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 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 to 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.

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.

[Acute purulent otitis media in children]

OBJECTIVE

Improving the effectiveness of inpatient care for children with acute purulent otitis media.

MATERIAL AND METHODS

100 children at the age from 0 to 18 years were inspected from January to August 2021. The main diagnostic methods included otoscopy, pharyngoscopy, rhinoscopy. Bacteriological examination of the pus from the ear was done for all patients.

RESULTS

Acute purulent otitis media is a common cause of hospitalization in children aged 0 to 3 years. The main causative agents of the disease in toddlers are Staphylococcus aureus and pneumococcus (38%), in preschoolers and primary school children - pyogenic streptococcus and pneumococcus (30%), in high school students - Staphylococcus aureus.

[Effectiveness of baloon dilation of Eustachian tube in children with otitis media with effusion]

Otitis media with effusion is one of the most common ENT diseases in childhood. Absence of acute symptoms, prevalence of pathology among preschoolers, who often cannot complain on discomfort in the ears and hearing loss, lead to late diagnosis and treatment. Standard surgery is highly effective, but it is not able to help all patients. A new, minimally invasive technique of surgical treatment of otitis media with effusion - balloon dilation of the Eustachian tube provides additional opportunities in solving these problems.

OBJECTIVE

To evaluate the effectiveness and possibilities of its increasing in balloon dilation of the auditory tube in children with chronic otitis media with effusion. 34 children with chronic otitis media with effusion were under observation, who underwent 54 operations using a balloon catheter for the auditory tubes. The mismatch between the pressure value and the baloon diameter has been experimentally shown, and therefore a technique for intraoperative control of the effectiveness of the procedure has been developed. The effectiveness of balloon dilation in the study was 30.8-64.3%, depending on the following factors: the stage of otitis media at which the treatment was carried out, the combination of balloon dilation with tympanostomy, the use of intraoperative efficiency control technique. The high safety of the operation and the possibility of its effective implementation in patients with an operated cleft-palate are shown.

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.

[The cochlear implantation in patients with syndromic deafness. Clinical examples]

OBJECTIVE

To describe clinical observations of patients with syndromic deafness.

RESULTS

Deaf patients with CHARGE, Crouzon, and Wildervanck syndromes were monitored at the Russian Research Clinical Center for Audiology and Hearing Rehabilitation (Moscow) in different years. All of them were diagnosed having bilateral congenital deafness. After collecting anamnesis, evaluating the results of computed tomography of the temporal bones, and audiological examination, it was decided to conduct the cochlear implantation.

CONCLUSION

The only method that allows patients with bilateral congenital deafness to gain hearing is the cochlear implantation. The malformations of the tympanic cavity structures, an abnormal course of the facial nerve canal lead to technical difficulties during the surgical stage of cochlear implantation. The navigation equipment, monitoring of the facial nerve makes it easier to find anatomical structures, as well as to avoid injuries.

[Peculiarities of preparing a patient with a cochlear implant for a magnetic resonance imaging]

OBJECTIVE

To develop an algorithm of actions aimed at preparing a patient with a cochlear implant for magnetic resonance imaging (MRI).

MATERIAL AND METHODS

A deaf patient after bilateral cochlear implantation (CI) came to St. Vladimir Children's City Clinical Hospital (Moscow) with symptoms of the demyelinating disease for MRI of the brain and spinal cord. Magnet were removed for MRI, then new magnets were installed.

CONCLUSION

The temporary removing magnet for MRI of the brain and spinal cord allows to significantly reduce artifacts of MRI images.

[The main steps in treatment of the children with otitis media with effusion]

MATERIAL AND METHODS

361 children at age from 11 months to 18 years with otitis media with effusion (OME) were inspected after tympanostomy during 2013-2018 years. Treatment was carried out in accordance with the stages of OME: secretory, mucous, fibrous. The main diagnostic methods were: otoscopy, tympanometry, endoscopy, computed tomography. Surgical treatment may be required already at the secretory stage of the disease, as well as in all cases with mucous and fibrous stages of OME.

RESULTS

In children with recurrences of OME and in patients with congenital cleft lip and palate, it is preferable to use long-wearing ventilation tubes and balloning of the auditory tubes. The effectiveness of surgical treatment of OME was 97.6%.

CONCLUSION

The authors recommend dispensary observation of patients with OME for 12-24 months.

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.

Conclusion

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 U.S. waters in March 2020.

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.).

Central monitoring in a randomized, open-label, controlled phase 3 clinical trial for a treatment-shortening regimen for pulmonary tuberculosis

INTRODUCTION

With the growing use of online study management systems and rapid availability of data, timely data review and quality assessments are necessary to ensure proper clinical trial implementation. In this report we describe central monitoring used to ensure protocol compliance and accurate data reporting, implemented during a large phase 3 clinical trial.

MATERIAL AND METHODS

The Tuberculosis Trials Consortium (TBTC) Study 31/AIDS Clinical Trials Group (ACTG) study A5349 (S31) is an international, multi-site, randomized, open-label, controlled, non-inferiority phase 3 clinical trial comparing two 4-month regimens to a standard 6 month regimen for treatment of drug-susceptible tuberculosis (TB) among adolescents and adults with a sample size of 2500 participants.

RESULTS

Central monitoring utilized primary study data in a five-tiered approach, including (1) real-time data checks & topic-specific intervention reports, (2) missing forms reports, (3) quality assurance metrics, (4) critical data reports and (5) protocol deviation identification, aimed to detect and resolve quality challenges. Over the course of the study, 240 data checks and reports were programed across the five tiers used.

DISCUSSION

This use of primary study data to identify issues rapidly allowed the study sponsor to focus quality assurance and data cleaning activities on prioritized data, related to protocol compliance and accurate reporting of study results. Our approach enabled us to become more efficient and effective as we informed sites about deviations, resolved missing or inconsistent data, provided targeted guidance, and gained a deeper understanding of challenges experienced at clinical trial sites.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov (Identifier: NCT02410772) on April 8, 2015.

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.

[The main steps in treatment of the children with otitis media with effusion]

THE AIM

Of the investigation was to establish the standard and improve the treatment of otitis media with effusion (OME) in children. 361 children at age from 11 months to 18 years were inspected after tympanostomy during 2013-2018 years. The main diagnostic methods were: otoscopy, tympanometry, endoscopy, CT.

MATERIAL AND METHODS

Treatment takes into consideration the reveal of OME: surgical initially. The tympanostomy preferable place is anterior-inferior quadrant.

RESULTS

In cases with cleft palate or reccurence OME long-term tubes and balloonisation of ET are preferable.

CONCLUSION

Authors received normalization of the hearing thresholds in 97.6% cases, but after surgery the patients have to be followed-up during 12-24 months.

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.

High-dose rifapentine with or without moxifloxacin for shortening treatment of pulmonary tuberculosis: Study protocol for TBTC study 31/ACTG A5349 phase 3 clinical trial

INTRODUCTION

Phase 2 clinical trials of tuberculosis treatment have shown that once-daily regimens in which rifampin is replaced by high dose rifapentine have potent antimicrobial activity that may be sufficient to shorten overall treatment duration. Herein we describe the design of an ongoing phase 3 clinical trial testing the hypothesis that once-daily regimens containing high dose rifapentine in combination with other anti-tuberculosis drugs administered for four months can achieve cure rates not worse than the conventional six-month treatment regimen.

METHODS/DESIGN

S31/A5349 is a multicenter randomized controlled phase 3 non-inferiority trial that compares two four-month regimens with the standard six-month regimen for treating drug-susceptible pulmonary tuberculosis in HIV-negative and HIV-positive patients. Both of the four-month regimens contain high-dose rifapentine instead of rifampin, with ethambutol replaced by moxifloxacin in one regimen. All drugs are administered seven days per week, and under direct observation at least five days per week. The primary outcome is tuberculosis disease-free survival at twelve months after study treatment assignment. A total of 2500 participants will be randomized; this gives 90% power to show non-inferiority with a 6.6% margin of non-inferiority.

DISCUSSION

This phase 3 trial formally tests the hypothesis that augmentation of rifamycin exposures can shorten tuberculosis treatment to four months. Trial design and standardized implementation optimize the likelihood of obtaining valid results. Results of this trial may have important implications for clinical management of tuberculosis at both individual and programmatic levels.

TRIAL REGISTRATION

NCT02410772. Registered 8 April 2015,https://www.clinicaltrials.gov/ct2/show/NCT02410772?term=02410772&rank=1.

Multidrug-resistant tuberculosis patients' views of interventions to reduce treatment loss to follow-up

SETTING

Patients who initiated treatment for multidrug-resistant tuberculosis (MDR-TB) at 15 Programmatic Management of Drug-resistant Tuberculosis (PMDT) health facilities in the Philippines between July and December 2012.

OBJECTIVES

To describe patients' views of current interventions, and suggest changes likely to reduce MDR-TB loss to follow-up.

METHODS

In-depth interviews were conducted between April and July 2014 with MDR-TB patients who were undergoing treatment, had finished treatment at the time of the interview (controls), or had been lost to follow-up (LTFU). Responses were thematically analyzed.

RESULTS

Interviews were conducted with 182 patients who were undergoing or had completed treatment and 91 LTFU patients. Views and suggestions could be thematically categorized as approaches to facilitate adherence or address barriers to adherence. The top themes were the need for transportation assistance or improvements to the current transportation assistance program, food assistance, and difficulties patients encountered related to their medications. These themes were addressed by respectively 63%, 60%, and 32% of the participants.

CONCLUSIONS

A more patient-centered approach is needed to improve MDR-TB treatment adherence. Programs should strive to provide assistance that considers patient preferences, is adequate to cover actual costs or needs, and is delivered in a timely, uninterrupted manner.

[The role of computer and magnetic resonance imaging in patients with deafness]

The objective of the present study was to evaluate the potential of CT and MRI for diagnostics of congenital and acquired pathology of the inner ear in the deaf patients. Two groups of the patients were examined. The first group consisted of 75 patients with congenital or acquired deafness etiology. The second group was comprised of 75 patients with deafness associated with acute bacterial meningitis suffered in the preceding period. All the patients were examined by CT and MRI of temporal bones. The results of the study provided a basis for the development of indications for the application of CT and MRI to examine the patients presenting with hearing loss and deafness.

CONCLUSION

CT and MRI make it possible to identify individual features of the temporal bone structure significant for the surgical treatment. MRI appears to have an advantage over CT for diagnostics of early obliteration of the cochlea. Both CT and MRI are the optional methods for the examination of the patients with deafness developing after meningitis.

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

Most commonly reported was medication side effects or fear of side effects.

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.

Multidrug-resistant tuberculosis patients lost to follow-up: self-reported readiness to restart treatment

SETTING

Multidrug-resistant tuberculosis (MDR-TB) patients lost to follow-up (LTFU) from Programmatic Management of Drug-resistant Tuberculosis facilities in the Philippines.

OBJECTIVES

To gain insight into patients' readiness to return to treatment.

METHODS

MDR-TB patients who initiated treatment and were categorized as LTFU were identified using TB registers, contacted, and asked to consent to an interview and medical record review. At the conclusion of the interview, patients' readiness to restart treatment was assessed and examined in relation to demographic, clinical, and interview data. Odds ratios were calculated.

RESULTS

When asked if they would consider restarting MDR-TB treatment, 3% of the 89 participating patients reported that they had already restarted, 34% indicated that they wanted to restart, 33% had not considered restarting, 28% were undecided, and 2% had decided against restarting. Patients who wanted to restart treatment were more likely to report having borrowed money for TB-related expenses (OR 5.97, 95%CI 1.27-28.18), and were less likely to report being self-employed (OR 0.08, 95%CI 0.01-0.67), or perceive themselves at low or no risk for TB relapse (OR 0.30, 95%CI 0.08-0.96) than patients who did not indicate an interest in restarting treatment.

CONCLUSIONS

Efforts to re-engage LTFU patients in care should consider financial barriers, knowledge gaps, and personal adherence challenges in patients.

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

Less toxic and less expensive drugs and shorter treatment regimens are needed.

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.

[Cholesteatoma of the external and middle ear in the childhood]

The objective of the present work was to enhance the effectiveness of diagnostics of cholesteatoma of the external and middle ear in the children. The study included 66 patients presenting with chronic suppurative otitis media and one child having cholesteatoma of the external auditory meatus. All the patients were examined with the use of otoendoscopy and CT of the temporal bones. It was shown that the frequent occurrence of acute suppurative otitis media, exudative suppurative otitis media, and adhesive otitis media is the risk factor of the development of cholesteatoma of the external and middle ear in the children. The following CT features of cholesteatoma of the external ear were revealed: the sclerotic or mixed type of the mastoid process, the presence of pathological contents in the epitympanic space, homogeneous character of pathological contents in the antrum, widened aditus, caries of antrum walls, the presence of soft tissues around the auditory ossicles, destruction of the long process of the anval bone, and a soft-tissue structure in the external auditory meatus.

Sputum culture conversion as a prognostic marker for end-of-treatment outcome in patients with multidrug-resistant tuberculosis: a secondary analysis of data from two observational cohort studies

BACKGROUND

Sputum culture conversion is often used as an early microbiological endpoint in phase 2 clinical trials of tuberculosis treatment on the basis of its assumed predictive value for end-of-treatment outcome, particularly in patients with drug-susceptible tuberculosis. We aimed to assess the validity of sputum culture conversion on solid media at varying timepoints, and the time to conversion, as prognostic markers for end-of-treatment outcome in patients with multidrug-resistant (MDR) tuberculosis.

METHODS

We analysed data from two large cohort studies of patients with MDR tuberculosis. We defined sputum culture conversion as two or more consecutive negative cultures from sputum samples obtained at least 30 days apart. To estimate the association of 2 month and 6 month conversion with successful treatment outcome, we calculated odds ratios (ORs) and 95% CIs with random-effects multivariable logistic regression. We calculated predictive values with bivariate random-effects generalised linear mixed modelling.

FINDINGS

We assessed data for 1712 patients who had treatment success, treatment failure, or who died. Among patients with treatment success, median time to sputum culture conversion was significantly shorter than in those who had poor outcomes (2 months [IQR 1-3] vs 7 months [3 to ≥24]; log-rank p<0·0001). Furthermore, conversion status at 6 months (adjusted OR 14·07 [95% CI 10·05-19·71]) was significantly associated with treatment success compared with failure or death. Sputum culture conversion status at 2 months was significantly associated with treatment success only in patients who were HIV negative (adjusted OR 4·12 [95% CI 2·25-7·54]) or who had unknown HIV infection (3·59 [1·96-6·58]), but not in those who were HIV positive (0·38 [0·12-1·18]). Thus, the overall association of sputum culture conversion with a successful outcome was substantially greater at 6 months than at 2 months. 2 month conversion had low sensitivity (27·3% [95% confidence limit 16·6-41·4]) and high specificity (89·8% [82·3-94·4]) for prediction of treatment success. Conversely, 6 month sputum culture conversion status had high sensitivity (91·8% [85·9-95·4]), but moderate specificity (57·8% [42·5-71·6]). The maximum combined sensitivity and specificity for sputum culture conversion was reached between month 6 and month 10 of treatment.

INTERPRETATION

Time to sputum culture conversion, conversion status at 6 months, and conversion status at 2 months in patients without known HIV infection can be considered as proxy markers of end-of-treatment outcome in patients with MDR tuberculosis, although the overall association with treatment success is substantially stronger for 6 month than for 2 month conversion status. Investigators should consider these results regarding the validity of sputum culture conversion at various timepoints as an early predictor of treatment efficacy when designing phase 2 studies before investing substantial resources in large, long-term, phase 3 trials of new treatments for MDR tuberculosis.

FUNDING

US Agency for International Development, US Centers for Disease Control and Prevention, Division of Intramural Research of the US National Institute of Allergy and Infectious Diseases, Korea Centers for Disease Control and Prevention.

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.

[Peculiarities of the treatment of the patients presenting with exudative otitis media]

The objective of the present study was to enhance the effectiveness of provision of medical assistance and to standardize the approaches to its realization for the patients presenting with exudative otitis media (EOM). A total of 67 children (103 cases) at the age varying from 11 months and 17 years were available for the examination after the surgical treatment. The secretory phase of exudative otitis media was diagnosed in 23.5% of the children, mucous phase in 68%, and fibrous phase in 8.5%. The results of the study indicate that diagnostics of EOM requires the application of such methods as otomicroscopy, endoscopy, and tympanometry. Computed tomography of temporal bones may be helpful to distinguish between the complicated cases of exudative otitis media and other diseases of the middle ear. Tympanostomy is possible to perform in the secretory phase of the disease and in all the patients at the mucous and fibrous stages. The preferred localization of tympanostomy is thea ntero-inferior quadrant of the tympanic membrane. It is recommended to place long-term ventilation tubes in the children presenting with recurrent EOM and labial or palatal cleft. The authors managed to achieve the 97.6% effectiveness of the surgical treatment of exudative otitis media. The 12-24 month long follow-up period is recommended.

Association between Mycobacterium tuberculosis complex phylogenetic lineage and acquired drug resistance

BACKGROUND

Development of resistance to antituberculosis drugs during treatment (i.e., acquired resistance) can lead to emergence of resistant strains and consequent poor clinical outcomes. However, it is unknown whether Mycobacterium tuberculosis complex species and lineage affects the likelihood of acquired resistance.

METHODS

We analyzed data from the U.S. National Tuberculosis Surveillance System and National Tuberculosis Genotyping Service for tuberculosis cases during 2004-2011 with assigned species and lineage and both initial and final drug susceptibility test results. We determined univariate associations between species and lineage of Mycobacterium tuberculosis complex bacteria and acquired resistance to isoniazid, rifamycins, fluoroquinolones, and second-line injectables. We used Poisson regression with backward elimination to generate multivariable models for acquired resistance to isoniazid and rifamycins.

RESULTS

M. bovis was independently associated with acquired resistance to isoniazid (adjusted prevalence ratio = 8.46, 95% CI 2.96-24.14) adjusting for HIV status, and with acquired resistance to rifamycins (adjusted prevalence ratio = 4.53, 95% CI 1.29-15.90) adjusting for homelessness, HIV status, initial resistance to isoniazid, site of disease, and administration of therapy. East Asian lineage was associated with acquired resistance to fluoroquinolones (prevalence ratio = 6.10, 95% CI 1.56-23.83).

CONCLUSIONS

We found an association between mycobacterial species and lineage and acquired drug resistance using U.S. surveillance data. Prospective clinical studies are needed to determine the clinical significance of these findings, including whether rapid genotyping of isolates at the outset of treatment may benefit patient management.

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.

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.

Predictors of sputum culture conversion among patients treated for multidrug-resistant tuberculosis

OBJECTIVE

To identify predictors of initial sputum culture conversion, estimate the usefulness of persistent positive cultures at different time points in predicting treatment failure, and evaluate different definitions of culture conversion for predicting failure among patients with multidrug-resistant tuberculosis (MDR-TB) in five countries, 2000-2004.

METHODS

Predictors of time to conversion were identified using multivariate Cox proportional hazards regression modeling. Receiver operating characteristic curves were plotted to visualize the effect of using different definitions of 'culture conversion' on the balance between sensitivity and specificity.

RESULTS

Overall, 1209/1416 (85%) of patients with baseline positive cultures converted in a median of 3.0 months (interquartile range 2.0-5.0). Independent predictors of less likely conversion included baseline positive smear (hazard ratio [HR] 0.60, 95%CI 0.53-0.68), resistance to pyrazinamide (HR 0.82, 95%CI 0.70-0.96), fluoroquinolones (FQs; HR 0.65, 95%CI 0.51-0.83) or thioamide (HR 0.83, 95%CI 0.71-0.96), previous use of FQs (HR 0.71, 95%CI 0.60-0.83), poor outcome of previous anti-tuberculosis treatment (HR 0.69, 95%CI 0.54-0.88) and alcoholism (HR 0.74, 95%CI 0.63-0.87). The maximum combined sensitivity (84%) and specificity (94%) in predicting treatment failure was based on lack of culture conversion at month 9 of treatment, assuming conversion is defined as five consecutive negative cultures.

CONCLUSION

Patients with identified risk factors were less likely to achieve sputum culture conversion during MDR-TB treatment.

Performance of Cepheid ® Xpert MTB/RIF ® and TB-Biochip ® MDR in two regions of Russia with a high prevalence of drug-resistant tuberculosis

The purpose of this study was to assess the performance of Cepheid® Xpert MTB/RIF® ("Xpert") and TB-Biochip® MDR ("TB-Biochip"). Sputum specimens from adults with presumptive tuberculosis (TB) were homogenized and split for: (1) direct Xpert and microscopy, and (2) concentration for Xpert, microscopy, culture [Lowenstein-Jensen (LJ) solid media and Mycobacteria Growth Indicator Tube® (MGIT)], indirect drug susceptibility testing (DST) using the absolute concentration method and MGIT, and TB-Biochip. In total, 109 of 238 (45.8 %) specimens were culture-positive for Mycobacterium tuberculosis complex (MTBC), and, of these, 67 isolates were rifampicin resistant (RIF-R) by phenotypic DST and 64/67 (95.5 %) were isoniazid resistant (INH-R). Compared to culture of the same specimen, a single direct Xpert was more sensitive for detecting MTBC [95.3 %, 95 % confidence interval (CI), 90.0-98.3 %] than direct (59.6 %, 95 % CI, 50.2-68.5 %) or concentrated smear (85.3 %, 95 % CI, 77.7-91.1 %) or LJ culture (80.8 %, 95 % CI, 72.4-87.5 %); the specificity was 86.0 % (95 % CI, 78.9-91.3 %). Compared with MGIT DST, Xpert correctly identified 98.2 % (95 % CI, 91.5-99.9 %) of RIF-R and 95.5 % (95 % CI, 85.8-99.2 %) of RIF-susceptible (RIF-S) specimens. In a subset of 104 specimens, the sensitivity of TB-Biochip for MTBC detection compared to culture was 97.3 % (95 % CI, 91.0-99.5 %); the specificity was 78.1 % (95 % CI, 61.5-89.9 %). TB-Biochip correctly identified 100 % (95 % CI, 94.2-100 %) of RIF-R, 94.7 % (95 % CI, 76.7-99.7 %) of RIF-S, 98.2 % (95 % CI, 91.4-99.9 %) of INH-R, and 78.6 % (95 % CI, 52.1-94.2 %) of INH-S specimens compared to MGIT DST. Xpert and Biochip were similar in accuracy for detecting MTBC and RIF resistance compared to conventional culture methods.

Prevalence of anti-tuberculosis drug resistance in foreign-born tuberculosis cases in the U.S. and in their countries of origin

BACKGROUND

Foreign-born individuals comprise >50% of tuberculosis (TB) cases in the U.S. Since anti-TB drug resistance is more common in most other countries, when evaluating a foreign-born individual for TB, one must consider the risk of drug resistance. Naturally, clinicians query The Global Project on Anti-tuberculosis Drug Resistance Surveillance (Global DRS) which provides population-based data on the prevalence of anti-TB drug resistance in 127 countries starting in 1994. However, foreign-born persons in the U.S. are a biased sample of the population of their countries of origin, and Global DRS data may not accurately predict their risk of drug resistance. Since implementing drug resistance surveillance in 1993, the U.S. National TB Surveillance System (NTSS) has accumulated systematic data on over 130,000 foreign-born TB cases from more than 200 countries and territories. Our objective was to determine whether the prevalence of drug resistance among foreign-born TB cases correlates better with data from the Global DRS or with data on foreign-born TB cases in the NTSS.

METHODS AND FINDINGS

We compared the prevalence of resistance to isoniazid and rifampin among foreign-born TB cases in the U.S., 2007-2009, with US NTSS data from 1993 to 2006 and with Global DRS data from 1994-2007 visually with scatterplots and statistically with correlation and linear regression analyses. Among foreign-born TB cases in the U.S., 2007-2009, the prevalence of isoniazid resistance and multidrug resistance (MDR, i.e. resistance to isoniazid and rifampin), correlated much better with 1993-2006 US surveillance data (isoniazid: r = 0.95, P<.001, MDR: r = 0.75, P<.001) than with Global DRS data, 1994-2007 (isoniazid: r = 0.55, P = .001; MDR: r = 0.50, P<.001).

CONCLUSION

Since 1993, the US NTSS has accumulated sufficient data on foreign-born TB cases to estimate the risk of drug resistance among such individuals better than data from the Global DRS.

Rifampicin-resistant Mycobacterium tuberculosis: susceptibility to isoniazid and other anti-tuberculosis drugs

Based on data from 14 Supranational Tuberculosis (TB) Reference Laboratories worldwide, the proportion of rifampicin (RMP) resistant isolates that were isoniazid (INH) susceptible by phenotypic drug susceptibility testing varied widely (0.5-11.6%). RMP-resistant isolates that were INH-susceptible had significantly lower rates of resistance to other first- and second-line anti-tuberculosis drugs (except rifabutin) compared to multidrug-resistant isolates. RMP resistance is not always a good proxy for a presumptive diagnosis of multidrug-resistant TB, which has implications for use of molecular assays that identify only RMP resistance-associated DNA mutations.

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.

Predictors of poor outcomes among patients treated for multidrug-resistant tuberculosis at DOTS-plus projects

The Objective of this analysis was to identify predictors of death, failure, and default among MDR-TB patients treated with second-line drugs in DOTS-plus projects in Estonia, Latvia, Philippines, Russia, and Peru, 2000-2004. Risk ratios (RR) with 95% confidence intervals (CI) were calculated using multivariable regression. Of 1768 patients, treatment outcomes were: cure/completed - 1156 (65%), died - 200 (11%), default - 241 (14%), failure - 118 (7%). Independent predictors of death included: age>45 years (RR = 1.90 (95%CI 1.29-2.80), HIV infection (RR = 4.22 (2.65-6.72)), extrapulmonary disease (RR = 1.54 (1.04-2.26)), BMI<18.5 (RR = 2.71 (1.91-3.85)), previous use of fluoroquinolones (RR = 1.91 (1.31-2.78)), resistance to any thioamide (RR = 1.59 (1.14-2.22)), baseline positive smear (RR = 2.22 (1.60-3.10)), no culture conversion by 3rd month of treatment (RR = 1.69 (1.19-2.41)); failure: cavitary disease (RR = 1.73 (1.07-2.80)), resistance to any fluoroquinolone (RR = 2.73 (1.71-4.37)) and any thioamide (RR = 1.62 (1.12-2.34)), and no culture conversion by 3rd month (RR = 5.84 (3.02-11.27)); default: unemployment (RR = 1.50 (1.12-2.01)), homelessness (RR = 1.52 (1.00-2.31)), imprisonment (RR = 1.86 (1.42-2.45)), alcohol abuse (RR = 1.60 (1.18-2.16)), and baseline positive smear (RR = 1.35 (1.07-1.71)). Patients with biomedical risk factors for treatment failure or death should receive heightened medical attention. To prevent treatment default, management of patients who are unemployed, homeless, alcoholic, or have a prison history requires extra measures to insure treatment completion.

Global isoniazid resistance patterns in rifampin-resistant and rifampin-susceptible tuberculosis

Following the World Health Organization's endorsement of the Xpert® MTB/RIF assay, which rapidly and simultaneously diagnoses tuberculosis (TB) and detects resistance to rifampin (RMP), the question arises to what extent RMP resistance is an adequate marker for multidrug-resistant TB (MDR-TB). A retrospective analysis of data from >81 countries and subnational settings demonstrated that >40% of RMP-resistant isolates from new TB cases did not display resistance to isoniazid (INH) in settings with relatively low MDR-TB prevalence (one third of all countries and subnational settings). Results indicated the need for INH susceptibility testing in addition to RMP susceptibility testing.

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.

Frequency and type of microbiological monitoring of multidrug-resistant tuberculosis treatment

Monthly culture is usually recommended to monitor treatment of multidrug-resistant tuberculosis (MDR-TB). As mycobacterial laboratory capacity is limited in many settings, TB programs need evidence to decide whether monthly cultures are necessary compared to other approaches. We simulated three alternative monitoring strategies (culture every 2 or 3 months, and monthly smears alone) in a cohort of MDR-TB patients in Estonia, Latvia, Philippines, Russia and Peru from 2000 to 2004. This retrospective analysis illustrated that less frequent testing delays confirmation of bacteriological conversion. This would prolong intensive treatment, hospitalization and respiratory isolation, increasing cost and toxicity. After conversion, less frequent testing could delay diagnosis of possible treatment failure.

Vitamin D status and antimicrobial peptide cathelicidin (LL-37) concentrations in patients with active pulmonary tuberculosis

BACKGROUND

Vitamin D insufficiency is common in industrialized and developing nations. Recent studies have shown that vitamin D insufficiency is associated with a higher risk of active tuberculosis. Laboratory studies provided a mechanism for this link on the basis of findings that vitamin D metabolites regulate the expression of cathelicidin (LL-37), which is an endogenous antimicrobial peptide with activity against Mycobacterium tuberculosis. Little information is available on the clinical relation between vitamin D, LL-37 concentrations, and disease severity in patients with tuberculosis.

OBJECTIVE

The primary objective of the study was to evaluate the relation between vitamin D nutriture, serum LL-37 concentrations, and tuberculosis by using samples stored in the Tuberculosis Trials Consortium serum repository.

DESIGN

We measured 25-hydroxyvitamin D [25(OH)D] and LL-37 concentrations in 95 serum specimens from patients with culture-confirmed pulmonary tuberculosis and correlated these concentrations to clinical and demographic variables.

RESULTS

The prevalence of vitamin D insufficiency [serum 25(OH)D concentration lt 30 ng/mL] in patients with active tuberculosis was 86% (n = 95) with a mean baseline serum 25(OH)D concentration of 20.4 ng/mL. Factors associated with vitamin D insufficiency were black race and indoor lifestyle. The mean ( plusmn SD) baseline LL-37 concentration was 49.5 plusmn 23.8 ng/mL. Higher LL-37 concentrations correlated with acid fast bacilli sputum smear positivity and weight gt 10% below ideal body weight. Serum vitamin D status of the study subjects did not correlate with serum LL-37 concentrations.

CONCLUSION

More prospectively designed studies are needed to evaluate the clinical implications of vitamin D insufficiency in patients with tuberculosis and the utility of circulating LL-37 as a potential biomarker in patients with active tuberculosis disease. The parent trial was registered at clinicaltrials.gov as NCT00023335.

[A social backing program and motivation provision in patients with tuberculosis]

The purpose of the study was to obtain information on tuberculosis patients' needs, perception, and expectations from health care as a whole and social backing in order to improve the implementation of a program for enhancing tuberculosis patients' motivation for recovery and treatment. Anonymous voluntary questioning using the standard questionnaire was carried out among new tuberculosis cases registered to be treated in 4 subjects of the Russian Federation (the Oryol, Vladimir, and Belgorod Regions, and the Republic of Mariy-El). Eighty-seven patients who had stopped being treated before the appointed time and 1302 patients who were receiving chemotherapy at the time of questioning were interviewed using the questionnaire. The main reasons for treatment discontinuance in those who stopped treatment before the appointed time were the necessity of earning their living (30%), alcohol consumption (30%), inadequate health education of the patients who considered themselves to be healthy (25%). Most patients (67%) preferred rewards as social backing, products/hot food (41%), and fare (32%). Among the proposed social backing schemes, the most popular ones were those that envisaged small daily rewards (23%) or a large final bonus (21%). The majority (67%) of patients preferred outpatient treatment. Thus, patients with tuberculosis face a great deal of problems that affect their motivation for treatment. To satisfy some of these problems is not the direct duties of an antituberculosis service due to the fact that the manning table lacks appropriate posts and an item of expenses. Therefore additional funds should be allocated from the budgets of a subject of the Russian Federation and/or municipal entities for adequate organization of social backing of patients with tuberculosis to enhance the efficiency of their treatment. Collaboration of antituberculosis services of the Russian Federation's subjects with social organizations and an addiction service along the availability of psychological and legal consultations to patients is the most optimum variant of social backing organization to improve the patients' motivation for treatment.

[The clinical and epidemic characteristics of new-onset tuberculosis in relation to the procedure of detection]

The outpatient cards and case histories of 456 patients with tuberculosis detected in Samara in the period from January 1, 1999 to December 31, 2003 were examined. Tuberculosis was identified in 58.3% of the patients when they were asking for medical aid; among them 54.2% were treated at general hospital where caseous pneumonia, disseminated tuberculosis, and tuberculous pleurisy were more frequently diagnosed. The unemployed able-bodied persons amounted to 43% of the detected patients with tuberculosis, of whom 81% being identified on recourse to a doctor. Primary drug resistance does not depend on the procedure of tuberculosis detection. Early detection and the initiation of treatment will improve a clinical prognosis in patients with new-onset tuberculosis.

[Specific features of detection of caseous pneumonia and its course in Samara]

A hundred and sixty-three cases of caseous pneumonia were analyzed in Samara. Males aged 35 to 60 years were most frequently ill with the pneumonia; the unemployed and those who had not undergone CC-fluorography for more than 2 years were more frequently ill. The lesion was more commonly bilateral, involving 3 lobes or more with multiple lung tissue destruction. Primary drug resistance was identified in 30.8% of cases. The classical onset of caseous pneumonia with well-defined clinical picture was observed in 75.5% of cases. The average time of diagnosis establishment was I month. One-year death was 34.6%. Progression into chronic forms creates a reservoir of tuberculous infection.