion rate in the first year of ART is high, especially among people with CD4+ cell count >250 cells/μl. A TST-based eligibility strategy at ART initiation may underestimate eligibility for preventive therapy for tuberculosis.

Impact of Isoniazid Preventive Therapy on Tuberculosis incidence among people living with HIV: A secondary data analysis using Inverse Probability Weighting of individuals attending HIV care and treatment clinics in Tanzania

BACKGROUND

Information on how well Isoniazid Preventive Therapy (IPT) works on reducing TB incidence among people living with HIV (PLHIV) in routine settings using robust statistical methods to establish causality in observational studies is scarce.

OBJECTIVES

To evaluate the effectiveness of IPT in routine clinical settings by comparing TB incidence between IPT and non-IPT groups.

METHODS

We used data from PLHIV enrolled in 315 HIV care and treatment clinic from January 2012 to December 2016. We used Inverse Probability of Treatment Weighting to adjust for the probability of receiving IPT; balancing the baseline covariates between IPT and non-IPT groups. The effectiveness of IPT on TB incidence was estimated using Cox regression using the weighted sample.

RESULTS

Of 171,743 PLHIV enrolled in the clinics over the five years, 10,326 (6.01%) were excluded leaving 161,417 available for the analysis. Of the 24,800 who received IPT, 1.00% developed TB disease whereas of the 136,617 who never received IPT 6,085 (4.98%) developed TB disease. In 278,545.90 person-years of follow up, a total 7,052 new TB cases were diagnosed. Using the weighted sample, the overall TB incidence was 11.57 (95% CI: 11.09-12.07) per 1,000 person-years. The TB incidence among PLHIV who received IPT was 10.49 (95% CI: 9.11-12.15) per 1,000 person-years and 12.00 (95% CI: 11.69-12.33) per 1,000 person-years in those who never received IPT. After adjusting for other covariates there was 52% lower risk of developing TB disease among those who received IPT compared to those who never received IPT: aHR = 0.48 (95% CI: 0.40-0.58, P<0.001).

CONCLUSION

IPT reduced TB incidence by 52% in PLHIV attending routine CTC in Tanzania. IPTW adjusted the groups for imbalances in the covariates associated with receiving IPT to achieve comparable groups of IPT and non-IPT. This study has added evidence on the effectiveness of IPT in routine clinical settings and on the use of IPTW to determine impact of interventions in observational studies.

Individual and Composite Adverse Pregnancy Outcomes in a Randomized Trial on Isoniazid Preventative Therapy Among Women Living With Human Immunodeficiency Virus

BACKGROUND

International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1078, a randomized noninferiority study designed to compare the safety of starting isoniazid preventive therapy (IPT) in women living with human immunodeficiency virus (HIV) either during pregnancy or after delivery, showed that IPT during pregnancy increased the risk of composite adverse pregnancy outcomes, but not individual outcomes. Many known factors are associated with adverse pregnancy outcomes: these factors' associations and effect modifications with IPT and pregnancy outcomes were examined.

METHODS

Pregnant women living with HIV from 8 countries with tuberculosis incidences >60/100 000 were randomly assigned to initiate 28 weeks of IPT either during pregnancy or at 12 weeks after delivery. Using univariable and multivariable logistic regression and adjusting for factors associated with pregnancy outcomes, composite and individual adverse pregnancy outcome measures were analyzed.

RESULTS

This secondary analysis included 925 mother-infant pairs. All mothers were receiving antiretrovirals. The adjusted odds of fetal demise, preterm delivery (PTD), low birth weight (LBW), or a congenital anomaly (composite outcome 1) were 1.63 times higher among women on immediate compared to deferred IPT (95% confidence interval [CI], 1.15-2.31). The odds of fetal demise, PTD, LBW, or neonatal death within 28 days (composite outcome 2) were 1.62 times higher among women on immediate IPT (95% CI, 1.14-2.30). The odds of early neonatal death within 7 days, fetal demise, PTD, or LBW (composite outcome 3) were 1.74 times higher among women on immediate IPT (95% CI, 1.22-2.49).

CONCLUSIONS

We confirmed higher risks of adverse pregnancy outcomes associated with the initiation of IPT during pregnancy, after adjusting for known risk factors for adverse pregnancy outcomes.

Assessment of the tuberculosis case-finding and prevention cascade among people living with HIV in Zambia - 2018: a cross-sectional cluster survey

BACKGROUND

The Ministry of Health Zambia recommends tuberculosis preventive treatment (TPT) with 6 months daily isoniazid for all people living with human immunodeficiency virus (HIV) after ruling out active tuberculosis disease. We sought to estimate the percentage of people living with HIV who progress through each stage of the tuberculosis case-finding and prevention cascade in two provinces with the highest tuberculosis burden in Zambia.

METHODS

In this cross-sectional survey, we used a two-stage cluster sampling method. We sampled 12 healthcare facilities with probability proportional to size. Patient volume determined facility cluster size. During October 2018, from each facility we systematically sampled medical records of adults and children living with HIV. Our primary outcome of interest was TPT initiation rate among eligible people living with HIV, weighted for complex survey design. The Rao-Scott adjusted chi-square test was used to test for differences in TPT initiation rate and other indicators from the tuberculosis prevention cascade by age group and province of residence. Additionally, we conducted semi-structured interviews with healthcare workers at each facility to assess TPT knowledge and identify challenges to its implementation.

RESULTS

We sampled 482 records of people living with HIV (including 128 children living with HIV). Excluding two people diagnosed with tuberculosis disease before enrollment in HIV care, 93.4% underwent tuberculosis symptom screening. Of those, 4.7% were diagnosed with tuberculosis disease and 95.3% were TPT-eligible, of whom 24.7% initiated TPT. TPT initiation was lower among eligible children (7.7%) compared with adults (25.2%, p = 0.03) and Copperbelt residents (3.1%) compared with Lusaka residents (35.8%, p < 0.01). TPT completion rate was 38.4% among people living with HIV who initiated the 6-month course. Among interviewed healthcare workers, 58.3% (unweighted) incorrectly relayed the number of symptoms needed for a positive tuberculosis symptom screen, 83.3% (unweighted) reported insufficient isoniazid stockpile for completion at the time of TPT initiation, and only 27.3% (unweighted) reported receiving TPT-specific training.

CONCLUSIONS

TPT uptake among people living with HIV in Zambia is challenged by inconsistent tuberculosis screening, lack of TPT training for healthcare workers, and supply chain inefficiencies. Addressing these barriers may increase TPT initiations and improve outcomes among people living with HIV.

Early-phase scale-up of isoniazid preventive therapy for people living with HIV in two districts in Malawi (2017)

Background

Isoniazid preventive therapy (IPT) against tuberculosis (TB) is a life-saving intervention for people living with HIV (PLHIV). In September 2017, Malawi began programmatic scale-up of IPT to eligible PLHIV in five districts with high HIV and TB burden. We measured the frequency and timeliness of early-phase IPT implementation to inform quality-improvement processes.

Methods and findings

We applied a two-stage cluster design with systematic, probability-proportional-to-size sampling of six U.S. Centers for Disease Control and Prevention (CDC)-affiliated antiretroviral therapy (ART) centers operating in the urban areas of Lilongwe and Blantyre, Malawi (November 2017). ART clinic patient volume determined cluster size. Within each cluster, we sequentially sampled approximately 50 PLHIV newly enrolled in ART care. We described a quality-of-care cascade for intensive TB case finding (ICF) and IPT in PLHIV. PLHIV newly enrolled in ART care were eligibility-screened for hepatitis and peripheral neuropathy, as well as for TB disease using a standardized four-symptom screening tool. Among eligible PLHIV, the overall weighted IPT initiation rate was 70% (95% CI: 46%–86%). Weighted IPT initiation among persons aged <15 years (30% [95% CI: 12%–55%]) was significantly lower than among persons aged ≥15 years (72% [95% CI: 47%–89%]; Rao-Scott chi-square P = 0.03). HIV-positive children aged <5 years had a weighted initiation rate of only 13% (95% CI: 1%–79%). For pregnant women, the weighted initiation rate was 67% (95% CI: 32%–90%), similar to non-pregnant women aged ≥15 years (72% [95% CI: 49%–87%]). Lastly, 95% (95% CI: 92%–97%) of eligible PLHIV started ART within one week of HIV diagnosis, and 92% (95% CI: 73%–98%) of patients receiving IPT began on the same day as ART.

Conclusions

Early-phase IPT uptake among adults at ART centers in Malawi was high. Child uptake needed improvement. National programs could adapt this framework to evaluate their ICF-IPT care cascades.

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.

HIV-associated tuberculosis

Tuberculosis (TB) remains a leading cause of morbidity and mortality among people living with HIV. HIV-associated TB disproportionally affects African countries, particularly vulnerable groups at risk for both TB and HIV. Currently available TB diagnostics perform poorly in people living with HIV; however, new diagnostics such as Xpert Ultra and lateral flow urine lipoarabinomannan assays can greatly facilitate diagnosis of TB in people living with HIV. TB preventive treatment has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Shorter regimens using rifapentine can support increased availability and scale-up. Mortality is high in people with HIV-associated TB, and timely initiation of ART is critical. Programs should provide decentralized and integrated TB and HIV care in settings with high burden of both diseases to improve access to services that diagnose TB and HIV as early as possible. The new prevention and diagnosis tools recently recommended by WHO offer an immense opportunity to advance our fight against HIV-associated TB. They should be made widely available and scaled up rapidly supported by adequate funding with robust monitoring of the uptake to advance global TB elimination.

Novel health system strategies for tuberculin skin testing at primary care clinics: Performance assessment and health economic evaluation

Background

Tuberculin skin test (TST) for guiding initiation of tuberculosis preventive therapy poses major challenges in high tuberculosis burden settings.

Methods

At a primary care clinic in Johannesburg, South Africa, 278 HIV-positive adults self-read their TST by reporting if they felt a bump (any induration) at the TST placement site. TST reading (in mm) was fast-tracked to reduce patient wait time and task-shifted to delegate tasks to lower cadre healthcare workers, and result was compared to TST reading by high cadre research staff. TST reading and placement cost to the health system and patients were estimated. Simulations of health system costs were performed for 5 countries (USA, Germany, Brazil, India, Russia) to evaluate generalizability.

Results

Almost all participants (269 of 278, 97%) correctly self-identified the presence or absence of any induration [sensitivity 89% (95% CI 80,95) and specificity 99.5% (95% CI 97,100)]. For detection of a positive TST (induration ≥ 5mm), sensitivity was 90% (95% CI 81,96) and specificity 99% (95% CI 97,100). TST reading agreement between low and high cadre staff was high (kappa 0.97, 95% CI 0.94, 1.00). Total TST cost was 2066 I$ (95% UI 594, 5243) per 100 patients, 87% (95% UI 53, 95) of which were patient costs. Combining fast-track and task-shifting, reduced total costs to 1736 I$ (95% UI 497, 4300) per 100 patients, with 31% (95% UI 15, 42) saving in health system costs. Combining fast-tracking, task-shifting and self-reading, lowered the TST health system costs from 16% (95% UI 8, 26) in Russia to 40% (95% UI 18, 54) in the USA.

Conclusion

A TST strategy where only patients with any self-read induration are asked to return for fast-tracked TST reading by lower cadre healthcare workers is a promising strategy that could be effective and cost-saving, but real-life cost-effectiveness should be further examined.

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.

The scale-up of antiretroviral therapy coverage was strongly associated with the declining tuberculosis morbidity in Africa during 2000-2018

OBJECTIVES

Antiretroviral therapy (ART) reduces the risk of tuberculosis (TB). We aimed to examine the association between ART coverage scale-up on the changes in TB incidence in Africa from 2000 to 2018.

STUDY DESIGN

The design of the study is a retrospective ecological study.

METHODS

Data for 54 countries were obtained from several institutional-based sources, including the World Health Organization, the Joint United Nations Programme on HIV/AIDS, and the World Bank. A fixed-effects regression method of longitudinal data analysis was used to estimate the association between ART coverage and changes in TB incidence rate during 2000-2018. Statistical analyses were conducted using STATA 15.0/IC.

RESULTS

The TB incidence declined significantly, by an average of 2.3% per year during 2000-2018. The highest significant declines occurred in eastern and southern Africa. In adjusted analysis, each 1% increase in ART coverage was associated with a 3.97 per 100,000 decline of TB incidence. However, the marginal effects of ART on overall population TB incidence was dependent on the prevalence of human immunodeficiency virus infection.

CONCLUSIONS

Investment in the widespread scale-up of ART may contribute to the control of the TB epidemic in Africa. However, interventions are also needed to augment the effect of ART on population TB incidence.

Factors associated with low tuberculosis preventive therapy prescription rates among health care workers in rural South Africa

Background

Despite extensive rollout of tuberculosis preventive therapy (TPT) in South Africa to reduce the incidence of tuberculosis among people living with HIV (PWH), rates of initiation and completion have remained suboptimal.

Objective

This study aimed to identify factors associated with low TPT prescription rates among health care workers (HCWs) in rural South Africa.

Methods

A cross-sectional study was conducted using an anonymous 39-item questionnaire guided by the Consolidated Framework for Implementation Research (CFIR). HCWs from a government district hospital and 14 primary healthcare clinics (PHCs) in the rural Msinga sub-district of KwaZulu-Natal were surveyed from November 2019 to January 2020. Self-reported data on prescription rates as well as knowledge, attitudes, beliefs, and practices regarding isoniazid preventative therapy, the current TPT regimen, were obtained. Factor analysis and logistic regression were used to determine associations with low prescription rates (< 50% of PWH) for TPT prescribers, and results were placed within CFIR-driven context.

Results

Among 160 HCWs, the median (IQR) age was 39 (33–46) years, 76% were women, 78% worked at a PHC, and 44% had experience prescribing TPT. On multivariable analysis, prescribers (n = 71) who believed their patients would not disclose TPT use to others were significantly less likely to prescribe TPT (aOR 4.19 95% CI 1.35–13.00; p = 0.01). Inadequate isoniazid supplies trended towards significance (aOR 10.10 95% CI 0.95–106.92; p = 0.06) in association with low prescription rates.

Conclusions

Strengthening HCW training to emphasize TPT prescription to all eligible PWH regardless of beliefs about patient disclosure and ensuring a consistent isoniazid supply at the health systems-level are both critical steps to enhancing TPT implementation in rural South Africa.