Comparison of Tuberculin Skin Testing and Interferon-γ Release Assays in Predicting Tuberculosis Disease.

Importance: Elimination of tuberculosis (TB) disease in the US hinges on the ability of tests to detect individual risk of developing disease to inform prevention. The relative performance of 3 available TB tests-the tuberculin skin test (TST) and 2 interferon-γ release assays (IGRAs; QuantiFERON-TB Gold In-Tube [QFT-GIT] and SPOT.TB [TSPOT])-in predicting TB disease development in the US remains unknown. Objective: To compare the performance of the TST with the QFT-GIT and TSPOT IGRAs in predicting TB disease in high-risk populations. Design, Setting, and Participants: This prospective diagnostic study included participants at high risk of TB infection (TBI) or progression to TB disease at 10 US sites between 2012 and 2020. Participants of any age who had close contact with a case patient with infectious TB, were born in a country with medium or high TB incidence, had traveled recently to a high-incidence country, were living with HIV infection, or were from a population with a high local prevalence were enrolled from July 12, 2012, through May 5, 2017. Participants were assessed for 2 years after enrollment and through registry matches until the study end date (November 15, 2020). Data analysis was performed in June 2023. Exposures: At enrollment, participants were concurrently tested with 2 IGRAs (QFT-GIT from Qiagen and TSPOT from Oxford Immunotec) and the TST. Participants were classified as case patients with incident TB disease when diagnosed more than 30 days from enrollment. Main Outcomes and Measures: Estimated positive predictive value (PPV) ratios from generalized estimating equation models were used to compare test performance in predicting incident TB. Incremental changes in PPV were estimated to determine whether predictive performance significantly improved with the addition of a second test. Case patients with prevalent TB were examined in sensitivity analysis. Results: A total of 22 020 eligible participants were included in this study. Their median age was 32 (range, 0-102) years, more than half (51.2%) were male, and the median follow-up was 6.4 (range, 0.2-8.3) years. Most participants (82.0%) were born outside the US, and 9.6% were close contacts. Tuberculosis disease was identified in 129 case patients (0.6%): 42 (0.2%) had incident TB and 87 (0.4%) had prevalent TB. The TSPOT and QFT-GIT assays performed significantly better than the TST (PPV ratio, 1.65 [95% CI, 1.35-2.02] and 1.47 [95% CI, 1.22-1.77], respectively). The incremental gain in PPV, given a positive TST result, was statistically significant for positive QFT-GIT and TSPOT results (1.64 [95% CI, 1.40-1.93] and 1.94 [95% CI, 1.65-2.27], respectively). Conclusions and Relevance: In this diagnostic study assessing predictive value, IGRAs demonstrated superior performance for predicting incident TB compared with the TST. Interferon-γ release assays provided a statistically significant incremental improvement in PPV when a positive TST result was known. These findings suggest that IGRA performance may enhance decisions to treat TBI and prevent TB.

Risk Factors for Progression in Patients Undergoing Surveillance for Pancreatic Cysts.

OBJECTIVE: To identify risk factors associated with the progression of pancreatic cysts in patients undergoing surveillance. BACKGROUND: Previous studies of intraductal papillary mucinous neoplasms (IPMNs) rely on surgical series to determine malignancy risk and have inconsistently identified characteristics associated with IPMN progression. METHODS: We conducted a retrospective review of 2197 patients presenting with imaging concerning for IPMN from 2010 to 2019 at a single institution. Cyst progression was defined as resection or pancreatic cancer development. RESULTS: The median follow-up time was 84 months from the presentation. The median age was 66 years, and 62% were female. Ten percent had a first-degree relative with pancreatic cancer, and 3.2% had a germline mutation or genetic syndrome associated with an increased risk of pancreatic ductal adenocarcinoma (PDAC). Cumulative incidence of progression was 17.8% and 20.0% at 12 and 60 months postpresentation, respectively. Surgical pathology for 417 resected cases showed noninvasive IPMN in 39% of cases and PDAC with or without associated IPMN in 20%. Only 18 patients developed PDAC after 6 months of surveillance (0.8%). On multivariable analysis, symptomatic disease [hazard ratio (HR)=1.58; 95% CI: 1.25-2.01], current smoker status (HR=1.58; 95% CI: 1.16-2.15), cyst size (HR=1.26; 95% CI: 1.20-1.33), main duct dilation (HR=3.17; 95% CI: 2.44-4.11), and solid components (HR=1.89; 95% CI: 1.34-2.66) were associated with progression. CONCLUSIONS: Worrisome features on imaging at presentation, current smoker status, and symptomatic presentation are associated with IPMN progression. Most patients progressed within the first year of presentation to Memorial Sloan Kettering Cancer Center (MSKCC). Further investigation is necessary to develop personalized cyst surveillance strategies.

Tuberculosis Diagnostic Delays and Treatment Outcomes among Patients with COVID-19, California, USA, 2020.

We assessed tuberculosis (TB) diagnostic delays among patients with TB and COVID-19 in California, USA. Among 58 persons, 43% experienced TB diagnostic delays, and a high proportion (83%) required hospitalization for TB. Even when viral respiratory pathogens circulate widely, timely TB diagnostic workup for at-risk persons remains critical for reducing TB-related illness.

Can Primary Care Drive Tuberculosis Elimination? Increasing Latent Tuberculosis Infection Testing and Treatment Initiation at a Community Health Center with a Large Non-U.S.-born Population.

Community health centers (CHC) play a key role in latent tuberculosis infection (LTBI) testing and treatment. We performed a retrospective analysis of LTBI testing and treatment among pediatric and adult patients at a CHC with a large non-U.S.-born (USB) population during a series of quality improvement (QI) interventions from 2010 to 2019. Among 124,695 patients with primary care visits, 40% of patients were tested for tuberculosis (TB) infection and among those tested, 20% tested positive, including 39% of adults aged 50-79 years. Compared to adults aged 18-49 years, children aged 6-17 had increased odds of LTBI testing and treatment initiation [odds ratio and 95% confidence interval 3.23 (3.10, 3.36) and 1.41 (1.12, 1.79), respectively], while age ≥ 65 was associated with lower odds of both testing and treatment initiation. Over the analysis period, coinciding with unfunded QI interventions intended to reduce barriers to LTBI care, there was a significant increase in the proportion of patients receiving LTBI testing for both adults (6% to 47%, p < 0.001) and children (23% to 80%, p < 0.001). During the analysis period, there was also a significant increase in the proportion of patients receiving prescriptions for LTBI treatment, as well as provider use of evidence-based strategies including rifamycin-based treatment. Our study suggests that primary care interventions can reduce barriers to LTBI treatment and drive TB elimination.

Solid organ transplant recipients with tuberculosis disease in California, 2010 to 2020.

Using California Tuberculosis (TB) Registry data from 2010-2020, we compared the presentation and outcomes of patients with TB aged >15 years with and without solid organ transplantation (SOT). We matched to the United Network for Organ Sharing registry for 1987-2020 and the estimated time from transplantation to the diagnosis of TB, the incidence of posttransplant TB, and the probability of death and graft failure in SOT recipients with TB, compared to those without TB. From 2010-2020, there were 148 posttransplant TB cases. Patients with posttransplant TB were more likely to have extrapulmonary disease and more than twice as likely to die as TB patients without SOT (relative risk [RR], 2.2; 95% confidence interval [CI], 1.6-2.9). The median time from transplantation to TB diagnosis was 1.2 years, with the shortest time among lung transplant recipients. The incidence of TB disease among Californians with SOT was 56.0 per 100 000 person-years. The risk of death was higher among SOT recipients with posttransplant TB than those without (adjusted hazard ratio, 2.8; 95% CI, 2.0-4.1); the risk of graft failure was higher among kidney transplant recipients with posttransplant TB than those without (adjusted hazard ratio, 3.4; 95% CI, 1.7-6.9). An increased risk of death and graft failure in SOT recipients with posttransplant TB highlights the need for enhanced pretransplant TB prevention.

Association of Area-Based Socioeconomic Measures with Tuberculosis Incidence in California.

We assessed the association of area-based socio-economic status (SES) measures with tuberculosis (TB) incidence in California. We used TB disease data for 2012-2016 (n = 9901), population estimates, and SES measures to calculate incidence rates, rate ratios, and 95% confidence intervals (95% CI) by SES and birth country. SES was measured by census tract and was categorized by quartiles for education, crowding, and the California Healthy Places Index (HPI)and by specific cutoffs for poverty. The lowest SES areas defined by education, crowding, poverty, and HPI had 39%, 40%, 41%, and 33% of TB cases respectively. SES level was inversely associated with TB incidence across all SES measures and birth countries. TB rates were 3.2 (95% CI 3.0-3.4), 2.1 (95% CI 1.9-2.2), 3.6 (95% CI 3.3-3.8), and 2.0 (95% CI 1.9-2.1) times higher in lowest SES areas vs. highest SES areas as defined by education, crowding, poverty and HPI respectively. Area-based SES measures are associated with TB incidence in California. This information could inform TB prevention efforts in terms of materials, partnerships, and prioritization.

Health insurance, healthcare utilization and language use among populations who experience risk for tuberculosis, California 2014-2017.

BACKGROUND: California tuberculosis (TB) prevention goals include testing more than ten million at-risk Californians and treating two million infected with tuberculosis. Adequate health insurance and robust healthcare utilization are crucial to meeting these goals, but information on these factors for populations that experience risk for TB is limited. METHODS: We used data from the 2014-2017 California Health Interview Survey (n = 82,758), a population-based dual-frame telephone survey to calculate survey proportions and 95% confidence intervals (CI) stratified by country of birth, focusing on persons from countries of birth with the highest number of TB cases in California. Survey proportions for recent doctor's visit, overall health, smoking, and diabetes were age-adjusted. RESULTS: Among 18-64 year-olds, 27% (CI: 25-30) of persons born in Mexico reported being uninsured in contrast with 3% (CI: 1-5) of persons born in India. Report of recent doctor's visit was highest among persons born in the Philippines, 84% (CI: 80-89) and lowest among Chinese-born persons, 70% (CI: 63-76). Persons born in Mexico were more likely to report community clinics as their usual source of care than persons born in China, Vietnam, or the Philippines. Poverty was highest among Mexican-born persons, 56% (CI: 54-58) and lowest among Indian-born persons, 9% (CI: 5-13). Of adults with a medical visit in a non-English language, 96% (CI: 96-97) were non-U.S.-born, but only 42% (CI: 40-44) of non-U.S.-born persons had a visit in a non-English language. DISCUSSION: Many, though not all, of the populations that experience risk for TB had health insurance and used healthcare. We found key differences in usual source of care and language use by country of birth which should be considered when planning outreach to specific providers, clinic systems, insurers and communities for TB prevention and case-finding.

Low-Dose Linezolid for Treatment of Patients With Multidrug-Resistant Tuberculosis.

Background: Linezolid has been prioritized for treating multidrug-resistant tuberculosis (MDR TB), but toxicity limits its use. We report treatment outcomes for MDR TB patients in California who received standard-dose linezolid vs those who switched to low-dose. Methods: We include culture-positive MDR TB cases treated with linezolid and receiving California MDR TB Service consultation during 2009-2016. Demographic, clinical, and laboratory data are analyzed using univariate analysis to compare patients who received linezolid of different dosing strategies. Analysis end points are linezolid treatment duration (measure of tolerability), treatment success (completion or cure), and adverse events (AEs). Results: Sixty-nine of 194 (36%) MDR TB patients met inclusion criteria. While all patients began linezolid treatment at 600 mg daily, 39 (57%) continued at this dosage (standard-dose), and 30 (43%) switched to 300 mg daily (29%) or intermittent dosing (14%) (low dose). Patients on standard-dose linezolid were treated for 240 days, compared with 535 for those on low-dose (P < .0001). Sixty-three patients (91%) achieved treatment success, 2 (2.9%) died, 1 (1.5%) failed treatment, 1 (1.5%) stopped treatment due to side effects, and 2 (2.9%) were lost or moved. Treatment success was higher (P = .03) in the low-dose group. Sixty-two patients experienced ≥1 hematologic (71%) or neurologic (65%) AE. Those on low-dose linezolid experienced significantly (P = .03) fewer AEs per linezolid-month after switching (0.32 vs 0.10). Conclusions: Patients who switched to low dose tolerated linezolid longer with better treatment outcomes and fewer recurring AEs.

Sociodemographic Characteristics, Comorbidities, and Mortality Among Persons Diagnosed With Tuberculosis and COVID-19 in Close Succession in California, 2020.

Importance: Tuberculosis (TB) and COVID-19 are respiratory diseases that disproportionately occur among medically underserved populations; little is known about their epidemiologic intersection. Objective: To characterize persons diagnosed with TB and COVID-19 in California. Design, Setting, and Participants: This cross-sectional analysis of population-based public health surveillance data assessed the sociodemographic, clinical, and epidemiologic characteristics of California residents who were diagnosed with TB (including cases diagnosed and reported between September 3, 2019, and December 31, 2020) and COVID-19 (including confirmed cases based on positive results on polymerase chain reaction tests and probable cases based on positive results on antigen assays reported through February 2, 2021) in close succession compared with those who were diagnosed with TB before the COVID-19 pandemic (between January 1, 2017, and December 31, 2019) or diagnosed with COVID-19 alone (through February 2, 2021). This analysis included 3 402 713 California residents with COVID-19 alone, 6280 with TB before the pandemic, and 91 with confirmed or probable COVID-19 diagnosed within 120 days of a TB diagnosis (ie, TB/COVID-19). Exposures: Sociodemographic characteristics, medical risk factors, factors associated with TB severity, and health equity index. Main Outcomes and Measures: Frequency of reported successive TB and COVID-19 (TB/COVID-19) diagnoses within 120 days, frequency of deaths, and age-adjusted mortality rates. Results: Among the 91 persons with TB/COVID-19, the median age was 58.0 years (range, 3.0-95.0 years; IQR, 41.0-73.0 years); 52 persons (57.1%) were male; 81 (89.0%) were born outside the US; and 28 (30.8%) were Asian or Pacific Islander, 4 (4.4%) were Black, 55 (60.4%) were Hispanic or Latino, 4 (4.4%) were White. The frequency of reported COVID-19 among those who received a TB diagnosis between September 3, 2019, and December 31, 2020, was 225 of 2210 persons (10.2%), which was similar to that of the general population (3 402 804 of 39 538 223 persons [8.6%]). Compared with persons with TB before the pandemic, those with TB/COVID-19 were more likely to be Hispanic or Latino (2285 of 6279 persons [36.4%; 95% CI, 35.2%-37.6%] vs 55 of 91 persons [60.4%; 95% CI, 49.6%-70.5%], respectively; P < .001), reside in low health equity census tracts (1984 of 6027 persons [32.9%; 95% CI, 31.7%-34.1%] vs 40 of 89 persons [44.9%; 95% CI, 34.4%-55.9%]; P = .003), live in the US longer before receiving a TB diagnosis (median, 19.7 years [IQR, 7.2-32.3 years] vs 23.1 years [IQR, 15.2-31.5 years]; P = .03), and have diabetes (1734 of 6280 persons [27.6%; 95% CI, 26.5%-28.7%] vs 42 of 91 persons [46.2%; 95% CI, 35.6%-56.9%]; P < .001). The frequency of deaths among those with TB/COVID-19 successively diagnosed within 30 days (8 of 34 persons [23.5%; 95% CI, 10.8%-41.2%]) was more than twice that of persons with TB before the pandemic (631 of 5545 persons [11.4%; 95% CI, 10.6%-12.2%]; P = .05) and 20 times that of persons with COVID-19 alone (42 171 of 3 402 713 persons [1.2%; 95% CI, 1.2%-1.3%]; P < .001). Persons with TB/COVID-19 who died were older (median, 81.0 years; IQR, 75.0-85.0 years) than those who survived (median, 54.0 years; IQR, 37.5-68.5 years; P < .001). The age-adjusted mortality rate remained higher among persons with TB/COVID-19 (74.2 deaths per 1000 persons; 95% CI, 26.2-122.1 deaths per 1000 persons) compared with either disease alone (TB before the pandemic: 56.3 deaths per 1000 persons [95% CI, 51.2-61.4 deaths per 1000 persons]; COVID-19 only: 17.1 deaths per 1000 persons [95% CI, 16.9-17.2 deaths per 1000 persons]). Conclusions and Relevance: In this cross-sectional analysis, TB/COVID-19 was disproportionately diagnosed among California residents who were Hispanic or Latino, had diabetes, or were living in low health equity census tracts. These results suggest that tuberculosis and COVID-19 occurring together may be associated with increases in mortality compared with either disease alone, especially among older adults. Addressing health inequities and integrating prevention efforts could avert the occurrence of concurrent COVID-19 and TB and potentially reduce deaths.

State-level prevalence estimates of latent tuberculosis infection in the United States by medical risk factors, demographic characteristics and nativity.

INTRODUCTION: Preventing tuberculosis (TB) disease requires treatment of latent TB infection (LTBI) as well as prevention of person-to-person transmission. We estimated the LTBI prevalence for the entire United States and for each state by medical risk factors, age, and race/ethnicity, both in the total population and stratified by nativity. METHODS: We created a mathematical model using all incident TB disease cases during 2013-2017 reported to the National Tuberculosis Surveillance System that were classified using genotype-based methods or imputation as not attributed to recent TB transmission. Using the annual average number of TB cases among US-born and non-US-born persons by medical risk factor, age group, and race/ethnicity, we applied population-specific reactivation rates (and corresponding 95% confidence intervals [CI]) to back-calculate the estimated prevalence of untreated LTBI in each population for the United States and for each of the 50 states and the District of Columbia in 2015. RESULTS: We estimated that 2.7% (CI: 2.6%-2.8%) of the U.S. population, or 8.6 (CI: 8.3-8.8) million people, were living with LTBI in 2015. Estimated LTBI prevalence among US-born persons was 1.0% (CI: 1.0%-1.1%) and among non-US-born persons was 13.9% (CI: 13.5%-14.3%). Among US-born persons, the highest LTBI prevalence was in persons aged ≥65 years (2.1%) and in persons of non-Hispanic Black race/ethnicity (3.1%). Among non-US-born persons, the highest LTBI prevalence was estimated in persons aged 45-64 years (16.3%) and persons of Asian and other racial/ethnic groups (19.1%). CONCLUSIONS: Our estimations of the prevalence of LTBI by medical risk factors and demographic characteristics for each state could facilitate planning for testing and treatment interventions to eliminate TB in the United States. Our back-calculation method feasibly estimates untreated LTBI prevalence and can be updated using future TB disease case counts at the state or national level.

Assessing Complexity Among Patients With Tuberculosis in California, 1993-2016.

BACKGROUND: Although the number of patients with active tuberculosis (TB) has decreased in the last 25 years, anecdotal reports suggest that the complexity of these patients has increased. However, this complexity and its components have never been quantified or defined. We therefore aimed to describe the complexity of patients with active TB in California during 1993-2016. METHODS: We analyzed data on patient comorbidities, clinical features, and demographics from the California Department of Public Health TB Registry. All adult patients who were alive at the time of TB diagnosis in California during 1993-2016 were included in the analyses. Factors deemed by an expert panel to increase complexity (ie, increased resources or expertise requirement for successful management) were analyzed and included the following: age >75 years, HIV infection, multidrug resistance (MDR), and extrapulmonary TB disease. Second, using additional information on other comorbidities available starting in 2010, we performed exploratory factor analysis on 25 variables in order to define the dimensions of complexity. RESULTS: Among the 67 512 patients analyzed, the proportion of patients with extrapulmonary disease, age >75 years, or MDR-TB each increased over the study period (P < .001), while the proportion of patients with HIV decreased. Furthermore, the proportion of patients with at least 1 factor of those increased, rising from 38.8% to 45.3% (P < .001) from 1993 to 2016. Dimensions of complexity identified in the exploratory factor analysis included the following: race/immigration, social features, elderly/institutionalized, advanced TB, comorbidity, and drug resistance risk. CONCLUSIONS: In this first description of complexity in the setting of TB, we found that the complexity of patients with active TB has risen over the last 25 years in California. These findings suggest that despite the overall decline in active TB cases, effective management of more complex patients may require additional attention and resource investment.

Modeling the Impact of Recommendations for Primary Care-Based Screening for Latent Tuberculosis Infection in California.

OBJECTIVE: Targeted testing and treatment of persons with latent tuberculosis infection (LTBI) is a critical component of the US tuberculosis (TB) elimination strategy. In January 2016, the California Department of Public Health issued a tool and user guide for TB risk assessment (California tool) and guidance for LTBI testing, and in September 2016, the US Preventive Services Task Force (USPSTF) issued recommendations for LTBI testing in primary care settings. We estimated the epidemiologic effect of adherence to both recommendations in California. METHODS: We used an individual-based Markov micro-simulation model to estimate the number of cases of TB disease expected through 2026 with baseline LTBI strategies compared with implementation of the USPSTF or California tool guidance. We estimated the risk of LTBI by age and country of origin, the probability of being in a targeted population, and the probability of presenting for primary care based on available data. We assumed 100% adherence to testing guidance but imperfect adherence to treatment. RESULTS: Implementation of USPSTF and California tool guidance would result in nearly identical numbers of tests administered and cases of TB disease prevented. Perfect adherence to either recommendation would result in approximately 7000 cases of TB disease averted (40% reduction compared with baseline) by 2026. Almost all of this decline would be driven by a reduction in the number of cases among non-US-born persons. CONCLUSIONS: By focusing on the non-US-born population, adherence to LTBI testing strategies recommended by the USPSTF and the California tool could substantially reduce the burden of TB disease in California in the next decade.

Residential urban tree canopy is associated with decreased mortality during tuberculosis treatment in California.

Trees can sequester air pollutants, and air pollution is associated with poor tuberculosis outcomes. However, the health impacts of urban trees on tuberculosis patients are unknown. To elucidate the effects of urban tree canopy on mortality during tuberculosis treatment, we evaluated patients diagnosed with active tuberculosis in California from 2000 through 2012, obtaining patient data from the California tuberculosis registry. Our primary outcome was all-cause mortality during tuberculosis treatment. We determined percent tree cover using 1 mresolution color infrared orthoimagery categorized into land cover classes, then linked tree cover to four circular buffer zones of 50-300 m radii around patient residential addresses. We used the Kaplan-Meier method to estimate survival probabilities and Cox regression models to determine mortality hazard ratios, adjusting for demographic, socioeconomic, and clinical covariates. Our cohort included 33,962 tuberculosis patients of median age 47, 59% male, 51% unemployed, and 4.9% HIV positive. Tuberculosis was microbiologically confirmed in 79%, and 1.17% were multi-drug resistant (MDR). Median tree cover was 7.9% (50 m buffer). Patients were followed for 23,280 person-years with 2370 deaths during tuberculosis treatment resulting in a crude mortality rate of 1018 deaths per 10,000 person-years. Increasing tree cover quintiles were associated with decreasing mortality risk during tuberculosis treatment in all buffers, and the magnitude of association decreased incrementally with increasing buffer radius: In the 50 m buffer, patients living in neighborhoods with the highest quintile tree cover experienced a 22% reduction in mortality (HR 0.78, 95%CI 0.68-0.90) compared to those living in lowest quintile tree cover; whereas for 100, 200, and 300 m buffers, a 21%, 13%, and 11% mortality risk reduction was evident. In conclusion, urban tree canopy was associated with decreased mortality during tuberculosis treatment even after adjusting for multiple demographic, socioeconomic, and clinical factors, suggesting that trees might play a role in improving tuberculosis outcomes.

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.

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.

Outlook for tuberculosis elimination in California: An individual-based stochastic model.

RATIONALE: As part of the End TB Strategy, the World Health Organization calls for low-tuberculosis (TB) incidence settings to achieve pre-elimination (<10 cases per million) and elimination (<1 case per million) by 2035 and 2050, respectively. These targets require testing and treatment for latent tuberculosis infection (LTBI). OBJECTIVES: To estimate the ability and costs of testing and treatment for LTBI to reach pre-elimination and elimination targets in California. METHODS: We created an individual-based epidemic model of TB, calibrated to historical cases. We evaluated the effects of increased testing (QuantiFERON-TB Gold) and treatment (three months of isoniazid and rifapentine). We analyzed four test and treat targeting strategies: (1) individuals with medical risk factors (MRF), (2) non-USB, (3) both non-USB and MRF, and (4) all Californians. For each strategy, we estimated the effects of increasing test and treat by a factor of 2, 4, or 10 from the base case. We estimated the number of TB cases occurring and prevented, and net and incremental costs from 2017 to 2065 in 2015 U.S. dollars. Efficacy, costs, adverse events, and treatment dropout were estimated from published data. We estimated the cost per case averted and per quality-adjusted life year (QALY) gained. MEASUREMENTS AND MAIN RESULTS: In the base case, 106,000 TB cases are predicted to 2065. Pre-elimination was achieved by 2065 in three scenarios: a 10-fold increase in the non-USB and persons with MRF (by 2052), and 4- or 10-fold increase in all Californians (by 2058 and 2035, respectively). TB elimination was not achieved by any intervention scenario. The most aggressive strategy, 10-fold in all Californians, achieved a case rate of 8 (95% UI 4-16) per million by 2050. Of scenarios that reached pre-elimination, the incremental net cost was $20 billion (non-USB and MRF) to $48 billion. These had an incremental cost per QALY of $657,000 to $3.1 million. A more efficient but somewhat less effective single-lifetime test strategy reached as low as $80,000 per QALY. CONCLUSIONS: Substantial gains can be made in TB control in coming years by scaling-up current testing and treatment in non-USB and those with medical risks.

Treatment Outcomes in Global Systematic Review and Patient Meta-Analysis of Children with Extensively Drug-Resistant Tuberculosis.

Extensively drug-resistant tuberculosis (XDR TB) has extremely poor treatment outcomes in adults. Limited data are available for children. We report on clinical manifestations, treatment, and outcomes for 37 children (<15 years of age) with bacteriologically confirmed XDR TB in 11 countries. These patients were managed during 1999-2013. For the 37 children, median age was 11 years, 32 (87%) had pulmonary TB, and 29 had a recorded HIV status; 7 (24%) were infected with HIV. Median treatment duration was 7.0 months for the intensive phase and 12.2 months for the continuation phase. Thirty (81%) children had favorable treatment outcomes. Four (11%) died, 1 (3%) failed treatment, and 2 (5%) did not complete treatment. We found a high proportion of favorable treatment outcomes among children, with mortality rates markedly lower than for adults. Regimens and duration of treatment varied considerably. Evaluation of new regimens in children is required.