TB Modeling and Translational Epi Group

Group Publications

Page Navigation:

12345678910

- January 2020 -

Levofloxacin versus placebo for the treatment of latent tuberculosis among contacts of patients with multidrug-resistant tuberculosis (the VQUIN MDR trial): a protocol for a randomised controlled trial. (2020). Fox GJ., Nguyen CB., Nguyen TA., Tran PT., Marais BJ., Graham SM., Nguyen BH., Velen K., Dowdy DW., Mason P., Britton WJ., Behr MA., Benedetti A., Menzies D., Nguyen VN., Marks GB, BMJ open, 10, e033945

View Abstract Text

INTRODUCTION: Treatment of latent tuberculosis infection (LTBI) plays a substantial role in the prevention of drug-susceptible tuberculosis (TB). However, clinical trials to evaluate the efficacy of preventive therapy for presumed multidrug-resistant (MDR) LTBI are lacking. This trial aims to evaluate the efficacy of the antibiotic levofloxacin in preventing the development of active TB among latently infected contacts of index patients with MDR-TB. METHODS AND ANALYSIS: A double-blind placebo-controlled parallel group randomised controlled trial will be conducted in 10 provinces of Vietnam. Household contacts living with patients with bacteriologically confirmed rifampicin-resistant or MDR-TB will be eligible for recruitment if they have a positive tuberculin skin test or are known to be immunosuppressed, and do not have active TB. Participants will be randomised to receive either levofloxacin or placebo tablets once per day for 6 months. Screening for incident TB will be performed at 6 months intervals. The primary study outcome is the incidence of bacteriologically confirmed TB within 30 months after randomisation. Analysis will be by intention to treat, using Poisson regression. ETHICS: Ethical approval from the University of Sydney Human Research Ethics Committee was obtained on 29 April 2015 (2014/929), and from the Vietnam Ministry of Health Institutional Review Board on 30 September 2015 (4040/QD-BYT). DISSEMINATION: Findings of the study will be published in peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: ACTRN12616000215426.

- December 2019 -

Clinical Impact of Rapid Drug Susceptibility Testing to Accompany Fluoroquinolone-Containing Universal Tuberculosis Regimens: A Markov Model. (2019). Kendall EA., Malhotra S., Cook-Scalise S., Dowdy DW., Denkinger CM, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 71, 2889-2896

View Abstract Text

BACKGROUND: To appropriately treat tuberculosis (TB) with regimens that combine novel and older drugs, evidence-based, context-specific strategies for drug-susceptibility testing (DST) will be required. METHODS: We created a Markov state-transition model of 100 000 adults with TB receiving a novel, fluoroquinolone (FQ)-containing regimen. We estimated clinical outcomes and resource utilization with no FQ-DST, universal FQ-DST, or FQ-DST only for patients with rifampin-resistant TB ("targeted FQ-DST"). We considered scenarios of stronger (South Africa) and weaker (Southeast Asia) correlation of fluoroquinolone resistance with rifampin resistance, with sensitivity analysis for other setting and regimen characteristics. RESULTS: Relative to no FQ-DST, targeted FQ-DST increased cure of FQ-resistant TB by 7.5% (interquartile range [IQR], 6.7%-9.2%) in South Africa and 1.7% (IQR, 0.7%-2.5%) in Southeast Asia. However, rare FQ resistance among the more prevalent rifampin-susceptible TB accounted for 50% of FQ-resistant TB in South Africa and 83% in Southeast Asia. As a result, universal FQ-DST further increased cure of FQ-resistant TB by 3.4% (IQR, 2.3%-5.4%) in South Africa and 5.8% (IQR, 5.1%-6.3%) in Southeast Asia. With targeted FQ-DST, 1 additional patient was cured per 50 (IQR, 42-70) tests in South Africa and 44 (IQR, 37-51) in Southeast Asia. When expanding from targeted to universal FQ-DST, 1 additional cure required 3500 (IQR, 2300-5500) tests in South Africa and 410 (IQR, 370-450) in Southeast Asia. CONCLUSIONS: FQ-DST improved patient outcomes and was particularly important for high-risk patient groups and less robust regimens. A universal strategy was favored in generalized epidemics of fluoroquinolone resistance.

Correction: Assessment of lung function in successfully treated tuberculosis reveals high burden of ventilatory defects and COPD. (2019). Gupte AN., Paradkar M., Selvaraju S., Thiruvengadam K., Shivakumar SVBY., Sekar K., Marinaik S., Momin A., Gaikwad A., Natrajan P., Prithivi M., Shivaramakrishnan G., Pradhan N., Kohli R., Raskar S., Jain D., Velu R., Karthavarayan B., Lokhande R., Suryavanshi N., Gupte N., Murali L., Salvi S., Checkley W., Golub J., Bollinger R., Mave V., Padmapriyadarasini C., Gupta A, PloS one, 14, e0226389

View Abstract Text

[This corrects the article DOI: 10.1371/journal.pone.0217289.].

Overcoming limitations of tuberculosis information systems: researcher and clinician perspectives. (2019). van der Heijden YF., Hughes J., Dowdy DW., Streicher E., Chihota V., Jacobson KR., Warren R., Theron G, Public health action, 9, 120-127

View Abstract Text

SETTING: Tuberculosis (TB) diagnosis and treatment requires patients to have multiple encounters with health care systems and the different stakeholders who play a role in curing them to coordinate their efforts. To optimize this process, high-quality, readily available data are required. Data systems to facilitate these linkages are a neglected priority which, if weak, fundamentally undermine TB control interventions. OBJECTIVE: To describe lessons learnt from the use of programmatic data for TB patient care and research. DESIGN: We did a survey of researcher and clinical provider experiences with information systems and developed a tiered approach to addressing frequently reported barriers to high-quality care. RESULTS: Unreliable linkages, incomplete data, lack of a reliable unique patient identifier, and lack of data management expertise were the most important data-related barriers to high-quality patient care and research. We propose the creation of health service delivery environments that facilitate, prioritize, and evaluate high-quality data entry during patient or specimen registration. CONCLUSION: An integrated approach, focused on high-quality data, and centered on unique patient identification will form the foundation for linkages across health systems that reduce patient management errors, bolster surveillance, and enhance the quality of research based on programmatic data.

Projecting the impact of variable MDR-TB transmission efficiency on long-term epidemic trends in South Africa and Vietnam. (2019). Salvatore PP., Kendall EA., Seabrook D., Brown J., Durham GH., Dowdy DW, Scientific reports, 9, 18099

View Abstract Text

Whether multidrug-resistant tuberculosis (MDR-TB) is less transmissible than drug-susceptible (DS-)TB on a population level is uncertain. Even in the absence of a genetic fitness cost, the transmission potential of individuals with MDR-TB may vary by infectiousness, frequency of contact, or duration of disease. We used a compartmental model to project the progression of MDR-TB epidemics in South Africa and Vietnam under alternative assumptions about the relative transmission efficiency of MDR-TB. Specifically, we considered three scenarios: consistently lower transmission efficiency for MDR-TB than for DS-TB; equal transmission efficiency; and an initial deficit in the transmission efficiency of MDR-TB that closes over time. We calibrated these scenarios with data from drug resistance surveys and projected epidemic trends to 2040. The incidence of MDR-TB was projected to expand in most scenarios, but the degree of expansion depended greatly on the future transmission efficiency of MDR-TB. For example, by 2040, we projected absolute MDR-TB incidence to account for 5% (IQR: 4-9%) of incident TB in South Africa and 14% (IQR: 9-26%) in Vietnam assuming consistently lower MDR-TB transmission efficiency, versus 15% (IQR: 8-27%)and 41% (IQR: 23-62%), respectively, assuming shrinking transmission efficiency deficits. Given future uncertainty, specific responses to halt MDR-TB transmission should be prioritized.

- November 2019 -

Lipid mediators of inflammation and Resolution in individuals with tuberculosis and tuberculosis-Diabetes. (2019). Shivakoti R., Dalli J., Kadam D., Gaikwad S., Barthwal M., Colas RA., Mazzacuva F., Lokhande R., Dharmshale S., Bharadwaj R., Kagal A., Pradhan N., Deshmukh S., Atre S., Sahasrabudhe T., Kakrani A., Kulkarni V., Raskar S., Suryavanshi N., Chon S., Gupte A., Gupta A., Gupte N., Arriaga MB., Fukutani KF., Andrade BB., Golub JE., Mave V, Prostaglandins & other lipid mediators, 147, 106398

View Abstract Text

Individuals with concurrent tuberculosis (TB) and Type 2 diabetes (DM) have a higher risk of adverse outcomes. To better understand potential immunological differences, we utilized a comprehensive panel to characterize pro-inflammatory and pro-resolving (i.e., mediators involved in the resolution of inflammation) lipid mediators in individuals with TB and TB-DM. A nested cross-sectional study of 40 individuals (20 newly diagnosed DM and 20 without DM) was conducted within a cohort of individuals with active drug-susceptible treatment-naïve pulmonary TB. Lipid mediators were quantified in serum samples through lipid mediator profiling. We conducted correlation-based analysis of these mediators. Overall, the arachidonic acid-derived leukotriene and prostaglandin families were the most abundant pro-inflammatory lipid mediators, while lipoxins and maresins families were the most abundant pro-resolving lipid mediators in individuals with TB and TB-DM. Individuals with TB-DM had increased correlations and connectivity with both pro-inflammatory and pro-resolving lipid mediators compared to those with TB alone. We identified the most abundant lipid mediator metabolomes in circulation among individuals with TB and TB-DM; in addition, our data shows a substantial number of significant correlations between both pro-inflammatory and pro-resolving lipid mediators in individuals with TB-DM, delineating a molecular balance that potentially defines this comorbidity.

Cost-effectiveness of QuantiFERON-TB Gold In-Tube versus tuberculin skin test for diagnosis and treatment of Latent Tuberculosis Infection in primary health care workers in Brazil. (2019). Loureiro RB., Maciel ELN., Caetano R., Peres RL., Fregona G., Golub JE., Braga JU, PloS one, 14, e0225197

View Abstract Text

OBJECTIVES: The goal of this study was to perform a cost-effectiveness analysis from the public health system perspective, comparing five strategies for Latent Tuberculosis Infection (LTBI) diagnosis in primary health care workers in Brazil. DESIGN: Analytical model for decision making, characterized by cost-effectiveness analysis. SETTING: Primary Care Level, considering primary health care workers in Brazil. PARTICIPANTS: An analytical model for decision making, characterized by a tree of probabilities of events, was developed considering a hypothetical cohort of 10,000 primary health care workers, using the software TreeAge Pro™ 2013 to simulate the clinical and economic impacts of new diagnostic technology (QuantiFERON®-TB Gold in-Tube) versus the traditional tuberculin skin test. METHODS: This model simulated five diagnostic strategies for LTBI in primary health care workers (HCW) in Brazil: tuberculin skin testing using ≥5 mm cut-off, tuberculin skin testing ≥10 mm cut-off, QuantiFERON®-TB Gold in-Tube, tuberculin skin testing using ≥5 mm cut-off confirmed by QuantiFERON®-TB Gold In-Tube if TST positive, tuberculin skin testing using ≥10 mm cut-off confirmed by QuantiFERON®-TB Gold In-Tube if TST positive. PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome measures are the number of individuals correctly classified by the test and the number of Tuberculosis cases avoided. RESULTS: The most cost-effective strategy was the tuberculin skin test considering ≥10mm cut-off. The isolated use of the QuantiFERON®-TB Gold In-Tube revealed the strategy of lower efficiency with incremental cost-effectiveness ratio (ICER) of US$ 146.05 for each HCW correctly classified by the test. CONCLUSIONS: The tuberculin skin test using ≥10 mm cut-off was the most cost-effective strategy in the diagnosis of Latent Tuberculosis Infection in primary health care works in Brazil.

Quality of care for patients evaluated for tuberculosis in the context of Xpert MTB/RIF scale-up. (2019). Farr K., Nalugwa T., Ojok C., Nantale M., Nabwire S., Oyuku D., Shete PB., Han AH., Fielding K., Joloba M., Mugabe F., Dowdy DW., Moore D., Davis JL., Katamba A., Cattamanchi A, Journal of clinical tuberculosis and other mycobacterial diseases, 15, 100099

View Abstract Text

RATIONALE: Many high-burden countries are scaling-up Xpert MTB/RIF using a hub-and-spoke model. We evaluated the quality of care for patients undergoing TB evaluation at microscopy centers (spokes) linked to Xpert testing sites (hubs) in Uganda. OBJECTIVES: To characterize the extent to which patients were receiving care in accordance with international and national guidelines. METHODS: We conducted a prospective cohort study of all adults with presumptive pulmonary TB at 24 health centers linked to Xpert testing sites. Health center staff photographed TB registers, and uploaded photos to a secure server bi-weekly. We assessed the proportion of patients (1) initiating testing; (2) completing testing; and (3) treated for confirmed TB within 14 days. MEASUREMENTS AND MAIN RESULTS: Between January to December 2017, 6744 patients underwent evaluation for pulmonary TB. Only 1316 patients had sputum referred for Xpert testing, including 1075/3229 (33.3%) people living with HIV and 241/3515 (6.9%) without HIV. Of 119 patients confirmed to have TB by Xpert testing, 44 (36%) did not initiate treatment. There were significant losses along the entire diagnostic cascade of care, with only 5330/6744 (79.0%) patients having samples referred for sputum-based testing, 2978/5330 (55.9%) patients completing recommended testing if referred, and 313/418 (74.9%) patients initiating treatment within 14 days if confirmed to have TB. CONCLUSIONS: Although coverage of Xpert testing services across Uganda is high, the quality of care delivered to patients undergoing TB evaluation remains poor. Further research is needed to identify health system interventions to facilitate uptake of Xpert testing and high-quality care.

Correction: Smoking, alcohol use disorder and tuberculosis treatment outcomes: A dual co-morbidity burden that cannot be ignored. (2019). Thomas BE., Thiruvengadam K., S R., Kadam D., Ovung S., Sivakumar S., Yogendra Shivakumar SVB., Paradkar M., Gupte N., Suryavanshi N., Dolla CK., Gupte AN., Kohli R., Pradhan N., Sivaramakrishnan GN., Gaikwad S., Kagal A., Dhanasekaran K., Deluca A., Golub JE., Mave V., Chandrasekaran P., Gupta A, PloS one, 14, e0224914

View Abstract Text

[This corrects the article DOI: 10.1371/journal.pone.0220507.].

- October 2019 -

Incidence of tuberculosis in HIV-infected adults on first- and second-line antiretroviral therapy in India. (2019). Gupte AN., Kadam D., Sangle S., Rewari BB., Salvi S., Chavan A., Nimkar S., Golub J., Gupte N., Gupta A., Marbaniang I., Mave V, BMC infectious diseases, 19, 914

View Abstract Text

BACKGROUND: Programmatic data on the baseline risk of tuberculosis in people living with HIV (PLHIV) are needed to evaluate long-term effectiveness of the ongoing isoniazid preventive therapy (IPT) roll-out in India. METHODS: We estimated the incidence rate and risk factors of tuberculosis disease in adult PLHIV initiating first- and second-line anti-retroviral therapy (ART) prior to widespread IPT in a public ART center in Pune, India. RESULTS: 4067 participants contributing 5205.7 person-years of follow-up on first-line ART and 871 participants contributing 1031.7 person-years of follow-up on second-line ART were included in the analysis. The incidence rate of tuberculosis was 4.39 cases (95%CI 3.86-5.00) per 100 person-years on first-line ART and 1.64 cases (95%CI 1.01-2.63) per 100 person-years on second-line ART (p < 0.001). After adjusting for competing risks, male sex (aSHR = 1.33, 95%CI 1.02-1.74, p = 0.03), urban residence (aSHR = 1.53, 95%CI 1.13-2.07, p = 0.006) and CD4+ counts < 350 cells/mm(3) (aSHR = 3.06 vs CD4 > 350 cells/mm(3), 95%CI 1.58-5.94, p < 0.001) at ART initiation were associated with higher risk of tuberculosis independent of ART regimen. CONCLUSION: Risk of tuberculosis was lower in PLHIV receiving second-line ART compared to first-line ART. Prioritizing IPT in PLHIV with low CD4+ counts, urban residence and in males may further mitigate the risk of tuberculosis during ART.

CD4+ cell count stratification to guide tuberculosis preventive therapy for people living with HIV. (2019). Chaisson LH., Saraceni V., Cohn S., Seabrook D., Cavalcante SC., Chaisson RE., Golub JE., Durovni B, AIDS (London, England), 34, 139-147

View Abstract Text

OBJECTIVES: In 2018, Brazilian guidelines changed to recommend tuberculosis (TB) preventive therapy for all people with HIV and a CD4 cell count 350 cells/μl or less, but only for those with a positive tuberculin skin test (TST) if CD4 cell count is than 350 cells/μl. We determined the potential effectiveness of CD4-based guidelines for TB testing and preventive therapy. DESIGN: Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT). METHODS: We analyzed data from 4114 newly registered patients with HIV in 29 clinics followed until TB diagnosis, death, or administrative censoring. We compared incidence rates of TB and TB/death between CD4, TST, IPT, and antiretroviral therapy categories. RESULTS: Initial CD4 cell count was 350 cells/μl or less in 2138 (52%) and more than 350 cells/μl in 1976 (48%) patients. TST was performed for 2922 (71%), of whom 657 (16%) were TST-positive [278 (13%) CD4 ≤ 350 vs. 379 (19%) CD4 > 350]. A total of 619 (15%) received IPT and 2806 (68%) received antiretroviral therapy. For patients with CD4 cell count 350 cells/μl or less who did not receive IPT, the incidence rate of TB was 1.79/100 person-years (pys) and TB/death was 3.89/100 pys. For patients with CD4 cell count more than 350 who did not receive IPT, the incidence rates of TB and TB/death were 0.57/100 and 1.49/100 pys for TST-negatives, and 1.05/100 and 1.64/100 pys for TST-unknowns. CONCLUSION: TB incidence was high among all patients who did not receive IPT, including those with CD4 cell count more than 350 cells/μl and negative or unknown TST results. TB preventive therapy should be provided to all people living with HIV in medium burden settings, regardless of CD4 cell count and TST status.

Implementation of Xpert(®) MTB/RIF: real challenges, real promise. (2019). Dowdy DW, The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 23, 1123

Delays and barriers to early treatment initiation for childhood tuberculosis in India. (2019). Valvi C., Chandanwale A., Khadse S., Kulkarni R., Kadam D., Kinikar A., Joshi S., Lokhande R., Pardeshi G., Garg P., Gupte N., Jain D., Suryavanshi N., Golub JE., Shankar A., Gupta A., Dhumal G., Deluca A., Bollinger RC, The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 23, 1090-1099

View Abstract Text

BACKGROUND: India accounts for 27% of global childhood tuberculosis (TB) burden. Understanding barriers to early diagnosis and treatment in children may improve care and outcomes.METHODS: A cross-sectional study was performed among 89 children initiated on anti-TB treatment from a public hospital in Pune during 2016, using a structured questionnaire and hospital records. Health care providers (HCPs) were defined as medical personnel consulted about the child's TB symptoms. Time-to-treatment initiation (TTI) was defined as the number of days between onset of TB symptoms and anti-TB treatment initiation. Based on Revised National TB Control Programme recommendations, delayed TTI was defined as >28 days.RESULTS: Sixty-seven (75%) of 89 enrolled children had significant TTI delays (median 51 days, interquartile range [IQR] 27-86). Sixty-six (74%) children visited 1-8 HCPs in the private sector before approaching the public sector. The median HCP delay was 28 days (IQR 10-75). Bacille Calmette-Guérin vaccination (aOR 10.96, P = 0.04) and loss of appetite (aOR 4.44, P = 0.04) were associated with delayed TTI.CONCLUSION: The majority of the children had TTI delays due to delays by HCPs in the private sector. Strengthening HCP competency in TB symptom screening and encouraging early referrals are crucial for rapid scaling up of early treatment initiation in childhood TB.

Comparative Modeling of Tuberculosis Epidemiology and Policy Outcomes in California. (2019). Menzies NA., Parriott A., Shrestha S., Dowdy DW., Cohen T., Salomon JA., Marks SM., Hill AN., Winston CA., Asay GR., Barry P., Readhead A., Flood J., Kahn JG., Shete PB, American journal of respiratory and critical care medicine, 201, 356-365

View Abstract Text

Rationale: Mathematical modeling is used to understand disease dynamics, forecast trends, and inform public health prioritization. We conducted a comparative analysis of tuberculosis (TB) epidemiology and potential intervention effects in California, using three previously developed epidemiologic models of TB.Objectives: To compare the influence of various modeling methods and assumptions on epidemiologic projections of domestic latent TB infection (LTBI) control interventions in California.Methods: We compared model results between 2005 and 2050 under a base-case scenario representing current TB services and alternative scenarios including: 1) sustained interruption of Mycobacterium tuberculosis (Mtb) transmission, 2) sustained resolution of LTBI and TB prior to entry of new residents, and 3) one-time targeted testing and treatment of LTBI among 25% of non-U.S.-born individuals residing in California.Measurements and Main Results: Model estimates of TB cases and deaths in California were in close agreement over the historical period but diverged for LTBI prevalence and new Mtb infections-outcomes for which definitive data are unavailable. Between 2018 and 2050, models projected average annual declines of 0.58-1.42% in TB cases, without additional interventions. A one-time LTBI testing and treatment intervention among non-U.S.-born residents was projected to produce sustained reductions in TB incidence. Models found prevalent Mtb infection and migration to be more significant drivers of future TB incidence than local transmission.Conclusions: All models projected a stagnation in the decline of TB incidence, highlighting the need for additional interventions including greater access to LTBI diagnosis and treatment for non-U.S.-born individuals. Differences in model results reflect gaps in historical data and uncertainty in the trends of key parameters, demonstrating the need for high-quality, up-to-date data on TB determinants and outcomes.

Clinical Consequences of Using an Indeterminate Range for Early Infant Diagnosis of HIV: A Decision Model. (2019). Salvatore P., Johnson K., Vojnov L., Doherty M., Dowdy D, Journal of acquired immune deficiency syndromes (1999), 82, 287-296

View Abstract Text

BACKGROUND: To minimize false-positive diagnoses of HIV in exposed infants, the World Health Organization recommends confirmatory testing for all infants initiating antiretroviral therapy (ART). In settings where confirmatory testing is not feasible or intermittently performed, clinical decisions may be aided by semi-quantitative cycle thresholds (Cts) that identify positive results most likely to be false-positive. METHODS: We developed a decision analysis model of HIV-exposed infants in sub-Saharan Africa to estimate the clinical consequences of deferring ART for infants with weakly positive ("indeterminate") results. We assessed the degree to which "indeterminate" results may reduce the number of infants starting ART unnecessarily while missing a small number of HIV-infected infants. Our primary outcome was the ratio of averted unnecessary ART regimens to additional HIV-related deaths (due to false-negative diagnosis) at different Ct cutoffs. RESULTS: The clinical consequences of adopting an indeterminate range varied with the prevalence of HIV and Ct cutoff. Considering a Ct cutoff ≥33, adopting an indeterminate range could prevent a median of 1.4 infants from receiving ART unnecessarily (95% UR: 1.0-2.0) for each additional HIV-related death. This ratio could be improved by prioritizing infants with indeterminate results for confirmatory testing [median 8.8 (95% UR: 6.0-13.3)] and by adopting a higher cutoff [median 82.3 (95% UR: 49.0-155.8) with Ct ≥36]. CONCLUSIONS: When implemented in settings where confirmatory testing is not universal, the benefits of classifying weakly positive results as "indeterminate" may outweigh the risks. Accordingly, the World Health Organization has recommended Ct values ≥33 be considered indeterminate for infant HIV diagnosis.

Ending the Human Immunodeficiency Virus Epidemic: Towards an Evidence-Based Approach. (2019). Fojo AT., Dowdy DW, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 69, 2199-2200

Guidance for Studies Evaluating the Accuracy of Tuberculosis Triage Tests. (2019). Nathavitharana RR., Yoon C., Macpherson P., Dowdy DW., Cattamanchi A., Somoskovi A., Broger T., Ottenhoff THM., Arinaminpathy N., Lonnroth K., Reither K., Cobelens F., Gilpin C., Denkinger CM., Schumacher SG, The Journal of infectious diseases, 220, S116-S125

View Abstract Text

Approximately 3.6 million cases of active tuberculosis (TB) go potentially undiagnosed annually, partly due to limited access to confirmatory diagnostic tests, such as molecular assays or mycobacterial culture, in community and primary healthcare settings. This article provides guidance for TB triage test evaluations. A TB triage test is designed for use in people with TB symptoms and/or significant risk factors for TB. Triage tests are simple and low-cost tests aiming to improve ease of access and implementation (compared with confirmatory tests) and decrease the proportion of patients requiring more expensive confirmatory testing. Evaluation of triage tests should occur in settings of intended use, such as community and primary healthcare centers. Important considerations for triage test evaluation include study design, population, sample type, test throughput, use of thresholds, reference standard (ideally culture), and specimen flow. The impact of a triage test will depend heavily on issues beyond accuracy, primarily centered on implementation.

Adherence to tuberculosis preventive therapy measured by urine metabolite testing among people with HIV. (2019). Kendall EA., Durovni B., Martinson NA., Cavalacante S., Masonoke K., Saraceni V., Lebina L., Efron A., Cohn S., Chon S., Chaisson RE., Dowdy DW., Golub JE, AIDS (London, England), 34, 63-71

View Abstract Text

OBJECTIVES: Tuberculosis preventive therapy for people living with HIV is effective, widely recommended, and increasingly prescribed, but completion rates are less than ideal, and adherence is not typically monitored. We sought to quantify adherence to isoniazid preventive therapy using a urine metabolite assay. DESIGN: Two cross-sectional surveys. SETTING: Rio de Janeiro, Brazil, 2008-2009; and Northwest Province, South Africa, 2018-2019. PARTICIPANTS: Two hundred and three Brazilian and 93 South African patients attending HIV clinics with active prescriptions for isoniazid preventive therapy MAIN OUTCOME MEASURES:: Self-reported isoniazid adherence, paired with semiquantitative measurement of urine isoniazid metabolites. RESULTS: By self-report, 90% of patients [95% confidence interval (CI) 86-93%] reported having taken a dose of isoniazid on the day of enrollment or the preceding day, and 91% (95% CI 87-94%) reported missing an average of one dose or fewer per week. By urine testing, only 65% (95% CI 59-70%) of all patients, and 69% (95% CI 63-74%) of those who reported having taken isoniazid on the current or preceding day, had detectable urine metabolites (expected in 95% of patients at 24 h). Longer time since starting preventive therapy was independently associated with a negative urine test for isoniazid metabolites (adjusted prevalence ratio 1.11 per month of isoniazid, 95% CI 1.05-1.18). CONCLUSION: Adherence to isoniazid preventive therapy among patients with HIV in Brazil and South Africa is inadequate, is overestimated by self-report, and declines with time on treatment. Shorter regimens for TB preventive therapy may improve adherence and completion, but adherence support for all patients may be necessary.

- September 2019 -

Promoting Tuberculosis Preventive Therapy for People Living with HIV in South Africa: Interventions Hindered by Complicated Clinical Guidelines and Imbalanced Patient-Provider Dynamics. (2019). Jarrett BA., Woznica DM., Tilchin C., Mpungose N., Motlhaoleng K., Golub JE., Martinson NA., Hanrahan CF, AIDS and behavior, 24, 1106-1117

View Abstract Text

Isoniazid preventive therapy (IPT) reduces the risk of active tuberculosis among people living with HIV, but implementation of IPT in South Africa and elsewhere remains slow. The objective of this study was to examine both nurse perceptions of clinical mentorship and patient perceptions of in-queue health education for promoting IPT uptake in Potchefstroom, South Africa. We measured adoption, fidelity, acceptability, and sustainability of the interventions using both quantitative and qualitative methods. Adoption, fidelity, and acceptability of the interventions were moderately high. However, nurses believed they could not sustain their increased prescriptions of IPT, and though many patients intended to ask nurses about IPT, few did. Most patients attributed their behavior to an imbalance of patient-provider power. National IPT guidelines should be unambiguous and easily implemented after minimal training on patient eligibility and appropriate medication durations, nurse-patient dynamics should empower the patient, and district-level support and monitoring should be implemented.

Estimating the impact of a novel drug regimen for treatment of tuberculosis: a modeling analysis of projected patient outcomes and epidemiological considerations. (2019). Kendall EA., Malhotra S., Cook-Scalise S., Denkinger CM., Dowdy DW, BMC infectious diseases, 19, 794

View Abstract Text

BACKGROUND: Regimens that could treat both rifampin-resistant (RR) and rifampin-susceptible tuberculosis (TB) while shortening the treatment duration have reached late-stage clinical trials. Decisions about whether and how to implement such regimens will require an understanding of their likely clinical impact and how this impact depends on local epidemiology and implementation strategy. METHODS: A Markov state-transition model of 100,000 representative South African adults with TB was used to simulate implementation of the regimen BPaMZ (bedaquiline, pretomanid, moxifloxacin, and pyrazinamide), either for RR-TB only or universally for all patients. Patient outcomes, including cure rates, time with active TB, and time on treatment, were compared to outcomes under current care. Sensitivity analyses varied the drug-resistance epidemiology, rifampin susceptibility testing practices, and regimen efficacy. RESULTS: Using BPaMZ exclusively for RR-TB increased the proportion of all RR-TB that was cured by initial treatment from 60 ± 1% to 67 ± 1%. Expanding use of BPaMZ to all patients increased cure of RR-TB to 89 ± 1% and cure of all TB from 87.3 ± 0.1% to 89.5 ± 0.1%, while shortening treatment by 1.9 months/person. In sensitivity analyses, reducing the coverage of rifampin susceptibility testing resulted in lower projected proportions of patients cured under all regimen scenarios (current care, RR-only BPaMZ, and universal BPaMZ), compared to the proportions projected using South Africa's high coverage; however, this reduced coverage resulted in greater expected incremental benefits of universal BPaMZ implementation, both when compared to RR-only BPaMZ implementation and when compared to to current care under the same low rifampin susceptibility testing coverage. In settings with higher RR-TB prevalence, the benefits of BPaMZ were magnified both for RR-specific and universal BPaMZ implementation. CONCLUSIONS: Novel regimens such as BPaMZ could improve RR-TB outcomes and shorten treatment for all patients, particularly with universal use. Decision-makers weighing early options for implementing such regimens at scale will want to consider the expected impact on patient outcomes and on the burden of treatment in their local context.

Page Navigation:

12345678910