Pyrazinamide Safety, Efficacy, and Dosing for Treating Drug-Susceptible Pulmonary Tuberculosis: A Phase 3, Randomized, Controlled Clinical Trial.

RATIONALE: Optimizing pyrazinamide dosing is critical to improve treatment efficacy while minimizing toxicity during tuberculosis treatment. Study 31/ACTG A5349 represents the largest Phase 3 randomized controlled therapeutic trial to date for such investigation. OBJECTIVES: We sought to report pyrazinamide pharmacokinetic parameters, risk factors for lower pyrazinamide exposure, and relationships between pyrazinamide exposure with efficacy and safety outcomes. We aimed to determine pyrazinamide dosing strategies that optimize risks and benefits. METHODS: We analyzed pyrazinamide steady-state pharmacokinetic data using population nonlinear mixed-effects models. We evaluated the contribution of pyrazinamide exposure to long-term efficacy using parametric time-to-event models and safety outcomes using logistic regression. We evaluated optimal dosing with therapeutic windows targeting ≥95% durable cure and safety within the observed proportion of the primary safety outcome. MEASUREMENTS AND MAIN RESULTS: Among 2255 participants with 6978 plasma samples, pyrazinamide displayed 7-fold exposure variability (151-1053 mg·h/L). Body weight was not a clinically relevant predictor of drug clearance and thus did not justify the need for weight-banded dosing. Both clinical and safety outcomes were associated with pyrazinamide exposure, resulting in a therapeutic window of 231-355 mg·h/L for the control and 226-349 mg·h/L for the rifapentine-moxifloxacin regimen. Flat dosing of pyrazinamide at 1000 mg would have permitted an additional 13.1% (n=96) participants allocated to the control and 9.2% (n=70) to the rifapentine-moxifloxacin regimen dosed within the therapeutic window, compared to the current weight-banded dosing. CONCLUSIONS: Flat dosing of pyrazinamide at 1000 mg daily would be readily implementable and could optimize treatment outcomes in drug-susceptible tuberculosis. Clinical trial registration available at www. CLINICALTRIALS: gov, ID: NCT02410772.

Pharmacokinetic-Pharmacodynamic Evidence From a Phase 3 Trial to Support Flat-Dosing of Rifampicin for Tuberculosis.

BACKGROUND: The optimal dosing strategy for rifampicin in treating drug-susceptible tuberculosis (TB) is still highly debated. In the phase 3 clinical trial Study 31/ACTG 5349 (NCT02410772), all participants in the control regimen arm received 600 mg rifampicin daily as a flat dose. Here, we evaluated relationships between rifampicin exposure and efficacy and safety outcomes. METHODS: We analyzed rifampicin concentration time profiles using population nonlinear mixed-effects models. We compared simulated rifampicin exposure from flat- and weight-banded dosing. We evaluated the effect of rifampicin exposure on stable culture conversion at 6 months; TB-related unfavorable outcomes at 9, 12, and 18 months using Cox proportional hazard models; and all trial-defined safety outcomes using logistic regression. RESULTS: Our model-derived rifampicin exposure ranged from 4.57 mg · h/L to 140.0 mg · h/L with a median of 41.8 mg · h/L. Pharmacokinetic simulations demonstrated that flat-dosed rifampicin provided exposure coverage similar to the weight-banded dose. Exposure-efficacy analysis (n = 680) showed that participants with rifampicin exposure below the median experienced similar hazards of stable culture conversion and TB-related unfavorable outcomes compared with those with exposure above the median. Exposure-safety analysis (n = 722) showed that increased rifampicin exposure was not associated with increased grade 3 or higher adverse events or serious adverse events. CONCLUSIONS: Flat-dosing of rifampicin at 600 mg daily may be a reasonable alternative to the incumbent weight-banded dosing strategy for the standard-of-care 6-month regimen. Future research should assess the optimal dosing strategy for rifampicin, at doses higher than the current recommendation.

Four-Month Rifapentine Regimens with or without Moxifloxacin for Tuberculosis.

BACKGROUND: Rifapentine-based regimens have potent antimycobacterial activity that may allow for a shorter course in patients with drug-susceptible pulmonary tuberculosis. METHODS: In an open-label, phase 3, randomized, controlled trial involving persons with newly diagnosed pulmonary tuberculosis from 13 countries, we compared two 4-month rifapentine-based regimens with a standard 6-month regimen consisting of rifampin, isoniazid, pyrazinamide, and ethambutol (control) using a noninferiority margin of 6.6 percentage points. In one 4-month regimen, rifampin was replaced with rifapentine; in the other, rifampin was replaced with rifapentine and ethambutol with moxifloxacin. The primary efficacy outcome was survival free of tuberculosis at 12 months. RESULTS: Among 2516 participants who had undergone randomization, 2343 had a culture positive for Mycobacterium tuberculosis that was not resistant to isoniazid, rifampin, or fluoroquinolones (microbiologically eligible population; 768 in the control group, 791 in the rifapentine-moxifloxacin group, and 784 in the rifapentine group), of whom 194 were coinfected with human immunodeficiency virus and 1703 had cavitation on chest radiography. A total of 2234 participants could be assessed for the primary outcome (assessable population; 726 in the control group, 756 in the rifapentine-moxifloxacin group, and 752 in the rifapentine group). Rifapentine with moxifloxacin was noninferior to the control in the microbiologically eligible population (15.5% vs. 14.6% had an unfavorable outcome; difference, 1.0 percentage point; 95% confidence interval [CI], -2.6 to 4.5) and in the assessable population (11.6% vs. 9.6%; difference, 2.0 percentage points; 95% CI, -1.1 to 5.1). Noninferiority was shown in the secondary and sensitivity analyses. Rifapentine without moxifloxacin was not shown to be noninferior to the control in either population (17.7% vs. 14.6% with an unfavorable outcome in the microbiologically eligible population; difference, 3.0 percentage points [95% CI, -0.6 to 6.6]; and 14.2% vs. 9.6% in the assessable population; difference, 4.4 percentage points [95% CI, 1.2 to 7.7]). Adverse events of grade 3 or higher occurred during the on-treatment period in 19.3% of participants in the control group, 18.8% in the rifapentine-moxifloxacin group, and 14.3% in the rifapentine group. CONCLUSIONS: The efficacy of a 4-month rifapentine-based regimen containing moxifloxacin was noninferior to the standard 6-month regimen in the treatment of tuberculosis. (Funded by the Centers for Disease Control and Prevention and others; Study 31/A5349 ClinicalTrials.gov number, NCT02410772.).

A Standardized Approach for Collection of Objective Data to Support Outcome Determination for Late-Phase Tuberculosis Clinical Trials.

Rationale: We developed a standardized method, possible poor treatment response (PPTR), to help ascertain efficacy endpoints in Study S31/A5349 (NCT02410772), an open-label trial comparing two 4-month rifapentine-based regimens with a standard 6-month regimen for the treatment of pulmonary tuberculosis (TB). Objectives: We describe the use of the PPTR process and evaluate whether the goals of minimizing bias in efficacy endpoint assessment and attainment of relevant data to determine outcomes for all participants were achieved. Methods: A PPTR event was defined as the occurrence of one or more prespecified triggers. Each PPTR required initiation of a standardized evaluation process that included obtaining multiple sputum samples for microbiology. Measurements and Main Results: Among 2,343 participants with culture-confirmed drug-susceptible TB, 454 individuals (19.4%) had a total of 534 individual PPTR events, of which 76.6% were microbiological (positive smear or culture at or after 17 wk). At least one PPTR event was experienced by 92.4% (133 of 144) of participants with TB-related unfavorable outcome and between 13.8% and 14.7% of participants with favorable and not-assessable outcomes. A total of 75% of participants with TB-related unfavorable outcomes had microbiological confirmation of failure to achieve a disease-free cure. Conclusions: Standardized methodologies, such as our PPTR approach, could facilitate unbiased efficacy outcome determinations, improve discrimination between outcomes that are related and unrelated to regimen efficacy, and enhance the ability to conduct pooled analyses of contemporary trials.

Efavirenz Pharmacokinetics and Human Immunodeficiency Virus Type 1 (HIV-1) Viral Suppression Among Patients Receiving Tuberculosis Treatment Containing Daily High-Dose Rifapentine.

BACKGROUND: A 4-month regimen containing rifapentine and moxifloxacin has noninferior efficacy compared to the standard 6-month regimen for drug-sensitive tuberculosis. We evaluated the effect of regimens containing daily, high-dose rifapentine on efavirenz pharmacokinetics and viral suppression in patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB). METHODS: In the context of a Phase 3 randomized controlled trial, HIV-positive individuals already virally suppressed on efavirenz--containing antiretroviral therapy (ART) (EFV1), or newly initiating efavirenz (EFV2) received TB treatment containing rifapentine (1200 mg), isoniazid, pyrazinamide, and either ethambutol or moxifloxacin. Mid-interval efavirenz concentrations were measured (a) during ART and TB cotreatment (Weeks 4, 8, 12, and 17, different by EFV group) and (b) when ART was taken alone (pre- or post-TB treatment, Weeks 0 and 22). Apparent oral clearance (CL/F) was estimated and compared. Target mid-interval efavirenz concentrations were > 1 mg/L. Co-treatment was considered acceptable if > 80% of participants had mid-interval efavirenz concentrations meeting this target. RESULTS: EFV1 and EFV2 included 70 and 41 evaluable participants, respectively. The geometric mean ratio comparing efavirenz CL/F with vs without TB drugs was 0.79 (90% confidence interval [CI] .72-.85) in EFV1 and 0.84 [90% CI .69-.97] in EFV2. The percent of participants with mid-interval efavirenz concentrations > 1mg/L in EFV1 at Weeks 0, 4, 8, and 17 was 96%, 96%, 88%, and 89%, respectively. In EFV2, at approximately 4 and 8 weeks post efavirenz initiation, the value was 98%. CONCLUSIONS: TB treatment containing high-dose daily rifapentine modestly decreased (rather than increased) efavirenz clearance and therapeutic targets were met supporting the use of efavirenz with these regimens, without dose adjustment. CLINICAL TRIALS REGISTRATION: NCT02410772.

Coronavirus Disease 2019 (COVID-19) in Americans Aboard the Diamond Princess Cruise Ship.

BACKGROUND: The Diamond Princess cruise ship was the site of a large outbreak of coronavirus disease 2019 (COVID-19). Of 437 Americans and their travel companions on the ship, 114 (26%) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We interviewed 229 American passengers and crew after disembarkation following a ship-based quarantine to identify risk factors for infection and characterize transmission onboard the ship. RESULTS: The attack rate for passengers in single-person cabins or without infected cabinmates was 18% (58/329), compared with 63% (27/43) for those sharing a cabin with an asymptomatic infected cabinmate, and 81% (25/31) for those with a symptomatic infected cabinmate. Whole genome sequences from specimens from passengers who shared cabins clustered together. Of 66 SARS-CoV-2-positive American travelers with complete symptom information, 14 (21%) were asymptomatic while on the ship. Among SARS-CoV-2-positive Americans, 10 (9%) required intensive care, of whom 7 were ≥70 years. CONCLUSIONS: Our findings highlight the high risk of SARS-CoV-2 transmission on cruise ships. High rates of SARS-CoV-2 positivity in cabinmates of individuals with asymptomatic infections suggest that triage by symptom status in shared quarters is insufficient to halt transmission. A high rate of intensive care unit admission among older individuals complicates the prospect of future cruise travel during the pandemic, given typical cruise passenger demographics. The magnitude and severe outcomes of this outbreak were major factors contributing to the Centers for Disease Control and Prevention's decision to halt cruise ship travel in US waters in March 2020.

Isoniazid and Rifampin-Resistance Mutations Associated With Resistance to Second-Line Drugs and With Sputum Culture Conversion.

BACKGROUND: Mutations in the genes inhA, katG, and rpoB confer resistance to anti-tuberculosis (TB) drugs isoniazid and rifampin. We questioned whether specific mutations in these genes were associated with different clinical and microbiological characteristics. METHODS: In a multicountry prospective cohort study of multidrug-resistant TB, we identified inhA, katG, and rpoB mutations in sputum isolates using the Hain MTBDRplus line probe assay. For specific mutations, we performed bivariate analysis to determine relative risk of baseline or acquired resistance to other TB drugs. We compared time to sputum culture conversion (TSCC) using Kaplan-Meier curves and stratified Cox regression. RESULTS: In total, 447 participants enrolled from January 2005 to December 2008 from 7 countries were included. Relative to rpoB S531L, isolates with rpoB D516V had less cross-resistance to rifabutin, increased baseline resistance to other drugs, and increased acquired fluoroquinolone resistance. Relative to mutation of katG only, mutation of inhA promoter and katG was associated with baseline extensively drug resistant (XDR) TB, increased acquired fluoroquinolone resistance, and slower TSCC (125.5 vs 89.0 days). CONCLUSIONS: Specific mutations in inhA and katG are associated with differences in resistance to other drugs and TSCC. Molecular testing may make it possible to tailor treatment and assess additional drug resistance risk according to specific mutation profile.

Public Health Responses to COVID-19 Outbreaks on Cruise Ships - Worldwide, February-March 2020.

An estimated 30 million passengers are transported on 272 cruise ships worldwide each year* (1). Cruise ships bring diverse populations into proximity for many days, facilitating transmission of respiratory illness (2). SARS-CoV-2, the virus that causes coronavirus disease (COVID-19) was first identified in Wuhan, China, in December 2019 and has since spread worldwide to at least 187 countries and territories. Widespread COVID-19 transmission on cruise ships has been reported as well (3). Passengers on certain cruise ship voyages might be aged ≥65 years, which places them at greater risk for severe consequences of SARS-CoV-2 infection (4). During February-March 2020, COVID-19 outbreaks associated with three cruise ship voyages have caused more than 800 laboratory-confirmed cases among passengers and crew, including 10 deaths. Transmission occurred across multiple voyages of several ships. This report describes public health responses to COVID-19 outbreaks on these ships. COVID-19 on cruise ships poses a risk for rapid spread of disease, causing outbreaks in a vulnerable population, and aggressive efforts are required to contain spread. All persons should defer all cruise travel worldwide during the COVID-19 pandemic.

Impact of GeneXpert MTB/RIF® on treatment initiation and outcomes of RIF-resistant and RIF-susceptible TB patients in Vladimir TB dispensary, Russia.

BACKGROUND: The main advantage of GeneXpert MTB/RIF® (Xpert) molecular diagnostic technology is the rapid detection of M.tuberculosis DNA and mutations associated with rifampicin (RIF) resistance for timely initiation of appropriate treatment and, consequently, preventing further transmission of the disease. We assessed time to treatment initiation and treatment outcomes of RIF-resistant and RIF-susceptible TB patients diagnosed and treated in Vladimir TB Dispensary, Russia in 2012, before and after implementation of GeneXpert MTB/RIF® diagnostic technology. METHODS: All adult patients suspected of having TB during February-December 2012 underwent a clinical examination, chest x-ray, microscopy, culture, and phenotypic drug susceptibility testing (DST). Starting August 2012 Xpert diagnostic technology became available in the facility. We used logistic regression to compare treatment outcomes in pre-Xpert and post-Xpert periods. Kaplan-Meier curves and log-rank test were used to compare the time to treatment initiation between the groups. RESULTS: Of 402 patients screened for TB during February-December 2012, 338 were diagnosed with TB (280 RIF-susceptible, 58 RIF-resistant). RIF-resistant patients in the post-Xpert group started treatment with second-line drugs (SLD) earlier than those in pre-Xpert group (median 11 vs. 37 days, Log-rank p = 0.02). The hazard ratio for time to SLD treatment initiation was significantly higher in post-Xpert group (HR:2.06; 95%CI:1.09,3.89) compared to pre-Xpert group. Among the 53/58 RIF-resistant TB patients with available treatment outcome, 28 (53%) had successful outcomes (cured/completed treatment) including 15/26 (58%) in post-Xpert group versus 13/27 (48%) in pre-Xpert group. The observed difference, however, was not statistically significant (OR:0.69; 95%CI:0.23,2.06). Among RIF-susceptible TB cases time to treatment initiation was not significantly different between the groups (2 vs. 3 days, Log-rank p = 0.73). Of 252/280 RIF-susceptible TB cases with treatment outcome, 199 (79%) cases had successful outcome including 94/114 (82%) in post-Xpert group versus 105/138 (76%) in pre-Xpert group (OR:0.68; 95%CI:0.36,1.26). CONCLUSION: We observed that availability of Xpert for initial diagnosis significantly reduced the time to SLD treatment for RIF-resistant patients in the Vladimir TB Dispensary. Although implementation of rapid diagnostics did not improve treatment outcomes, early diagnosis of MDR-TB is important for selection of appropriate treatment regimen and prevention of transmission of drug-resistant strains of TB.

Factors Associated with Loss to Follow-up during Treatment for Multidrug-Resistant Tuberculosis, the Philippines, 2012-2014.

To identify factors associated with loss to follow-up during treatment for multidrug-resistant (MDR) tuberculosis (TB) in the Philippines, we conducted a case-control study of adult patients who began receiving treatment for rifampin-resistant TB during July 1-December 31, 2012. Among 91 case-patients (those lost to follow-up) and 182 control-patients (those who adhered to treatment), independent factors associated with loss to follow-up included patients' higher self-rating of the severity of vomiting as an adverse drug reaction and alcohol abuse. Protective factors included receiving any type of assistance from the TB program, better TB knowledge, and higher levels of trust in and support from physicians and nurses. These results provide insights for designing interventions aimed at reducing patient loss to follow-up during treatment for MDR TB.

Epidemiology of Primary Multidrug-Resistant Tuberculosis, Vladimir Region, Russia.

We studied the epidemiology of drug-resistant tuberculosis (TB) in Vladimir Region, Russia, in 2012. Most cases of multidrug-resistant TB (MDR TB) were caused by transmission of drug-resistant strains, and >33% were in patients referred for testing after mass radiographic screening. Early diagnosis of drug resistance is essential for preventing transmission of MDR TB.

Additional drug resistance of multidrug-resistant tuberculosis in patients in 9 countries.

Data from a large multicenter observational study of patients with multidrug-resistant tuberculosis (MDR TB) were analyzed to simulate the possible use of 2 new approaches to treatment of MDR TB: a short (9-month) regimen and a bedaquiline-containing regimen. Of 1,254 patients, 952 (75.9%) had no resistance to fluoroquinolones and second-line injectable drugs and thus would qualify as candidates for the 9-month regimen; 302 (24.1%) patients with resistance to a fluoroquinolone or second-line injectable drug would qualify as candidates for a bedaquiline-containing regimen in accordance with published guidelines. Among candidates for the 9-month regimen, standardized drug-susceptibility tests demonstrated susceptibility to a median of 5 (interquartile range 5-6) drugs. Among candidates for bedaquiline, drug-susceptibility tests demonstrated susceptibility to a median of 3 (interquartile range 2-4) drugs; 26% retained susceptibility to <2 drugs. These data may assist national TB programs in planning to implement new drugs and drug regimens.

Association between Regimen Composition and Treatment Response in Patients with Multidrug-Resistant Tuberculosis: A Prospective Cohort Study.

BACKGROUND: For treating multidrug-resistant tuberculosis (MDR TB), the World Health Organization (WHO) recommends a regimen of at least four second-line drugs that are likely to be effective as well as pyrazinamide. WHO guidelines indicate only marginal benefit for regimens based directly on drug susceptibility testing (DST) results. Recent evidence from isolated cohorts suggests that regimens containing more drugs may be beneficial, and that DST results are predictive of regimen effectiveness. The objective of our study was to gain insight into how regimen design affects treatment response by analyzing the association between time to sputum culture conversion and both the number of potentially effective drugs included in a regimen and the DST results of the drugs in the regimen. METHODS AND FINDINGS: We analyzed data from the Preserving Effective Tuberculosis Treatment Study (PETTS), a prospective observational study of 1,659 adults treated for MDR TB during 2005-2010 in nine countries: Estonia, Latvia, Peru, Philippines, Russian Federation, South Africa, South Korea, Thailand, and Taiwan. For all patients, monthly sputum samples were collected, and DST was performed on baseline isolates at the US Centers for Disease Control and Prevention. We included 1,137 patients in our analysis based on their having known baseline DST results for at least fluoroquinolones and second-line injectable drugs, and not having extensively drug-resistant TB. These patients were followed for a median of 20 mo (interquartile range 16-23 mo) after MDR TB treatment initiation. The primary outcome of interest was initial sputum culture conversion. We used Cox proportional hazards regression, stratifying by country to control for setting-associated confounders, and adjusting for the number of drugs to which patients' baseline isolates were resistant, baseline resistance pattern, previous treatment history, sputum smear result, and extent of disease on chest radiograph. In multivariable analysis, receiving an average of at least six potentially effective drugs (defined as drugs without a DST result indicating resistance) per day was associated with a 36% greater likelihood of sputum culture conversion than receiving an average of at least five but fewer than six potentially effective drugs per day (adjusted hazard ratio [aHR] 1.36, 95% CI 1.09-1.69). Inclusion of pyrazinamide (aHR 2.00, 95% CI 1.65-2.41) or more drugs to which baseline DST indicated susceptibility (aHR 1.65, 95% CI 1.48-1.84, per drug) in regimens was associated with greater increases in the likelihood of sputum culture conversion than including more drugs to which baseline DST indicated resistance (aHR 1.33, 95% CI 1.18-1.51, per drug). Including in the regimen more drugs for which DST was not performed was beneficial only if a minimum of three effective drugs was present in the regimen (aHR 1.39, 95% CI 1.09-1.76, per drug when three effective drugs present in regimen). The main limitation of this analysis is that it is based on observational data, not a randomized trial, and drug regimens varied across sites. However, PETTS was a uniquely large and rigorous observational study in terms of both the number of patients enrolled and the standardization of laboratory testing. Other limitations include the assumption of equivalent efficacy across drugs in a category, incomplete data on adherence, and the fact that the analysis considers only initial sputum culture conversion, not reversion or long-term relapse. CONCLUSIONS: MDR TB regimens including more potentially effective drugs than the minimum of five currently recommended by WHO may encourage improved response to treatment in patients with MDR TB. Rapid access to high-quality DST results could facilitate the design of more effective individualized regimens. Randomized controlled trials are necessary to confirm whether individualized regimens with more than five drugs can indeed achieve better cure rates than current recommended regimens.

Mortality among tuberculosis patients with acquired resistance to second-line antituberculosis drugs--United States, 1993-2008.

BACKGROUND: Resistance to second-line antituberculosis drugs (SLDs) severely compromises treatment options of drug-resistant tuberculosis. We assessed the association between acquisition of resistance (AR) to second-line injectable drugs (SLIs) or fluoroquinolones (FQs) and mortality among tuberculosis cases confirmed by positive culture results with available initial and final drug susceptibility test (DST) results. METHODS: We analyzed data from the US National Tuberculosis Surveillance System, 1993-2008. Acquired resistance was defined as drug susceptibility at initial DST but resistance to the same drug at final DST. We compared survival with Kaplan-Meier curves and analyzed the association between AR and mortality using a univariate extended Cox proportional hazards model adjusted for age. RESULTS: Of 2329 cases with both initial and final DSTs to SLIs, 49 (2.1%) acquired resistance; 13 of 49 (26.5%) had treatment terminated by death compared with 222 (10.0%) of those without AR to SLIs (P < .001). Of 1187 cases with both initial and final DSTs to FQs, 32 (2.8%) acquired resistance; 12 of 32 (37.5%) had treatment terminated by death compared with 121 (10.9%) of those without AR to FQs (P = .001). Controlling for age, mortality was significantly greater among cases with AR to SLDs than among cases without AR (adjusted hazard ratio [aHR] for SLIs: 2.8; 95% confidence interval [CI],1.4-5.4; aHR for FQ: 1.9; 95% CI, 1.0-3.5). Multidrug-resistant tuberculosis at treatment initiation, positive human immunodeficiency virus status, and extrapulmonary disease were also significantly associated with mortality. CONCLUSIONS: Mortality was significantly greater among tuberculosis cases with AR to SLDs. Providers should consider AR to SLDs early in treatment, monitor DST results, and avoid premature deaths.

Epidemiology of pyrazinamide-resistant tuberculosis in the United States, 1999-2009.

BACKGROUND: Pyrazinamide (PZA) is essential in tuberculosis treatment. We describe the prevalence, trends, and predictors of PZA resistance in Mycobacterium tuberculosis complex (MTBC) in the United States. METHODS: We analyzed culture-positive MTBC cases with reported drug susceptibility tests for PZA in 38 jurisdictions routinely testing for PZA susceptibility from 1999 to 2009. National Tuberculosis Genotyping Service data for 2004-2009 were used to distinguish M. tuberculosis from Mycobacterium bovis and determine phylogenetic lineage. RESULTS: Overall 2.7% (2167/79 321) of MTBC cases had PZA resistance, increasing annually from 2.0% to 3.3% during 1999-2009 (P < .001), largely because of an increase in PZA monoresistance. PZA-monoresistant MTBC (vs drug-susceptible) was associated with an age of 0-24 years (adjusted prevalence ratio [aPR],1.50; 95% confidence interval [CI], 1.31-1.71), Hispanic ethnicity (aPR, 3.52; 95% CI, 2.96-4.18), human immunodeficiency virus infection (aPR, 1.43; 95% CI, 1.15-1.77), extrapulmonary disease (aPR, 3.02; 95% CI, 2.60-3.52), and normal chest radiograph (aPR, 1.88; 95% CI, 1.63-2.16) and was inversely associated with Asian (aPR, 0.59; 95% CI, .47-.73) and black (aPR, 0.37; 95% CI, .29-.49) race. Among multidrug-resistant (MDR) cases, 38.0% were PZA-resistant; PZA resistance in MDR MTBC was associated with female sex (aPR, 1.25; 95% CI, 1.08-1.46) and previous tuberculosis diagnosis (aPR, 1.37; 95% CI, 1.16-1.62). Of 28 080 cases with genotyping data, 925 (3.3%) had PZA resistance; 465 of 925 (50.3%) were M. bovis. In non-MDR M. tuberculosis cases, PZA resistance was higher in the Indo-Oceanic than the East Asian lineage (2.2% vs 0.9%, respectively; aPR, 2.26; 95% CI, 1.53-3.36), but in MDR cases it was lower in the Indo-Oceanic lineage (22.0% vs 43.4%, respectively; aPR, 0.54; 95% CI, .32-.90). CONCLUSIONS: Specific human and mycobacterial characteristics were associated with PZA-resistant MTBC, reflecting both specific subgroups of the population and phylogenetic lineages of the mycobacteria.

Acquired resistance to second-line drugs among persons with tuberculosis in the United States.

BACKGROUND: Acquired resistance to second-line drugs (SLDs) is a problem in treating patients with drug-resistant tuberculosis worldwide. The objectives of this study were to identify risk factors for acquired resistance (AR) to injectable SLDs (INJ SLDs) and fluoroquinolones in the US National tuberculosis Surveillance System, 1993-2008. METHODS: We selected cases for which the initial and final drug susceptibility test (DST) results had been reported. We defined AR as resistance at the final DST but susceptibility to the same drug at the initial DST. We analyzed AR using 2-way frequency tables and multivariable logistic regression. RESULTS: The baseline prevalence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis was 12.6% (1864/14 770) and 0.38% (56/14 770), respectively. Of 2274 individuals without initial resistance to INJ SLDs, 49 (2.2%) acquired resistance. Of 1141 initially susceptible to fluoroquinolones, 32 (2.8%) acquired resistance. The AR to INJ SLDs was associated with age group 25-44 years (adjusted odds ratio [aOR], 2.7; 95% confidence interval [CI], 1.2-6.3), positive HIV (human immunodeficiency virus) status (aOR, 2.5; 95% CI, 1.3-4.7), MDR at treatment initiation (aOR, 5.5; 95% CI, 2.9-10.5), and treatment with any SLD (aOR, 2.4; 95% CI,1.2-4.7). The AR to fluoroquinolones was associated with MDR tuberculosis at treatment initiation (aOR, 6.5; 95% CI, 2.9-14.6). CONCLUSIONS: Among patients with initial and final DST reported, the risk factors for AR to INJ SLDs included age, positive HIV status, MDR tuberculosis and initial treatment with any SLD, while the only predictor for AR to fluoroquinolones was MDR tuberculosis at treatment initiation. Providers should consider monitoring SLD DST for MDR tuberculosis patients in the indicated subgroups.

Site of extrapulmonary tuberculosis is associated with HIV infection.

BACKGROUND: In the United States, the proportion of patients with extrapulmonary tuberculosis (EPTB) has increased relative to cases of pulmonary tuberculosis. Patients with central nervous system (CNS)/meningeal and disseminated EPTB and those with human immunodeficiency virus (HIV)/AIDS have increased mortality. The purpose of our study was to determine risk factors associated with particular types of EPTB. METHODS: We retrospectively reviewed 320 cases of EPTB from 1995-2007 at a single urban US public hospital. Medical records were reviewed to determine site of EPTB and patient demographic and clinical characteristics. Multivariable logistic regression analyses were performed to determine independent associations between patient characteristics and site of disease. RESULTS: Patients were predominantly male (67%), African American (82%), and US-born (76%). Mean age was 40 years (range 18-89). The most common sites of EPTB were lymphatic (28%), disseminated (23%), and CNS/meningeal (22%) disease. One hundred fifty-four (48.1%) were HIV-infected, 40% had concomitant pulmonary tuberculosis, and 14.7% died within 12 months of EPTB diagnosis. Multivariable analysis demonstrated that HIV-infected patients were less likely to have pleural (adjusted odds ratio [AOR] 0.3; 95% confidence interval [CI] .2, .6) as site of EPTB disease than HIV-uninfected patients. Among patients with EPTB and HIV-infection, patients with CD4 lymphocyte cell count <100 were more likely to have severe forms of EPTB (CNS/meningeal and/or disseminated) (AOR 1.6; 95% CI, 1.0, 2.4). CONCLUSIONS: Among patients hospitalized with EPTB, patients coinfected with HIV and low CD4 counts were more likely to have CNS/meningeal and disseminated disease. Care for similar patients should include consideration of these forms of EPTB since they carry a high risk of death.

Challenges and controversies in defining totally drug-resistant tuberculosis.

In March 2012, in response to reports of tuberculosis (TB) resistant to all anti-TB drugs, the World Health Organization convened an expert consultation that identified issues to be resolved before defining a new category of highly drug-resistant TB. Proposed definitions are ambiguous, and extensive drug resistance is encompassed by the already defined extensively drug-resistant (XDR) TB. There is no evidence that proposed totally resistant TB differs from strains encompassed by XDR TB. Susceptibility tests for several drugs are poorly reproducible. Few laboratories can test all drugs, and there is no consensus list of all anti-TB drugs. Many drugs are used off-label for highly drug resistant TB, and new drugs formulated to combat resistant strains would render the proposed category obsolete. Labeling TB strains as totally drug resistant might lead providers to think infected patients are untreatable. These challenges must be addressed before defining a new category for highly drug-resistant TB.

Optimizing drug inventory management with a web-based information system: The TBTC Study 31/ACTG A5349 experience.

INTRODUCTION: Efficient management of study drug inventory shipments is critical to keep research sites enrolling into multisite clinical treatment trials. A standard manual drug-management process used by the Tuberculosis Trials Consortium (TBTC), did not accommodate import permit approval timelines, shipment transit-times and time-zone differences. We compared a new web-based solution with the manual process, during an international 34-site clinical trial conducted by the TBTC and the AIDS Clinical Trials Group (ACTG); TBTC Study 31/ACTG A5349. MATERIAL AND METHODS: We developed and implemented a technological solution by integrating logistical and regulatory requirements for drug importation with statistical simulations that estimated stock-out times in an online Drug Management Module (DMM). We measured the average shipment-related drug stock-outs and time to drug availability, to assess the efficiency of the DMM compared to the manual approach. RESULTS: An Interrupted Time-Series (ITS) analysis showed a 15.4% [p-value = 0.03; 95% C.I. (-28.8%, -2.0%)] reduction in average shipment-related study drug stock-out after DMM implementation. The DMM streamlined the restocking process at study sites, reducing median transit-time for sites associated with a depot by 2 days [95% C.I. (-3.0, -1.0)]. Under the DMM, study drugs were available for treatment assignment on the day received, compared to one day after receipt under the manual process. DISCUSSION: The DMM provided TBTC's Data and Coordinating Center and site staff with more efficient procedures to manage and consistently maintain study drug inventory at enrolling sites. This DMM framework can improve efficiency in future multicenter clinical trials. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov (Identifier: NCT02410772) on April 8, 2015.