The Prevalence of Latent Tuberculosis Infection in the United States

Factors Associated With the Discontinuation of Two Short-Course Tuberculosis Preventive Therapies in Programmatic Settings in the United States

Background

The objective of this study was to investigate timing and risk factors for discontinuation of short-course tuberculosis preventive therapy (TPT) comparing directly observed 3-month isoniazid/rifapentine (3HP) vs self-administered 4-month rifampin (4R).

Methods

This was a subanalysis of a 6-month health department cohort (2016-2017) of 993 latent tuberculosis infection (LTBI) patients initiating 3HP (20%) or 4R (80%). Time at risk of TPT discontinuation was compared across regimens. Risk factors were assessed using mixed-effects Cox models.

Results

Short-course TPT discontinuation was higher with 4R (31% vs 14%; P < .0001), though discontinuation timing was similar. Latino ethnicity (hazard ratio [HR], 1.80; 95% CI, 1.20-2.90) and adverse events (HR, 4.30; 95% CI, 2.60-7.30) increased 3HP discontinuation risk. Social-behavioral factors such as substance misuse (HR, 12.00; 95% CI, 2.20-69.00) and congregate living (HR, 21.00; 95% CI, 1.20-360.00) increased 4R discontinuation risk.

Conclusions

TPT discontinuation differed by regimen, with distinct risk factors. Addressing social determinants of health within TPT programs is critical to enhance completion rates and reduce TB disease risk in marginalized populations.

Interpreter usage and associations with latent tuberculosis infection treatment acceptance and completion in the USA among non-U.S.-born persons, 2012-2017

BACKGROUND

Latent tuberculosis infection (LTBI) screening and treatment interventions that are tailored to optimize acceptance among the non-U.S.-born population are essential for U.S. tuberculosis elimination. We investigated the impact of medical interpreter use on LTBI treatment acceptance and completion among non-U.S.-born persons in a multisite study.

METHODS

The Tuberculosis Epidemiologic Studies Consortium was a prospective cohort study that enrolled participants at high risk for LTBI at ten U.S. sites with 18 affiliated clinics from 2012 to 2017. Non-U.S.-born participants with at least one positive tuberculosis infection test result were included in analyses. Characteristics associated with LTBI treatment offer, acceptance, and completion were evaluated using multivariable logistic regression with random intercepts to account for clustering by enrollment site. Our primary outcomes were whether use of an interpreter was associated with LTBI treatment acceptance and completion. We also evaluated whether interpreter usage was associated treatment offer and whether interpreter type was associated with treatment offer, acceptance, or completion.

RESULTS

Among 8,761 non-U.S.-born participants, those who used an interpreter during the initial interview had a significantly greater odds of accepting LTBI treatment than those who did not use an interpreter. There was no association between use of an interpreter and a clinician's decision to offer treatment or treatment completion once accepted. Characteristics associated with lower odds of treatment being offered included experiencing homelessness and identifying as Pacific Islander persons. Lower treatment acceptance was observed in Black and Latino persons and lower treatment completion by participants experiencing homelessness. Successful treatment completion was associated with use of shorter rifamycin-based regimens. Interpreter type was not associated with LTBI treatment offer, acceptance, or completion.

CONCLUSIONS

We found greater LTBI treatment acceptance was associated with interpreter use among non-U.S.-born individuals.

Prevalence estimates of tuberculosis infection in adults in Denmark: a retrospective nationwide register-based cross-sectional study, 2010 to 2018

BackgroundTuberculosis (TB) elimination requires identifying and treating persons with TB infection (TBI).AimWe estimate the prevalence of positive interferon gamma release assay (IGRA) tests (including TB) and TBI (excluding TB) in Denmark based on TBI screening data from patients with inflammatory bowel disease (IBD) or inflammatory rheumatic disease (IRD).MethodsUsing nationwide Danish registries, we included all patients with IBD or IRD with an IGRA test performed between 2010 and 2018. We estimated the prevalence of TBI and positive IGRA with 95% confidence intervals (CI) in adolescents and adults aged 15-64 years after sample weighting adjusting for distortions in the sample from the background population of Denmark for sex, age group and TB incidence rates (IR) in country of birth.ResultsIn 13,574 patients with IBD or IRD, 12,892 IGRA tests (95.0%) were negative, 461 (3.4%) were positive and 221 (1.6%) were indeterminate, resulting in a weighted TBI prevalence of 3.2% (95% CI: 2.9-3.5) and weighted positive IGRA prevalence of 3.8% (95% CI: 3.5-4.2) among adults aged 15-64 years in the background population of Denmark. Unweighted TBI prevalence increased with age and birthplace in countries with a TB IR higher than 10/100,000 population.ConclusionEstimated TBI prevalence is low in Denmark. We estimate that 200,000 persons have TBI and thus are at risk of developing TB. Screening for TBI and preventive treatment, especially in persons born in high TB incidence countries or immunosuppressed, are crucial to reduce the risk of and eliminate TB.

Prevalence and factors associated with tuberculosis infection in India

BACKGROUND

The risk of tuberculosis (TB) disease is higher in individuals with TB infection. In a TB endemic country like India, it is essential to understand the current burden of TB infection at the population level. The objective of the present analysis is to estimate the prevalence of TB infection in India and to explore the factors associated with TB infection.

METHODS

Individuals aged > 15 years in the recently completed National TB prevalence survey in India who were tested for TB infection by QuantiFERON-TB Gold Plus (QFT-Plus) assay were considered for this sub-analysis. TB infection was defined as positive by QFT-Plus (value >0.35 IU/ml). The estimates for prevalence, prevalence ratio (PR) and adjusted risk ratio (aRR) estimates with 95% confidence intervals (CIs) were calculated.

RESULTS

Of the 16864 individuals analysed, the prevalence of TB infection was 22.6% (95% CI:19.4 -25.8). Factors more likely to be associated with TB infection include age > 30 years (aRR:1.49;95% CI:1.29-1.73), being male (aRR:1.26; 95%CI: 1.18-1.34), residing in urban location (aRR:1.58; 95%CI: 1.03-2.43) and past history of TB (aRR:1.49; 95%CI: 1.26-1.76).

CONCLUSION

About one fourth (22.6%) of the individuals were infected with TB in India. Individuals aged > 30 years, males, residing in urban location, and those with past history of TB were more likely to have TB infection. Targeted interventions for prevention of TB and close monitoring are essential to reduce the burden of TB in India.

Examining Test Cutoffs to Optimize Diagnosis of Latent Tuberculosis Infection in People Born Outside the United States

Rationale: Detection of latent tuberculosis infection (LTBI) in persons born in high tuberculosis (TB) incidence countries living in low TB incidence countries is key to TB elimination in low-incidence countries. Optimizing LTBI tests is critical to targeting treatment. Objectives: To compare the sensitivity and specificity of tuberculin skin test (TST) and two interferon-γ release assays at different cutoffs and of a single test versus dual testing. Methods: We examined a subset (N = 14,167) of a prospective cohort of people in the United States tested for LTBI. We included non-U.S.-born, human immunodeficiency virus-seronegative people ages 5 years and older with valid TST, QuantiFERON-TB Gold-in-Tube (QFT), and T-SPOT.TB (TSPOT) results. The sensitivity/specificity of different test cutoffs and test combinations, obtained from a Bayesian latent class model, were used to construct receiver operating characteristic (ROC) curves and assess the area under the curve (AUC) for each test. The sensitivity/specificity of dual testing was calculated. Results: The AUC of the TST ROC curve was 0.81 (95% credible interval (CrI), 0.78-0.86), with sensitivity/specificity at cutoffs of 5, 10, and 15 mm of 86.5%/61.6%, 81.7%/71.3%, and 55.6%/88.0%, respectively. The AUC of the QFT ROC curve was 0.89 (95% CrI, 0.86-0.93), with sensitivity/specificity at cutoffs of 0.35, 0.7, and 1.0 IU/mL of 77.7%/98.3%, 66.9%/99.1%, and 61.5%/99.4%. The AUC of the TSPOT ROC curve was 0.92 (95% CrI, 0.88-0.96) with sensitivity/specificity for five, six, seven, and eight spots of 79.2%/96.7%, 76.8%/97.7%, 74.0%/98.6%, and 71.8%/99.5%. Sensitivity/specificity of TST-QFT, TST-TSPOT, and QFT-TSPOT at standard cutoffs were 73.1%/99.4%, 64.8%/99.8%, and 65.3%/100%. Conclusion: Interferon-γ release assays have a better predictive ability than TST in people at high risk of LTBI.

Challenges in the Management of Psoriatic Arthritis in Latin America: A Systematic Review

PURPOSE

In 2020, the International League of Associations for Rheumatology published recommendations for managing psoriatic arthritis (PsA), aiming to adapt the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis and the European Alliance of Associations for Rheumatology recommendations to low-income countries. At that time, the paucity of clinical studies examining the management of patients with PsA in Latin America was remarked on by the international working group. Therefore, the primary objective of this systematic literature review was to investigate the main challenges in managing PsA in Latin America as described in recent publications.

METHODS

A systematic literature review of trials reporting at least one challenge/difficulty in the management of PsA in Latin America was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. References published in the PubMed, EMBASE, and LILACS (Latin American and Caribbean Health Sciences Literature) databases between 1980 and February 2023 were included. The selection of references was conducted independently by 2 researchers in the Rayyan Qatar Computing Research Institute program. Two other reviewers independently extracted data. All challenges were noted and categorized into domains. Data analysis was descriptive.

FINDINGS

The search strategy yielded 2085 references, with 21 studies included in the final analysis. Most studies were conducted in Brazil (66.6%; n = 14) and were observational studies (100%; N = 21). Difficulties faced by PsA patients and physicians included the high incidence of opportunistic infections (described in 42.8% of the publications; n = 9), followed by nonadherence to therapy, discordance between patients and physicians regarding remission rates, low drug persistence, limited access to disease-modifying antirheumatic drugs, issues related to the storage of biologic drugs, elevated cost of biologic drugs, limited access to medical care, diagnostic delay, and the individual- and country-level impact of socioeconomic factors on work- and health-related outcomes.

IMPLICATIONS

Challenges in the management of PsA in Latin America extend beyond the care of opportunistic infections, encompassing several other socioeconomic factors. More research is needed to better understand the peculiarities of treating PsA in Latin America to improve patient care. PROSPERO identifier: CRD42021228297.

Latent Tuberculosis in India: An Overview

Treatment of latent tuberculosis infection (LTBI) is essential for tuberculosis (TB) eradication. LTBI patients serve as a reservoir for active TB cases. The WHO's End TB Strategy now prioritises the detection and treatment of LTBI. A comprehensive approach focused on integrated LTBI control is required to accomplish this goal. This review aims to summarise what we know about LTBI in the existing literature, its prominence, diagnostic strategies, and new interventions to alert people of its occurrence and symptoms. We used Medical Subject Heading (MeSH) phrases to search for published publications on the English language in PubMed, Scopus, and Google Scholar. To provide clarity and impact, we examined several government websites to identify the most effective and current treatment regimens. LTBI is a spectrum of infections, such as intermittent, transitory, or progressive, with early, subclinical, and ultimately active TB cases. The global burden of LTBI cannot be firmly established because no "gold-standard" test exists. Screening is advised for high-risk individuals, such as immigrants, occupants and staff members of congregate living facilities, and those who are HIV-positive. The most reliable form of LTBI screening is still the targeted tuberculin skin test (TST). Although LTBI therapy is challenging, for India to become TB-free, it must first focus on testing and treating LTBI. The government should focus on generalising the new diagnostic criteria and adopting a more specific treatment known to all to eliminate TB once and for all.

Multicenter Analysis of Attrition from the Pediatric Tuberculosis Infection Care Cascade in Boston

OBJECTIVE

To characterize losses from the pediatric tuberculosis (TB) infection care cascade to identify ways to improve TB infection care delivery.

STUDY DESIGN

We conducted a retrospective cohort study of children (age <18 years) screened for TB within 2 Boston-area health systems between January 2017 and May 2019. Patients who received a tuberculin skin test (TST) and/or an interferon gamma release assay (IGRA) were included.

RESULTS

We included 13 353 tests among 11 622 patients; 93.9% of the tests were completed. Of 199 patients with positive tests for whom TB infection evaluation was clinically appropriate, 59.3% completed treatment or were recommended to not start treatment. Age 12-17 years (vs < 5 years; aOR 1.59; 95% CI, 1.32-1.92), non-English/non-Spanish language preference (vs English; aOR, 1.34; 95% CI, 1.02-1.76), and receipt of an IGRA (vs TST, aOR, 30.82; 95% CI, 21.92-43.34) were associated with increased odds of testing completion. Odds of testing completion decreased as census tract social vulnerability index quartile increased (ie, social vulnerability worsened; most vulnerable quartile vs least vulnerable quartile, aOR, 0.77; 95% CI, 0.60-0.99). Odds of completing treatment after starting treatment were higher in females (vs males; aOR, 2.35; 95% CI, 1.14-4.85) and were lower in patients starting treatment in a primary care clinic (vs TB/infectious diseases clinic; aOR, 0.44; 95% CI, 0.27-0.71).

CONCLUSIONS

Among children with a high proportion of negative TB infection tests, completion of testing was high, but completion of evaluation and treatment was moderate. Transitions toward IGRA testing will improve testing completion; interventions addressing social determinants of health are important to improve treatment completion.

Evaluation of the Latent Tuberculosis Care Cascade Among Public Health Clinics in the United States

BACKGROUND

Tuberculosis (TB) elimination within the United States will require scaling up TB preventive services. Many public health departments offer care for latent tuberculosis infection (LTBI), although gaps in the LTBI care cascade are not well quantified. An understanding of these gaps will be required to design targeted public health interventions.

METHODS

We conducted a cohort study through the Tuberculosis Epidemiologic Studies Consortium (TBESC) within 15 local health department (LHD) TB clinics across the United States. Data were abstracted on individuals receiving LTBI care during 2016-2017 through chart review. Our primary objective was to quantify the LTBI care cascade, beginning with LTBI testing and extending through treatment completion.

RESULTS

Among 23 885 participants tested by LHDs, 46% (11 009) were male with a median age of 31 (interquartile range [IQR] 20-46). A median of 35% of participants were US-born at each site (IQR 11-78). Overall, 16 689 (70%) received a tuberculin skin test (TST), 6993 (29%) received a Quantiferon (QFT), and 1934 (8%) received a T-SPOT.TB; 5% (1190) had more than one test. Among those tested, 2877 (12%) had at least one positive test result (3% among US-born, and 23% among non-US-born, P < .01). Of 2515 (11%) of the total participants diagnosed with LTBI, 1073 (42%) initiated therapy, of whom 817 (76%) completed treatment (32% of those with LTBI diagnosis).

CONCLUSIONS

Significant gaps were identified along the LTBI care cascade, with less than half of individuals diagnosed with LTBI initiating therapy. Further research is needed to better characterize the factors impeding LTBI diagnosis, treatment initiation, and treatment completion.

Two-stage TKA for tuberculosis septic arthritis of the knee masquerading as pigmented villonodular synovitis: A case report

A 25-year-old female presented with left knee pain following arthroscopic synovectomy for presumed pigmented villonodular synovitis (PVNS). Radiographs and magnetic resonance imaging demonstrated tricompartmental arthritic changes. She underwent a two-stage procedure first involving antibiotic spacer implantation, followed 1 week later by spacer removal and definitive total knee arthroplasty (TKA) once initial intraoperative culture results were negative. Subsequent cultures confirmed tuberculosis septic arthritis. Repeat evaluation 1 year postoperatively showed no complications and patient satisfaction with left knee function. This is a unique case report in the United States describing 1-year outcomes following staged TKA for tuberculosis septic arthritis masquerading as PVNS.

Latent Tuberculosis Infection in Haematopoietic Stem Cell Transplant Recipients: A Retrospective Italian Cohort Study in Tor Vergata University Hospital, Rome

The results of tuberculosis (TB) screening and reactivation in a cohort of 323 adult patients undergoing haematopoietic stem cell transplantation (HSCT) from 2015 to 2019 at the University Hospital of Tor Vergata, Rome, Italy, were reported. A total of 260 patients, 59 (18.3%) autologous and 264 (81.7%) allogeneic transplants, underwent Interferon Release (IFN)-γ (IGRA) test screening: 228 (87.7%) were negative, 11 (4.2%) indeterminate and 21 (8.1%) positive. Most of the IGRA-positive patients were of Italian origin (95.2%) and significantly older than the IGRA-negative (p < 0.001); 22 (8.5%) patients underwent a second IGRA during the first year after transplantation, and 1 tested positive for IGRA. Significantly lower monocyte (p = 0.044) and lymphocyte counts (p = 0.009) were detected in IGRA negative and IGRA indeterminate patients, respectively. All latent TB patients underwent isoniazid prophylaxis, and none of them progressed to active TB over a median follow-up period of 63.4 months. A significant decline in TB screening practices was shown from 2015 to 2019, and approximately 19% of patients were not screened. In conclusion, 8.1% of our HSCT population had LTBI, all received INH treatment, and no reactivation of TB was observed during the follow-up period. In addition, 19% escaped screening and 8% of these came from countries with a medium TB burden, therefore at higher risk of possible development of TB.

Prevalence trends of latent tuberculosis infection at the global, regional, and country levels from 1990-2019

OBJECTIVES

To track the prevalence trends of latent tuberculosis infection (LTBI) at the global, regional, and national levels.

METHODS

Data on the prevalence of LTBI were extracted from the Global Burden of Disease database. The average annual percent change (AAPC) was estimated by joinpoint regression and was used to evaluate the epidemic of the disease.

RESULTS

Globally, the prevalence rate of LTBI decreased from 30.66% in 1990 to 23.67% in 2019, with an AAPC of -0.9%. The prevalence rate of LTBI varied from 5.02% (Jordan) to 48.35% (Uganda) in 1990 and from 2.51% (Jordan) to 43.75% (Vietnam) in 2019 at the country level. The prevalence decreased in all the six World Health Organization (WHO) regions and in most countries, with the AAPC ranging from -0.5% in the Western Pacific Region to -2.1% in the European Region and from -4.3% (Bhutan) to -0.1% (Malaysia, Myanmar, South Africa, Tokelau, and Vietnam), respectively. Disparities were also observed among different sex and age groups.

CONCLUSION

The prevalence of LTBI decreased slightly worldwide in the last three decades, but the decrease is slow and not sufficient to meet the targets of WHO tuberculosis elimination. Much more effort and progress should be made in order to decrease the prevalence of LTBI.

Latent Tuberculosis Infection Testing and Treatment at a Federally Qualified Health Center in Southern California: A Quality Improvement Project

BACKGROUND

A key strategy to eliminate tuberculosis (TB) in the United States is to increase latent tuberculosis infection (LTBI) screening, testing, and treatment among non-US-born Asian populations.

PURPOSE

The purpose was to increase LTBI screening, testing, and treatment at a community clinic.

METHODS

Retrospective baseline LTBI data were retrieved through electronic medical record review. Interventions included adoption of standardized TB risk assessment, training providers to use shorter LTBI treatment regimens, and use of a care coordinator. Chart abstraction to examine outcomes was conducted postintervention at 4 months.

RESULTS

In 2017, only 3 patients (7%) with LTBI were started on treatment. At 4 months postintervention, 28 (72%) patients with LTBI were started on treatment, of which 27 (96%) were placed on 3- to 4-month regimens.

CONCLUSIONS

Training for providers and changes to clinic workflow, including use of a care coordinator, can help increase LTBI screening, testing, and treatment in community clinics.

Testing and treatment for latent tuberculosis infection in people living with HIV and substance dependence: a prospective cohort study

OBJECTIVE

To quantify the proportion of people living with HIV (PLWH) with other tuberculosis (TB) risk factors that completed the latent tuberculosis infection (LTBI) care cascade and describe factors associated with attrition. The care cascade was defined as follows: (1) receipt of an LTBI test and result, (2) initiation of LTBI treatment and (3) completion of LTBI treatment.

DESIGN

Prospective cohort study.

SETTING

Reactivation of LTBI remains a large source of active TB disease in the USA. PLWH and those who use substances are at greater risk and are harder to engage and retain in care.

PARTICIPANTS

Participants enrolled in a Boston cohort of PLWH from 2012 to 2014.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome was the number and proportion of participants who completed each stage of the cascade and the factors associated with completing each stage. Our secondary outcomes were differences between participants tested with an interferon gamma release assay (IGRA) versus tuberculin skin test and differences between participants who tested positive versus negative for LTBI.

RESULTS

Only 189 of 219 (86.3%) participants completed testing. Five of the 11 with LTBI initiated and three completed treatment. Participants tested with an IGRA were more likely to complete testing (OR 3.87, 95% CI 1.05 to 14.30) while among participants successfully tested, being foreign-born was associated with a positive test result (OR 3.95; 95% CI 1.13 to 13.77).

CONCLUSIONS

Although the majority completed LTBI testing, our findings warrant further investigation in a larger cohort to better understand factors that lead to suboptimal treatment initiation and completion in a low-burden country.

Reporting of Latent TB Infection Among Non-US-Born Persons Adjusting Their Immigration Status to Permanent Residents: An Opportunity to Enhance TB Prevention

From October 15, 2019, to June 12, 2020, Public Health-Seattle & King County conducted phone outreach to individuals referred to the public health department by civil surgeons. The objective was to explore common barriers and facilitators to treatment of latent tuberculosis infection (LTBI) among this population. Civil surgeons are mandated to report cases of LTBI to the state or local health department. Outreach revealed a wide variation in patient understanding of LTBI and provider practices around discussing LTBI and recommending LTBI treatment. The results of this small-scale study can inform public health strategies to engage with civil surgeons and their patients to both improve reporting practices and increase rates of LTBI treatment completion in patients born in high TB burden countries. In addition, these findings provide insight into what challenges and opportunities may emerge when health jurisdictions mandate LTBI reporting at a state or county level.

Emergency department screening for latent tuberculosis infection

OBJECTIVE

Approximately 12.4 million people in the U.S. have latent tuberculosis infection (LTBI), 73% of whom are non-U.S. born. Identification and treatment of LTBI are essential for tuberculosis eradication. We evaluated an emergency department (ED) - based LTBI screening and linkage to care program.

METHODS

We queried electronic records of a clinical prevention program located in a Midwestern, urban, academic ED that serves as the region's safety-net hospital. Program staff approached non-U.S. born ED patients from TB endemic areas. Patients received QuantiFERON-TB Gold Plus (QFT) blood testing and, if positive, were referred to treatment. The primary outcome was the proportion of tested patients newly diagnosed with LTBI. We secondarily report the number of patients linked to care who initiated LTBI treatment.

RESULTS

The program approached 33 patients, of whom 24 (72.7%) were eligible, and 23 (95.8%) were tested. The majority were male (13, 56.5%), median age was 33 years (IQR 27-45), and 13 (56.5%) were from Latin America. Three patients (13.0%, 95% CI 0.03-0.35) were newly diagnosed with LTBI and linked to care; two (66.7%) started LTBI treatment.

CONCLUSIONS

In this first report of an ED-based LTBI screening program implemented in a region with low TB prevalence, over 10% of high-risk ED patients tested positive for LTBI and were linked to treatment. Screening populations at risk for LTBI in EDs and linking them to public health treatment services should be prioritized in order to achieve TB elimination in the U.S.

Challenges in LTBI care in the United States identified using a nationwide TB medical consultation database

BACKGROUND

Identifying and treating individuals with latent TB infection (LTBI) represents a critical and challenging component of national TB elimination. Medical consultations by the Centers for Disease Control and Prevention (CDC) funded TB Centers of Excellence (COEs) are an important resource for healthcare professionals (HCPs) caring for individuals with LTBI. This study aimed to identify the most common clinical concerns regarding LTBI care and to describe epidemiologic and clinical features of patients discussed in these consultations.

METHODS

This mixed-methods study randomly sampled 125 consultation inquiries related to LTBI from the COEs' medical consultation database in 2018. Text from consultation records were reviewed and coded to identify reasons for the inquiries and common epidemiologic and clinical patient characteristics.

RESULTS

The most common topics of inquiry for consultation included accurate LTBI diagnosis (36%), management of LTBI treatment-related issues (22%), and choice of appropriate LTBI treatment regimen (17%). Patients for whom consultations were requested commonly had another medical condition (34%), were non-U.S. born (31%), were children (25%), and had a history of travel to TB-endemic areas (18%).

CONCLUSION

Our findings emphasize the challenge of managing patients with either suspected or confirmed LTBI, highlighting the need for ongoing medical consultation support for nuanced clinical and epidemiologic scenarios.

Tuberculosis Screening in Silica-Exposed Workers : Developing a Tool for Health Care Providers

Both the Occupational Safety and Health Administration and Washington State require safety and health protections for workers exposed to respirable crystalline silica, including tuberculosis (TB) screening as part of occupational medical surveillance. We describe the creation of a TB screening tool for silica-exposed workers receiving regulated medical surveillance examinations in Washington State. The tool provides relevant clinical recommendations to assist health care providers and public health practitioners who choose to use the tool when performing such examinations. A cross-disciplinary team at the Washington State Department of Labor and Industries created the TB screening tool to help health care providers identify silica-exposed workers who should receive a comprehensive evaluation for active TB disease and workers who should or must receive testing for latent TB infection. The Washington State Adult Tuberculosis Screening Tool for Workers Exposed to Respirable Crystalline Silica benefits occupational and respiratory clinicians and public health practitioners by aiding both the individual- and population-level delivery of occupational health and TB screening services to silica-exposed workers receiving required medical surveillance examinations.

Factors Associated With Latent Tuberculosis Infection Treatment Failure Among Patients With Commercial Health Insurance-United States, 2005-2016

CONTEXT

Approximately 80% of US tuberculosis (TB) cases verified during 2015-2016 were attributed to untreated latent TB infection (LTBI). Identifying factors associated with LTBI treatment failure might improve treatment effectiveness.

OBJECTIVE

To identify patients with indicators of isoniazid (INH) LTBI treatment initiation, completion, and failure.

METHODS

We searched inpatient and outpatient claims for International Classification of Diseases (Ninth and Tenth Revisions), National Drug, and Current Procedural Terminology codes. We defined treatment completion as 180 days or more of INH therapy during a 9-month period. We defined LTBI treatment failure as an active TB disease diagnosis more than 1 year after starting LTBI treatment among completers and used exact logistic regression to model possible differences between groups. Among treatment completers, we matched 1 patient who failed treatment with 2 control subjects and fit regression models with covariates documented on medical claims paid 6 months or less before INH treatment initiation.

PARTICIPANTS

Commercially insured US patients in a large commercial database with insurance claims paid during 2005-2016.

MAIN OUTCOME MEASURES

(1) Trends in treatment completion; (2) odds ratios (ORs) for factors associated with treatment completion and treatment failure.

RESULTS

Of 21 510 persons who began LTBI therapy during 2005-2016, 10 725 (49.9%) completed therapy. Treatment noncompletion is associated with those younger than 45 years, living in the Northeast or South Census regions, and women. Among persons who completed treatment, 30 (0.3%) progressed to TB disease. Diagnoses of rheumatoid arthritis during the 6 months before treatment initiation and being aged 65 years or older (reference: ages 0-24 years) were significantly associated with INH LTBI treatment failure (adjusted exact OR = 5.1; 95% CI, 1.2-28.2; and adjusted exact OR = 5.1; 95% CI, 1.2-25.3, respectively).

CONCLUSION

Approximately 50% of persons completed INH LTBI therapy, and of those, treatment failure was associated with rheumatoid arthritis and persons 65 years or older among a cohort of US LTBI patients with commercial health insurance.

Infection Mitigation Strategies for Multiple Sclerosis Patients on Oral and Monoclonal Disease-Modifying Therapies

PURPOSE OF REVIEW

The newer, higher-efficacy disease-modifying therapies (DMTs) for multiple sclerosis (MS)-orals and monoclonals-have more profound immunomodulatory and immunosuppressive properties than the older, injectable therapies and require risk mitigation strategies to reduce the risk of serious infections. This review will provide a systematic framework for infectious risk mitigation strategies relevant to these therapies.

RECENT FINDINGS

We classify risk mitigation strategies according to the following framework: (1) screening and patient selection, (2) vaccinations, (3) antibiotic prophylaxis, (4) laboratory and MRI monitoring, (5) adjusting dose and frequency of DMT, and (6) behavioral modifications to limit the risk of infection. We systematically apply this framework to the infections for which risk mitigations are available: hepatitis B, herpetic infections, progressive multifocal leukoencephalopathy, and tuberculosis. We also discuss up-to-date recommendations regarding COVID-19 vaccinations for patients on DMTs. We offer a practical, comprehensive, DMT-specific framework of derisking strategies designed to minimize the risk of infections associated with the newer MS therapies.

Surveillance of Employees of Swiss Federal Asylum Centres for Latent Tuberculosis Infection

BACKGROUND

Asylum seekers in Switzerland have to register in federal asylum centres (FACs) before formal permission to enter the country. Some of them may have active tuberculosis (TB), exposing fellow refugees and employees.

OBJECTIVES

The aim of this study was to assess the risk of TB infection among employees of Swiss FACs.

METHODS

Between 2010 and 2018, a free interferon-gamma release assay (IGRA) was offered to all employees of 8 FACs, at employment and at yearly intervals. We defined latent TB infection as IGRA conversion from negative to positive. IGRA-positive employees were referred to a medical centre for further clinical follow-up.

RESULTS

1,427 tests were performed among 737 employees (54.6% male). 403 (55%) persons were tested only once; 330 (44.5%) were tested several times; for 4 (0.5%) persons, the number of IGRA tests is unknown. Twenty employees (2.7%) had a positive IGRA at baseline, 2 (0.6%) converted from negative to positive during follow-up, resulting in an incidence of 22/10,000 person-years. We observed no case of active TB among employees.

CONCLUSIONS

The prevalence of latent TB among employees to Swiss FACs and the risk of acquiring TB infection through work-related exposure are low. Yearly IGRA controls in the absence of documented TB exposure seem unnecessary.

Self-Reported Engagement in Care among U.S. Residents with Latent Tuberculosis Infection - 2011-2012

RATIONALE

A central strategy of tuberculosis (TB) control in the United States is reducing the burden of latent TB infection (LTBI) through targeted testing and treatment of persons with untreated LTBI.

OBJECTIVES

The objective of the study was to provide estimates of and risk factors for engagement in LTBI care in the overall U.S. population and among specific risk groups.

METHODS

We used nationally representative data from 7,080 participants in the 2011-2012 National Health and Nutrition Examination Survey. Engagement in LTBI care was assessed by estimating the proportion with a history of testing, diagnosis, treatment initiation and treatment completion. Weighted methods were used to account for the complex survey design and to derive national estimates.

RESULTS

Only 1.4 million (10%) of an estimated 14.0 million individuals with LTBI had previously completed treatment. Of the 12.6 million who did not complete LTBI treatment, 3.7 million (29%) had never been tested and 7.2 million (57%) received testing but had no history of diagnosis. High-risk groups showed low levels of engagement, including TB contacts and persons born outside the United States.

CONCLUSIONS

There is a reservoir of more than 12 million individuals in the U.S. who may be at risk for progression to TB disease and potential transmission. TB control programs and community providers should consider focused efforts to increase testing, diagnosis, and treatment for LTBI.

Rational laboratory testing in uveitis: A Bayesian analysis

Uveitis encompasses a heterogeneous group of clinical entities with the common feature of intraocular inflammation. In addition to patient history and examination, a focused set of laboratory investigations is frequently necessary to establish a specific diagnosis. There is limited consensus among uveitis specialists regarding appropriate laboratory evaluation for many distinct patient presentations. The appropriateness of a laboratory test for a given case of uveitis will depend on patient-specific as well as epidemiologic factors. Bayesian analysis is a widely used framework for the interpretation of laboratory testing, but is seldom adhered to in clinical practice. Bayes theorem states that the predictive value of a particular laboratory test depends on the sensitivity and specificity of that test, as well as the prevalence of disease in the population being tested. In this review we will summarize the performance of commonly-utilized laboratory tests for uveitis, as well as the prevalence of uveitic diagnoses in different geographic practice settings. We will propose a logical framework for effective laboratory testing in uveitic disease through rigorous application of Bayesian analysis. Finally, we will demonstrate that while many highly sensitive laboratory tests offer an effective means to rule out associated systemic disease, limited test specificity and low pretest probability often preclude the diagnosis of systemic disease association with any high degree of certainty, even in the face of positive testing.

Interferon gamma release assay tests are associated with persistence and completion of latent tuberculosis infection treatment in the United States: Evidence from commercial insurance data

Background

Risk-targeted testing and treatment of latent tuberculosis infection (LTBI) is a critical component of the United States’ (US) tuberculosis (TB) elimination strategy, but relatively low treatment completion rates remain a challenge. Both treatment persistence and completion may be facilitated by diagnosing LTBI using interferon gamma release assays (IGRA) rather than tuberculin skin tests (TST).

Methods

We used a national sample of administrative claims data to explore associations diagnostic test choice (TST, IGRA, TST with subsequent IGRA) and treatment persistence and completion in persons initiating a daily dose isoniazid LTBI treatment regimen in the US private healthcare sector between July 2011 and March 2014. Associations were analyzed with a generalized ordered logit model (completion) and a negative binomial regression model (persistence).

Results

Of 662 persons initiating treatment, 327 (49.4%) completed at least the 6-month regimen and 173 (26.1%) completed the 9-month regimen; 129 (19.5%) persisted in treatment one month or less. Six-month completion was least likely in persons receiving a TST (42.2%) relative to persons receiving an IGRA (55.0%) or TST then IGRA (67.2%; p = 0.001). Those receiving an IGRA or a TST followed by an IGRA had higher odds of completion compared to those receiving a TST (aOR = 1.59 and 2.50; p = 0.017 and 0.001, respectively). Receiving an IGRA or a TST and subsequent IGRA was associated with increased treatment persistence relative to TST (aIRR = 1.14 and 1.25; p = 0.027 and 0.009, respectively).

Conclusions

IGRA use is significantly associated with both higher levels of LTBI treatment completion and treatment persistence. These differences are apparent both when IGRAs alone were administered and when IGRAs were administered subsequent to a TST. Our results suggest that IGRAs contribute to more effective LTBI treatment and consequently individual and population protections against TB.

Prevalence of Latent Tuberculosis Infection among Non-U.S.-Born Persons by Country of Birth - United States, 2012-2017

BACKGROUND

Most tuberculosis (TB) disease in the U.S. is attributed to reactivation of remotely acquired latent TB infection (LTBI) in non-U.S.-born persons who were likely infected with Mycobacterium tuberculosis in their countries of birth. Information on LTBI prevalence by country of birth could help guide local providers and health departments to scale up the LTBI screening and preventive treatment needed to advance progress towards TB elimination.

METHODS

13 805 non-U.S.-born persons at high risk of TB infection or progression to TB disease were screened for LTBI at 16 clinical sites located across the United States with a tuberculin skin test, QuantiFERON ® Gold In-Tube test, and T-SPOT ®.TB test. Bayesian latent class analysis was applied to test results to estimate LTBI prevalence and associated credible intervals (CRI) for each country or world region of birth.

RESULTS

Among the study population, the estimated LTBI prevalence was 31% (95% CRI 26% - 35%). Country-of-birth-level LTBI prevalence estimates were highest for persons born in Haiti, Peru, Somalia, Ethiopia, Vietnam, and Bhutan, ranging from 42%-55%. LTBI prevalence estimates were lowest for persons born in Colombia, Malaysia, and Thailand, ranging from 8%-13%.

CONCLUSIONS

LTBI prevalence in persons born outside the United States varies widely by country. These estimates can help target community outreach efforts to the highest risk groups.

Estimated Latent Tuberculosis Infection Prevalence and Tuberculosis Reactivation Rates Among Non-U.S.-Born Residents in the United States, from the 2011-2012 National Health and Nutrition Examination Survey

Increased testing and treatment of latent tuberculosis infection (LTBI) among US-residents who were born (or lived) in countries with high rates of TB can hasten progress toward TB elimination. We calculated LTBI prevalence using QuantiFERON®-TB Gold In-Tube results from the 2011 to 2012 National Health and Nutrition Examination Survey (NHANES). LTBI prevalence was highest for persons born in India (31.7%, 95% confidence interval [21.2, 44.5]). Non-Hispanic white persons had the lowest LTBI prevalence (6.3% [1.9, 18.9]). TB reactivation rate, defined as the number of TB cases not associated with recent transmission per 100 person-years of life with LTBI, was highest for persons born in Vietnam [0.183 (0.117, 0.303)]. Reactivation rates were lower among persons who had resided in the United States for ≥ 10 years than among those who had resided for < 10 years. Results among high risk populations can guide LTBI targeted testing and treatment among non-U.S.-born residents.

Programmatic Effectiveness of Latent Tuberculosis Care Cascade in a Community Health Center

Our aim was to quantify successful completion of steps of the latent tuberculosis (LTBI) care cascade in a community health center (CHC) with a large foreign-born population. We conducted a retrospective cohort study of individuals with a positive test for tuberculosis (TB) infection from 2015 to 2017 at Baltimore Medical Systems (BMS). During the study period, 3,984 individuals were tested for TB. Of the 418 individuals with positive tests, 152 (36%) were referred elsewhere for care, whereas 266 (64%) were retained in care at BMS. Treatment was prescribed for 157 of the 214 (73%) diagnosed with LTBI and retained in care at BMS (125/157 [80%] four months of rifampin; 32/157 [20%] nine months of isoniazid). One hundred forty-one patients (141/157, 90%) initiated treatment, of which 119 completed therapy (119/141, 84%). Our study identified several gaps in the LTBI care cascade in a CHC. Nonetheless, a large proportion of those treated for LTBI at the CHC completed therapy.

The utility of endobronchial ultrasound-transbronchial needle aspiration in patients with suspected extra-pulmonary sarcoidosis without thoracic lymphadenopathy

BACKGROUND

Diagnosis of extra-pulmonary sarcoidosis can be difficult, and a biopsy is usually required. We evaluated the utility of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) in patients with suspected extra-pulmonary sarcoidosis with thoracic lymph nodes ≤10 mm on chest computed tomography (CT) and no or minimal pulmonary infiltrates.

METHODS

The Cleveland Clinic bronchoscopy registry was screened. Patients with thoracic lymph nodes >10 mm on short axis or significant pulmonary infiltrates in the chest CT scan were excluded. Two separate analyses using expert consensus (before and after release of bronchoscopy results) were the reference standard.

RESULTS

15 patients met the inclusion criteria. 40% had suspected ocular, 33% cardiac and 27% neurologic sarcoidosis. Six patients (40%) had EBUS-TBNA compatible with sarcoidosis. When the reference standard was the consensus diagnosis blinded to bronchoscopy results, the sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA were 56%, 83%, 83%, and 56% respectively. The combination of a positive EBUS-TBNA and BAL CD4/CD8 improved the specificity from 83 to 100%, but the difference was not statistically significant (p = 0.074). When the reference standard was the consensus diagnosis with the bronchoscopic results, the sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA were 75%, 100%, 100%, and 78% respectively.

CONCLUSIONS

In patients with suspected extra-pulmonary sarcoidosis, the EBUS-TBNA may be useful in the diagnosis of patients with thoracic lymph nodes ≤10 mm and no or minimal pulmonary infiltrates on chest CT. Larger and prospective studies are needed to validate our findings.

A Framework for Network-Based Epidemiological Modeling of Tuberculosis Dynamics Using Synthetic Datasets

We present a framework for discrete network-based modeling of TB epidemiology in US counties using publicly available synthetic datasets. We explore the dynamics of this modeling framework by simulating the hypothetical spread of disease over 2 years resulting from a single active infection in Washtenaw County, MI. We find that for sufficiently large transmission rates that active transmission outweighs reactivation, disease prevalence is sensitive to the contact weight assigned to transmissions between casual contacts (that is, contacts that do not share a household, workplace, school, or group quarter). Workplace and casual contacts contribute most to active disease transmission, while household, school, and group quarter contacts contribute relatively little. Stochastic features of the model result in significant uncertainty in the predicted number of infections over time, leading to challenges in model calibration and interpretation of model-based predictions. Finally, predicted infections were more localized by household location than would be expected if they were randomly distributed. This modeling framework can be refined in later work to study specific county and multi-county TB epidemics in the USA.

Comparative Modeling of Tuberculosis Epidemiology and Policy Outcomes in California

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.

Prevalence of Latent Tuberculosis in the Multiple Sclerosis Clinic and Effect of Multiple Sclerosis Treatment on Tuberculosis Testing

Background

Patients with a compromised immune system are at risk for converting from latent tuberculosis infection (LTBI) to active tuberculosis (TB) infection. Multiple sclerosis (MS) therapies may put individuals with LTBI at higher risk of TB.

Methods

Patients at the Beth Israel Deaconess Medical Center MS Clinic were screened for TB as part of routine testing with the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay (Cellestis Ltd) from 2013 to 2017. Patients were tested either before or during immunomodulatory therapy.

Results

Four of 222 patients (1.8%; 95% CI, 0.1%-3.6%) had positive QFT-GIT results; three patients had risk factors for TB, having emigrated from TB-endemic countries or worked in the health care industry. Twenty-eight of 222 patients (12.6%) had an indeterminate assay result, and 75.0% of these occurred in patients taking dimethyl fumarate. Fingolimod, natalizumab, or anti-CD20 treatments showed 0% to 7.7% indeterminate results.

Conclusions

The prevalence of LTBI was 1.8% in the Beth Israel Deaconess Medical Center MS Clinic. Not all LTBI cases were associated with known risk factors for TB. Screening for LTBI before starting immunosuppressive agents for MS could help prevent activation of TB. Dimethyl fumarate use is associated with indeterminate QFT-GIT results, possibly due to functional effects on lymphocytes and levels of cytokines, such as interferon gamma. In contrast, fingolimod use was rarely associated with indeterminate QFT-GIT results despite a high rate of lymphopenia in virtually all patients.

High Completion Rate for 12 Weekly Doses of Isoniazid and Rifapentine as Treatment for Latent Mycobacterium tuberculosis Infection in the Federal Bureau of Prisons

CONTEXT

Correctional facilities provide unique opportunities to diagnose and treat persons with latent tuberculosis infection (LTBI). Studies have shown that 12 weekly doses of isoniazid and rifapentine (INH-RPT) to treat LTBI resulted in high completion rates with good tolerability.

OBJECTIVE

To evaluate completion rates and clinical signs or reported symptoms associated with discontinuation of 12 weekly doses of INH-RPT for LTBI treatment.

SETTING/PARTICIPANTS

During July 2012 to February 2015, 7 Federal Bureau of Prisons facilities participated in an assessment of 12 weekly doses of INH-RPT for LTBI treatment among 463 inmates.

MAIN OUTCOME MEASURES

Fisher exact test was used to assess the associations between patient sociodemographic characteristics and clinical signs or symptoms with discontinuation of treatment.

RESULTS

Of 463 inmates treated with INH-RPT, 424 (92%) completed treatment. Reasons for discontinuation of treatment for 39 (8%) inmates included the following: 17 (44%) signs/symptoms, 9 (23%) transfer or release, 8 (21%) treatment refusal, and 5 (13%) provider error. A total of 229 (49.5%) inmates reported experiencing at least 1 sign or symptom during treatment; most frequently reported were fatigue (16%), nausea (13%), and abdominal pain (7%). Among these 229 inmates, signs/symptoms significantly associated with discontinuation of treatment included abdominal pain (P < .001), appetite loss (P = .02), fever/chills (P = .01), nausea (P = .03), sore muscles (P = .002), and elevation of liver transaminases 5× upper limits of normal or greater (P = .03).

CONCLUSIONS

The LTBI completion rates were high for the INH-RPT regimen, with few inmates discontinuing because of signs or symptoms related to treatment. This regimen also has practical advantages to aid in treatment completion in the correctional setting and can be considered a viable alternative to standard LTBI regimens.

Treatment of Latent Tuberculosis Infection-An Update

Treatment of latent tuberculosis infection (LTBI) is an important component of TB control and elimination. LTBI treatment regimens include once-weekly isoniazid plus rifapentine for 3 months, daily rifampin for 4 months, daily isoniazid plus rifampin for 3-4 months, and daily isoniazid for 6-9 months. Isoniazid monotherapy is efficacious in preventing TB disease, but the rifampin- and rifapentine-containing regimens are shorter and have similar efficacy, adequate safety, and higher treatment completion rates. Novel vaccine strategies, host immunity-directed therapies and ultrashort antimicrobial regimens for TB prevention, such as daily isoniazid plus rifapentine for 1 month, are under evaluation.

Diagnostic Tests for Latent Tuberculosis Infection

Diagnosing latent tuberculosis (TB) infection (LTBI) is important globally for TB prevention. LTBI diagnosis requires a positive test for infection and negative evaluation for active disease. Current tests measure an immunologic response and include the tuberculin skin test (TST) and interferon-gamma release assays (IGRAs), T-SPOT.TB and QuantiFERON. The IGRAs are preferred in bacille Calmette-Guérin-vaccinated populations. The TST is still used when cost or logistical advantages over the IGRAs exist. Both TST and IGRAs have low positive predictive values. Tests that differentiate the TB spectrum and better predict future TB risk are needed.

Distinct Human NK Cell Phenotypes and Functional Responses to Mycobacterium tuberculosis in Adults From TB Endemic and Non-endemic Regions

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), which leads to an estimated 1. 5 million deaths worldwide each year. Although the immune correlates of protection against Mtb infection and TB disease have not been well-defined, natural killer (NK) cells are increasingly recognized as a key component of the innate immune response to Mtb and as a link between innate and adaptive immunity. In this study, we evaluated NK cell phenotypic and functional profiles in QuantiFERON-TB (QFT)⁺ and QFT⁻ adults in a TB endemic setting in Kisumu, Kenya, and compared their NK cell responses to those of Mtb-naïve healthy adult controls in the U.S. We used flow cytometry to define the phenotypic profile of NK cells and identified distinct CD56^dim NK cell phenotypes that differentiated the Kenyan and U.S. groups. Additionally, among Kenyan participants, NK cells from QFT⁺ individuals with latent Mtb infection (LTBI) were characterized by significant downregulation of the natural cytotoxicity receptor NKp46 and the inhibitory receptor TIGIT, compared with QFT⁻ individuals. Moreover, the distinct CD56^dim phenotypic profiles in Kenyan individuals correlated with dampened NK cell responses to tumor cells and diminished activation, degranulation, and cytokine production following stimulation with Mtb antigens, compared with Mtb-naïve U.S. healthy adult controls. Taken together, these data provide evidence that the phenotypic and functional profiles of NK cells are modified in TB endemic settings and will inform future studies aimed at defining NK cell-mediated immune correlates that may be protective against acquisition of Mtb infection and progression to TB disease.

Optimizing the Design of Latent Tuberculosis Treatment Trials: Insights from Mathematical Modeling

Rationale: Noninferiority trials of treatment for latent tuberculosis infection (LTBI) are challenging because of imperfect LTBI diagnostic tests.Objectives: To assess the effect on study outcomes of different enrollment strategies for a noninferiority trial of LTBI treatment.Methods: We mathematically simulated a two-arm randomized clinical trial of LTBI in which the experimental therapy was 50% efficacious and the control was 80% efficacious, with an absolute 0.75% noninferiority margin. Five enrollment strategies were assessed: 1) enroll based on no LTBI diagnostic test; 2) enroll based on a positive tuberculin skin test (TST); 3) enroll based on a positive IFN-γ release assay (IGRA); 4) enroll based on either a positive TST or IGRA; and 5) enroll regardless of test result, assuming 70% had negative TSTs, 20% positive TSTs, and 10% unknown results.Measurements and Main Results: Under most LTBI prevalence assumptions, enrolling based on a positive IGRA was least likely to result in falsely declaring noninferiority of the experimental regimen. Enrolling based on no test or regardless of test result led to falsely declaring noninferiority unless LTBI prevalence in the underlying population was higher than 45%. Enrolling based on a mix of TST and IGRA substantially reduced the likelihood of falsely declaring noninferiority over enrolling based on TST alone, even if as many as 70% of participants were enrolled based on positive TST.Conclusions: Noninferiority trials of LTBI should enroll based on the most specific diagnostic tests available (i.e., IGRAs) to avoid misclassifying inferior treatment regimens as noninferior.

Addressing Latent Tuberculosis Infection Treatment Through a Collaborative Care Model With Community Pharmacies and a Health Department

Introduction

The objective of this study was to evaluate a novel collaborative care model using community pharmacies as additional access points for latent tuberculosis infection (LTBI) treatment for patients using combination weekly therapy with isoniazid and rifapentine (3HP) plus directly observed therapy for 12 weeks.

Methods

This prospective pilot study included adult patients diagnosed with LTBI. Patients were eligible for study participation if they spoke English or Spanish and were followed by the New Mexico Department of Health (NM DOH). Patients were excluded if they were pregnant, receiving concomitant HIV antiretroviral therapy, or had contraindications to 3HP due to allergy or drug interactions. Community pharmacy sites included chain, independent, and hospital outpatient pharmacies in Albuquerque and Santa Fe, New Mexico.

Results

A total of 40 patients initiated treatment with 3HP and were included. Most were female (55%) and had a mean age of 46 years (standard deviation, 12.6 y). A total of 75.0% of patients completed LTBI treatment with 3HP in a community pharmacy site. Individuals of Hispanic ethnicity were more likely to complete treatment (76.7% vs 40.0%, P = .04). Most patients (60%; n = 24) reported experiencing an adverse drug event (ADE) with 3HP therapy. Patients who completed treatment were less likely to experience an ADE than patients who discontinued treatment (50.0% vs 90.0%, P = .03). Pharmacists performed 398 LTBI treatment visits (40 initial visits, 358 follow-up visits), saving the NM DOH approximately 143 hours in patient contact time.

Conclusion

High completion rates and safe administration of LTBI treatment can be achieved in the community pharmacy setting.

Robustness of NHANES Estimates of the US Prevalence of a Positive Tuberculin Skin Test

BACKGROUND

A single 2-year National Health and Nutrition Examination Survey (NHANES) cycle is designed to provide accurate and stable estimates of conditions with prevalence of at least 10%. Recent NHANES-based estimates of a tuberculin skin test (TST) ≥10 mm in the noninstitutionalized US civilian population are at most 6.3%.

METHODS

NHANES included a TST in 1971-1972, 1999-2000, and 2011-2012. We examined the robustness of NHANES-based estimates of the US population prevalence of a skin test ≥10 mm with a bias analysis that considered the influence of non-US birth distributions and within-household skin test results, reclassified borderline-positive results, and adjusted for TST item nonresponse.

RESULTS

The weighted non-US birth distribution among NHANES participants was similar to that in the overall US population; further adjustment was unnecessary. We found no evidence of bias due to sampling multiple participants per household. Prevalence estimates changed 0.3% with reclassification of borderline-positive TST results and 0.2%-0.3% with adjustment for item nonresponse.

CONCLUSIONS

For estimating the national prevalence of a TST ≥10 mm during these three survey cycles, a conventional NHANES analysis using the standard participant weights and masked design parameters that are provided in the public-use datasets appears robust. See video abstract at, http://links.lww.com/EDE/B636.

Tuberculosis Prevention in the Private Sector: Using Claims-Based Methods to Identify and Evaluate Latent Tuberculosis Infection Treatment With Isoniazid Among the Commercially Insured

CONTEXT

Targeted identification and treatment of people with latent tuberculosis infection (LTBI) are key components of the US tuberculosis elimination strategy. Because of recent policy changes, some LTBI treatment may shift from public health departments to the private sector.

OBJECTIVES

To (1) develop methodology to estimate initiation and completion of treatment with isoniazid for LTBI using claims data, and (2) estimate treatment completion rates for isoniazid regimens from commercial insurance claims.

METHODS

Medical and pharmacy claims data representing insurance-paid services rendered and prescriptions filled between January 2011 and March 2015 were analyzed.

PARTICIPANTS

Four million commercially insured individuals 0 to 64 years of age.

MAIN OUTCOME MEASURES

Six-month and 9-month treatment completion rates for isoniazid LTBI regimens.

RESULTS

There was an annual isoniazid LTBI treatment initiation rate of 12.5/100 000 insured persons. Of 1074 unique courses of treatment with isoniazid for which treatment completion could be assessed, almost half (46.3%; confidence interval, 43.3-49.3) completed 6 or more months of therapy. Of those, approximately half (48.9%; confidence interval, 44.5-53.3) completed 9 months or more.

CONCLUSIONS

Claims data can be used to identify and evaluate LTBI treatment with isoniazid occurring in the commercial sector. Completion rates were in the range of those found in public health settings. These findings suggest that the commercial sector may be a valuable adjunct to more traditional venues for tuberculosis prevention. In addition, these newly developed claims-based methods offer a means to gain important insights and open new avenues to monitor, evaluate, and coordinate tuberculosis prevention.

Ambulatory independence is associated with higher incidence of latent tuberculosis infection in long-term care facilities in Taiwan

BACKGROUND/PURPOSE

Tuberculosis (TB) in the elderly population remains a major challenge in areas with intermediate disease burden like Taiwan. Despite the increasing burden and high risks of TB in the elderly population, particularly those living in long-term care facilities (LTCFs), diagnostic testing for latent tuberculosis infection (LTBI) has not been carefully evaluated in this group. This study aimed to investigate the prevalence and predictors of LTBI in older adults living in LTCFs.

METHODS

Older adults living in seven LTCFs in Taiwan were prospectively enrolled between January and July 2017. Interferon-gamma release assay (IGRA) through QuantiFERON-TB Gold In-tube was used to determine presence of LTBI. Predictors for LTBI were analyzed.

RESULTS

A total of 258 participants were enrolled, including 240 older residents (mean age, 81.6 years; male, 51.2%) and 18 employees (mean age, 64.8 years; male, 22.2%). The proportion of independent status in ambulation assessments significantly declined with aging (p < 0.001). The IGRA-positivity rate in LTCFs was 31.4% (81/258), which consisted of 73 (30.4%) residents and 8 (44.4%) employees. The IGRA results were different with respect to the ambulation status (p = 0.052). In the multivariate logistic regression analysis, the only independent predictor of LTBI among older adults in LTCFs was independent ambulation (odds ratio, 2.16; 95% confidence interval, 1.09-4.28; p = 0.027).

CONCLUSIONS

There was a high prevalence of LTBI among older adults in LTCFs in Taiwan. Independent ambulation was the only independent predictor of LTBI.

The global prevalence of latent tuberculosis: a systematic review and meta-analysis

In 1999, the World Health Organization (WHO) estimated that one-third of the world's population had latent tuberculosis infection (LTBI), which was recently updated to one-fourth. However, this is still based on controversial assumptions in combination with tuberculin skin test (TST) surveys. Interferon-γ release assays (IGRAs) with a higher specificity than TST have since been widely implemented, but never used to estimate the global LTBI prevalence.We conducted a systematic review and meta-analysis of LTBI estimates based on both IGRA and TST results published between 2005 and 2018. Regional and global estimates of LTBI prevalence were calculated. Stratification was performed for low, intermediate and high TB incidence countries and a pooled estimate for each area was calculated using a random effects model.Among 3280 studies screened, we included 88 studies from 36 countries with 41 IGRA (n=67 167) and 67 TST estimates (n=284 644). The global prevalence of LTBI was 24.8% (95% CI 19.7-30.0%) and 21.2% (95% CI 17.9-24.4%), based on IGRA and a 10-mm TST cut-off, respectively. The prevalence estimates correlated well to WHO incidence rates (Rs=0.70, p<0.001).In the first study of the global prevalence of LTBI derived from both IGRA and TST surveys, we found that one-fourth of the world's population is infected. This is of relevance, as both tests, although imperfect, are used to identify individuals eligible for preventive therapy. Enhanced efforts are needed targeting the large pool of latently infected individuals, as this constitutes an enormous source of potential active tuberculosis.

Tuberculosis screening in multiple sclerosis: effect of disease-modifying therapies and lymphopenia on the prevalence of indeterminate TB screening results in the clinical setting

Background

Tuberculosis screening is recommended in multiple sclerosis patients starting certain disease-modifying therapies. Disease-modifying therapies may affect interferon-gamma release assay results.

Objective

To determine the effects of multiple sclerosis disease-modifying therapies on interferon-gamma release assay results.

Methods

Indeterminate interferon-gamma release assay results among multiple sclerosis patients were compared across disease-modifying therapies by Fisher's exact test. Logistic regression evaluated the effects of lymphopenia on interferon-gamma release assay results.

Results

A total of 1058 patients underwent interferon-gamma release assay: 2.0% (21) positive, 6.1% (65) indeterminate, with 59.4% (628) on disease-modifying therapies. Results were significantly different across disease-modifying therapies (P = 0.002). Absolute lymphocyte count less than 0.5 k/μL had 9.39 times (95% confidence interval 5.2-17.0) increased odds of indeterminate interferon-gamma release assay results.

Conclusions

Disease-modifying therapies affecting lymphocytes had a higher risk of indeterminate interferon-gamma release assay results.

Timing of treatment interruption among latently infected tuberculosis cases treated with a nine-month course of daily isoniazid: findings from a time to event analysis

Background

Treatment of latent tuberculosis infection (LTBI) in high-risk groups is an effective strategy for TB control and elimination in low incidence settings. A nine-month course of daily isoniazid (INH) has been the longest prescribed therapy; however, completion rates are suboptimal. We need data to guide TB program outreach efforts to optimize LTBI treatment completion rates.

Methods

We pooled seven (2009–2015) years of LTBI treatment outcome data. We computed the probability of INH treatment disruption over time by patient demographic and clinical risk factors. We used log-rank tests and Cox proportional hazards models to assess the risk factors for treatment disruption.

Results

We analyzed data from 12,495 persons with complete data on INH treatment initiation. Pediatric cases (0–17 years), recent contacts of active TB patients, and non-U.S.-born adults living in the United States ≤5 years represented 25.2, 13.0, and 59.2% of the study population, respectively. Overall, 48.4% failed to complete therapy. The median treatment duration was 306 days (95% CI: 297, 315). A significant drop in adherence could be observed around day 30 of treatment initiation. Indeed, by day 30 of treatment, 17.0% (95% CI: 16.4, 17.7) of patients had defaulted on therapy. Pediatric patients (HR = 0.83, 95% CI: 0.78, 0.89), recent contacts (HR = 0.74, 95% CI: 0.68, 0.81), patients with diabetes (HR = 0.77, 95% CI: 0.60, 0.98), and patients with HIV (HR = 0.39, 95% CI: 0.30, 0.51) had a lower risk of treatment default. However, black patients (HR = 1.57, 95% CI: 1.44, 1.70), Hispanic patients (HR = 1.54, 95% CI: 1.43, 1.66), and non-U.S.-born persons living in the United States ≤5 years (HR = 1.25, 95% CI: 1.18, 1.32) were significantly more likely to default on therapy.

Conclusions

In this analysis of INH treatment outcome, we see high levels of treatment discontinuation. On average, patients defaulted on their prescribed nine-month daily INH therapy within 30 days of initiating treatment, and those at increased risk of progression to active disease were most likely to do so. We highlight the need to introduce patient-centered programs to increase treatment adherence in this population.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7524-4) contains supplementary material, which is available to authorized users.

Impact and Effectiveness of State-Level Tuberculosis Interventions in California, Florida, New York, and Texas: A Model-Based Analysis

The incidence of tuberculosis (TB) in the United States has stabilized, and additional interventions are needed to make progress toward TB elimination. However, the impact of such interventions depends on local demography and the heterogeneity of populations at risk. Using state-level individual-based TB transmission models calibrated to California, Florida, New York, and Texas, we modeled 2 TB interventions: 1) increased targeted testing and treatment (TTT) of high-risk populations, including people who are non-US-born, diabetic, human immunodeficiency virus (HIV)-positive, homeless, or incarcerated; and 2) enhanced contact investigation (ECI) for contacts of TB patients, including higher completion of preventive therapy. For each intervention, we projected reductions in active TB incidence over 10 years (2016-2026) and numbers needed to screen and treat in order to avert 1 case. We estimated that TTT delivered to half of the non-US-born adult population could lower TB incidence by 19.8%-26.7% over a 10-year period. TTT delivered to smaller populations with higher TB risk (e.g., HIV-positive persons, homeless persons) and ECI were generally more efficient but had less overall impact on incidence. TTT targeted to smaller, highest-risk populations and ECI can be highly efficient; however, major reductions in incidence will only be achieved by also targeting larger, moderate-risk populations. Ultimately, to eliminate TB in the United States, a combination of these approaches will be necessary.

Evaluating vaccination strategies for tuberculosis in endemic and non-endemic settings

According to the World Health Organization, tuberculosis (TB) is the leading cause of death from infectious disease worldwide (WHO, 2017). While there is no effective vaccine against adult pulmonary TB, more than a dozen vaccine candidates are in the clinical trial pipeline. These include both pre-exposure vaccines to prevent initial infections and post-exposure vaccines to prevent reactivation of latent disease. Many epidemiological models have been used to study TB, but most have not included a continuous age structure and the possibility of both pre- and post-exposure vaccination. Incorporating age-dependent death rates, disease properties, and social contact data allows for more realistic modeling of disease spread. We propose a continuous age-structured model for the epidemiology of tuberculosis with pre- and post-exposure vaccination. We use uncertainty and sensitivity analysis to make predictions about the efficacy of different vaccination strategies in a non-endemic setting (United States) and an endemic setting (Cambodia). In particular, we determine optimal age groups to target for pre-exposure and post-exposure vaccination in both settings. We find that the optimal age groups tend to be younger for Cambodia than for the US, and that post-exposure vaccination has a significantly larger effect than pre-exposure vaccination in the US.

Mathematical modelling of the impact of treating latent tuberculosis infection in the elderly in a city with intermediate tuberculosis burden

Hong Kong is a high-income city with intermediate tuberculosis (TB) burden primarily driven by endogenous reactivations. A high proportion of remote latently infected people, particularly elderly, hinders the effectiveness of current strategies focusing on passive TB detection. In this study, we developed a mathematical model to evaluate the impact of treating latent TB infection (LTBI) in the elderly in addition to current TB control strategies. The model was calibrated using the annual age-stratified TB notifications from 1965-2013 in Hong Kong. Our results showed that at present, approximately 75% of annual new notifications were from reactivations. Given the present treatment completion rate, even if only a low to moderate proportion (approximately 20% to 40%) of elderly people were screened and treated for LTBI, the overall TB incidence could be reduced by almost 50%, to reach the 2025 milestone of the global End TB Strategy. Nevertheless, due to a high risk of hepatotoxicity in elderly population, benefit-risk ratios were mostly below unity; thus, intervention programs should be carefully formulated, including prioritising LTBI treatment for high-risk elderly groups who are closely monitored for possible adverse side effects.

Latent Tuberculosis Infection Beliefs and Testing and Treatment Health Behaviors Amongst Non-US-Born South Asians in New Jersey: A Cross-Sectional Community Survey

Latent tuberculosis infection (LTBI) remains a problem in the United States as reactivation leads to active TB disease particularly in persons with risk factors. The objective of this study is to assess the knowledge, attitudes and health behaviors related to testing and treatment of LTBI among non-US-born South Asians (SA) in New Jersey (NJ). A cross-sectional, community-based survey was the primary tool for gathering data. Eligibility criteria included being at least 18 years of age, self-identifying as SA, verbal consent for participation, and birth in a high TB endemic country. A hardcopy survey was distributed at local South Asian health fairs. The survey included questions about demographics, knowledge, beliefs on TB, and health behaviors (testing and treatment). Descriptive statistics were performed for all survey responses. Logistic regression models were constructed to assess the association of characteristics/beliefs and study outcomes. The survey sample size included 387 respondents. A total of 197 (54%) of respondents reported ever been tested for TB. Those who were tested for TB were generally younger, had higher educational levels, higher household incomes, and were more likely to have health insurance than those not ever tested for TB. Significantly more respondents who self-reported ever been tested for TB believed that TB was very or extremely serious (71.1% vs. 56.2%, p = 0.004). Also, significantly more respondents who self-reported ever been tested for TB believed that it was important to get tested (91.2% vs. 63.3%, p < 0.001). The survey analysis concluded that high-risk SA residents in NJ demonstrated a low rate of testing for TB.