Bedaquiline-pretomanid-moxifloxacin-pyrazinamide for drug-sensitive and drug-resistant pulmonary tuberculosis treatment: a phase 2c, open-label, multicentre, partially randomised controlled trial

BACKGROUND

The current tuberculosis (TB) drug development pipeline is being re-populated with candidates, including nitroimidazoles such as pretomanid, that exhibit a potential to shorten TB therapy by exerting a bactericidal effect on non-replicating bacilli. Based on results from preclinical and early clinical studies, a four-drug combination of bedaquiline, pretomanid, moxifloxacin, and pyrazinamide (BPaMZ) regimen was identified with treatment-shortening potential for both drug-susceptible (DS) and drug-resistant (DR) TB. This trial aimed to determine the safety and efficacy of BPaMZ. We compared 4 months of BPaMZ to the standard 6 months of isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE) in DS-TB. 6 months of BPaMZ was assessed in DR-TB.

METHODS

SimpliciTB was a partially randomised, phase 2c, open-label, clinical trial, recruiting participants at 26 sites in eight countries. Participants aged 18 years or older with pulmonary TB who were sputum smear positive for acid-fast bacilli were eligible for enrolment. Participants with DS-TB had Mycobacterium tuberculosis with sensitivity to rifampicin and isoniazid. Participants with DR-TB had M tuberculosis with resistance to rifampicin, isoniazid, or both. Participants with DS-TB were randomly allocated in a 1:1 ratio, stratified by HIV status and cavitation on chest radiograph, using balanced block randomisation with a fixed block size of four. The primary efficacy endpoint was time to sputum culture-negative status by 8 weeks; the key secondary endpoint was unfavourable outcome at week 52. A non-inferiority margin of 12% was chosen for the key secondary outcome. Safety and tolerability outcomes are presented as descriptive analyses. The efficacy analysis population contained patients who received at least one dose of medication and who had efficacy data available and had no major protocol violations. The safety population contained patients who received at least one dose of medication. This study is registered with ClinicalTrials.gov (NCT03338621) and is completed.

FINDINGS

Between July 30, 2018, and March 2, 2020, 455 participants were enrolled and received at least one dose of study treatment. 324 (71%) participants were male and 131 (29%) participants were female. 303 participants with DS-TB were randomly assigned to 4 months of BPaMZ (n=150) or HRZE (n=153). In a modified intention-to-treat (mITT) analysis, by week 8, 122 (84%) of 145 and 70 (47%) of 148 participants were culture-negative on 4 months of BPaMZ and HRZE, respectively, with a hazard ratio for earlier negative status of 2·93 (95% CI 2·17-3·96; p<0·0001). Median time to negative culture (TTN) was 6 weeks (IQR 4-8) on 4 months of BPaMZ and 11 weeks (6-12) on HRZE. 86% of participants with DR-TB receiving 6 months of BPaMZ (n=152) reached culture-negative status by week 8, with a median TTN of 5 weeks (IQR 3-7). At week 52, 120 (83%) of 144, 134 (93%) of 144, and 111 (83%) of 133 on 4 months of BPaMZ, HRZE, and 6 months of BPaMZ had favourable outcomes, respectively. Despite bacteriological efficacy, 4 months of BPaMZ did not meet the non-inferiority margin for the key secondary endpoint in the pre-defined mITT population due to higher withdrawal rates for adverse hepatic events. Non-inferiority was demonstrated in the per-protocol population confirming the effect of withdrawals with 4 months of BPaMZ. At least one liver-related treatment-emergent adverse effect (TEAE) occurred among 45 (30%) participants on 4 months of BPaMZ, 38 (25%) on HRZE, and 33 (22%) on 6 months of BPaMZ. Serious liver-related TEAEs were reported by 20 participants overall; 11 (7%) among those on 4 months of BPaMZ, one (1%) on HRZE, and eight (5%) on 6 months of BPaMZ. The most common reasons for discontinuation of trial treatment were hepatotoxicity (ten participants [2%]), increased hepatic enzymes (nine participants [2%]), QTcF prolongation (three participants [1%]), and hypersensitivity (two participants [<1%]).

INTERPRETATION

For DS-TB, BPaMZ successfully met the primary efficacy endpoint of sputum culture conversion. The regimen did not meet the key secondary efficacy endpoint due to adverse events resulting in treatment withdrawal. Our study demonstrated the potential for treatment-shortening efficacy of the BPaMZ regimen for DS-TB and DR-TB, providing clinical validation of a murine model widely used to identify such regimens. It also highlights that novel, treatment-shortening TB treatment regimens require an acceptable toxicity and tolerability profile with minimal monitoring in low-resource and high-burden settings. The increased risk of unpredictable severe hepatic adverse events with 4 months of BPaMZ would be a considerable obstacle to implementation of this regimen in settings with high burdens of TB with limited infrastructure for close surveillance of liver biochemistry. Future research should focus on improving the preclinical and early clinical detection and mitigation of safety issues together and further efforts to optimise shorter treatments.

FUNDING

TB Alliance.

Validation and application of an online extraction and liquid chromatography tandem mass spectrometry assay for the analysis of delamanid and its DM-6705 metabolite in human breast milk

We developed and validated a bioanalytical assay to quantify delamanid and its key metabolite (DM-6705) in breast milk and aimed to quantify the secretion of these compounds in breast milk. Due to the hydrophobic nature of the analytes, special care was taken during sample preparation to prevent the formation of fatty deposits during protein precipitation. This was followed by online solid phase extraction and liquid chromatography with tandem mass spectrometry for detection. A Restek Viva BiPh C18 column (1.0 mm×50 mm, 5 µm) was used for extraction while chromatographic separation was performed using a Waters Xterra MS C18 (2.1 mm×100 mm, 5 μm) analytical column with an isocratic mobile phase consisting of acetonitrile, methanol, and 5 mM ammonium carbonate. The mass spectrometric detection of the analytes was performed using an AB Sciex 3200 mass spectrometer employing electrospray ionisation in the positive mode with multiple reaction motoring of the relevant precursor and product ions. Delamanid-d4 and OPC-14714 were used as internal standards. A quadratic (weighted 1/x concentration) regression was used to fit calibration curves for delamanid and DM-6705 over the concentration range of 10.0 - 1000 ng/mL. The intra- and inter-day validation accuracies of the quality control samples were between 92.1% and 98.3% for delamanid, and 97.0% and 102.8% for DM-6705. The percentage coefficient of variation (precision) was less than 7.8%. To our knowledge, this is the first report describing the concentrations of delamanid and DM-6705 in the breast milk of patients treated for rifampicin-resistant tuberculosis.

Southern African HIV Clinicians Society 2023 Guideline for post-exposure prophylaxis: Updated recommendations

No abstract available.

Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a 2023 TBnet/RESIST-TB consensus statement

Drug-resistant tuberculosis is a substantial health-care concern worldwide. Despite culture-based methods being considered the gold standard for drug susceptibility testing, molecular methods provide rapid information about the Mycobacterium tuberculosis mutations associated with resistance to anti-tuberculosis drugs. This consensus document was developed on the basis of a comprehensive literature search, by the TBnet and RESIST-TB networks, about reporting standards for the clinical use of molecular drug susceptibility testing. Review and the search for evidence included hand-searching journals and searching electronic databases. The panel identified studies that linked mutations in genomic regions of M tuberculosis with treatment outcome data. Implementation of molecular testing for the prediction of drug resistance in M tuberculosis is key. Detection of mutations in clinical isolates has implications for the clinical management of patients with multidrug-resistant or rifampicin-resistant tuberculosis, especially in situations when phenotypic drug susceptibility testing is not available. A multidisciplinary team including clinicians, microbiologists, and laboratory scientists reached a consensus on key questions relevant to molecular prediction of drug susceptibility or resistance to M tuberculosis, and their implications for clinical practice. This consensus document should help clinicians in the management of patients with tuberculosis, providing guidance for the design of treatment regimens and optimising outcomes.

A cohort study of post-COVID-19 condition across the Beta, Delta, and Omicron waves in South Africa: 6-month follow-up of hospitalized and nonhospitalized participants

OBJECTIVES

The study aimed to describe the prevalence of and risk factors for post-COVID-19 condition (PCC).

METHODS

This was a prospective, longitudinal observational cohort study. Hospitalized and nonhospitalized adults were randomly selected to undergo telephone assessment at 1, 3, and 6 months. Participants were assessed using a standardized questionnaire for the evaluation of symptoms and health-related quality of life. We used negative binomial regression models to determine factors associated with the presence of ≥1 symptoms at 6 months.

RESULTS

A total of 46.7% of hospitalized and 18.5% of nonhospitalized participants experienced ≥1 symptoms at 6 months (P ≤0.001). Among hospitalized people living with HIV, 40.4% had persistent symptoms compared with 47.1% among participants without HIV (P = 0.108). The risk factors for PCC included older age, female sex, non-Black race, presence of a comorbidity, greater number of acute COVID-19 symptoms, hospitalization/COVID-19 severity, and wave period (lower risk of persistent symptoms for the Omicron compared with the Beta wave). There were no associations between self-reported vaccination status with persistent symptoms.

CONCLUSION

The study revealed a high prevalence of persistent symptoms among South African participants at 6 months but decreased risk for PCC among participants infected during the Omicron BA.1 wave. These findings have serious implications for countries with resource-constrained health care systems.

Evaluation of two short standardised regimens for the treatment of rifampicin-resistant tuberculosis (STREAM stage 2): an open-label, multicentre, randomised, non-inferiority trial

BACKGROUND

The STREAM stage 1 trial showed that a 9-month regimen for the treatment of rifampicin-resistant tuberculosis was non-inferior to the 20-month 2011 WHO-recommended regimen. In STREAM stage 2, we aimed to compare two bedaquiline-containing regimens with the 9-month STREAM stage 1 regimen.

METHODS

We did a randomised, phase 3, non-inferiority trial in 13 hospital clinics in seven countries, in individuals aged 15 years or older with rifampicin-resistant tuberculosis without fluoroquinolone or aminoglycoside resistance. Participants were randomly assigned 1:2:2:2 to the 2011 WHO regimen (terminated early), a 9-month control regimen, a 9-month oral regimen with bedaquiline (primary comparison), or a 6-month regimen with bedaquiline and 8 weeks of second-line injectable. Randomisations were stratified by site, HIV status, and CD4 count. Participants and clinicians were aware of treatment-group assignments, but laboratory staff were masked. The primary outcome was favourable status (negative cultures for Mycobacterium tuberculosis without a preceding unfavourable outcome) at 76 weeks; any death, bacteriological failure or recurrence, and major treatment change were considered unfavourable outcomes. All comparisons used groups of participants randomly assigned concurrently. For non-inferiority to be shown, the upper boundary of the 95% CI should be less than 10% in both modified intention-to-treat (mITT) and per-protocol analyses, with prespecified tests for superiority done if non-inferiority was shown. This trial is registered with ISRCTN, ISRCTN18148631.

FINDINGS

Between March 28, 2016, and Jan 28, 2020, 1436 participants were screened and 588 were randomly assigned. Of 517 participants in the mITT population, 133 (71%) of 187 on the control regimen and 162 (83%) of 196 on the oral regimen had a favourable outcome: a difference of 11·0% (95% CI 2·9-19·0), adjusted for HIV status and randomisation protocol (p<0·0001 for non-inferiority). By 76 weeks, 108 (53%) of 202 participants on the control regimen and 106 (50%) of 211 allocated to the oral regimen had an adverse event of grade 3 or 4; five (2%) participants on the control regimen and seven (3%) on the oral regimen had died. Hearing loss (Brock grade 3 or 4) was more frequent in participants on the control regimen than in those on the oral regimen (18 [9%] vs four [2%], p=0·0015). Of 134 participants in the mITT population who were allocated to the 6-month regimen, 122 (91%) had a favourable outcome compared with 87 (69%) of 127 participants randomly assigned concurrently to the control regimen (adjusted difference 22·2%, 95% CI 13·1-31·2); six (4%) of 143 participants on the 6-month regimen had grade 3 or 4 hearing loss.

INTERPRETATION

Both bedaquiline-containing regimens, a 9-month oral regimen and a 6-month regimen with 8 weeks of second-line injectable, had superior efficacy compared with a 9-month injectable-containing regimen, with fewer cases of hearing loss.

FUNDING

USAID and Janssen Research & Development.

Caregiver willingness to give TPT to children living with drug-resistant TB patients

BACKGROUND Pediatric household contacts (HHCs) of patients with multidrug-resistant TB (MDR-TB) are at high risk of infection and active disease. Evidence of caregiver willingness to give MDR-TB preventive therapy (TPT) to children is limited.METHODS This was a cross-sectional study of HHCs of patients with MDR-TB to assess caregiver willingness to give TPT to children aged <13 years.RESULTS Of 743 adult and adolescent HHCs, 299 reported caring for children aged <13 years of age. The median caregiver age was 35 years (IQR 27-48); 75% were women. Among caregivers, 89% were willing to give children MDR TPT. In unadjusted analyses, increased willingness was associated with TB-related knowledge (OR 5.1, 95% CI 2.3-11.3), belief that one can die of MDR-TB (OR 5.2, 95% CI 1.2-23.4), concern for MDR-TB transmission to child (OR 4.5, 95% CI 1.6-12.4), confidence in properly taking TPT (OR 4.5, 95% CI 1.6-12.6), comfort telling family about TPT (OR 5.5, 95% CI 2.1-14.3), and willingness to take TPT oneself (OR 35.1, 95% CI 11.0-112.8).CONCLUSIONS A high percentage of caregivers living with MDR- or rifampicin-resistant TB patients were willing to give children a hypothetical MDR TPT. These results provide important evidence for the potential uptake of effective MDR TPT when implemented.

Post-COVID-19 condition 3 months after hospitalisation with SARS-CoV-2 in South Africa: a prospective cohort study

BACKGROUND

Post COVID-19 condition (PCC), as defined by WHO, refers to a wide range of new, returning, or ongoing health problems in people who have had COVID-19, and it represents a rapidly emerging public health priority. We aimed to establish how this developing condition has affected patients in South Africa and which population groups are at risk.

METHODS

In this prospective cohort study, we used the DATCOV national hospital surveillance system to identify participants aged 18 years or older who had been hospitalised with laboratory-confirmed SARS-CoV-2 infection in South Africa. Participants underwent telephone follow-up assessment at 1 month and 3 months after hospital discharge. Participants were assessed using a standardised questionnaire for the evaluation of symptoms, functional status, health-related quality of life, and occupational status. We used negative binomial regression models to determine factors associated with PCC.

FINDINGS

Of 241 159 COVID-19 admissions reported to DATCOV between Dec 1, 2020, and Aug 23, 2021, 8309 were randomly selected for enrolment. Of the 3094 patients that we were able to contact, 2410 (77·9%) consented to participate in the study at 1 month after discharge. Of these, 1873 (77·7%) were followed up at 3 months after hospital discharge. Participants had a median age of 52 years (IQR 41-62) and 960 (51·3%) were women. At 3 months of follow-up, 1249 (66·7%) of 1873 participants reported new or persistent COVID-19-related symptoms, compared with 1978 (82·1%) of 2410 at 1 month after hospital discharge. The most common symptoms reported at 3 months were fatigue (50·3%), shortness of breath (23·4%), confusion or lack of concentration (17·5%), headaches (13·8%), and problems seeing or blurred vision (10·1%). On multivariable analysis, the factors associated with persistent symptoms after acute COVID-19 were being female (adjusted incident rate ratio 1·20, 95% CI 1·04-1·38) and admission to an intensive care unit (1·17, 1·01-1·37).

INTERPRETATION

Most participants in this cohort of individuals previously hospitalised with COVID-19 reported persistent symptoms 3 months after hospital discharge and a significant impact of PCC on their functional and occupational status. The large burden of PCC symptoms identified in this study emphasises the need for a national health strategy. This should include the development of clinical guidelines and training of health-care workers for identifying, assessing, and caring for patients affected by PCC; establishment of multidisciplinary health services; and provision of information and support to people who have PCC.

FUNDING

Bill & Melinda Gates Foundation, UK Foreign, Commonwealth & Development Office, and Wellcome.

Bedaquiline-Pretomanid-Linezolid Regimens for Drug-Resistant Tuberculosis

BACKGROUND

The bedaquiline-pretomanid-linezolid regimen has been reported to have 90% efficacy against highly drug-resistant tuberculosis, but the incidence of adverse events with 1200 mg of linezolid daily has been high. The appropriate dose of linezolid and duration of treatment with this agent to minimize toxic effects while maintaining efficacy against highly drug-resistant tuberculosis are unclear.

METHODS

We enrolled participants with extensively drug-resistant (XDR) tuberculosis (i.e., resistant to rifampin, a fluoroquinolone, and an aminoglycoside), pre-XDR tuberculosis (i.e., resistant to rifampin and to either a fluoroquinolone or an aminoglycoside), or rifampin-resistant tuberculosis that was not responsive to treatment or for which a second-line regimen had been discontinued because of side effects. We randomly assigned the participants to receive bedaquiline for 26 weeks (200 mg daily for 8 weeks, then 100 mg daily for 18 weeks), pretomanid (200 mg daily for 26 weeks), and daily linezolid at a dose of 1200 mg for 26 weeks or 9 weeks or 600 mg for 26 weeks or 9 weeks. The primary end point in the modified intention-to-treat population was the incidence of an unfavorable outcome, defined as treatment failure or disease relapse (clinical or bacteriologic) at 26 weeks after completion of treatment. Safety was also evaluated.

RESULTS

A total of 181 participants were enrolled, 88% of whom had XDR or pre-XDR tuberculosis. Among participants who received bedaquiline-pretomanid-linezolid with linezolid at a dose of 1200 mg for 26 weeks or 9 weeks or 600 mg for 26 weeks or 9 weeks, 93%, 89%, 91%, and 84%, respectively, had a favorable outcome; peripheral neuropathy occurred in 38%, 24%, 24%, and 13%, respectively; myelosuppression occurred in 22%, 15%, 2%, and 7%, respectively; and the linezolid dose was modified (i.e., interrupted, reduced, or discontinued) in 51%, 30%, 13%, and 13%, respectively. Optic neuropathy developed in 4 participants (9%) who had received linezolid at a dose of 1200 mg for 26 weeks; all the cases resolved. Six of the seven unfavorable microbiologic outcomes through 78 weeks of follow-up occurred in participants assigned to the 9-week linezolid groups.

CONCLUSIONS

A total of 84 to 93% of the participants across all four bedaquiline-pretomanid-linezolid treatment groups had a favorable outcome. The overall risk-benefit ratio favored the group that received the three-drug regimen with linezolid at a dose of 600 mg for 26 weeks, with a lower incidence of adverse events reported and fewer linezolid dose modifications. (Funded by the TB Alliance and others; ZeNix ClinicalTrials.gov number, NCT03086486.).

Cost-effectiveness of bedaquiline, pretomanid and linezolid for treatment of extensively drug-resistant tuberculosis in South Africa, Georgia and the Philippines

OBJECTIVES

Patients with highly resistant tuberculosis have few treatment options. Bedaquiline, pretomanid and linezolid regimen (BPaL) is a new regimen shown to have favourable outcomes after six months. We present an economic evaluation of introducing BPaL against the extensively drug-resistant tuberculosis (XDR-TB) standard of care in three epidemiological settings.

DESIGN

Cost-effectiveness analysis using Markov cohort model.

SETTING

South Africa, Georgia and the Philippines.

PARTICIPANTS

XDR-TB and multidrug-resistant tuberculosis (MDR-TB) failure and treatment intolerant patients.

INTERVENTIONS

BPaL regimen. PRIMARY AND SECONDARY OUTCOME MEASURES: (1) Incremental cost per disability-adjusted life years averted by using BPaL against standard of care at the Global Drug Facility list price. (2) The potential maximum price at which the BPaL regimen could become cost neutral.

RESULTS

BPaL for XDR-TB is likely to be cost saving in all study settings when pretomanid is priced at the Global Drug Facility list price. The magnitude of these savings depends on the prevalence of XDR-TB in the country and can amount, over 5 years, to approximately US$ 3 million in South Africa, US$ 200 000 and US$ 60 000 in Georgia and the Philippines, respectively. In South Africa, related future costs of antiretroviral treatment (ART) due to survival of more patients following treatment with BPaL reduced the magnitude of expected savings to approximately US$ 1 million. Overall, when BPaL is introduced to a wider population, including MDR-TB treatment failure and treatment intolerant, we observe increased savings and clinical benefits. The potential threshold price at which the probability of the introduction of BPaL becoming cost neutral begins to increase is higher in Georgia and the Philippines (US$ 3650 and US$ 3800, respectively) compared with South Africa (US$ 500) including ART costs.

CONCLUSIONS

Our results estimate that BPaL can be a cost-saving addition to the local TB programmes in varied programmatic settings.

Detection of isoniazid, fluoroquinolone, ethionamide, amikacin, kanamycin, and capreomycin resistance by the Xpert MTB/XDR assay: a cross-sectional multicentre diagnostic accuracy study

BACKGROUND

The WHO End TB Strategy requires drug susceptibility testing and treatment of all people with tuberculosis, but second-line diagnostic testing with line-probe assays needs to be done in experienced laboratories with advanced infrastructure. Fewer than half of people with drug-resistant tuberculosis receive appropriate treatment. We assessed the diagnostic accuracy of the rapid Xpert MTB/XDR automated molecular assay (Cepheid, Sunnyvale, CA, USA) to overcome these limitations.

METHODS

We did a prospective study involving individuals presenting with pulmonary tuberculosis symptoms and at least one risk factor for drug resistance in four sites in India (New Delhi and Mumbai), Moldova, and South Africa between July 31, 2019, and March 21, 2020. The Xpert MTB/XDR assay was used as a reflex test to detect resistance to isoniazid, fluoroquinolones, ethionamide, amikacin, kanamycin, and capreomycin in adults with positive results for Mycobacterium tuberculosis complex on Xpert MTB/RIF or Ultra (Cepheid). Diagnostic performance was assessed against a composite reference standard of phenotypic drug-susceptibility testing and whole-genome sequencing. This study is registered with ClinicalTrials.gov, number NCT03728725.

FINDINGS

Of 710 participants, 611 (86%) had results from both Xpert MTB/XDR and the reference standard for any drug and were included in analysis. Sensitivity for Xpert MTB/XDR detection of resistance was 94% (460 of 488, 95% CI 92-96) for isoniazid, 94% (222 of 235, 90-96%) for fluoroquinolones, 54% (178 of 328, 50-61) for ethionamide, 73% (60 of 82, 62-81) for amikacin, 86% (181 of 210, 81-91) for kanamycin, and 61% (53 of 87, 49-70) for capreomycin. Specificity was 98-100% for all drugs. Performance was equivalent to that of line-probe assays. The non-determinate rate of Xpert MTB/XDR (ie, invalid M tuberculosis complex detection) was 2·96%.

INTERPRETATION

The Xpert MTB/XDR assay showed high diagnostic accuracy and met WHO's minimum target product profile criteria for a next-generation drug susceptibility test. The assay has the potential to diagnose drug-resistant tuberculosis rapidly and accurately and enable optimum treatment.

FUNDING

German Federal Ministry of Education and Research through KfW, Dutch Ministry of Foreign Affairs, and Australian Department of Foreign Affairs and Trade.

Proposed linezolid dosing strategies to minimize adverse events for treatment of extensively drug-resistant tuberculosis

BACKGROUND

We evaluated clinical trial data (Nix-TB, NCT02333799) to provide data-driven dosing recommendations to potentially minimize linezolid toxicity in patients with extensively drug-resistant tuberculosis.

METHODS

Based on 104 participants, a pharmacokinetic model and toxicodynamic models for peripheral neuropathy, hemoglobin, and platelets were developed. Simulations compared safety outcomes for daily linezolid of 1200 and 600 mg, with and without dose adjustments for toxicity. Severe neuropathy was based on symptom scores from the Brief Peripheral Neuropathy Screen. Severe anemia and thrombocytopenia were defined as ≥grade 3 adverse events according to the Division of Microbiology and Infectious Disease Adult Toxicity table.

RESULTS

Predicted individual concentration-time profiles were a major predictor in all three toxicodynamic models. Simulations showed higher percentages of patients with severe neuropathy (median: 19% (90%CI: 17-22%) vs 5% (4-7%)) and severe anemia (15% (12-17%) vs 1% (0-2%)) between 1200 and 600 mg daily linezolid. No differences in severe thrombocytopenia were observed (median: <1% for both daily doses). Generally, neuropathy occurred after 3 to 6 months of treatment and, with protocol-specified management, reversed within 15 months after onset. Simulations indicated that a >10% decrease from pretreatment in hemoglobin level after 4 weeks of treatment would have maximum sensitivity (82%) and specificity (84%) for predicting severe anemia. Reducing dose from 1200 to 600 mg triggered by this marker may prevent 60% (90%CI: 45-72) of severe anemia.

CONCLUSIONS

Simple neuropathy symptom and hemoglobin monitoring may guide linezolid dosing to avoid toxicities, but prospective testing is needed to confirm benefit-to-risk ratio.

Effectiveness of GenoType MTBDRsl in excluding TB drug resistance in a clinical trial

OBJECTIVES: To assess the performance of the GenoType MTBDRsl v1, a line-probe assay (LPA), to exclude baseline resistance to fluoroquinolones (FQs) and second-line injectables (SLIs) in the Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB 1 (STREAM 1) trial.METHODS: Direct sputum MTBDRsl results in the site laboratories were compared to indirect phenotypic drug susceptibility testing (pDST) results in the central laboratory, with DNA sequencing as a reference standard.RESULTS: Of 413 multidrug-resistant TB (MDR-TB) patients tested using MTBDRsl and pDST, 389 (94.2%) were FQ-susceptible and 7 (1.7%) FQ-resistant, while 17 (4.1%) had an inconclusive MTBDRsl result. For SLI, 372 (90.1%) were susceptible, 5 (1.2%) resistant and 36 (8.7%) inconclusive. There were 9 (2.3%) FQ discordant pDST/MTBDRsl results, of which 3 revealed a mutation and 5 (1.3%) SLI discordant pDST/MTBDRsl results, none of which were mutants on sequencing. Among the 17 FQ- and SLI MTBDRsl-inconclusive samples, sequencing showed 1 FQ- and zero SLI-resistant results, similar to frequencies among the conclusive MTBDRsl. The majority of inconclusive MTBDRsl results were associated with low bacillary load samples (acid-fast bacilli smear-negative or scantily positive) compared to conclusive results (P < 0.001).CONCLUSION: MTBDRsl can facilitate the rapid exclusion of FQ and SLI resistances for enrolment in clinical trials.

QT effects of bedaquiline, delamanid, or both in patients with rifampicin-resistant tuberculosis: a phase 2, open-label, randomised, controlled trial

BACKGROUND

Bedaquiline and delamanid are the first drugs of new classes registered for tuberculosis treatment in 40 years. Each can prolong the QTc interval, with maximum effects occurring weeks after drug initiation. The cardiac safety and microbiological activity of these drugs when co-administered are not well-established. Our aim was to characterise the effects of bedaquiline, delamanid, or both on the QTc interval, longitudinally over 6 months of multidrug treatment, among patients with multidrug-resistant or rifampicin-resistant tuberculosis taking multidrug background therapy.

METHODS

ACTG A5343 is a phase 2, open-label, randomised, controlled trial in which adults with multidrug-resistant or rifampicin-resistant tuberculosis receiving multidrug background treatment were randomly assigned 1:1:1 by centrally, computer-generated randomisation, by means of permuted blocks to receive bedaquiline, delamanid, or both for 24 weeks. Participants were enrolled at TASK in Cape Town and the South African Tuberculosis Vaccine Initiative in Worcester, both in South Africa, and Hospital Maria Auxiliadora in Peru. Individuals with QTc greater than 450 ms were excluded. HIV-positive participants received dolutegravir-based antiretroviral therapy. Clofazimine was disallowed, and levofloxacin replaced moxifloxacin. ECG in triplicate and sputum cultures were done fortnightly. The primary endpoint was mean QTcF change from baseline (averaged over weeks 8-24); cumulative culture conversation at week 8-24 was an exploratory endpoint. Analyses included all participants who initiated study tuberculosis treatment (modified intention-to-treat population). This trial is registered with ClinicalTrials.gov, NCT02583048 and is ongoing.

FINDINGS

Between Aug 26, 2016 and July 13, 2018, of 174 screened, 84 participants (28 in each treatment group, and 31 in total with HIV) were enrolled. Two participants did not initiate study treatment (one in the delamanid group withdrew consent and one in the bedaquiline plus delamanid group) did not meet the eligibility criterion). Mean change in QTc from baseline was 12·3 ms (95% CI 7·8-16·7; bedaquiline), 8·6 ms (4·0-13·1; delamanid), and 20·7 ms (16·1-25·3) (bedaquiline plus delamanid). There were no grade 3 or 4 adverse QTc prolongation events and no deaths during study treatment. Cumulative culture conversion by week 8 was 21 (88%) of 24 (95% CI 71-97; bedaquiline), 20 (83%) of 24 (65-95; delamanid), and 19 (95%) of 20 (79-100; bedaquiline plus delamanid) and was 92% (77-99) for bedaquiline, 91% (76-99), for delamanid, and 95% (79-100) for bedaquiline plus delamanid at 24 weeks.

INTERPRETATION

Combining bedaquiline and delamanid has a modest, no more than additive, effect on the QTc interval, and initial microbiology data are encouraging. This study provides supportive evidence for use of these agents together in patients with multidrug-resistant or rifampicin-resistant tuberculosis with normal baseline QTc values.

FUNDING

Division of AIDS, National Institutes of Health.

Pretomanid with bedaquiline and linezolid for drug-resistant TB: a comparison of prospective cohorts

BACKGROUND: There are no data comparing the 6-9 month oral three-drug Nix regimen (bedaquiline, pretomanid and linezolid [BPaL]) to conventional regimens containing bedaquiline (B, BDQ) and linezolid (L, LZD).METHODS: Six-month post end-of-treatment outcomes were compared between Nix-TB (n = 109) and 102 prospectively recruited extensively drug-resistant TB patients who received an ˜18-month BDQ-based regimen (median of 8 drugs). A subset of patients received BDQ and LZD (n = 86), and a subgroup of these (n = 75) served as individually matched controls in a pairwise comparison to determine differences in regimen efficacy.RESULTS: Favourable outcomes (%) were significantly better with BPaL than with the B-L-based combination regimen (98/109, 89.9% vs. 56/86, 65.1%; adjusted relative risk ratio [aRRR] 1.35; P < 0.001) and in the matched pairwise analysis (67/75, 89.3% vs. 48/75, 64.0%; aRRR 1.39; P = 0.001), despite significantly higher baseline bacterial load and prior second-line drug exposure in the BPaL cohort. Time to culture conversion (P < 0.001), time to unfavourable outcome (P < 0.01) and time to death (P < 0.03) were significantly better or lower with BPaL than the B-L-based combinations.CONCLUSION: The BPaL regimen (and hence substitution of multiple other drugs by pretomanid and/or higher starting-dose LZD) may improve outcomes in drug-resistant TB patients with poor prognostic features. However, prospective controlled studies are required to definitively answer this question.

Implementing novel regimens for drug-resistant TB in South Africa: what can the world learn?

Worldwide uptake of new drugs in the treatment of rifampicin-resistant tuberculosis (RR-TB) has been extremely low. In June 2018, ahead of the release of the updated WHO guidelines for the management of RR-TB, South Africa announced that bedaquiline (BDQ) would be provided to virtually all RR-TB patients on shorter or longer regimens. South Africa has been the global leader in accessing BDQ for patients with RR-TB, who now represent 60% of the global BDQ cohort. The use of BDQ within a shorter modified regimen has generated the programmatic data underpinning the most recent change in WHO guidelines endorsing a shorter, injectable-free regimen. Progressive policies on access to new drugs have resulted in improved favourable outcomes and a reduction in mortality among RR-TB patients in South Africa. This supported global policy change. The strategies underpinning these bold actions include close collaboration between the South African National TB Programme and partners, introduction of new TB diagnostic tools in closely monitored conditions and the use of locally generated programmatic evidence to inform country policy changes. In this paper, we summarise a decade´s work that led to the bold decision to use a modified, short, injectable-free regimen with BDQ and linezolid under carefully monitored programmatic conditions.

A partially randomised trial of pretomanid, moxifloxacin and pyrazinamide for pulmonary TB

BACKGROUND: Treatment for TB is lengthy and toxic, and new regimens are needed.METHODS: Participants with pulmonary drug-susceptible TB (DS-TB) were randomised to receive: 200 mg pretomanid (Pa, PMD) daily, 400 mg moxifloxacin (M) and 1500 mg pyrazinamide (Z) for 6 months (6Pa200MZ) or 4 months (4Pa200MZ); 100 mg pretomanid daily for 4 months in the same combination (4Pa100MZ); or standard DS-TB treatment for 6 months. The primary outcome was treatment failure or relapse at 12 months post-randomisation. The non-inferiority margin for between-group differences was 12.0%. Recruitment was paused following three deaths and not resumed.RESULTS: Respectively 4/47 (8.5%), 11/57 (19.3%), 14/52 (26.9%) and 1/53 (1.9%) DS-TB outcomes were unfavourable in patients on 6Pa200MZ, 4Pa200MZ, 4Pa100MZ and controls. There was a 6.6% (95% CI -2.2% to 15.4%) difference per protocol and 9.9% (95%CI -4.1% to 23.9%) modified intention-to-treat difference in unfavourable responses between the control and 6Pa200MZ arms. Grade 3+ adverse events affected 68/203 (33.5%) receiving experimental regimens, and 19/68 (27.9%) on control. Ten of 203 (4.9%) participants on experimental arms and 2/68 (2.9%) controls died.CONCLUSION: PaMZ regimens did not achieve non-inferiority in this under-powered trial. An ongoing evaluation of PMD remains a priority.

Investigation of the efficacy of the short regimen for rifampicin-resistant TB from the STREAM trial

BACKGROUND

The STREAM trial demonstrated that a 9-11-month "short" regimen had non-inferior efficacy and comparable safety to a 20+ month "long" regimen for the treatment of rifampicin-resistant tuberculosis. Imbalance in the components of the composite primary outcome merited further investigation.

METHODS

Firstly, the STREAM primary outcomes were mapped to alternatives in current use, including WHO programmatic outcome definitions and other recently proposed modifications for programmatic or research purposes. Secondly, the outcomes were re-classified according to the likelihood that it was a Failure or Relapse (FoR) event on a 5-point Likert scale: Definite, Probable, Possible, Unlikely, and Highly Unlikely. Sensitivity analyses were employed to explore the impact of informative censoring. The protocol-defined modified intention-to-treat (MITT) analysis population was used for all analyses.

RESULTS

Cure on the short regimen ranged from 75.1 to 84.2% across five alternative outcomes. However, between-regimens results did not exceed 1.3% in favor of the long regimen (95% CI upper bound 10.1%), similar to the primary efficacy results from the trial. Considering only Definite or Probable FoR events, there was weak evidence of a higher risk of FoR in the short regimen, HR 2.19 (95%CI 0.90, 5.35), p = 0.076; considering only Definite FoR events, the evidence was stronger, HR 3.53 (95%CI 1.05, 11.87), p = 0.030. Cumulative number of grade 3-4 AEs was the strongest predictor of censoring. Considering a larger effect of informative censoring attenuated treatment differences, although 95% CI were very wide.

CONCLUSION

Five alternative outcome definitions gave similar overall results. The risk of failure or relapse (FoR) may be higher in the short regimen than in the long regimen, highlighting the importance of how loss to follow-up and other censoring is accounted for in analyses. The outcome of time to FoR should be considered as a primary outcome for future drug-sensitive and drug-resistant TB treatment trials, provided sensitivity analyses exploring the impact of departures from independent censoring are also included.

Responding to SARS-CoV-2 in South Africa: what can we learn from drug-resistant tuberculosis?

The novel coronavirus strain, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first reported from China in December 2019 [1]. As of 14 May, 2020, more than 4.4 million individuals have tested positive for SARS-COV-2 globally [2]. More than 300 000 individuals have died globally due to SARS-COV-2 [2]. In South Africa, cumulatively at the same time point, 12 739 individuals have been infected and 238 deaths reported [2]. Tuberculosis (TB) is the leading infectious disease cause of death with 1.4 million deaths in 2018 [3]. Drug-resistant tuberculosis (DR-TB) is a threat to TB control globally. Over the past decade, several interventions have improved the outcomes of DR-TB patients and reduced the burden of disease. We discuss lessons from DR-TB interventions in South Africa that could be helpful in the fight against SARS-COV-2.

Rapid adoption of new diagnostic tools, parallel process of research and implementation, decentralisation of services, the use of personal protective equipment, as well as strong partnership and collaboration, could strengthen the fight against COVID-19https://bit.ly/2XupDNe

Standardised shorter regimens versus individualised longer regimens for rifampin- or multidrug-resistant tuberculosis

We sought to compare the effectiveness of two World Health Organization (WHO)-recommended regimens for the treatment of rifampin- or multidrug-resistant (RR/MDR) tuberculosis (TB): a standardised regimen of 9-12 months (the "shorter regimen") and individualised regimens of ≥20 months ("longer regimens").We collected individual patient data from observational studies identified through systematic reviews and a public call for data. We included patients meeting WHO eligibility criteria for the shorter regimen: not previously treated with second-line drugs, and with fluoroquinolone- and second-line injectable agent-susceptible RR/MDR-TB. We used propensity score matched, mixed effects meta-regression to calculate adjusted odds ratios and adjusted risk differences (aRDs) for failure or relapse, death within 12 months of treatment initiation and loss to follow-up.We included 2625 out of 3378 (77.7%) individuals from nine studies of shorter regimens and 2717 out of 13 104 (20.7%) individuals from 53 studies of longer regimens. Treatment success was higher with the shorter regimen than with longer regimens (pooled proportions 80.0% versus 75.3%), due to less loss to follow-up with the former (aRD -0.15, 95% CI -0.17- -0.12). The risk difference for failure or relapse was slightly higher with the shorter regimen overall (aRD 0.02, 95% CI 0-0.05) and greater in magnitude with baseline resistance to pyrazinamide (aRD 0.12, 95% CI 0.07-0.16), prothionamide/ethionamide (aRD 0.07, 95% CI -0.01-0.16) or ethambutol (aRD 0.09, 95% CI 0.04-0.13).In patients meeting WHO criteria for its use, the standardised shorter regimen was associated with substantially less loss to follow-up during treatment compared with individualised longer regimens and with more failure or relapse in the presence of resistance to component medications. Our findings support the need to improve access to reliable drug susceptibility testing.

Treatment of Highly Drug-Resistant Pulmonary Tuberculosis

BACKGROUND

Patients with highly drug-resistant forms of tuberculosis have limited treatment options and historically have had poor outcomes.

METHODS

In an open-label, single-group study in which follow-up is ongoing at three South African sites, we investigated treatment with three oral drugs - bedaquiline, pretomanid, and linezolid - that have bactericidal activity against tuberculosis and to which there is little preexisting resistance. We evaluated the safety and efficacy of the drug combination for 26 weeks in patients with extensively drug-resistant tuberculosis and patients with multidrug-resistant tuberculosis that was not responsive to treatment or for which a second-line regimen had been discontinued because of side effects. The primary end point was the incidence of an unfavorable outcome, defined as treatment failure (bacteriologic or clinical) or relapse during follow-up, which continued until 6 months after the end of treatment. Patients were classified as having a favorable outcome at 6 months if they had resolution of clinical disease, a negative culture status, and had not already been classified as having had an unfavorable outcome. Other efficacy end points and safety were also evaluated.

RESULTS

A total of 109 patients were enrolled in the study and were included in the evaluation of efficacy and safety end points. At 6 months after the end of treatment in the intention-to-treat analysis, 11 patients (10%) had an unfavorable outcome and 98 patients (90%; 95% confidence interval, 83 to 95) had a favorable outcome. The 11 unfavorable outcomes were 7 deaths (6 during treatment and 1 from an unknown cause during follow-up), 1 withdrawal of consent during treatment, 2 relapses during follow-up, and 1 loss to follow-up. The expected linezolid toxic effects of peripheral neuropathy (occurring in 81% of patients) and myelosuppression (48%), although common, were manageable, often leading to dose reductions or interruptions in treatment with linezolid.

CONCLUSIONS

The combination of bedaquiline, pretomanid, and linezolid led to a favorable outcome at 6 months after the end of therapy in a high percentage of patients with highly drug-resistant forms of tuberculosis; some associated toxic effects were observed. (Funded by the TB Alliance and others; ClinicalTrials.gov number, NCT02333799.).

Willingness to Take Multidrug-resistant Tuberculosis (MDR-TB) Preventive Therapy Among Adult and Adolescent Household Contacts of MDR-TB Index Cases: An International Multisite Cross-sectional Study

BACKGROUND

Household contacts (HHCs) of individuals with multidrug-resistant tuberculosis (MDR-TB) are at high risk of infection and subsequent disease. There is limited evidence on the willingness of MDR-TB HHCs to take MDR-TB preventive therapy (MDR TPT) to decrease their risk of TB disease.

METHODS

In this cross-sectional study of HHCs of MDR-TB and rifampicin-resistant tuberculosis (RR-TB) index cases from 16 clinical research sites in 8 countries, enrollees were interviewed to assess willingness to take a hypothetical, newly developed MDR TPT if offered. To identify factors associated with willingness to take MDR TPT, a marginal logistic model was fitted using generalized estimating equations to account for household-level clustering.

RESULTS

From 278 MDR-TB/RR-TB index case households, 743 HHCs were enrolled; the median age of HHCs was 33 (interquartile range, 22-49) years, and 62% were women. HHC willingness to take hypothetical MDR TPT was high (79%) and remained high even with the potential for mild side effects (70%). Increased willingness was significantly associated with current employment or schooling (adjusted odds ratio [aOR], 1.83 [95% confidence interval {CI}, 1.07-3.13]), appropriate TB-related knowledge (aOR, 2.22 [95% CI, 1.23-3.99]), confidence in taking MDR TPT (aOR, 7.16 [95% CI, 3.33-15.42]), and being comfortable telling others about taking MDR TPT (aOR, 2.29 [95% CI, 1.29-4.06]).

CONCLUSIONS

The high percentage of HHCs of MDR-TB/RR-TB index cases willing to take hypothetical MDR TPT provides important evidence for the potential uptake of effective MDR TPT when implemented. Identified HHC-level variables associated with willingness may inform education and counseling efforts to increase HHC confidence in and uptake of MDR TPT.

Feasibility of Identifying Household Contacts of Rifampin-and Multidrug-resistant Tuberculosis Cases at High Risk of Progression to Tuberculosis Disease

BACKGROUND

We assessed multidrug-resistant tuberculosis (MDR-TB) cases and their household contacts (HHCs) to inform the development of an interventional clinical trial.

METHODS

We conducted a cross-sectional study of adult MDR-TB cases and their HHCs in 8 countries with high TB burdens. HHCs underwent symptom screenings, chest radiographies, sputum TB bacteriologies, TB infection (TBI) testing (tuberculin skin test [TST] and interferon gamma release assay [IGRA]), and human immunodeficiency virus (HIV) testing.

RESULTS

From October 2015 to April 2016, 1016 HHCs from 284 MDR-TB cases were enrolled. At diagnosis, 69% of MDR-TB cases were positive for acid-fast bacilli sputum smears and 43% had cavitary disease; at study entry, 35% remained smear positive after a median MDR-TB treatment duration of 8.8 weeks. There were 9 HHCs that were diagnosed with TB prior to entry and excluded. Of the remaining 1007 HHCs, 41% were male and the median age was 25 years. There were 121 (12%) HHCs that had new cases of TB identified: 17 (2%) were confirmed, 33 (3%) probable, and 71 (7%) possible TB cases. The TBI prevalence (defined as either TST or IGRA positivity) was 72% and varied by age, test used, and country. Of 1007 HHCs, 775 (77%) were considered high-risk per these mutually exclusive groups: 102 (10%) were aged <5 years; 63 (6%) were aged ≥5 and were infected with HIV; and 610 (61%) were aged ≥5 years, were negative for HIV or had an unknown HIV status, and were TBI positive. Only 21 (2%) HHCs were on preventive therapy.

CONCLUSIONS

The majority of HHCs in these high-burden countries were at high risk of TB disease and infection, yet few were receiving routine preventive therapy. Trials of novel, preventive therapies are urgently needed to inform treatment policy and practice.

Challenges and opportunities to prevent tuberculosis in people living with HIV in low-income countries

People living with the human immunodeficiency virus (HIV) (PLHIV) are at high risk for tuberculosis (TB), and TB is a major cause of death in PLHIV. Preventing TB in PLHIV is therefore a key priority. Early initiation of antiretroviral therapy (ART) in asymptomatic PLHIV has a potent TB preventive effect, with even more benefits in those with advanced immunodeficiency. Applying the most recent World Health Organization recommendations that all PLHIV initiate ART regardless of clinical stage or CD4 cell count could provide a considerable TB preventive benefit at the population level in high HIV prevalence settings. Preventive therapy can treat tuberculous infection and prevent new infections during the course of treatment. It is now established that isoniazid preventive therapy (IPT) combined with ART among PLHIV significantly reduces the risk of TB and mortality compared with ART alone, and therefore has huge potential benefits for millions of sufferers. However, despite the evidence, this intervention is not implemented in most low-income countries with high burdens of HIV-associated TB. HIV and TB programme commitment, integration of services, appropriate screening procedures for excluding active TB, reliable drug supplies, patient-centred support to ensure adherence and well-organised follow-up and monitoring that includes drug safety are needed for successful implementation of IPT, and these features would also be needed for future shorter preventive regimens. A holistic approach to TB prevention in PLHIV should also include other important preventive measures, such as the detection and treatment of active TB, particularly among contacts of PLHIV, and control measures for tuberculous infection in health facilities, the homes of index patients and congregate settings.

Bedaquiline, moxifloxacin, pretomanid, and pyrazinamide during the first 8 weeks of treatment of patients with drug-susceptible or drug-resistant pulmonary tuberculosis: a multicentre, open-label, partially randomised, phase 2b trial

BACKGROUND

New anti-tuberculosis regimens that are shorter, simpler, and less toxic than those that are currently available are needed as part of the global effort to address the tuberculosis epidemic. We aimed to investigate the bactericidal activity and safety profile of combinations of bedaquiline, pretomanid, moxifloxacin, and pyrazinamide in the first 8 weeks of treatment of pulmonary tuberculosis.

METHODS

In this multicentre, open-label, partially randomised, phase 2b trial, we prospectively recruited patients with drug-susceptible or rifampicin-resistant pulmonary tuberculosis from seven sites in South Africa, two in Tanzania, and one in Uganda. Patients aged 18 years or older with sputum smear grade 1+ or higher were eligible for enrolment, and a molecular assay (GeneXpert or MTBDRplus) was used to confirm the diagnosis of tuberculosis and to distinguish between drug-susceptible and rifampicin-resistant tuberculosis. Patients who were HIV positive with a baseline CD4 cell count of less than 100 cells per uL were excluded. Patients with drug-susceptible tuberculosis were randomly assigned (1:1:1) using numbered treatment packs with sequential allocation by the pharmacist to receive 56 days of treatment with standard tuberculosis therapy (oral isoniazid, rifampicin, pyrazinamide, and ethambutol; HRZE), or pretomanid (oral 200 mg daily) and pyrazinamide (oral 1500 mg daily) with either oral bedaquiline 400 mg daily on days 1-14 then 200 mg three times per week (B_loadPaZ) or oral bedaquiline 200 mg daily (B₂₀₀PaZ). Patients with rifampicin-resistant tuberculosis received 56 days of the B₂₀₀PaZ regimen plus moxifloxacin 400 mg daily (BPaMZ). All treatment groups were open label, and randomisation was not stratified. Patients, trial investigators and staff, pharmacists or dispensers, laboratory staff (with the exception of the mycobacteriology laboratory staff), sponsor staff, and applicable contract research organisations were not masked. The primary efficacy outcome was daily percentage change in time to sputum culture positivity (TTP) in liquid medium over days 0-56 in the drug-susceptible tuberculosis population, based on non-linear mixed-effects regression modelling of log₁₀ (TTP) over time. The efficacy analysis population contained patients who received at least one dose of medication and who had efficacy data available and had no major protocol violations. The safety population contained patients who received at least one dose of medication. This study is registered with ClinicalTrials.gov, NCT02193776, and all patients have completed follow-up.

FINDINGS

Between Oct 24, 2014, and Dec 15, 2015, we enrolled 180 patients with drug-susceptible tuberculosis (59 were randomly assigned to B_loadPaZ, 60 to B₂₀₀PaZ, and 61 to HRZE) and 60 patients with rifampicin-resistant tuberculosis. 57 patients in the B_loadPaZ group, 56 in the B₂₀₀PaZ group, and 59 in the HRZE group were included in the primary analysis. B₂₀₀PaZ produced the highest daily percentage change in TTP (5·17% [95% Bayesian credibility interval 4·61-5·77]), followed by B_loadPaZ (4·87% [4·31-5·47]) and HRZE group (4·04% [3·67-4·42]). The bactericidal activity in B₂₀₀PaZ and B_loadPaZ groups versus that in the HRZE group was significantly different. Higher proportions of patients in the B_loadPaZ (six [10%] of 59) and B₂₀₀PaZ (five [8%] of 60) groups discontinued the study drug than in the HRZE group (two [3%] of 61) because of adverse events. Liver enzyme elevations were the most common grade 3 or 4 adverse events and resulted in the withdrawal of ten patients (five [8%] in the B_loadPaZ group, three [5%] in the B₂₀₀PaZ group, and two [3%] in the HRZE group). Serious treatment-related adverse events affected two (3%) patients in the B_loadPaZ group and one (2%) patient in the HRZE group. Seven (4%) patients with drug-susceptible tuberculosis died and four (7%) patients with rifampicin-resistant tuberculosis died. None of the deaths were considered to be related to treatment.

INTERPRETATION

B₂₀₀PaZ is a promising regimen to treat patients with drug-susceptible tuberculosis. The bactericidal activity of both these regimens suggests that they have the potential to shorten treatment, and the simplified dosing schedule of B₂₀₀PaZ could improve treatment adherence in the field. However, these findings must be investigated further in a phase 3 trial assessing treatment outcomes.

FUNDING

TB Alliance, UK Department for International Development, Bill & Melinda Gates Foundation, US Agency for International Development, Directorate General for International Cooperation of the Netherlands, Irish Aid, Australia Department of Foreign Affairs and Trade, and the Federal Ministry for Education and Research of Germany.

HIV and Solid Organ Transplantation: Where Are we Now

PURPOSE OF REVIEW

We review the international evolution of HIV and solid organ transplantation over 30 years. We emphasise recent developments in solid organ transplantation from HIV-infected to HIV-uninfected individuals, and their implications.

RECENT FINDINGS

In 2017, Johannesburg, South Africa, a life-saving partial liver transplant from an HIV-infected mother to her HIV-uninfected child was performed. This procedure laid the foundation not only for consideration of HIV-infected individuals as living donors, but also for the possibility that HIV-uninfected individuals could receive organs from HIV-infected donors. Recent advances in this field are inclusion of HIV-infected individuals as living organ donors and the possibility of offering HIV-uninfected individuals organs from HIV-infected donors who are well-controlled on combination antiretroviral therapy (cART). The large number of HIV-infected individuals on cART is an unutilised source of otherwise eligible living organ donors. HIV-positive-to-HIV-negative organ transplantation has become a reality, providing possible new therapeutic options to address extreme organ shortages.

HIV testing uptake among the household contacts of multidrug-resistant tuberculosis index cases in eight countries

SETTING

The household contacts (HHCs) of multidrug-resistant tuberculosis (MDR-TB) index cases are at high risk of tuberculous infection and disease progression, particularly if infected with the human immunodeficiency virus (HIV). HIV testing is important for risk assessment and clinical management.

METHODS

This was a cross-sectional, multi-country study of adult MDR-TB index cases and HHCs. All adult and child HHCs were offered HIV testing if never tested or if HIV-negative >1 year previously when last tested. We measured HIV testing uptake and used logistic regression to evaluate predictors.

RESULTS

A total of 1007 HHCs of 284 index cases were enrolled in eight countries. HIV status was known at enrolment for 226 (22%) HHCs; 39 (4%) were HIV-positive. HIV testing was offered to 769 (98%) of the 781 remaining HHCs; 544 (71%) agreed to testing. Of 535 who were actually tested, 26 (5%) were HIV-infected. HIV testing uptake varied by site (median 86%, range 0-100%; P < 0.0001), and was lower in children aged <18 years than in adults (59% vs. 78%; adjusted for site P < 0.0001).

CONCLUSIONS

HIV testing of HHCs of MDR-TB index cases is feasible and high-yield, with 5% testing positive. Reasons for low test uptake among children and at specific sites-including sites with high HIV prevalence-require further study to ensure all persons at risk for HIV are aware of their status.

Needs must: living donor liver transplantation from an HIV-positive mother to her HIV-negative child in Johannesburg, South Africa

The world's first living donor liver transplant from an HIV-positive mother to her HIV-negative child, performed by our team in Johannesburg, South Africa (SA) in 2017, was necessitated by disease profile and health system challenges. In our country, we have a major shortage of donor organs, which compels us to consider innovative solutions to save lives. Simultaneously, the transition of the HIV pandemic, from a death sentence to a chronic illness with excellent survival on treatment required us to rethink our policies regarding HIV infection and living donor liver transplantation . Although HIV infection in the donor is internationally considered an absolute contraindication for transplant to an HIV-negative recipient, there have been a very small number of unintentional transplants from HIV-positive deceased donors to HIV-negative recipients. These transplant recipients do well on antiretroviral medication and their graft survival is not compromised. We have had a number of HIV-positive parents in our setting express a desire to be living liver donors for their critically ill children. Declining these parents as living donors has become increasingly unjustifiable given the very small deceased donor pool in SA; and because many of these parents are virally suppressed and would otherwise fulfil our eligibility criteria as living donors. This paper discusses the evolution of HIV and transplantation in SA, highlights some of the primary ethical considerations for us when embarking on this case and considers the new ethical issues that have arisen since we undertook this transplant.

A Trial of a Shorter Regimen for Rifampin-Resistant Tuberculosis

BACKGROUND

Cohort studies in Bangladesh showed promising cure rates among patients with multidrug-resistant tuberculosis who received existing drugs in regimens shorter than that recommended by the World Health Organization (WHO) in 2011.

METHODS

We conducted a phase 3 noninferiority trial in participants with rifampin-resistant tuberculosis that was susceptible to fluoroquinolones and aminoglycosides. Participants were randomly assigned, in a 2:1 ratio, to receive a short regimen (9 to 11 months) that included high-dose moxifloxacin or a long regimen (20 months) that followed the 2011 WHO guidelines. The primary efficacy outcome was a favorable status at 132 weeks, defined by cultures negative for Mycobacterium tuberculosis at 132 weeks and at a previous occasion, with no intervening positive culture or previous unfavorable outcome. An upper 95% confidence limit for the between-group difference in favorable status that was 10 percentage points or less was used to determine noninferiority.

RESULTS

Of 424 participants who underwent randomization, 383 were included in the modified intention-to-treat population. Favorable status was reported in 79.8% of participants in the long-regimen group and in 78.8% of those in the short-regimen group - a difference, with adjustment for human immunodeficiency virus status, of 1.0 percentage point (95% confidence interval [CI], -7.5 to 9.5) (P = 0.02 for noninferiority). The results with respect to noninferiority were consistent among the 321 participants in the per-protocol population (adjusted difference, -0.7 percentage points; 95% CI, -10.5 to 9.1). An adverse event of grade 3 or higher occurred in 45.4% of participants in the long-regimen group and in 48.2% in the short-regimen group. Prolongation of either the QT interval or the corrected QT interval (calculated with Fridericia's formula) to 500 msec occurred in 11.0% of participants in the short-regimen group, as compared with 6.4% in the long-regimen group (P = 0.14); because of the greater incidence in the short-regimen group, participants were closely monitored and some received medication adjustments. Death occurred in 8.5% of participants in the short-regimen group and in 6.4% in the long-regimen group, and acquired resistance to fluoroquinolones or aminoglycosides occurred in 3.3% and 2.3%, respectively.

CONCLUSIONS

In persons with rifampin-resistant tuberculosis that was susceptible to fluoroquinolones and aminoglycosides, a short regimen was noninferior to a long regimen with respect to the primary efficacy outcome and was similar to the long regimen in terms of safety. (Funded by the U.S. Agency for International Development and others; Current Controlled Trials number, ISRCTN78372190; ClinicalTrials.gov number, NCT02409290.).

High treatment success rate for multidrug-resistant and extensively drug-resistant tuberculosis using a bedaquiline-containing treatment regimen

South African patients with rifampicin-resistant tuberculosis (TB) and resistance to fluoroquinolones and/or injectable drugs (extensively drug-resistant (XDR) and preXDR-TB) were granted access to bedaquiline through a clinical access programme with strict inclusion and exclusion criteria.PreXDR-TB and XDR-TB patients were treated with 24 weeks of bedaquiline within an optimised, individualised background regimen that could include levofloxacin, linezolid and clofazimine as needed. 200 patients were enrolled: 87 (43.9%) had XDR-TB, 99 (49.3%) were female and the median age was 34 years (interquartile range (IQR) 27-42). 134 (67.0%) were living with HIV; the median CD4⁺ count was 281 cells·μL^-1 (IQR 130-467) and all were on antiretroviral therapy.16 out of 200 patients (8.0%) did not complete 6 months of bedaquiline: eight were lost to follow-up, six died, one stopped owing to side effects and one was diagnosed with drug-sensitive TB. 146 out of 200 patients (73.0%) had favourable outcomes: 139 (69.5%) were cured and seven (3.5%) completed treatment. 25 patients (12.5%) died, 20 (10.0%) were lost from treatment and nine (4.5%) had treatment failure. 22 adverse events were attributed to bedaquiline, including a QT interval corrected using the Fridericia formula (QTcF) >500 ms (n=5), QTcF increase >50 ms from baseline (n=11) and paroxysmal atrial flutter (n=1).Bedaquiline added to an optimised background regimen was associated with a high rate of successful treatment outcomes for this preXDR-TB and XDR-TB cohort.

Frequency of Circulating CD4+Ki67+HLA-DR- T Regulatory Cells Prior to Treatment for Multidrug Resistant Tuberculosis Can Differentiate the Severity of Disease and Predict Time to Culture Conversion

Identifying a blood circulating cellular biomarker that can be used to assess severity of disease and predict the time to culture conversion (TCC) in patients with multidrug resistant tuberculosis (MDR-TB) would facilitate monitoring response to treatment and may be of value in the design of future drug trials. We report on the frequency of blood Ki67⁺HLA-DR^- CD4+ T regulatory (Treg) cells in predicting microbiological outcome before initiating second-line treatment for MDR-TB. Fifty-one patients with MDR-TB were enrolled and followed over 18 months; a subset of patients was sputum culture (SC) negative at baseline (n = 9). SC positive patients were divided into two groups, based on median TCC: rapid responders (≤71 days TCC; n = 21) and slow responders (>71 days TCC; n = 21). Whole blood at baseline, months 2 and 6 was stimulated with M tuberculosis (Mtb) antigens and Treg cells were then identified as CD3⁺CD4⁺CD25^hiFoxP3⁺CD127^-CD69^- and further delineated as Ki67⁺HLA-DR^- Treg. The frequency of these cells was significantly enlarged at baseline in SC positive relative to SC negative and smear positive relative to smear negative patients and in those with lung cavitation. This difference was further supported by unsupervised hierarchical clustering showing a significant grouping at baseline of total and early differentiated memory Treg cells in slow responders. Conversely, there was a clustering of a lower proportion of Treg cells and activated IFNγ-expressing T cells at baseline in the rapid responders. Examining changes over time revealed a more gradual reduction of Treg cells in slow responders relative to rapid responders to treatment. Receiver operating curve analysis showed that baseline Mtb-stimulated Ki67⁺HLA-DR^- Treg cells could predict the TCC of MDR-TB treatment response with 81.2% sensitivity and 85% specificity (AUC of 0.87, p < 0.0001), but this was not the case after 2 months of treatment. In conclusion, our data show that the frequency of a highly defined Mtb-stimulated blood Treg cell population at baseline can discriminate MDR-TB disease severity and predict time to culture clearance.

Persistently high early mortality despite rapid diagnostics for drug-resistant tuberculosis cases in South Africa

OBJECTIVE

To describe the timing and predictors of mortality among multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB) patients reported in the South African electronic drug-resistant TB register (EDRweb), 2012-2014.

DESIGN

We present time-to-event survival analysis and Cox proportional hazards regression. Identity numbers were matched to the National Vital Statistics Register.

RESULTS

Of the 20 653 patients included in the analysis (median age 35 years, interquartile range 28-43), over half were male (n = 10 944, 53.0%). Most were human immunodeficiency virus (HIV) positive (n = 14 174, 68.9%), most of whom were on antiretroviral therapy (ART; n = 12 471, 88.0%). At 24 months, 4689 patients had died (22.7%); 2072 deaths (44.2%) were reported within 12 weeks of initiating treatment for MDR/RR-TB. From week 12 to week 24, there were 717 deaths/18 048 persons; 59.5% of mortality occurred within the first 24 weeks. During the first 12 weeks, the adjusted hazard rate (aHR) for mortality was highest among patients with a missing baseline culture result (aHR 3.78, 95%CI 2.94-4.86) and among HIV-positive, ART-naïve patients (aHR 3.40, 95%CI 2.90-3.99). Patients initiating MDR/RR-TB treatment within 4 weeks of diagnosis had higher mortality than those with delayed initiation (aHR 1.57, 95%CI 1.41-1.75).

CONCLUSION

In EDRweb, mortality is highest in the first few weeks after MDR/RR-TB treatment initiation.

Incremental Cost Effectiveness of Bedaquiline for the Treatment of Rifampicin-Resistant Tuberculosis in South Africa: Model-Based Analysis

BACKGROUND

Nearly 20,000 people were diagnosed with multi-drug and rifampicin-resistant tuberculosis (MDR/RR-TB) in South Africa in 2015, yet only one-half of the patients who start treatment are expected to have a successful outcome. There is increasing evidence of the effectiveness and safety of new drug regimens containing bedaquiline for MDR/RR-TB; however, whether they are affordable for high-burden, limited-resource settings is uncertain.

OBJECTIVE

Our objective was to determine the incremental cost effectiveness of a bedaquiline-based regimen for MDR/RR-TB treatment in South Africa compared with the standard kanamycin-based regimen.

METHODS

We established a Markov model for ambulatory treatment of MDR/RR-TB in a high-HIV prevalence setting, parameterized using clinical outcomes from the South African National TB Programme (SA NTP) before (2012-2014) and after (2015-2016) bedaquiline roll-out. The effectiveness of treatment was evaluated in disability-adjusted life-years (DALYs). Ingredient costs from the provider's perspective were collected in 2016 South African Rand and converted to $US, including bedaquiline at $US675.23 per 6-month treatment course. Culture conversion rates were derived from the phase IIb trial of bedaquiline, and disability adjustments were adapted from published literature. Costs and effectiveness were discounted at 3%.

RESULTS

For non-bedaquiline regimens, the total expected cost over the 10-year time horizon for a patient with MDR/RR-TB was $US4439 with disability-adjusted survival of 5.1 years. Replacing capreomycin with bedaquiline in patients who failed MDR/RR-TB treatment and required treatment for extensively drug-resistant (XDR-TB) resulted in cost savings ($US4356; 1.8% less) and similar effectiveness (0.02 DALYs averted). As a result, the standard regimen (no bedaquiline) was dominated. Replacing kanamycin with bedaquiline to provide all patients with MDR/RR-TB access to bedaquiline cost $US4647 (4.3% more) and averted 0.17 DALYs compared with the no bedaquiline regimen. The incremental cost-effectiveness ratio was $US1242/DALY averted.

CONCLUSION

Markov modelling indicates providing bedaquiline for all patients with MDR/RR-TB could increase the 24-month treatment success rate in South Africa from 56.3% using the current regimen to 60.6%, at a cost $US2.6 million over a 10-year horizon, less than 1% of the estimated $US425 million SA NTP annual budget.

South African HIV self-testing policy and guidance considerations

The gap in HIV testing remains significant and new modalities such as HIV self-testing (HIVST) have been recommended to reach key and under-tested populations. In December 2016, the World Health Organization (WHO) released the Guidelines on HIV Self-Testing and Partner Notification: A Supplement to the Consolidated Guidelines on HIV Testing Services (HTS) and urged member countries to develop HIVST policy and regulatory frameworks. In South Africa, HIVST was included as a supplementary strategy in the National HIV Testing Services Policy in 2016, and recently, guidelines for HIVST were included in the South African National Strategic Plan for HIV, sexually transmitted infections and tuberculosis 2017–2022. This document serves as an additional guidance for the National HIV Testing Services Policy 2016, with specific focus on HIVST. It is intended for policy advocates, clinical and non-clinical HTS providers, health facility managers and healthcare providers in private and public health facilities, non-governmental, community-based and faith-based organisations involved in HTS and outreach, device manufacturers, workplace programmes and institutes of higher education.

Adult antiretroviral therapy guidelines 2017

These guidelines are intended as an update to those published in the Southern African Journal of HIV Medicine in 2014 and the update on when to initiate antiretroviral therapy in 2015. Since the release of the previous guidelines, the scale-up of antiretroviral therapy (ART) in southern Africa has continued. New antiretroviral drugs have become available with improved efficacy, safety and robustness. The guidelines are intended for countries in the southern African region, which vary between lower and middle income.

A combination of baseline plasma immune markers can predict therapeutic response in multidrug resistant tuberculosis

OBJECTIVE

To identify plasma markers predictive of therapeutic response in patients with multidrug resistant tuberculosis (MDR-TB).

METHODS

Fifty HIV-negative patients with active pulmonary MDR-TB were analysed for six soluble analytes in plasma at the time of initiating treatment (baseline) and over six months thereafter. Patients were identified as sputum culture positive or negative at baseline. Culture positive patients were further stratified by the median time to sputum culture conversion (SCC) as fast responders (< 76 days) or slow responders (≥ 76 days). Chest X-ray scores, body mass index, and sputum smear microscopy results were obtained at baseline.

RESULTS

Unsupervised hierarchical clustering revealed that baseline plasma levels of IP-10/CXCL10, VEGF-A, SAA and CRP could distinguish sputum culture and cavitation status of patients. Among patients who were culture positive at baseline, there were significant positive correlations between plasma levels of CRP, SAA, VEGF-A, sIL-2Rα/CD40, and IP-10 and delayed SCC. Using linear discriminant analysis (LDA) and Receiver Operating Curves (ROC), we showed that a combination of MCP-1/CCL2, IP-10, sIL-2Rα, SAA, CRP and AFB smear could distinguish fast from slow responders and were predictive of delayed SCC with high sensitivity and specificity.

CONCLUSION

Plasma levels of specific chemokines and inflammatory markers measured before MDR-TB treatment are candidate predictive markers of delayed SCC. These findings require validation in a larger study.

Turning the tide against tuberculosis

Despite affecting men, women, and children for millennia, tuberculosis (TB) is the most neglected disease. In contrast, the global response to HIV has reached a defining moment. By uniting efforts, promptly integrating major scientific findings for both treatment and prevention, and scaling up services, the once inconceivable end to the HIV epidemic may no longer be an illusion. "The world has made defeating AIDS a top priority. This is a blessing. But TB remains ignored" - Nelson Mandela. While there is no doubt that revolutionary diagnostics and new and repurposed drugs have provided some hope in the fight against TB, it is evident that scientific advances on their own are inadequate to achieve the World Health Organization's ambitious goal to end TB by 2035. In this article, the consequences of a myopic and conventional biomedical approach to TB, which has ultimately permeated to the level of individual patient care, are highlighted.

Excellent retention, virologic and clinical outcomes after transitioning from an antiretroviral treatment clinical trial to locally-provided care and treatment in Africa

<p class="abstract"><strong>Background:</strong> Little is known about outcomes among clinical trial participants following completion of study-provided care and treatment in resource limited settings. We sought to describe outcomes among HIV clinical trial participants after transitioning to local routine care in Africa<span lang="EN-IN">. </span></p><p class="abstract"><strong>Methods:</strong> In the OCTANE study, 741 women with CD4 &lt;200 cells/mm³ in 7 African countries were randomized to initiate antiretroviral treatment (ART) with tenofovir/emtricitabine (TDF/FTC) plus either lopinavir/ritonavir (LPV/r) or nevirapine (NVP). When study-specified ART ended (48-191 weeks after study entry), participants transitioned to locally-provided HIV care and non-study ART. Consenting participants were interviewed and had toxicity labs, CD4 and HIV-1 RNA testing, and clinical outcomes assessed at 12 and 72 weeks after transition to local care<span lang="EN-IN">.</span></p><p class="abstract"><strong>Results:</strong> Five hundred thirteen (77%) of the 669 women in follow-up at completion of the interventional trial participate in the extended follow-up. 513 women, 476 (93%) had HIV-1 RNA &lt;400 cp/mL at time of transition, and 489 (95%) completed follow-up.  Seventy-seven women (19%) had a total of 99 antiretroviral regimen changes during post-trial follow-up. 30% of the 99 regimen changes-were due to lack of local drug availability. Thirteen (3%) women had Grade ≥3 laboratory abnormalities and 3 experienced worsening of the WHO HIV stage. Two women died. Eighty-nine percent of 484 with results had HIV-1 RNA ≤400 cp/mL at 72 weeks after transition to local non-study HIV care and treatment<span lang="EN-IN">.  </span></p><p class="abstract"><strong>Conclusions:</strong> The vast majority of women were able to continue key components of their ART and to maintain virologic suppression through 72 weeks of locally-provided post-study care.</p><p><strong>Trial registration:</strong> ClinicalTrials.gov NCT00089505</p>

Tenofovir stock shortages have limited impact on clinic- and patient-level HIV treatment outcomes in public sector clinics in South Africa

OBJECTIVE

Using data from four public sector clinics in South Africa, we sought to investigate provider- and patient-level outcomes, to understand how the 2012 tenofovir stock shortage affected the HIV care and monitoring of ART patients.

METHODS

Prospective cohort analysis of ART-naïve, non-pregnant, HIV-infected patients >18 years initiating first-line ART between 1 July 2011-31 March 2013. Linear regression was used for all outcomes (number of ART initiates, days between pharmacy visits, transfers, single-drug substitutions, treatment interruptions, missed pharmacy visits, loss to follow-up and elevated viral load). We fit splines to smooth curves with knots at the beginning (1 February 2012) and end (31 August 2012) of the stock shortage and displayed results graphically by clinic. Difference-in-difference models were used to evaluate the effect of the stock shortage on outcomes.

RESULTS

Results suggest a potential shift in the management of patients during the shortage, mainly fewer average days between visits during the shortage vs. before or after at all four clinics, and a significant difference in the proportion of patients missing visits during vs. before (RD: 1.2%; 95% CI: 0.5%, 2.0%). No significant difference was seen in other outcomes.

CONCLUSION

While South Africa has made great strides to extend access to ART and increase the quality of the health services provided, patient care can be affected when stock shortages/outs occur. While our results show little effect on treatment outcomes, this most likely reflects the clinics' ability to mitigate the crisis by continuing to keep patient care and treatment as consistent as possible.

Southern African guidelines on the safe use of pre-exposure prophylaxis in persons at risk of acquiring HIV-1 infection

The Southern African HIV Clinicians Society published its first set of oral pre-exposure prophylaxis (PrEP) guidelines in June 2012 for men who have sex with men (MSM) who are at risk of HIV infection. With the flurry of data that has been generated in PrEP clinical research since the first guideline, it became evident that there was a need to revise and expand the PrEP guidelines with new evidence of safety and efficacy of PrEP in several populations, including MSM, transgender persons, heterosexual men and women, HIV-serodiscordant couples and people who inject drugs. This need is particularly relevant following the World Health Organization (WHO) Consolidated Treatment Guidelines released in September 2015. These guidelines advise that PrEP is a highly effective, safe, biomedical option for HIV prevention that can be incorporated with other combination prevention strategies in Southern Africa, given the high prevalence of HIV in the region. PrEP should be tailored to populations at highest risk of HIV acquisition, whilst further data from studies in the region accrue to guide optimal deployment to realise the greatest impact regionally. PrEP may be used intermittently during periods of perceived HIV acquisition risk, rather than continually and lifelong, as is the case with antiretroviral treatment. Recognition and accurate measurement of potential risk in individuals and populations also warrants discussion, but are not extensively covered in these guidelines.

Southern African guidelines on the safe use of pre-exposure prophylaxis in persons at risk of acquiring HIV-1 infection

The Southern African HIV Clinicians Society published its first set of oral pre-exposure prophylaxis (PrEP) guidelines in June 2012 for men who have sex with men (MSM) who are at risk of HIV infection. With the flurry of data that has been generated in PrEP clinical research since the first guideline, it became evident that there was a need to revise and expand the PrEP guidelines with new evidence of safety and efficacy of PrEP in several populations, including MSM, transgender persons, heterosexual men and women, HIV-serodiscordant couples and people who inject drugs. This need is particularly relevant following the World Health Organization (WHO) Consolidated Treatment Guidelines released in September 2015. These guidelines advise that PrEP is a highly effective, safe, biomedical option for HIV prevention that can be incorporated with other combination prevention strategies in Southern Africa, given the high prevalence of HIV in the region. PrEP should be tailored to populations at highest risk of HIV acquisition, whilst further data from studies in the region accrue to guide optimal deployment to realise the greatest impact regionally. PrEP may be used intermittently during periods of perceived HIV acquisition risk, rather than continually and lifelong, as is the case with antiretroviral treatment. Recognition and accurate measurement of potential risk in individuals and populations also warrants discussion, but are not extensively covered in these guidelines.

What is the role of CD4 count in a large public health antiretroviral programme?

No abstract available.