Impact of Prior Tuberculosis Treatment With New/Companion Drugs on Clinical Outcomes in Patients Receiving Concomitant Bedaquiline and Delamanid for Multidrug- and Rifampicin-Resistant Tuberculosis

BACKGROUND

There are scarce data on the clinical outcomes of persons retreated with new/companion anti-tuberculosis (TB) drugs for multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB). We sought to evaluate the efficacy and safety of bedaquiline and delamanid containing regimens among patients with and without prior exposure to the new/companion drugs (bedaquiline, delamanid, linezolid, clofazimine, and fluoroquinolones).

METHODS

We conducted a retrospective cohort study among patients with pulmonary MDR/RR-TB in Georgia who received bedaquiline and delamanid combination as a part of a salvage regimen from November 2017 to December 2020 in a programmatic setting.

RESULTS

Among 106 persons with a median age of 39.5 years, 44 (41.5%) were previously treated with new/companion TB drugs. Patients with prior exposure to new/companion drugs had higher rates of baseline resistance compared to those without exposure to new/companion TB drugs (bedaquiline 15.2% vs 1.8%, linezolid 22.2% vs 16.7%). Sputum culture conversion rates among patients exposed and not exposed to new/companion drugs were 65.9% vs 98.0%, respectively (P < .001). Among patients with and without prior new/companion TB drug use, favorable outcome rates were 41.0% and 82.3%, respectively (P < .001). Treatment adherence in 32 (30.2%) patients was ≤80%. Five of 21 patients (23.8%) who had a baseline and repeat susceptibility test had acquired bedaquiline resistance. QTC/F prolongation (>500 ms) was rare (2.8%).

CONCLUSIONS

Prior exposure to new/companion TB drugs was associated with poor clinical outcomes and acquired drug resistance. Tailoring the TB regimen to each patient's drug susceptibility test results and burden of disease and enhancing adherence support may improve outcomes.

HIV co-infection increases the risk of post-tuberculosis mortality among persons who initiated treatment for drug-resistant tuberculosis

Little is known regarding the relationship between common comorbidities in persons with tuberculosis (TB) (including human immunodeficiency virus [HIV], diabetes, and hepatitis C virus [HCV]) with post-TB mortality. We conducted a retrospective cohort study among persons who initiated treatment for rifampicin-resistant and multi/extensively drug-resistant (RR and M/XDR) TB reported to the country of Georgia's TB surveillance during 2009-2017. Exposures included HIV serologic status, diabetes, and HCV status. Our outcome was all-cause post-TB mortality determined by cross-validating vital status with Georgia's death registry through November 2019. We estimated adjusted hazard rate ratios (aHR) and 95% confidence intervals (CI) of post-TB mortality among participants with and without comorbidities using cause-specific hazard regressions. Among 1032 eligible participants, 34 (3.3%) died during treatment and 87 (8.7%) died post-TB treatment. Among those who died post-TB treatment, the median time to death was 21 months (interquartile range 7-39) post-TB treatment. After adjusting for confounders, the hazard rates of post-TB mortality were higher among participants with HIV co-infection (aHR=3.74, 95%CI 1.77-7.91) compared to those without HIV co-infection. In our cohort, post-TB mortality occurred most commonly in the first three years post-TB treatment. Linkage to care for common TB comorbidities post-treatment may reduce post-TB mortality rates.

Combined cerebrospinal fluid metabolomic and cytokine profiling in tuberculosis meningitis reveals robust and prolonged changes in immunometabolic networks

Much of the high mortality in tuberculosis meningitis (TBM) is attributable to excessive inflammation, making it imperative to identify targets for host-directed therapies that reduce pathologic inflammation and mortality. In this study, we investigate how cytokines and metabolites in the cerebral spinal fluid (CSF) associate with TBM at diagnosis and during TBM treatment. At diagnosis, TBM patients (n = 17) demonstrate significant increases of cytokines and chemokines that promote inflammation and cell migration including IL-17A, IL-2, TNFα, IFNγ, and IL-1β versus asymptomatic controls without known central nervous system pathology (n = 20). Inflammatory immune signaling had a strong positive correlation with immunomodulatory metabolites including kynurenine, lactic acid, and carnitine and strong negative correlations with tryptophan and itaconate. Inflammatory immunometabolic networks were only partially reversed with two months of effective TBM treatment and remained significantly different compared to CSF from controls. Together, these data highlight a critical role for host metabolism in regulating the inflammatory response to TBM and indicate the timeline for restoration of immune homeostasis in the CSF is prolonged.

Pharmacometabolomics in TB Meningitis - understanding the pharmacokinetic, metabolic, and immune factors associated with anti-TB drug concentrations in cerebrospinal fluid

Poor penetration of many anti-tuberculosis (TB) antibiotics into the central nervous system (CNS) is thought to be a major driver of morbidity and mortality in TB meningitis (TBM). While the amount of a particular drug that crosses into the cerebrospinal fluid (CSF) varies from person to person, little is known about the host factors associated with interindividual differences in CSF concentrations of anti-TB drugs. In patients diagnosed with TBM from the country of Georgia (n=17), we investigate the association between CSF concentrations of anti-TB antibiotics and multiple host factors including serum drug concentrations and CSF concentrations of metabolites and cytokines. We found >2-fold differences in CSF concentrations of anti-TB antibiotics from person to person for all drugs tested including cycloserine, ethambutol, imipenem, isoniazid, levofloxacin, linezolid, moxifloxacin pyrazinamide, and rifampin. While serum drug concentrations explained over 40% of the variation in CSF drug concentrations for cycloserine, isoniazid, linezolid, and pyrazinamide (adjusted R 2 >0.4, p<0.001 for all), there was no evidence of an association between serum concentrations of imipenem and ethambutol and their respective CSF concentrations. CSF concentrations of carnitines were significantly associated with concentrations of ethambutol and imipenem (q<0.05), and imipenem was the only antibiotic significantly associated with CSF cytokine concentrations. These results indicate that there is high interindividual variability in CSF drug concentrations in patients treated for TBM, which is only partially explained by differences in serum drug concentrations and not associated with concentrations of cytokines and chemokines in the CSF.

The effect of anti-tuberculosis drug pharmacokinetics on QTc prolongation

BACKGROUND

Implementation of newer anti-tuberculosis (TB) drugs may prolong the QT interval, increasing the risk of arrythmias and sudden cardiac death. The potential for cardiac adverse events has prompted recommendations for frequent cardiac monitoring during treatment. However, unknowns remain, including the association between drug concentrations and QT interval.

METHODS

An observational prospective cohort study design was used. Patients undergoing treatment for drug-resistant TB in Georgia were assessed. Serial blood samples were collected at 4-6 weeks for pharmacokinetics. Electrocardiograms were recommended to be performed monthly. A generalized estimating equation spline model was used to investigate (1) the effect difference between bedaquiline and delamanid, (2) the cumulative effect of number of anti-TB drugs, and (3) the relationship between serum drug concentrations on QTc interval.

RESULTS

Among 94 patients receiving either bedaquiline (n = 64) or delamanid (n = 30)-based treatment, most were male (82%), and the mean age was 39 years. The mean maximum QTc increase during the first six months was 37.5 ms (IQR: 17.8-56.8). Bedaquiline- and delamanid-based regimens displayed similar increased mean QTc change from baseline during drug administration (P = 0.12). Increasing number of anti-TB drugs was associated with an increased QTc (P = 0.01), but participants trended back towards baseline after drug discontinuation (P = 0.25). A significant association between AUC, Cmin, Cmax, and increased QTc interval was found for bedaquiline (months 1-6) and levofloxacin (months 1-12).

CONCLUSION

Bedaquiline- and delamanid-based regimens and increasing number of QT prolonging agents led to modest increases in the QTc interval with minimal clinical effect.

Combined cerebrospinal fluid metabolomic and cytokine profiling in tuberculosis meningitis reveals robust and prolonged changes in immunometabolic networks

Much of the high mortality in tuberculosis meningitis (TBM) is attributable to excessive inflammation, making it imperative to identify targets for host-directed therapies that reduce pathologic inflammation and mortality. In this study, we investigate how cytokines and metabolites in the cerebral spinal fluid (CSF) associate with TBM at diagnosis and during TBM treatment. At diagnosis, TBM patients demonstrate significant increases versus controls of cytokines and chemokines that promote inflammation and cell migration including IL-17A, IL-2, TNFα, IFNγ, and IL-1β. Inflammatory immune signaling was strongly correlated with immunomodulatory metabolites including kynurenine, lactic acid, carnitine, tryptophan, and itaconate. Inflammatory immunometabolic networks were only partially reversed with two months of effective TBM treatment and remained significantly different versus control CSF. Together, these data highlight a critical role for host metabolism in regulating the inflammatory response to TBM and indicate the timeline for restoration of immune homeostasis in the CSF is prolonged.

Updated considerations in the diagnosis and management of tuberculosis infection and disease: integrating the latest evidence-based strategies

INTRODUCTION

Tuberculosis (TB) is a leading infectious cause of global morbidity and mortality, affecting nearly a quarter of the human population and accounting for over 10 million deaths each year. Over the past several decades, TB incidence and mortality have gradually declined, but 2021 marked a threatening reversal of this trend highlighting the importance of accurate diagnosis and effective treatment of all forms of TB.

AREAS COVERED

This review summarizes advances in TB diagnostics, addresses the treatment of people with TB infection and TB disease including recent evidence for treatment regimens for drug-susceptible and drug-resistant TB, and draws attention to special considerations in children and during pregnancy.

EXPERT OPINION

Improvements in diagnosis and management of TB have expanded the available options for TB control. Molecular testing has enhanced the detection of TB disease, but better diagnostics are still needed, particularly for certain populations such as children. Novel treatment regimens have shortened treatment and improved outcomes for people with TB. However, important questions remain regarding the optimal management of TB. Work must continue to ensure the potential of the latest developments is realized for all people affected by TB.

Hepatitis C care cascade among patients with and without tuberculosis: Nationwide observational cohort study in the country of Georgia, 2015-2020

BACKGROUND

The Eastern European country of Georgia initiated a nationwide hepatitis C virus (HCV) elimination program in 2015 to address a high burden of infection. Screening for HCV infection through antibody testing was integrated into multiple existing programs, including the National Tuberculosis Program (NTP). We sought to compare the hepatitis C care cascade among patients with and without tuberculosis (TB) diagnosis in Georgia between 2015 and 2019 and to identify factors associated with loss to follow-up (LTFU) in hepatitis C care among patients with TB.

METHODS AND FINDINGS

Using national ID numbers, we merged databases of the HCV elimination program, NTP, and national death registry from January 1, 2015 to September 30, 2020. The study population included 11,985 adults (aged ≥18 years) diagnosed with active TB from January 1, 2015 through December 31, 2019, and 1,849,820 adults tested for HCV antibodies between January 1, 2015 and September 30, 2020, who were not diagnosed with TB during that time. We estimated the proportion of patients with and without TB who were LTFU at each step of the HCV care cascade and explored temporal changes. Among 11,985 patients with active TB, 9,065 (76%) patients without prior hepatitis C treatment were tested for HCV antibodies, of which 1,665 (18%) had a positive result; LTFU from hepatitis C care was common, with 316 of 1,557 (20%) patients with a positive antibody test not undergoing viremia testing and 443 of 1,025 (43%) patients with viremia not starting treatment for hepatitis C. Overall, among persons with confirmed viremic HCV infection, due to LTFU at various stages of the care cascade only 28% of patients with TB had a documented cure from HCV infection, compared to 55% among patients without TB. LTFU after positive antibody testing substantially decreased in the last 3 years, from 32% among patients diagnosed with TB in 2017 to 12% among those diagnosed in 2019. After a positive HCV antibody test, patients without TB had viremia testing sooner than patients with TB (hazards ratio [HR] = 1.46, 95% confidence intervals [CI] [1.39, 1.54], p < 0.001). After a positive viremia test, patients without TB started hepatitis C treatment sooner than patients with TB (HR = 2.05, 95% CI [1.87, 2.25], p < 0.001). In the risk factor analysis adjusted for age, sex, and case definition (new versus previously treated), multidrug-resistant (MDR) TB was associated with an increased risk of LTFU after a positive HCV antibody test (adjusted risk ratio [aRR] = 1.41, 95% CI [1.12, 1.76], p = 0.003). The main limitation of this study was that due to the reliance on existing electronic databases, we were unable to account for the impact of all confounding factors in some of the analyses.

CONCLUSIONS

LTFU from hepatitis C care after a positive antibody or viremia test was high and more common among patients with TB than in those without TB. Better integration of TB and hepatitis C care systems can potentially reduce LTFU and improve patient outcomes both in Georgia and other countries that are initiating or scaling up their nationwide hepatitis C control efforts and striving to provide personalized TB treatment.

Outpatient Parenteral Antibiotic Therapy for Diabetic Foot Osteomyelitis in an Uninsured and Underinsured Cohort

Background

Diabetic foot osteomyelitis (DFO) is usually treated with prolonged outpatient parenteral antibiotic therapy (OPAT). Evaluation and treatment of non-antibiotic aspects of DFO (e.g., peripheral artery disease [PAD]) are also recommended. There is limited data regarding OPAT practice patterns and outcomes for DFO.

Methods

Single-center observational study of patients receiving OPAT for DFO in a large United States public hospital between January 2017 and July 2019. We abstracted data regarding microbiology test, antibiotics, clinical outcomes, and non-antibiotic DFO management.

Results

Ninety-six patients were included and some had >1 DFO-OPAT course during the study period (106 DFO-OPAT courses included). No culture was obtained in 40 (38%) of courses. Methicillin-resistant S. aureus (MRSA) was cultured in 15 (14%) and P. aeruginosa in 1 (1%) of DFO-OPAT courses. An antibiotic with MRSA activity (vancomycin or daptomycin) was used in 79 (75%) of courses and a parenteral antibiotic with anti-pseudomonal activity was used in 7 (6%) of courses. Acute kidney injury occurred in 19 (18%) DFO-OPAT courses. An ankle-brachial index measurement was obtained during or 6 months prior to the first DFO-OPAT course for 44 (49%) of patients. Forty-two (44%) patients died or had an amputation within 12 months of their initial hospital discharge.

Conclusions

We found high rates of empiric antibiotic therapy for DFO and low uptake of the non-antibiotic aspects of DFO care. Better implementation of microbiological tests for DFO in addition to stronger integration of infectious disease and non-infectious diseases care could improve DFO outcomes.

Association of Treated and Untreated Chronic Hepatitis C With the Incidence of Active Tuberculosis Disease: A Population-Based Cohort Study

BACKGROUND

Hepatitis C virus (HCV) infection causes dysregulation and suppression of immune pathways involved in the control of tuberculosis (TB) infection. However, data on the role of chronic hepatitis C as a risk factor for active TB are lacking. We sought to evaluate the association between HCV infection and the development of active TB.

METHODS

We conducted a cohort study in Georgia among adults tested for HCV antibodies (January 2015-September 2020) and followed longitudinally for the development of newly diagnosed active TB. Data were obtained from the Georgian national programs of hepatitis C and TB. The exposures of interest were untreated and treated HCV infection. A Cox proportional hazards model was used to calculate adjusted hazard ratios (aHRs).

RESULTS

A total of 1 828 808 adults were included (median follow-up time: 26 months; IQR: 13-39 months). Active TB was diagnosed in 3163 (0.17%) individuals after a median of 6 months follow-up (IQR: 1-18 months). The incidence rate per 100 000 person-years was 296 among persons with untreated HCV infection, 109 among those with treated HCV infection, and 65 among HCV-negative persons. In multivariable analysis, both untreated (aHR = 2.9; 95% CI: 2.4-3.4) and treated (aHR = 1.6; 95% CI: 1.4-2.0) HCV infections were associated with a higher hazard of active TB, compared with HCV-negative persons.

CONCLUSIONS

Adults with HCV infection, particularly untreated individuals, were at higher risk of developing active TB disease. Screening for latent TB infection and active TB disease should be part of clinical evaluation of people with HCV infection, especially in high-TB-burden areas.

Diagnostic performance of the GenoType MTBDRplus VER 2.0 line probe assay for the detection of isoniazid resistant Mycobacterium tuberculosis in Ethiopia

BACKGROUND

Isoniazid (INH) resistant Mycobacterium tuberculosis (Hr-TB) is the most common type of drug resistant TB, and is defined as M tuberculosis complex (MTBC) strains resistant to INH but susceptible to rifampicin (RIF). Resistance to INH precedes RIF resistance in almost all multidrug resistant TB (MDR-TB) cases, across all MTBC lineages and in all settings. Therefore, early detection of Hr-TB is critical to ensure rapid initiation of appropriate treatment, and to prevent progression to MDR-TB. We assessed the performance of the GenoType MTBDRplus VER 2.0 line probe assay (LPA) in detecting isoniazid resistance among MTBC clinical isolates.

METHODS

A retrospective study was conducted among M. tuberculosis complex (MTBC) clinical isolates obtained from the third-round Ethiopian national drug resistance survey (DRS) conducted between August 2017 and December 2019. The sensitivity, specificity, positive predictive value, and negative predictive value of the GenoType MTBDRplus VER 2.0 LPA in detecting INH resistance were assessed and compared to phenotypic drug susceptibility testing (DST) using the Mycobacteria Growth Indicator Tube (MGIT) system. Fisher's exact test was performed to compare the performance of LPA between Hr-TB and MDR-TB isolates.

RESULTS

A total of 137 MTBC isolates were included, of those 62 were Hr-TB, 35 were MDR-TB and 40 were INH susceptible. The sensitivity of the GenoType MTBDRplus VER 2.0 for detecting INH resistance was 77.4% (95% CI: 65.5-86.2) among Hr-TB isolates and 94.3% (95% CI: 80.4-99.4) among MDR-TB isolates (P = 0.04). The specificity of the GenoType MTBDRplus VER 2.0 for detecting INH resistance was 100% (95% CI: 89.6-100). The katG 315 mutation was observed in 71% (n = 44) of Hr-TB phenotypes and 94.3% (n = 33) of MDR-TB phenotypes. Mutation at position-15 of the inhA promoter region alone was detected in four (6.5%) Hr-TB isolates, and concomitantly with katG 315 mutation in one (2.9%) MDR-TB isolate.

CONCLUSIONS

GenoType MTBDRplus VER 2.0 LPA demonstrated improved performance in detecting INH resistance among MDR-TB cases compared to Hr-TB cases. The katG315 mutation is the most common INH resistance conferring gene among Hr-TB and MDR-TB isolates. Additional INH resistance conferring mutations should be evaluated to improve the sensitivity of the GenoType MTBDRplus VER 2.0 for the detection of INH resistance among Hr-TB cases.

Cerebrospinal fluid concentrations of fluoroquinolones and carbapenems in tuberculosis meningitis

Background: Tuberculosis meningitis (TBM) is the most lethal form of TB. It is difficult to treat in part due to poor or uncertain drug penetration into the central nervous system (CNS). To help fill this knowledge gap, we evaluated the cerebrospinal fluid (CSF) concentrations of fluoroquinolones and carbapenems in patients being treated for TBM. Methods: Serial serum and CSF samples were collected from hospitalized patients being treated for TBM. CSF was collected from routine lumbar punctures between alternating timepoints of 2 and 6 h after drug administration to capture early and late CSF penetration. Rich serum sampling was collected after drug administration on day 28 for non-compartmental analysis. Results: Among 22 patients treated for TBM (8 with confirmed disease), there was high use of fluoroquinolones (levofloxacin, 21; moxifloxacin, 10; ofloxacin, 6) and carbapenems (imipenem, 11; meropenem, 6). Median CSF total concentrations of levofloxacin at 2 and 6 h were 1.34 mg/L and 3.36 mg/L with adjusted CSF/serum ratios of 0.41 and 0.63, respectively. For moxifloxacin, the median CSF total concentrations at 2 and 6 h were 0.78 mg/L and 1.02 mg/L with adjusted CSF/serum ratios of 0.44 and 0.62. Serum and CSF concentrations of moxifloxacin were not affected by rifampin use. Among the 76 CSF samples measured for carbapenem concentrations, 79% were undetectable or below the limit of detection. Conclusion: Fluoroquinolones demonstrated high CSF penetration indicating their potential usefulness for the treatment of TBM. Carbapenems had lower than expected CSF concentrations.

A case report of persistent drug-sensitive pulmonary tuberculosis after treatment completion

Background

Mycobacterium tuberculosis (Mtb) has been found to persist within cavities in patients who have completed their anti-tuberculosis therapy. The clinical implications of Mtb persistence after therapy include recurrence of disease and destructive changes within the lungs. Data on residual changes in patients who completed anti-tuberculosis therapy are scarce. This case highlights the radiological and pathological changes that persist after anti-tuberculosis therapy completion and the importance of achieving sterilization of cavities in order to prevent these changes.

Case presentation

This is a case report of a 33 year old female with drug-sensitive pulmonary tuberculosis who despite successfully completing standard 6-month treatment had persistent changes in her lungs on radiological imaging. The patient underwent multiple adjunctive surgeries to resect cavitary lesions, which were culture positive for Mtb. After surgical treatment, the patient’s chest radiographies improved, symptoms subsided, and she was given a definition of cure.

Conclusions

Medical therapy alone, in the presence of severe cavitary lung lesions may not be able to achieve sterilizing cure in all cases. Cavities can not only cause reactivation but also drive inflammatory changes and subsequent lung damage leading to airflow obstruction, bronchiectasis, and fibrosis. Surgical removal of these foci of bacilli can be an effective adjunctive treatment necessary for a sterilizing cure and improved long term lung health.

Brief Report: Financial Burden of Toxoplasmosis Encephalitis Treatment at a Safety Net Hospital

BACKGROUND

Although the price increase of pyrimethamine in 2015 received heavy media coverage, there are little data regarding specific implications to hospitals and the total costs of treating inpatients with toxoplasmosis encephalitis (TE).

METHODS

Using average drug wholesale costs, we estimated the inpatient drug costs of TE drugs 3 years prepyrimethamine and postpyrimethamine price increase in August 2015. The drug regimens and total doses were determined through retrospective chart review of patients living with HIV who received treatment for TE while inpatient during this period.

RESULTS

The 3-year pre-increase TE drug costs for 66 admissions were estimated at $50,310 compared with a total drug cost of $1,026,006 for 61 admissions postincrease. Pyrimethamine made up 98% of the drug costs postincrease, compared with 57% pre-increase. Pyrimethamine-based regimens were the most frequently used throughout the study period.

CONCLUSIONS

The price increase of pyrimethamine in 2015 led to a substantial and unnecessary financial burden to hospitals. This required health care systems to shift valuable resources to continue to provide medications to a vulnerable patient population. There has been more focus on providing high-value care in recent years. Our study highlights the need for further examination of pharmaceutical companies' arbitrary determination of medication costs and how they contribute to patient care.

Linezolid Exposure Is Associated with Cytopenias in Patients Treated for Multidrug-Resistant Tuberculosis

Although linezolid is effective for multidrug-resistant TB (MDR-TB) tuberculosis treatment, it is associated with cytopenias after 4 weeks of administration. Data on toxicities with long-term use of linezolid and drug pharmacodynamics in MDR-TB treatment are limited, and concerns about toxicity present barriers to wider implementation. This was a secondary analysis of a prospective cohort study of patients treated for MDR-TB in the country of Georgia from 2015 to 2017. Intensive blood sampling 4 to 6 weeks after treatment initiation with linezolid 600 mg daily was performed for pharmacokinetic (PK) analysis, including linezolid trough concentration (Cmin) and area under the curve from 0 to 24 hours (AUC0-24). Linezolid exposure was defined using literature-reported thresholds. Cytopenias were defined using an NIH adverse event (AE) scale. Logistic regression was used to evaluate the relationship between linezolid exposure and cytopenias. Among 76 patients receiving linezolid in their baseline treatment regimen and who had PK data available, cytopenia AEs occurred in 30 (39.5%) for an incidence rate of 46 per 100 person-years. The median duration of linezolid therapy was 526 days. No patients required dose reduction or interruption due to cytopenias. Median linezolid Cmin was 0.235 mg/L (interquartile range [IQR], 0.069 to 0.529), and median AUC0-24 was 89.6 mg·h/L (IQR, 69.2 to 116.2). Cytopenias were associated with linezolid PK parameters (Cmin > 2 mg/L and AUC0-24 > 160 mg·h/L). Cytopenias occurred frequently with long-term use of linezolid 600 mg/day and were associated with PK parameters but did not result in the need for treatment interruption in the management of a cohort of patients with MDR-TB.

Minimum inhibitory concentrations of rifampin and isoniazid among multidrug and isoniazid resistant Mycobacterium tuberculosis in Ethiopia

Introduction

Traditionally, single critical concentrations of drugs are utilized for Mycobacterium tuberculosis (Mtb) drug susceptibility testing (DST); however, the level of drug resistance can impact treatment choices and outcomes. Mutations at the katG gene are the major genetic mutations in multidrug resistant (MDR) Mtb and usually associated with high level resistance. We assessed the minimum inhibitory concentrations (MICs) of MDR or rifampin resistant (RR) and isoniazid (INH) resistant Mtb isolates to determine the quantification of drug resistance among key anti-tuberculosis drugs.

Methods

The study was conducted on stored Mtb isolates collected as part of a national drug resistance survey in Ethiopia. MIC values were determined using Sensititre^™ MYCOTB plates. A line probe assay (MTBDRplus) was also performed to identify genetic determinants of resistance for all isolates.

Results

MIC testing was performed on 74 Mtb isolates including 46 MDR, 2 RR and 26 INH phenotypically resistant isolates as determined by the Löwenstein Jensen (LJ) method. Four (15%) INH resistant Mtb isolates were detected as borderline rifampin resistance (MIC = 1 μg/ml) using MYCOTB MIC plates and no rifampin resistance mutations were detected by LPA. Among the 48 MDR/RR TB cases, 9 (19%) were rifabutin susceptible (MIC was between ≤0.25 and 0.5μg/ml). Additionally, the MIC for isoniazid was between 2–4 μg/ml (moderate resistance) for 58% of MDR TB isolates and 95.6% (n = 25) of the isolates had mutations at the katG gene.

Conclusion

Our findings suggest a role for rifabutin treatment in a subset of RR TB patients, thus potentially preserving an important drug class. The high proportion of moderate level INH resistant among MDR Mtb isolates indicates the potential benefit of high dose isoniazid treatment in a high proportion of katG gene harboring MDR Mtb isolates.

Cycloserine and Linezolid for Tuberculosis Meningitis: Pharmacokinetic Evidence of Potential Usefulness

BACKGROUND

The ability of antituberculosis drugs to cross the blood-brain barrier and reach the central nervous system is critical to their effectiveness in treating tuberculosis meningitis (TBM). We sought to fill a critical knowledge gap by providing data on the ability of new and repurposed antituberculosis drugs to penetrate into the cerebrospinal fluid (CSF).

METHODS

We conducted a clinical pharmacology study among patients treated for TBM in Tbilisi, Georgia, from January 2019 until January 2020. Serial serum and CSF samples were collected while patients were hospitalized. CSF was collected from routine lumbar punctures with the timing of the lumbar puncture alternating between 2 and 6 hours to capture early and late CSF penetration.

RESULTS

A total of 17 patients treated for TBM (8 with confirmed disease) were included; all received linezolid, with a subset receiving cycloserine (5), clofazimine (5), delamanid (4), and bedaquiline (2). All CSF measurements of bedaquiline (12), clofazimine (24), and delamanid (19) were below the limit of detection. The median CSF concentrations of cycloserine at 2 and 6 hours were 15.90 and 15.10 µg/mL with adjusted CSF/serum ratios of 0.52 and 0.66. CSF concentrations of linezolid were 0.90 and 3.14 µg/mL at 2 and 6 hours, with adjusted CSF/serum ratios of 0.25 and 0.59, respectively. CSF serum linezolid concentrations were not affected by rifampin coadministration.

CONCLUSIONS

Based on moderate to high CSF penetration, linezolid and cycloserine may be effective drugs for TBM treatment, whereas the utility of bedaquiline, delamanid, and clofazimine is uncertain given their low CSF penetration.

The Impact of Diabetes and Prediabetes on Prevalence of Mycobacterium tuberculosis Infection Among Household Contacts of Active Tuberculosis Cases in Ethiopia

Background

It is uncertain whether diabetes affects the risk of developing latent tuberculosis infection (LTBI) following exposure to Mycobacterium tuberculosis (Mtb). We assessed the relationship of diabetes or prediabetes and LTBI among close and household contacts (HHCs) of patients with active pulmonary tuberculosis (TB) disease in Addis Ababa, Ethiopia.

Methods

In this cross-sectional study, we performed interferon-γ release assays, TB symptom screening, and point-of-care glycolated hemoglobin (HbA1c) testing among HHCs of active TB cases. Diabetes status was classified into diabetes (HbA1c ≥6.5% or self-reported diagnosis), prediabetes (5.7%-6.4%), and euglycemia (≤5.6%). Multivariable logistic regression was used to determine the association of diabetes with LTBI.

Results

Among 597 study participants, 123 (21%) had dysglycemia including diabetes (n = 31) or prediabetes (n = 92); 423 (71%) participants were diagnosed with LTBI. Twelve of 31 (39%) HHCs with diabetes were previously undiagnosed with diabetes. The prevalence of LTBI among HHCs with diabetes, prediabetes, and euglycemia was 87% (27/31), 73% (67/92), and 69% (329/474), respectively. In multivariable analysis adjusted for age, sex, and HIV status, the odds of LTBI among HHCs with diabetes were 2.33 (95% confidence interval [CI], .76-7.08) times the odds of LTBI without diabetes. When assessing interaction with age, the association of diabetes and LTBI was robust among participants aged ≥40 years (adjusted odds ratio [aOR], 3.68 [95% CI, .77-17.6]) but not those <40 years (aOR, 1.15 [95% CI, .22-6.1]).

Conclusions

HHCs with diabetes may be more likely to have LTBI than those with euglycemia. Further investigations are needed to assess mechanisms by which diabetes may increase risk of LTBI after Mtb exposure.

Long term outcomes of patients with tuberculous meningitis: The impact of drug resistance

BACKGROUND

Little is known about the impact of drug-resistance on clinical outcomes among patients with tuberculosis meningitis (TBM).

METHODS

A retrospective cohort study among patients treated for TBM in Tbilisi, Georgia. We performed medical chart abstraction to collect patient data. Long-term vital status was assessed using the Georgia National Death Registry. We utilized a Cox proportional-hazards model to evaluate the association of drug-resistance and mortality.

RESULTS

Among 343 TBM suspects, 237 had a presentation consistent with TBM. Drug resistance was suspected (n = 5) or confirmed (n = 31) in 36 patients including 30 with multidrug- or rifampin-resistance and 6 with isoniazid-resistance. Thirty-four patients had HIV. The median follow-up time was 1331 days (IQR, 852-1767). Overall, 73 of 237 (30%) people died with 50 deaths occurring during and 23 after treatment. The proportion of death was higher among patients with drug-resistant vs. drug-susceptible disease (67% vs. 24%, p<0.001) and with HIV versus no HIV (59% vs 27%, p<0.001). Mortality was significantly higher in patients with drug-resistant TBM after 90 days of treatment (aHR = 7.2, CI95% [3.6-14.3], p < 0.001).

CONCLUSIONS

Mortality was high among patients with drug-resistant TBM with many deaths occurring post treatment. More effective treatment options are urgently needed for drug-resistant TBM.

Clinical evaluation of the Diagnostic Analyzer for Selective Hybridization (DASH): A point-of-care PCR test for rapid detection of SARS-CoV-2 infection

BACKGROUND

An ideal test for COVID-19 would combine the sensitivity of laboratory-based PCR with the speed and ease of use of point-of-care (POC) or home-based rapid antigen testing. We evaluated clinical performance of the Diagnostic Analyzer for Selective Hybridization (DASH) SARS-CoV-2 POC rapid PCR test.

METHODS

We conducted a cross-sectional study of adults with and without symptoms of COVID-19 at four clinical sites where we collected two bilateral anterior nasal swabs and information on COVID-19 symptoms, vaccination, and exposure. One swab was tested with the DASH SARS-CoV-2 POC PCR and the second in a central laboratory using Cepheid Xpert Xpress SARS-CoV-2 PCR. We assessed test concordance and calculated sensitivity, specificity, negative and positive predictive values using Xpert as the "gold standard".

RESULTS

We enrolled 315 and analyzed 313 participants with median age 42 years; 65% were female, 62% symptomatic, 75% had received ≥2 doses of mRNA COVID-19 vaccine, and 16% currently SARS-CoV-2 positive. There were concordant results for 307 tests indicating an overall agreement for DASH of 0.98 [95% CI 0.96, 0.99] compared to Xpert. DASH performed at 0.96 [95% CI 0.86, 1.00] sensitivity and 0.98 [95% CI 0.96, 1.00] specificity, with a positive predictive value of 0.85 [95% CI 0.73, 0.96] and negative predictive value of 0.996 [95% CI 0.99, 1.00]. The six discordant tests between DASH and Xpert all had high Ct values (>30) on the respective positive assay. DASH and Xpert Ct values were highly correlated (R = 0.89 [95% CI 0.81, 0.94]).

CONCLUSIONS

DASH POC SARS-CoV-2 PCR was accurate, easy to use, and provided fast results (approximately 15 minutes) in real-life clinical settings with an overall performance similar to an EUA-approved laboratory-based PCR.

Don't forget about human factors: Lessons learned from COVID-19 point-of-care testing

During the COVID-19 pandemic, the development of point-of-care (POC) diagnostic testing accelerated in an unparalleled fashion. As a result, there has been an increased need for accurate, robust, and easy-to-use POC testing in a variety of non-traditional settings (i.e., pharmacies, drive-thru sites, schools). While stakeholders often express the desire for POC technologies that are "as simple as digital pregnancy tests," there is little discussion of what this means in regards to device design, development, and assessment. The design of POC technologies and systems should take into account the capabilities and limitations of the users and their environments. Such "human factors" are important tenets that can help technology developers create POC technologies that are effective for end-users in a multitude of settings. Here, we review the core principles of human factors and discuss lessons learned during the evaluation process of SARS-CoV-2 POC testing.

SARS-CoV-2 seroprevalence among healthcare personnel at a large health system in Atlanta

Background

Estimates of the prevalence of SARS-CoV-2 antibodies and factors associated with infection among healthcare personnel (HCP) vary widely. We conducted a serosurvey of HCP at a large public healthcare system in the Atlanta area.

Materials and methods

All employees of Grady Health System were invited to participate in mid-2020; a volunteer sample of those completing testing was included. Asymptomatic HCP were offered testing for IgG antibody and for SARS-CoV-2 RNA using polymerase chain reaction (PCR). Symptomatic HCP were offered PCR testing. Antibody index values for IgG and cycle threshold values for PCR were evaluated for those with a positive result. An online survey was distributed at the time of testing.

Results

624 of 1677 distributed surveys (37.2%) were completed by 608 unique HCP. The majority were female (76.4%) and provided clinical care (70.9%). The most common occupations were clinician (24.8%) and nurse (23.5%). 37 of 608 (6.1%) HCP had detectable IgG. Exposure to a confirmed case of COVID-19 outside of the hospital was associated with detectable IgG (12.8% vs 4.4%, p = 0.02), but exposure to a patient with COVID-19 was not.

Conclusions

Among HCP in a large healthcare system, 6.1% had detectable SARS-CoV-2 IgG. Seropositivity was associated with exposures outside of the healthcare setting.

Tuberculosis screening among ambulatory people living with HIV: a systematic review and individual participant data meta-analysis

BACKGROUND

The WHO-recommended tuberculosis screening and diagnostic algorithm in ambulatory people living with HIV is a four-symptom screen (known as the WHO-recommended four symptom screen [W4SS]) followed by a WHO-recommended molecular rapid diagnostic test (eg Xpert MTB/RIF [hereafter referred to as Xpert]) if W4SS is positive. To inform updated WHO guidelines, we aimed to assess the diagnostic accuracy of alternative screening tests and strategies for tuberculosis in this population.

METHODS

In this systematic review and individual participant data meta-analysis, we updated a search of PubMed (MEDLINE), Embase, the Cochrane Library, and conference abstracts for publications from Jan 1, 2011, to March 12, 2018, done in a previous systematic review to include the period up to Aug 2, 2019. We screened the reference lists of identified pieces and contacted experts in the field. We included prospective cross-sectional, observational studies and randomised trials among adult and adolescent (age ≥10 years) ambulatory people living with HIV, irrespective of signs and symptoms of tuberculosis. We extracted study-level data using a standardised data extraction form, and we requested individual participant data from study authors. We aimed to compare the W4SS with alternative screening tests and strategies and the WHO-recommended algorithm (ie, W4SS followed by Xpert) with Xpert for all in terms of diagnostic accuracy (sensitivity and specificity), overall and in key subgroups (eg, by antiretroviral therapy [ART] status). The reference standard was culture. This study is registered with PROSPERO, CRD42020155895.

FINDINGS

We identified 25 studies, and obtained data from 22 studies (including 15 666 participants; 4347 [27·7%] of 15 663 participants with data were on ART). W4SS sensitivity was 82% (95% CI 72-89) and specificity was 42% (29-57). C-reactive protein (≥10 mg/L) had similar sensitivity to (77% [61-88]), but higher specificity (74% [61-83]; n=3571) than, W4SS. Cough (lasting ≥2 weeks), haemoglobin (<10 g/dL), body-mass index (<18·5 kg/m2), and lymphadenopathy had high specificities (80-90%) but low sensitivities (29-43%). The WHO-recommended algorithm had a sensitivity of 58% (50-66) and a specificity of 99% (98-100); Xpert for all had a sensitivity of 68% (57-76) and a specificity of 99% (98-99). In the one study that assessed both, the sensitivity of sputum Xpert Ultra was higher than sputum Xpert (73% [62-81] vs 57% [47-67]) and specificities were similar (98% [96-98] vs 99% [98-100]). Among outpatients on ART (4309 [99·1%] of 4347 people on ART), W4SS sensitivity was 53% (35-71) and specificity was 71% (51-85). In this population, a parallel strategy (two tests done at the same time) of W4SS with any chest x-ray abnormality had higher sensitivity (89% [70-97]) and lower specificity (33% [17-54]; n=2670) than W4SS alone; at a tuberculosis prevalence of 5%, this strategy would require 379 more rapid diagnostic tests per 1000 people living with HIV than W4SS but detect 18 more tuberculosis cases. Among outpatients not on ART (11 160 [71·8%] of 15 541 outpatients), W4SS sensitivity was 85% (76-91) and specificity was 37% (25-51). C-reactive protein (≥10 mg/L) alone had a similar sensitivity to (83% [79-86]), but higher specificity (67% [60-73]; n=3187) than, W4SS and a sequential strategy (both test positive) of W4SS then C-reactive protein (≥5 mg/L) had a similar sensitivity to (84% [75-90]), but higher specificity than (64% [57-71]; n=3187), W4SS alone; at 10% tuberculosis prevalence, these strategies would require 272 and 244 fewer rapid diagnostic tests per 1000 people living with HIV than W4SS but miss two and one more tuberculosis cases, respectively.

INTERPRETATION

C-reactive protein reduces the need for further rapid diagnostic tests without compromising sensitivity and has been included in the updated WHO tuberculosis screening guidelines. However, C-reactive protein data were scarce for outpatients on ART, necessitating future research regarding the utility of C-reactive protein in this group. Chest x-ray can be useful in outpatients on ART when combined with W4SS. The WHO-recommended algorithm has suboptimal sensitivity; Xpert for all offers slight sensitivity gains and would have major resource implications.

FUNDING

World Health Organization.

Low BMI increases all-cause mortality rates in patients with drug-resistant TB

BACKGROUND: Loss to follow-up (LTFU) is common among patients with drug-resistant TB (DR-TB) receiving second-line TB treatment; however, little is known about outcomes after LTFU, including mortality.OBJECTIVE: To determine rates of and factors associated with all-cause mortality among patients with DR-TB who were LTFU.METHODS: Retrospective cohort study of adult patients with DR-TB in Georgia who initiated second-line TB treatment during 2011-2014 and were LTFU. Survival analyses were used to estimate all-cause mortality rates and adjusted hazard ratios (aHR).RESULTS: During 2011-2014, 2,437 second-line treatment episodes occurred and 695 patients were LTFU. Among 695 LTFU patients, 143 (21%) died during 2,686 person-years (PY) post-LTFU (all-cause mortality rate 5.1%, 95% CI 4.3-6.0 per 100 PY). In multivariable analysis, low weight (BMI < 18.5 kg/m²) at treatment initiation (aHR 3.2, 95% CI 2.2-4.7), return to treatment after LTFU (aHR 3.1, 95% CI 2.2-4.4), <12 months of treatment (aHR 2.4, 95% CI 1.4-4.1) and a pre-LTFU positive culture (aHR 3.3, 95% CI 2.2-4.9) were associated with all-cause mortality.CONCLUSION: High all-cause mortality occurred among patients with DR-TB after LTFU despite a low HIV prevalence. Providing additional assistance for patients during DR-TB treatment to prevent LTFU and use of new and shorter treatment regimens may reduce mortality among LTFU.

Developing customized stepwise MIRU-VNTR typing for tuberculosis surveillance in Georgia

Introduction

Mycobacterial Interspersed Repetitive Units–Variable Tandem Repeats (MIRU-VNTR) typing has been widely used for molecular epidemiological studies of tuberculosis (TB). However, genotyping tools for Mycobacterium tuberculosis (Mtb) may be limiting in some settings due to high cost and workload. In this study developed a customized stepwise MIRU-VNTR typing that prioritizes high discriminatory loci and validated this method using penitentiary system cohort in the country of Georgia.

Methods

We used a previously generated MIRU-VNTR dataset from recurrent TB cases (32 cases) in Georgia and a new dataset of TB cases from the penitentiary system (102 cases) recruited from 2014 to 2015. A Hunter-Gaston Discriminatory Index (HGDI) was calculated utilizing a 24 standard loci panel, to select high discriminatory power loci, subsequently defined as the customized Georgia-specific set of loci for initial typing. The remaining loci were scored and hierarchically grouped for second and third step typing of the cohort. We then compared the processing time and costs of the customized stepwise method to the standard 24-loci method.

Results

For the customized Georgia-specific set that was used for initial typing, 10 loci were selected with a minimum value of 0.32 to the highest HGDI score locus. Customized 10 loci (step 1) typing of 102 Mtb patient isolates revealed 35.7% clustered cases. This proportion was reduced to 19.5% after hierarchical application of 2nd and 3rd step typing with the corresponding groups of loci. Our customized stepwise MIRU-VNTR genotyping approach reduced the quantity of samples to be typed and therefore overall processing time and costs by 42.6% each.

Conclusion

Our study shows that our customized stepwise MIRU-VNTR typing approach is a valid alternative of standard MIRI-VNTR typing panels for molecular epidemiological investigation in Georgia that saves time, workload and costs. Similar approaches could be developed for other settings.

American Medical Trainee Perspectives on Ethical Conflicts during a Short-Term Global Health Rotation in Ethiopia: A Qualitative Analysis of 30 Cases

There has been a significant increase in the number of students, residents, and fellows from high-income settings participating in short-term global health experiences (STGHEs) during their medical training. This analysis explores a series of ethical conflicts reported by medical residents and fellows from Emory University School of Medicine in the United States who participated in a 1-month global health rotation in Ethiopia. A constant comparative analysis was conducted using 30 consecutive reflective essays to identify emerging categories and themes of ethical conflicts experienced by the trainees. Ethical conflicts were internal; based in the presence of the visiting trainee and their personal interactions; or external, occurring due to witnessed events. Themes within internal conflicts include issues around professional identity and insufficient preparation for the rotation. External experiences were further stratified by the trainee's perception that Ethiopian colleagues agreed that the scenario represented an ethical conflict (congruent) or disagreed with the visiting trainee's perspective (incongruent). Examples of congruent themes included recognizing opportunities for collaboration and witnessing ethical conflicts that are similar to those experienced in the United States. Incongruent themes included utilization of existing resources, issues surrounding informed consent, and differing expectations of clinical outcomes. By acknowledging the frequency and roots of ethical conflicts experienced during STGHEs, sponsors may better prepare visiting trainees and reframe these conflicts as collaborative educational experiences that benefit both the visiting trainee and host providers.

Clinical evaluation of the Diagnostic Analyzer for Selective Hybridization (DASH): a point-of-care PCR test for rapid detection of SARS-CoV-2 infection

BACKGROUND

Rapid and accurate testing for SARS-CoV-2 is an essential tool in the medical and public health response to the COVID-19 pandemic. An ideal test for COVID-19 would combine the sensitivity of laboratory-based PCR combined with the speed and ease of use of point-of-care (POC) or home-based rapid antigen testing.

METHODS

To evaluate the performance of the Diagnostic Analyzer for Selective Hybridization (DASH) SARS-CoV-2 POC PCR (sample insertion to result time of 16 minutes), we conducted a cross-sectional study of adults with and without symptoms of COVID-19 at four clinical sites. We collected two bilateral anterior nasal swabs from each participant and information on COVID-19 symptoms, vaccination, and exposure. One swab was tested with the DASH SARS-CoV-2 POC PCR and the second in a central laboratory using Cepheid Xpert Xpress SARS-CoV-2 PCR. We assessed test concordance and calculated sensitivity, specificity, negative and positive predictive values using Xpert as the "gold standard."

RESULTS

We enrolled 315 and analyzed 313 participants with median age 42 years; 65% were female, 62% symptomatic, 75% had received ≥2 doses of mRNA COVID-19 vaccine, and 16% currently COVID-19 positive. There were concordant results for 307 tests indicating an overall agreement for DASH of 0.98 [95% CI 0.96, 0.99] compared to Xpert. DASH performed at 0.96 [95% CI 0.86, 1.00] sensitivity and 0.98 [95% CI 0.96, 1.00] specificity, with a positive predictive value of 0.85 [95% CI 0.73, 0.96] and negative predictive value of 0.996 [95% CI 0.99, 1.00]. The six discordant tests between DASH and Xpert all had high Ct values (>30) on the respective positive assay. DASH and Xpert Ct values were highly correlated (R=0.89 [95% CI 0.81, 0.94]).

CONCLUSIONS

DASH POC SARS-CoV-2 PCR was accurate, easy to use, and provided fast results in real-life clinical settings with an overall performance similar to an EUA-approved laboratory-based PCR. Its compact design and ease of use are optimal for a variety of healthcare, and potentially community settings, including areas with lack of access to central laboratory-based PCR testing.

SUMMARY

DASH is an accurate, easy to use, and fast point-of-care test with applications for diagnosis and screening of SARS-CoV-2 infection.

Authorship trends in infectious diseases society of America affiliated journal articles conducted in low-income countries, 1998-2018

An increasing amount of infectious diseases research is conducted in low-income countries (LIC) given their high burden of disease; however, the contribution of LIC investigators as measured by authorship metrics, specifically to infectious diseases research, has not been thoroughly studied. We performed a literature search for primary research conducted either within LICs or using samples from LIC participants published between 1998-2017 in the Infectious Disease Society of America-affiliated journals Clinical Infectious Diseases, Journal of Infectious Diseases, and Open Forum Infectious Diseases. Primary outcomes included proportion of LIC-affiliated first and last authors (i.e. lead authors) per year and authorship trends over time. Secondary outcomes included proportion of LIC-affiliated authorship by geographic distribution and disease focus. Among 1308 publications identified, 50% had either a first or last LIC-affiliated author. Among these authors, 48% of LIC-affiliated first authors and 52% of LIC-affiliated last authors also reported a non-LIC institutional affiliation. While the absolute number of articles by LIC-affiliated lead authors increased over the 20-year period, the proportion of articles with LIC-affiliated lead authors decreased. There is a growing literature for infectious disease research conducted in LICs yet authorship trends in a small subset of these publications demonstrate a pronounced and worsening exclusion of LIC-affiliated investigators from publishing as lead authors.

Xpert MTB/RIF Use Is Associated With Earlier Treatment Initiation and Culture Conversion Among Patients With Sputum Smear-Negative Multidrug-Resistant Tuberculosis

Background

Although rapid molecular diagnostic tests for tuberculosis (TB) have decreased detection time of Mycobacterium tuberculosis and drug resistance, whether their use improves clinical care and outcomes is uncertain. To address these knowledge gaps, we evaluated whether use of the Xpert MTB/RIF assay impacts treatment and clinical outcome metrics among patients treated for sputum smear-negative multidrug-resistant (MDR)-TB.

Methods

We conducted a retrospective cohort study of adult patients initiating treatment for sputum smear-negative MDR-TB at the National Center for Tuberculosis and Lung Diseases in Tbilisi, Georgia from 2011 to 2016. The Xpert MTB/RIF was introduced in Georgia in 2010 and implemented into programmatic use in 2014. Exposure was availability of an Xpert result at time of diagnosis. Time to second-line treatment initiation, sputum culture conversion, and end-of-treatment outcomes were determined. Time to event was compared using a Cox proportional hazards model.

Results

Among 151 patients treated for sputum smear-negative MDR-TB (96% culture positive), the Xpert was utilized in the clinical management of 78 (52%) patients and not used in 73 (48%). An adjusted analysis controlling for potential confounders found that patients in the Xpert group had shorter median time to second-line treatment (13 vs 56 days; adjusted hazard ratio [aHR], 10.21; P < .0001) and culture conversion (61 vs 93 days; aHR, 1.93; P < .001). There was no difference in treatment outcomes.

Conclusions

Use of the Xpert in the management of sputum smear-negative MDR-TB decreases time to second-line therapy and sputum culture conversion, providing evidence of its clinical impact and supporting its programmatic utility.

Clinical outcomes among patients with tuberculous meningitis receiving intensified treatment regimens

SETTING: National Center for Tuberculosis and Lung Diseases (NCTLD), Tbilisi, Georgia.OBJECTIVE: To determine clinical outcomes of patients with tuberculous meningitis (TBM) treated with an intensified regimen including a fluoroquinolone (FQ) and an injectable agent.DESIGN: Prospective cohort of patients aged ≥16 years initiating treatment for TBM at the NCTLD from January 2018 to December 2019. Treatment outcomes and neurologic disability at 1, 6 and 12 months after treatment initiation were assessed.RESULTS: Among 77 patients with median follow-up time of 363 days (IQR 269-374), 97% received a FQ, 62% an injectable agent, 44% linezolid and 39% a carbapenem. Fifty-seven patients (74%) successfully completed treatment, 2 (2.6%) had treatment failure, 6 (7.8%) died, and the remainder (12%) were lost to follow up. Among 11 patients treated for multidrug-resistant TBM, the median follow-up time was 467 days and one patient (8%) died. Regarding neurologic outcomes, 14/76 (18%) patients had Modified Rankin Scores of 0 at baseline, improving to 85% (56/66) and 94% (47/50) at 6 and 12 months, respectively.CONCLUSION: Intensified multidrug treatment regimens including a FQ and an injectable agent in all patients and newly implemented drugs in patients with multidrug-resistant TBM resulted in low mortality and favorable neurologic outcomes.

Adjunctive surgery versus medical treatment among patients with cavitary multidrug-resistant tuberculosis

OBJECTIVES

Surgical resection is recommended as adjunctive treatment for multidrug-resistant (MDR) tuberculosis (TB) in certain scenarios; however, data are limited. We sought to evaluate the impact of surgery by comparing TB outcomes among patients with cavitary disease who received medical versus combined medical and surgical treatment.

METHODS

A cohort of all patients with cavitary MDR or extensively drug-resistant (XDR) TB treated in Tbilisi, Georgia, between 2008 and 2012. Patients meeting indications for surgery underwent adjunctive resection in addition to medical treatment. We compared TB outcomes (proportions achieving cure/complete) among patients who received adjunctive surgery to those who received medical treatment alone using an adjusted robust Poisson regression.

RESULTS

Among 408 patients, 299 received medical treatment alone and 109 combined medical and surgical treatment. Patients in the non-surgical group were older and had higher rates of tobacco and alcohol use and bilateral disease compared to the surgical group. Patients in the surgical group had higher rates of XDR disease (28% vs 15%). Favourable outcomes were higher among the surgical versus non-surgical group cohort (76% vs 41%). After adjusting for multiple factors, the association between adjunctive resection and favourable outcome remained (adjusted risk ratio 1.6, 95% confidence interval 1.3-2.0); the relationship was also observed in secondary models that excluded patients with bilateral disease (contraindication for surgery) and patients receiving <6 months of treatment. Major postoperative complications occurred among 8 patients (7%) with no postoperative mortality.

CONCLUSIONS

Adjunctive surgery is safe and may improve the effectiveness of treatment among select patients with cavitary MDR- and XDR-TB.

Impact of repeated nasal sampling on detection and quantification of SARS-CoV-2

The impact of repeated sample collection on COVID-19 test performance is unknown. The FDA and CDC currently recommend the primary collection of diagnostic samples to minimize the perceived risk of false-negative findings. We therefore evaluated the association between repeated sample collection and test performance among 325 symptomatic patients undergoing COVID-19 testing in Atlanta, GA. High concordance was found between consecutively collected mid-turbinate samples with both molecular (n = 74, 100% concordance) and antigen-based (n = 147, 97% concordance, kappa = 0.95, CI = 0.88-1.00) diagnostic assays. Repeated sample collection does not decrease COVID-19 test performance, demonstrating that multiple samples can be collected for assay validation and clinical diagnosis.

Multidisciplinary assessment of the Abbott BinaxNOW SARS-CoV-2 point-of-care antigen test in the context of emerging viral variants and self-administration

While there has been significant progress in the development of rapid COVID-19 diagnostics, as the pandemic unfolds, new challenges have emerged, including whether these technologies can reliably detect the more infectious variants of concern and be viably deployed in non-clinical settings as "self-tests". Multidisciplinary evaluation of the Abbott BinaxNOW COVID-19 Ag Card (BinaxNOW, a widely used rapid antigen test, included limit of detection, variant detection, test performance across different age-groups, and usability with self/caregiver-administration. While BinaxNOW detected the highly infectious variants, B.1.1.7 (Alpha) first identified in the UK, B.1.351 (Beta) first identified in South Africa, P.1 (Gamma) first identified in Brazil, B.1.617.2 (Delta) first identified in India and B.1.2, a non-VOC, test sensitivity decreased with decreasing viral loads. Moreover, BinaxNOW sensitivity trended lower when devices were performed by patients/caregivers themselves compared to trained clinical staff, despite universally high usability assessments following self/caregiver-administration among different age groups. Overall, these data indicate that while BinaxNOW accurately detects the new viral variants, as rapid COVID-19 tests enter the home, their already lower sensitivities compared to RT-PCR may decrease even more due to user error.

Pharmacokinetics of bedaquiline, delamanid and clofazimine in patients with multidrug-resistant tuberculosis

BACKGROUND

Pharmacokinetic data are needed for newly implemented anti-tuberculosis drugs to help optimize their use.

OBJECTIVES

To help fill existing knowledge gaps, we evaluated the pharmacokinetic parameters of novel and repurposed anti-tuberculosis drugs among patients with drug-resistant pulmonary tuberculosis.

METHODS

A prospective cohort study among patients ≥16 years with confirmed pulmonary drug-resistant TB was conducted in Tbilisi, Georgia. Patients receiving bedaquiline, delamanid and/or clofazimine were included. Blood samples were collected 4-6 weeks after drug initiation, and serum concentrations were measured using validated liquid chromatography tandem mass spectrometry assays. A non-compartmental analysis was performed, and the association of exposure parameters with covariates was explored.

RESULTS

Among 99 patients, the average age and weight were 40 years and 65 kg, respectively. The median Cmin was 0.68 mg/L for bedaquiline, 0.17 mg/L for delamanid, and 0.52 mg/L for clofazimine. The median AUC0-24 was 30.6 mg·h/L for bedaquiline, 16.1 mg·h/L for clofazimine, and the AUC0-12 was 2.9 mg·h/L for delamanid. Among the significant covariates associated with drug exposure parameters were weight and sex for bedaquiline, alcohol use for delamanid, and weight for clofazimine.

CONCLUSIONS

We found a strong association of weight with bedaquiline and clofazimine exposure parameters, suggesting the need for weight-based dosing for those agents.

Long-Term Mortality and Active Tuberculosis Disease Among Patients Who Were Lost to Follow-Up During Second-Line Tuberculosis Treatment in 2011-2014: Population-Based Study in the Country of Georgia

BACKGROUND

High rates of loss to follow-up (LFU) exist among patients with multidrug and extensively drug-resistant tuberculosis (M/XDR TB). We aimed to identify long-term clinical outcomes of patients who were LFU during second-line TB treatment.

METHODS

We conducted a follow-up study among adults who received second-line TB treatment in the country of Georgia during 2011-2014 with a final outcome of LFU. We attempted to interview all LFU patients, administered a structured questionnaire, and obtained sputum samples. Active TB at follow-up was defined by positive sputum Xpert-TB/RIF or culture.

RESULTS

Follow-up information was obtained for 461 patients. Among these patients, 107 (23%) died and 177 (38%) were contacted. Of those contacted, 123 (69%) consented to participate and 92 provided sputum samples. Thirteen (14%) had active TB with an estimated infectious time period for transmitting drug-resistant TB in the community of 480 days (interquartile range = 803). In multivariable analysis, positive culture at the time of LFU was associated with active TB at the time of our study (adjusted risk ratio = 13.3; 95% confidence interval, 4.2-42.2).

CONCLUSIONS

Approximately one quarter of patients on second-line TB treatment who were LFU died. Among those LFU evaluated in our study, 1 in 7 remained in the community with positive sputum cultures. To reduce death and transmission of disease, additional strategies are needed to encourage patients to complete treatment.

Genomic analyses of Mycobacterium tuberculosis from human lung resections reveal a high frequency of polyclonal infections

Polyclonal infections occur when at least two unrelated strains of the same pathogen are detected in an individual. This has been linked to worse clinical outcomes in tuberculosis, as undetected strains with different antibiotic resistance profiles can lead to treatment failure. Here, we examine the amount of polyclonal infections in sputum and surgical resections from patients with tuberculosis in the country of Georgia. For this purpose, we sequence and analyse the genomes of Mycobacterium tuberculosis isolated from the samples, acquired through an observational clinical study (NCT02715271). Access to the lung enhanced the detection of multiple strains (40% of surgery cases) as opposed to just using a sputum sample (0-5% in the general population). We show that polyclonal infections often involve genetically distant strains and can be associated with reversion of the patient's drug susceptibility profile over time. In addition, we find different patterns of genetic diversity within lesions and across patients, including mutational signatures known to be associated with oxidative damage; this suggests that reactive oxygen species may be acting as a selective pressure in the granuloma environment. Our results support the idea that the magnitude of polyclonal infections in high-burden tuberculosis settings is underestimated when only testing sputum samples.

Loss of Smell and Taste Among Healthcare Personnel Screened for Coronavirus 2019

Among 283 symptomatic healthcare personnel (HCP) tested for SARS-CoV-2, 51 (18%) were positive. Among those 51 HCP, self reported loss of smell and taste were present in 51% and 52.9%, respectively, with either present in 60.8%. These symptoms had high specificity (93% each, 96% for either) for a positive SARS-CoV-2 test.

Evaluation of a Cryptococcal Antigen Lateral Flow Assay and Cryptococcal Antigen Positivity at a Large Public Hospital in Atlanta, Georgia

BACKGROUND

Cryptococcus neoformans is a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected persons worldwide, and there are scarce recent data on cryptococcal antigen (CrAg) positivity in the United States We sought to determine the frequency of cryptococcal disease and compare the performance of a CrAg lateral flow assay (LFA) versus latex agglutination (LA) test.

METHODS

All patients from Grady Health System in Atlanta who had a serum or cerebrospinal fluid (CSF) sample sent for CrAg testing as part of clinical care from November 2017 to July 2018 were included. Percentage positivity and test agreement were calculated.

RESULTS

Among 467 patients, 557 diagnostic tests were performed; 413 on serum and 144 on CSF. The mean age was 44 years, and most were male (69%) and had HIV (79%). Twenty-four (6.4%, 95% confidence interval [CI] = 4.1-9.4) patients were serum CrAg positive, and 8 (5.8%, 95% CI = 2.6-11.2) individuals tested positive for CSF CrAg. Although overall agreement between the LA and LFA was substantial to high for CSF (κ = 0.71, 95% CI = 0.51-0.91) and serum (κ = 0.93, 95% CI = 0.86-1.00), respectively, there were important discrepancies. Five patients had false-positive CSF LA tests that affected clinical care, and 4 patients had discordant serum tests.

CONCLUSIONS

We found a moderately high proportion of cryptococcal disease and important discrepancies between the LA test and LFA. Clinical implications of these findings include accurate detection of serum CrAg and averting unnecessary treatment of meningitis with costly medications associated with high rates of adverse events.

Treatment Outcomes Among Pediatric Patients With Highly Drug-Resistant Tuberculosis: The Role of New and Repurposed Second-Line Tuberculosis Drugs

BACKGROUND

Among pediatric patients with multidrug-resistant tuberculosis (MDR-TB), limited data exist regarding treatment outcomes in the context of the new and repurposed second-line TB drugs (SLDs). We aimed to describe the treatment outcomes among pediatric MDR-TB patients receiving new and repurposed SLDs including the proportion who achieved favorable outcomes.

METHODS

We conducted a retrospective cohort study among pediatric patients (age ≤18 years) treated for MDR-TB in the country of Georgia from 2009 to 2016. A "new and repurposed" SLD regimen was defined as a regimen that included linezolid, bedaquiline, and/or delamanid. Favorable treatment outcome was defined by treatment completion or documented microbial "cure" status at the end of treatment. We assessed the association between the use of the new and repurposed SLDs with MDR-TB treatment outcomes using bivariate analyses and log-binomial regression.

RESULTS

There were 124 pediatric MDR-TB patients (median age: 13.7; interquartile range: 4.6-16.0) initiating treatment; 119 (96.0%) had a treatment outcome recorded and were included in our analyses. Eighteen (15.1%) patients received new and repurposed SLDs from 2015 or later. After adjusting for potential confounders, the proportion achieving favorable MDR-TB treatment outcomes was higher among patients treated with SLD regimens that included new and/or repurposed drugs when compared with those treated without (adjusted risk ratio: 1.17; 95% confidence interval: 0.51-2.72).

CONCLUSIONS

We observed a high proportion of favorable treatment outcomes among pediatric patients with MDR-TB receiving the new and repurposed SLDs. Further studies to evaluate the efficacy and children's tolerability of the new and repurposed SLDs are still warranted.

Clinical Outcomes Among Patients With Drug-resistant Tuberculosis Receiving Bedaquiline- or Delamanid-Containing Regimens

BACKGROUND

Bedaquiline and delamanid are newly available drugs for treating multidrug-resistant tuberculosis (MDR-TB); however, there are limited data guiding their use and no comparison studies.

METHODS

We conducted a prospective, observational study among patients with MDR-TB in Georgia who were receiving a bedaquiline- or delamanid-based treatment regimen. Monthly sputum cultures, minimal inhibitory concentration testing, and adverse event monitoring were performed. Primary outcomes were culture conversion rates and clinical outcomes. Targeted maximum likelihood estimation and super learning were utilized to produce a covariate-adjusted proportion of outcomes for each regimen.

RESULTS

Among 156 patients with MDR-TB, 100 were enrolled and 95 were receiving a bedaquiline-based (n = 64) or delamanid-based (n = 31) regimen. Most were male (82%) and the median age was 38 years. Rates of previous treatment (56%) and cavitary disease (61%) were high. The most common companion drugs included linezolid, clofazimine, cycloserine, and a fluoroquinolone. The median numbers of effective drugs received among patients on bedaquiline-based (4; interquartile range [IQR], 4-4) and delamanid-based (4; IQR, 3.5-5) regimens were similar. Rates of acquired drug resistance were significantly higher among patients receiving delamanid versus bedaquiline (36% vs 10%, respectively; P < .01). Adjusted rates of sputum culture conversion at 2 months (67% vs 47%, respectively; P = .10) and 6 months (95% vs 74%, respectively; P < .01), as well as more favorable clinical outcomes (96% vs 72%, respectively; P < .01), were higher among patients receiving bedaquiline versus delamanid.

CONCLUSIONS

Among patients with MDR-TB, bedaquiline-based regimens were associated with higher rates of sputum culture conversion, more favorable outcomes, and a lower rate of acquired drug resistance versus delamanid-based regimens.

Barriers to diabetic foot care in a disadvantaged population: A qualitative assessment

OBJECTIVE

We explored barriers to proper foot care in this population using a qualitative approach with focus group discussions (FGD).

METHODS

Participants were recruited from clinics at a safety-net hospital in Atlanta, Georgia and stratified into two groups: diabetic foot ulcer (DFU) and minor amputation (below ankle). The FGDs addressed patient experience in receiving care with a goal of understanding: foot care knowledge, barriers to care, and preferred educational methods. Surveys were performed to supplement FGDs.

RESULTS

Forty participants (90% Black) were enrolled. Dominant themes emerging from FGDs were: 1-Patients reported adequate understanding of recommended foot care practices; 2-Personal barriers to self-care included lack of motivation, high cost, poor insurance coverage of supplies, and difficulty limiting activity for proper offloading; 3-Hospital system barriers included difficulty making timely appointments and reaching a provider to arrange care; 4-Access to footcare-related information and services improved with greater disease severity. Participants stressed that improved access often came too late to alter their course. They expressed interest in developing peer support groups to facilitate learning and sharing information relating to DFU.

CONCLUSION

We found that patients with DFU or minor amputations have adequate footcare-related knowledge, but personal and systemic barriers limited appropriate foot care.

Percutaneous Bone Biopsy for Diabetic Foot Osteomyelitis: A Systematic Review and Meta-Analysis

Background

Diabetes is the leading cause of lower extremity nontraumatic amputation globally, and diabetic foot osteomyelitis (DFO) is usually the terminal event before limb loss. Although guidelines recommend percutaneous bone biopsy (PBB) for microbiological diagnosis of DFO in several common scenarios, it is unclear how frequently PBBs yield positive cultures and whether they cause harm or improve outcomes.

Methods

We searched the PubMed, EMBASE, and Cochrane Trials databases for articles in any language published up to December 31, 2019, reporting the frequency of culture-positive PBBs. We calculated the pooled proportion of culture-positive PBBs using a random-effects meta-analysis model and reported on PBB-related adverse events, DFO outcomes, and antibiotic adjustment based on PBB culture results where available.

Results

Among 861 articles, 11 studies met inclusion criteria and included 780 patients with 837 PBBs. Mean age ranged between 56.6 and 71.0 years old. The proportion of males ranged from 62% to 86%. All studies were longitudinal observational cohorts, and 10 were from Europe. The range of culture-positive PBBs was 56%-99%, and the pooled proportion of PBBs with a positive culture was 84% (95% confidence interval, 73%-91%). There was heterogeneity between studies and no consistency in definitions used to define adverse events. Impact of PBB on DFO outcomes or antibiotic management were seldom reported.

Conclusions

This meta-analysis suggests PBBs have a high yield of culture-positive results. However, this is an understudied topic, especially in low- and middle-income countries, and the current literature provides very limited data regarding procedure safety and impact on clinical outcomes or antibiotic management.

Tryptophan catabolism reflects disease activity in human tuberculosis

There is limited understanding of the role of host metabolism in the pathophysiology of human tuberculosis (TB). Using high-resolution metabolomics with an unbiased approach to metabolic pathway analysis, we discovered that the tryptophan pathway is highly regulated throughout the spectrum of TB infection and disease. This regulation is characterized by increased catabolism of tryptophan to kynurenine, which was evident not only in active TB disease but also in latent TB infection (LTBI). Further, we found that tryptophan catabolism is reversed with effective treatment of both active TB disease and LTBI in a manner commensurate with bacterial clearance. Persons with active TB and LTBI also exhibited increased expression of indoleamine 2,3-dioxygenase-1 (IDO-1), suggesting IDO-1 mediates observed increases in tryptophan catabolism. Together, these data indicate IDO-1-mediated tryptophan catabolism is highly preserved in the human response to Mycobacterium tuberculosis and could be a target for biomarker development as well as host-directed therapies.

Internal thoracic lymphadenopathy and pulmonary tuberculosis

OBJECTIVE

Internal thoracic lymphadenopathy (ITL) has been associated with malignancies and non-tuberculous empyema. However, the association between ITL and active pulmonary tuberculosis (PTB) and the correlation between ITL and other imaging characteristics of active PTB has not been examined.

MATERIALS AND METHODS

A retrospective cohort study comprising 137 adults with active PTB who had a concomitant chest CT over a seven-year period was conducted. Two thoracic radiologists evaluated for ITL as well as nine other imaging characteristics of active tuberculosis, including total lung involvement (as measured by a total severity score), number of nodules, presence of tree-in-bud nodularity, highest extent of tree-in-bud nodularity in a lobe, miliary pattern, cavitary lesions, pleural effusion, lymphadenopathy (excluding internal thoracic lymph nodes), and empyema. The Wilcoxon rank-sum test and chi-squared tests were used to assess the correlation between ITL and additional imaging findings.

RESULTS

Internal thoracic lymphadenopathy was present in 50 of 137 cases (36.5%); most commonly bilateral (19.0%) or isolated on the right side (13.7%), and less commonly isolated on the left side (3.7%). Pleural effusion, lymphadenopathy (apart from internal thoracic compartment), and empyema all showed statistically significant correlations with ITL (p-values of <0.0001).

CONCLUSIONS

While the presence of ITL - particularly when accompanied by other imaging findings such as pleural effusion - may prompt a radiologist to first consider malignancy, active PTB should be an additional consideration in the appropriate clinical context.

Rates and risk factors for nephrotoxicity and ototoxicity among tuberculosis patients in Tbilisi, Georgia

SETTING: Treatment of multidrug-resistant tuberculosis (MDR-TB) is lengthy and utilizes second-line anti-TB drugs associated with frequent adverse drug reactions (ADRs).OBJECTIVE: To evaluate the prevalence of and risk factors for ADRs among patients with MDR- and extensively drug-resistant TB (XDR-TB).DESIGN: A retrospective chart review of patients initiating treatment for M/XDR-TB in 2010-2012 in Tbilisi, Georgia.RESULTS: Eighty (54%) and 38 (26%) of 147 patients developed nephrotoxicity per RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) classification and ototoxicity, respectively. Twenty-five (17%) patients required permanent interruption of injectables due to an ADR. Median hospital stay, total treatment duration and number of regimen changes were higher among those with nephrotoxicity and/or ototoxicity, compared to those without (P < 0.01). Multinomial logistic regression analysis identified increasing age (per year) as a risk factor for nephrotoxicity (aOR 1.08, 95%CI 1.03-1.12) and for both, nephro- and ototoxicity (aOR 1.11, 95%CI 1.05-1.17). Low baseline creatinine clearance (CrCl) was a significant risk factor for developing nephrotoxicity (aOR 1.05, 95%CI 1.02-1.07).CONCLUSION: Second-line injectable drug-related ADRs are common among M/XDR-TB patients. Patients with increasing age and low baseline CrCl should be monitored closely for injectable-related ADRs. Notably, our findings support WHO's latest recommendations on introduction of injectable free anti-TB treatment regimens.