Prevention of Early Mortality by Presumptive Tuberculosis Therapy Study: An Open Label, Randomized Controlled Trial

Bacterial pathogens in Xpert MTB/RIF Ultra-negative sputum samples of patients with presumptive tuberculosis in a high TB burden setting: a 16S rRNA analysis

In patients with presumptive tuberculosis (TB) in whom the diagnosis of TB was excluded, understanding the bacterial etiology of lower respiratory tract infections (LRTIs) is important for optimal patient management. A secondary analysis was performed on a cohort of 250 hospitalized patients with symptoms of TB. Bacterial DNA was extracted from sputum samples for Illumina 16S rRNA sequencing to identify bacterial species based on amplicon sequence variant level. The bacterial pathogen most likely to be responsible for the patients' LRTI could only be identified in a minority (6.0%, 13/215) of cases based on 16S rRNA amplicon sequencing: Mycoplasma pneumoniae (n = 7), Bordetella pertussis (n = 2), Acinetobacter baumanii (n = 2), and Pseudomonas aeruginosa (n = 2). Other putative pathogens were present in similar proportions of Xpert Ultra-positive and Xpert Ultra-negative sputum samples. The presence of Streptococcus (pseudo)pneumoniae appeared to increase the odds of radiological abnormalities (aOR 2.5, 95% CI 1.12-6.16) and the presence of S. (pseudo)pneumoniae (aOR 5.31, 95% CI 1.29-26.6) and Moraxella catarrhalis/nonliquefaciens (aOR 12.1, 95% CI 2.67-72.8) increased the odds of 6-month mortality, suggesting that these pathogens might have clinical relevance. M. pneumoniae, B. pertussis, and A. baumanii appeared to be the possible causes of TB-like symptoms. S. (pseudo)pneumoniae and M. catarrhalis/nonliquefaciens also appeared of clinical relevance based on 16S rRNA amplicon sequencing. Further research using tools with higher discriminatory power than 16S rRNA sequencing is required to develop optimal diagnostic and treatment strategies for this population.IMPORTANCEThe objective of this study was to identify possible bacterial lower respiratory tract infection (LRTI) pathogens in hospitalized patients who were initially suspected to have TB but later tested negative using the Xpert Ultra test. Although 16S rRNA was able to identify some less common or difficult-to-culture pathogens such as Mycoplasma pneumoniae and Bordetella pertussis, one of the main findings of the study is that, in contrast to what we had hypothesized, 16S rRNA is not a method that can be used to assist in the management of patients with presumptive TB having a negative Xpert Ultra test. Even though this could be considered a negative finding, we believe it is an important finding to report as it highlights the need for further research using different approaches.

Interventions to reduce deaths in people living with HIV admitted to hospital in low- and middle-income countries: A systematic review

People living with HIV (PLHIV) admitted to hospital have a high risk of death. We systematically appraised evidence for interventions to reduce mortality among hospitalised PLHIV in low- and middle-income countries (LMICs). Using a broad search strategy with terms for HIV, hospitals, and clinical trials, we searched for reports published between 1 Jan 2003 and 23 August 2021. Studies of interventions among adult HIV positive inpatients in LMICs were included if there was a comparator group and death was an outcome. We excluded studies restricted only to inpatients with a specific diagnosis (e.g. cryptococcal meningitis). Of 19,970 unique studies identified in search, ten were eligible for inclusion with 7,531 participants in total: nine randomised trials, and one before-after study. Three trials investigated systematic screening for tuberculosis; two showed survival benefit for urine TB screening vs. no urine screening, and one which compared Xpert MTB/RIF versus smear microscopy showed no difference in survival. One before-after study implemented 2007 WHO guidelines to improve management of smear negative tuberculosis in severely ill PLHIV, and showed survival benefit but with high risk of bias. Two trials evaluated complex interventions aimed at overcoming barriers to ART initiation in newly diagnosed PLHIV, one of which showed survival benefit and the other no difference. Two small trials evaluated early inpatient ART start, with no difference in survival. Two trials investigated protocol-driven fluid resuscitation for emergency-room attendees meeting case-definitions for sepsis, and showed increased mortality with use of a protocol for fluid administration. In conclusion, ten studies published since 2003 investigated interventions that aimed to reduce mortality in hospitalised adults with HIV, and weren't restricted to people with a defined disease diagnosis. Inpatient trials of diagnostics, therapeutics or a package of interventions to reduce mortality should be a research priority. Trial registration: PROSPERO Number: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019150341.

Building sustainable clinical trial sites in Sub-Saharan Africa through networking, infrastructure improvement, training and conducting clinical studies: The PanACEA approach

INTRODUCTION

The Pan-African Consortium for the Evaluation of Anti-Tuberculosis Antibiotics (PanACEA) was designed to build tuberculosis (TB) trial capacity whilst conducting clinical trials on novel and existing agents to shorten and simplify TB treatment. PanACEA has now established a dynamic network of 11 sub-Saharan clinical trial sites and four European research institutions.

OBJECTIVES

In 2011, a capacity development program, funded by the European & Developing Countries Clinical Trials Partnership (EDCTP), was launched with four objectives, aiming at strengthening collaborating TB research sites to reach the ultimate goal of becoming self-sustainable institutions: networking; training; conducting clinical trials; and infrastructure scaling-up of sites.

METHODS

Assessment in six sub-Saharan TB-endemic countries (Gabon, Kenya, South Africa, Tanzania, Uganda and Zambia) were performed through a structured questionnaire, site visits, discussion with the PanACEA consortium, setting of milestones and identification of priorities and followed-up with evaluations of each site. The results of this needs-based assessment was then translated into capacity development measures.

RESULTS

In the initial phase, over a four-year period (March 2011 - June 2014), the programme scaled-up six sites; conducted a monitoring training program for 11 participants; funded five MSc and four PhD students, fostering gender balance; conducted four epidemiological studies; supported sites to conduct five Phase II studies and formed a sustainable platform for TB research (panacea-tb.net).

CONCLUSION

Our experience of conducting TB clinical trials within the PanACEA programme environment of mentoring, networking and training has provided a sound platform for establishing future sustainable research centres. Our goal of facilitating emergent clinical TB trial sites to better initiate and lead research activities has been mostly successful.

Early Empirical Tuberculosis Treatment in HIV-Positive Patients Admitted to Hospital in South Africa: An Observational Cohort Study

BACKGROUND

Empirical tuberculosis (TB) treatment in human immunodeficiency virus (HIV)-positive inpatients is common and may undermine the impact of new diagnostics. We sought to describe empirical TB treatment and compare characteristics and outcomes with patients treated for TB after screening.

METHODS

This was a retrospective observational cohort study of HIV-positive inpatients treated empirically for TB prior to TB screening. Data on clinical characteristics, investigations, and outcomes were collected from medical records. Comparison cohorts with microbiologically confirmed or empirical TB treatment after TB screening with Xpert MTB/RIF and urine lipoarabinomannan assays were taken from South African Screening for Tuberculosis to Reduce AIDS-Related Mortality in Hospitalized Patients in Africa (STAMP) trial site. In-hospital mortality was compared using a competing-risks analysis adjusted for age, sex, and CD4 cell count.

RESULTS

Between January 2016 and September 2017, 100 patients excluded from STAMP were treated for TB empirically prior to TB screening. After enrollment in STAMP and TB screening, 240 of 1177 (20.4%) patients received TB treatment, of whom 123 had positive TB tests and 117 were treated empirically. Characteristics were similar among early empirically treated patients and those treated after TB screening. 50% of early empirical TB treatment was based on radiological investigations, 22% on cerebrospinal or pleural fluid testing, and 28% on clinical features alone. Only 11 of 100 empirically treated patients had subsequent microbiological confirmation. In-hospital mortality was lower in patients with microbiologically confirmed TB compared to those treated empirically (adjusted subdistribution hazard ratio, 0.5 [95% confidence interval, .3-.9).

CONCLUSIONS

Empirical TB treatment remains common in severely ill HIV-positive inpatients. These patients may benefit from TB screening using existing rapid diagnostics, both to improve confirmation of TB disease and reduce overtreatment for TB.

A Parsimonious Host Inflammatory Biomarker Signature Predicts Incident Tuberculosis and Mortality in Advanced Human Immunodeficiency Virus

BACKGROUND

People with advanced human immunodeficiency virus (HIV) (CD4 < 50) remain at high risk of tuberculosis (TB) or death despite the initiation of antiretroviral therapy (ART). We aimed to identify immunological profiles that were most predictive of incident TB disease and death.

METHODS

The REMEMBER randomized clinical trial enrolled 850 participants with HIV (CD4 < 50 cells/µL) at ART initiation to receive either empiric TB treatment or isoniazid preventive therapy (IPT). A case-cohort study (n = 257) stratified by country and treatment arm was performed. Cases were defined as incident TB or all-cause death within 48 weeks after ART initiation. Using multiplexed immunoassay panels and ELISA, 26 biomarkers were assessed in plasma.

RESULTS

In total, 52 (6.1%) of 850 participants developed TB; 47 (5.5%) died (13 of whom had antecedent TB). Biomarkers associated with incident TB overlapped with those associated with death (interleukin [IL]-1β, IL-6). Biomarker levels declined over time in individuals with incident TB while remaining persistently elevated in those who died. Dividing the cohort into development and validation sets, the final model of 6 biomarkers (CXCL10, IL-1β, IL-10, sCD14, tumor necrosis factor [TNF]-α, and TNF-β) achieved a sensitivity of 0.90 (95% confidence interval [CI]: .87-.94) and a specificity of 0.71(95% CI: .68-.75) with an area under the curve (AUC) of 0.81 (95% CI: .78-.83) for incident TB.

CONCLUSION

Among people with advanced HIV, a parsimonious inflammatory biomarker signature predicted those at highest risk for developing TB despite initiation of ART and TB preventive therapies. The signature may be a promising stratification tool to select patients who may benefit from increased monitoring and novel interventions.

CLINICAL TRIALS REGISTRATION

NCT01380080.

Systematic or Test-Guided Treatment for Tuberculosis in HIV-Infected Adults

BACKGROUND

In regions with high burdens of tuberculosis and human immunodeficiency virus (HIV), many HIV-infected adults begin antiretroviral therapy (ART) when they are already severely immunocompromised. Mortality after ART initiation is high in these patients, and tuberculosis and invasive bacterial diseases are common causes of death.

METHODS

We conducted a 48-week trial of empirical treatment for tuberculosis as compared with treatment guided by testing in HIV-infected adults who had not previously received ART and had CD4+ T-cell counts below 100 cells per cubic millimeter. Patients recruited in Ivory Coast, Uganda, Cambodia, and Vietnam were randomly assigned in a 1:1 ratio to undergo screening (Xpert MTB/RIF test, urinary lipoarabinomannan test, and chest radiography) to determine whether treatment for tuberculosis should be started or to receive systematic empirical treatment with rifampin, isoniazid, ethambutol, and pyrazinamide daily for 2 months, followed by rifampin and isoniazid daily for 4 months. The primary end point was a composite of death from any cause or invasive bacterial disease within 24 weeks (primary analysis) or within 48 weeks after randomization.

RESULTS

A total of 522 patients in the systematic-treatment group and 525 in the guided-treatment group were included in the analyses. At week 24, the rate of death from any cause or invasive bacterial disease (calculated as the number of first events per 100 patient-years) was 19.4 with systematic treatment and 20.3 with guided treatment (adjusted hazard ratio, 0.95; 95% confidence interval [CI], 0.63 to 1.44). At week 48, the corresponding rates were 12.8 and 13.3 (adjusted hazard ratio, 0.97 [95% CI, 0.67 to 1.40]). At week 24, the probability of tuberculosis was lower with systematic treatment than with guided treatment (3.0% vs. 17.9%; adjusted hazard ratio, 0.15; 95% CI, 0.09 to 0.26), but the probability of grade 3 or 4 drug-related adverse events was higher with systematic treatment (17.4% vs. 7.2%; adjusted hazard ratio 2.57; 95% CI, 1.75 to 3.78). Serious adverse events were more common with systematic treatment.

CONCLUSIONS

Among severely immunosuppressed adults with HIV infection who had not previously received ART, systematic treatment for tuberculosis was not superior to test-guided treatment in reducing the rate of death or invasive bacterial disease over 24 or 48 weeks and was associated with more grade 3 or 4 adverse events. (Funded by the Agence Nationale de Recherches sur le Sida et les Hépatites Virales; STATIS ANRS 12290 ClinicalTrials.gov number, NCT02057796.).

Role of empiric treatment in hospitalized patients with Xpert MTB/RIF-negative presumptive pulmonary tuberculosis: A prospective cohort study

OBJECTIVES

The ability of clinical algorithms to identify tuberculosis disease and the impact of empiric treatment on survival in people with a negative Xpert MTB/RIF (Xpert) result remains poorly documented.

METHODS

Hospitalized Xpert-negative patients (125 initiated on empiric tuberculosis treatment based on a clinical algorithm and 125 in whom tuberculosis treatment was not started) were enrolled. Sputum samples were evaluated for Mycobacterium tuberculosis by culture. All study participants were followed up for 6 months.

RESULTS

Xpert-negative inpatients in whom empiric tuberculosis treatment was initiated were more likely to have microbiological confirmed tuberculosis compared to those in whom empiric tuberculosis treatment was not started (24.8% vs 6.4%, p=0.0001). Six-month risk of death was 5.2%, but the risk was twice as high in people with bacteriological confirmation of TB (10.3% vs 4.3%, p=0.12). Cardinal symptoms of TB were associated with bacteriological confirmation and a decision to start empiric treatment. The positive predictive value of the clinical algorithm was 24.8% and empiric treatment did not affect 6-month risk of death (5.6% vs 4.8%, p=0.78).

CONCLUSIONS

Clinical algorithm identifies the majority of confirmed tuberculosis cases among Xpert-negative inpatients. Empiric treatment did not impact survival and resulted in substantial overtreatment. The more sensitive Xpert Ultra assay should be used to eliminate the need for empiric tuberculosis treatment.

Algorithm-guided empirical tuberculosis treatment for people with advanced HIV (TB Fast Track): an open-label, cluster-randomised trial

BACKGROUND

Tuberculosis, which is often undiagnosed, is the major cause of death among HIV-positive people. We aimed to test whether the use of a clinical algorithm enabling the initiation of empirical tuberculosis treatment by nurses in primary health-care clinics would reduce mortality compared with standard of care for adults with advanced HIV disease.

METHODS

In this open-label cluster-randomised controlled trial, we recruited individuals from 24 primary health-care clinics in South Africa. The clinics were randomly assigned (1:1) to either deliver an intervention or routine care (control) using computer-generated random numbers. Eligible participants were HIV-positive adults (aged ≥18 years) with CD4 counts of 150 cells per μL or less, who had not had antiretroviral therapy (ART) in the past 6 months or tuberculosis treatment in the past 3 months, and did not require urgent hospital referral. In intervention clinics, study nurses assessed participants on the basis of tuberculosis symptoms, body-mass index, point-of-care haemoglobin concentrations, and urine lipoarabinomannan assay results. Participants classified by a study algorithm as having high probability of tuberculosis (positive urine lipoarabinomannan assay, body-mass index <18·5 kg/m², or haemoglobin concentration <100 g/L) were recommended to start tuberculosis treatment immediately followed by ART 2 weeks later; participants classified as medium probability (tuberculosis symptoms, no high probability criteria) were recommended to have symptom-guided investigation; and participants classified as low probability (no tuberculosis symptoms or high probability criteria) were recommended to start ART immediately. In standard-of-care clinics, participants received treatment in accordance with South African guidelines. Investigators and participants were aware of treatment allocation. The primary outcome was all-cause mortality at 6 months, assessed in the intention-to-treat population. Safety was also analysed in the intention-to treat population. This trial is registered with the ISRCTN registry, ISRCTN35344604, and the South African National Clinical Trials Register, DOH-27-0812-3902.

FINDINGS

Between Dec 19, 2012, and Dec 18, 2014, 3091 individuals were screened for eligibility, of whom 3053 were recruited, and 3022 (1507 participants in the intervention group and 1515 participants in the control group) were analysed for the primary outcome. 930 (61·7%) of 1507 participants in the intervention group versus 172 (11·4%) of 1515 participants in the control group had started tuberculosis treatment by 2 months. At 6 months, the mortality rate was 19·0 deaths per 100 person-years for the intervention group versus 21·6 deaths per 100 person-years in the control group (unadjusted hazard ratio [HR] 0·92, 95% CI 0·67-1·26, p=0·58; adjusted HR 0·87, 0·61-1·24, p=0·41). 28 (1·9%) of 1507 participants in the intervention group and ten (0·7%) of 1515 participants in the control group reported serious or severe adverse events. Grade 3 or 4 nausea and vomiting was the most common adverse event (ten participants in the intervention group and four participants in the control group). Among participants with adverse events, eight participants (six participants in the intervention group and two participants in the control group) died; none of the six deaths in the intervention group were attributed to the study intervention.

INTERPRETATION

Our intervention substantially increased coverage of tuberculosis treatment in this high-risk population, but did not reduce mortality.

FUNDING

Joint Global Health Trials (Medical Research Council, Department for International Development, Wellcome Trust).

Rapid antiretroviral therapy initiation in low- and middle-income countries: A resource-based approach

In an Essay, Mark Tenforde and colleagues advocate continued provision of baseline CD4 cell count testing in HIV care in low- and middle-income countries.

Treatment decisions and mortality in HIV-positive presumptive smear-negative TB in the Xpert™ MTB/RIF era: a cohort study

BACKGROUND

The Xpert™ MTB/RIF (XP) has a higher sensitivity than sputum smear microscopy (70% versus 35%) for TB diagnosis and has been endorsed by the WHO for TB high burden countries to increase case finding among HIV co-infected presumptive TB patients. Its impact on the diagnosis of smear-negative TB in a routine care setting is unclear. We determined the change in diagnosis, treatment and mortality of smear-negative presumptive TB with routine use of Xpert MTB/RIF (XP).

METHODS

Prospective cohort study of HIV-positive smear-negative presumptive TB patients during a 12-month period after XP implementation in a well-staffed and trained integrated TB/HIV clinic in Kampala, Uganda. Prior to testing clinicians were asked to decide whether they would treat empirically prior to Xpert result; actual treatment was decided upon receipt of the XP result. We compared empirical and XP-informed treatment decisions and all-cause mortality in the first year.

RESULTS

Of 411 smear-negative presumptive TB patients, 175 (43%) received an XP; their baseline characteristics did not differ. XP positivity was similar in patients with a pre-XP empirical diagnosis and those without (9/29 [17%] versus 14/142 [10%], P = 0.23). Despite XP testing high levels of empirical treatment prevailed (18%), although XP results did change who ultimately was treated for TB. When adjusted for CD4 count, empirical treatment was not associated with higher mortality compared to no or microbiologically confirmed treatment.

CONCLUSIONS

XP usage was lower than expected. The lower sensitivity of XP in smear-negative HIV-positive patients led experienced clinicians to use XP as a "rule-in" rather than "rule-out" test, with the majority of patients still treated empirically.

Enhanced laboratory capacity development: a boost for effective tuberculosis control in resource-limited settings

Both routine and research tuberculosis (TB) laboratory capacity urgently need to be expanded in large parts of Sub-Saharan Africa. In 2009, the Centre de Recherches Médicales de Lambaréné (CERMEL) took a strategic decision to expand its activities by building TB laboratory capacity to address research questions and to improve routine diagnostic and treatment capacity. Over the past 7 years, a standard laboratory has been developed that is contributing significantly to TB diagnosis, treatment, and control in Gabon; training has also been provided for TB research staff in Central Africa. CERMEL has a cordial relationship with the Gabon National TB Control Programme (PNLT), which has culminated in a successful Global Fund joint application. This endeavour is considered a model for similar developments needed in areas of high TB prevalence and where TB control remains poor to date.