Practice guidelines for the treatment of tuberculosis

Direct Detection of Pyrazinamide Resistance in Mycobacterium tuberculosis by Use of pncA PCR Sequencing

An in-house-developed pncA sequencing assay for analysis of pyrazinamide (PZA) resistance was evaluated using 162 archived Mycobacterium tuberculosis complex (MTBC) isolates with phenotypic PZA susceptibility profiles that were well defined by analysis of Bactec MGIT 960 PZA kit and PZase activity data. Preliminary results showed 100% concordance between pncA sequencing and phenotypic PZA drug susceptibility test (DST) results among archived isolates. Also, 637 respiratory specimens were prospectively collected, and 158 were reported as MTBC positive by the Abbott Realtime MTB assay (96.3% sensitivity [95% confidence interval {CI}: 92.2% to 98.7%]; 100% specificity [95% CI: 99.2% to 100.0%]). Genotypic and phenotypic PZA resistance profiles of these 158 MTBC-positive specimens were analyzed by pncA sequencing and Bactec MGIT 960 PZA kit, respectively. For analysis of PZA resistance, pncA sequencing detected pncA mutations in 5/5 (100%) phenotypic PZA-resistant respiratory specimens within 4 working days. No pncA mutations were detected among PZA-susceptible specimens. Combining archived isolates with prospective specimens, 27 were identified as phenotypic PZA resistant with pncA mutation. Among these 27 samples, 6/27 (22.2%) phenotypic PZA-resistant strains carried novel pncA mutations without rpsA and panD mutations. These included 5 with mutations (a deletion [Del] at 383T [Del383T], Del 380 to 390, insertion of A [A Ins] at position 127, A Ins at position 407, and G Ins at position 508) in pncA structural genes and 1 with a mutation (T-12C) at the pncA promoter region. All six of these strains had no or reduced PZase activities, indicating that the novel mutations might confer PZA resistance. Additionally, 25/27 phenotypic PZA-resistant strains were confirmed multidrug-resistant tuberculosis (MDR-TB) strains. As PZA is commonly used in MDR-TB treatment regimens, direct pncA sequencing will rapidly detect PZA resistance and facilitate judicious use of PZA in treating PZA-susceptible MDR-TB.

Nanomaterials in the Prevention, Diagnosis, and Treatment of Mycobacterium Tuberculosis Infections

Despite the tremendous advancements that have been made in biomedical research, Mycobacterium tuberculosis (TB) still remains one of the top 10 causes of death worldwide, outpacing the Human Immunodeficiency Virus as a leading cause of death from an infectious disease. In the light of such significant disease burden, tremendous efforts have been made worldwide to stem this burgeoning spread of disease. The use of nanomaterials in TB management has increased in the past decade, particularly in the areas of early TB detection, prevention, and treatment. Nanomaterials have been proven to be efficacious in the rapid and accurate detection of TB pathogens. Novel nanocarriers have also shown tremendous promise in improving drug delivery, potentially enhancing drug concentrations in target organs while at the same time, reducing treatment frequency. In addition, the engineering of antigen nanocarriers represents an exciting front in TB research, potentially paving the way for the successful development of a new class of effective TB vaccines. This article discusses epidemiology and pathogenesis of TB infections, current TB therapeutics, advanced nanomaterials for anti-TB drug delivery, and TB vaccines. In addition, challenges and future perspectives in developing safe and effective nanomaterials in TB diagnosis and therapy are also presented.

Demographic factors associated with dietary supplement prescriptions filled by United States Military Service Members 2005-2013

BACKGROUND

Dietary supplements (DSs) can be purchased over-the-counter but may also be prescribed by medical personnel for specific therapeutic reasons. Few studies have examined this latter source of DSs despite the fact that 79% of physicians and 82% of nurses have recommended DSs to their patients. This investigation examined demographic factors associated with temporal trends in oral DS prescriptions filled by all United States (US) service members (SMs) from 2005 to 2013 (n = 1,427,080 ± 22,139, mean ± standard deviation per year).

METHODS

The Food and Drug Administration National Drug Code database and the formularies of the US Defense Health Agency's Pharmacoeconomic Center were queried to identify DSs available to SMs. The number of these DS prescriptions filled by all SMs from 2005 through 2013 was then obtained from the US Department of Defense Pharmacy Data Transaction System. Data were grouped by American Hospital Formulary System (AHFS) pharmacologic-therapeutic classifications and examined over time. Denominators (number of SMs each year) were obtained from the Defense Health Agency.

RESULTS

Major findings included 1) generally greater prevalence of prescriptions filled by women and older SMs for most AHFS categories; 2) a temporal decline in total prescriptions filled by Marine Corps personnel accounted for by a decline in the prevalence of zinc preparations filled by younger male Marines; 3) a temporal decline in the prevalence of iron preparations filled by women; 4) a temporal increase in the prevalence of prescriptions for replacement preparations filled by women accounted for largely by more prescriptions for calcium compounds; and 5) a temporal decline in the prevalence of prescriptions filled for cathartics/laxatives in older SMs accounted for largely by a decline in prescriptions for sodium/potassium compounds.

CONCLUSIONS

These temporal trends may be associated with the greater health care utilization of women and older SMs as well as the perceptions of prescribers and/or patients on appropriate roles of these substances in medicine and public health.

Conformational Response of 30S-bound IF3 to A-Site Binders Streptomycin and Kanamycin

Aminoglycoside antibiotics are widely used to treat infectious diseases. Among them, streptomycin and kanamycin (and derivatives) are of importance to battle multidrug-resistant (MDR) Mycobacterium tuberculosis. Both drugs bind the small ribosomal subunit (30S) and inhibit protein synthesis. Genetic, structural, and biochemical studies indicate that local and long-range conformational rearrangements of the 30S subunit account for this inhibition. Here, we use intramolecular FRET between the C- and N-terminus domains of the flexible IF3 to monitor real-time perturbations of their binding sites on the 30S platform. Steady and pre-steady state binding experiments show that both aminoglycosides bring IF3 domains apart, promoting an elongated state of the factor. Binding of Initiation Factor IF1 triggers closure of IF3 bound to the 30S complex, while both aminoglycosides revert the IF1-dependent conformation. Our results uncover dynamic perturbations across the 30S subunit, from the A-site to the platform, and suggest that both aminoglycosides could interfere with prokaryotic translation initiation by modulating the interaction between IF3 domains with the 30S platform.

Mycobacterial infections in solid organ transplant recipients

Mycobacterial infections represent a growing challenge for solid organ transplant recipients (SOT). The adverse effects of tuberculosis (TB) therapy present a major difficulty, due to the interactions with immunosuppressive drugs and direct drug toxicity. While TB may be donor-transmitted or community-acquired, it usually develops at a latent infection site in the recipient. Pre-transplant prevention efforts will improve transplant outcomes and avoid the complications associated with post-transplant diagnosis and treatment. The present review and consensus manuscript is based on the updated published information and expert recommendations. The current data about epidemiology, diagnosis, new regimens for the treatment of latent TB infection (LTBI), the experience with rifamycins for the treatment of active TB in the post-transplant period and the experience with isoniazid for LTBI in the liver transplant population, are also reviewed. We attempt to provide useful recommendations for each transplant period and problem concerning mycobacterial infections in SOT recipients.

Pharmacokinetics and Metabolism of Delamanid, a Novel Anti-Tuberculosis Drug, in Animals and Humans: Importance of Albumin Metabolism In Vivo

Delamanid, a new anti-tuberculosis drug, is metabolized to M1, a unique metabolite formed by cleavage of the 6-nitro-2,3-dihydroimidazo[2,1-b] oxazole moiety, in plasma albumin in vitro. The metabolic activities in dogs and humans are higher than those in rodents. In this study, we characterized the pharmacokinetics and metabolism of delamanid in animals and humans. Eight metabolites (M1-M8) produced by cleavage of the imidazooxazole moiety of delamanid were identified in the plasma after repeated oral administration by liquid chromatography-mass spectrometry analysis. Delamanid was initially catalyzed to M1 and subsequently metabolized by three separate pathways, which suggested that M1 is a crucial starting point. The major pathway in humans was hydroxylation of the oxazole moiety of M1 to form M2 and then successive oxidation to the ketone form (M3) mainly by CYP3A4. M1 had the highest exposure among the eight metabolites after repeated oral dosing in humans, which indicated that M1 was the major metabolite. The overall metabolism of delamanid was qualitatively similar across nonclinical species and humans but was quantitatively different among the species. After repeated administration, the metabolites had much higher concentrations in dogs and humans than in rodents. The in vitro metabolic activity of albumin on delamanid probably caused the species differences observed. We determined that albumin metabolism is a key component of the pharmacokinetics and metabolism of delamanid. Nonhepatic formation of M1 and multiple separate pathways for metabolism of M1 suggest that clinically significant drug-drug interactions with delamanid and M1 are limited.

Sertraline enhances the activity of antimicrobial agents against pathogens of clinical relevance

BACKGROUND

Serotonin reuptake inhibitors were recently reported to possess antimicrobial potentials, potentiate activity of several antibiotics, reverse multidrug resistant phenotypes of bacteria and make them susceptible to previously resistant drugs. We investigated antimicrobial potentials of sertraline (SR) against ATCC strains, clinical isolates of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa alone and in-combination with seven antibiotics. Antifungal activity was investigated against four fungal strains including Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, and Fusarium solani. Intrinsic antibacterial action and Minimum Inhibitory Concentrations (MICs) were determined using well assay, nutrient broth and agar dilution techniques. Disk diffusion and nutrient broth methods were used to study bacterial susceptibility to SR. Minimum Fungicidal Concentrations (MFCs) of SR were determined using Sabouraud dextrose Agar (SDA).

RESULTS

Sertraline possesses strong intrinsic antibacterial, antifungal activities and has augmented the antibacterial activities of antibiotics. For S. aureus ATCC 6538, E. coli ATCC 8739 and P. aeruginosa ATCC 9027, the MICs of SR were 20, 40 and 60 μg ml(-1), respectively, whereas 55.5% clinical isolates of S. aureus and 50% of E. coli strains were inhibited at 20 and 60 μg ml(-1) of SR, respectively. Among the tested fungi, 60% of A. niger and A. fumigatus were inhibited at 40 and 80 μg ml(-1), respectively. MFCs were 60 and 80 μg ml(-1) for A. flavus and F. solani, respectively. Antibacterial activities of all antibiotics were significantly increased (p < 0.001) with the addition of SR 100 μg ml(-1) against all tested bacteria.

CONCLUSION

Combination study revealed that SR had significantly increased the activity of antibiotics, and some previously resistant strains were made susceptible. Thus antidepressants are potential sources of resistance modifying agents when used in combination.

Tuberculosis prophylaxis with levofloxacin in liver transplant patients is associated with a high incidence of tenosynovitis: safety analysis of a multicenter randomized trial

BACKGROUND

It is necessary to develop a safe alternative to isoniazid for tuberculosis prophylaxis in liver transplant recipients. This study was designed to investigate the efficacy and safety of levofloxacin.

METHODS

An open-label, prospective, multicenter, randomized study was conducted to compare the efficacy and safety of levofloxacin (500 mg q24h for 9 months) initiated in patients awaiting liver transplantation and isoniazid (300 mg q24h for 9 months) initiated post-transplant when liver function was stabilized. Efficacy was measured by tuberculosis incidence at 18 months after transplantation. All adverse events related to the medication were recorded.

RESULTS

CONSORT guidelines were followed in order to present the results. The safety committee suspended the study through a safety analysis when 64 patients had been included (31 in the isoniazid arm and 33 in the levofloxacin arm). The reason for suspension was an unexpected incidence of severe tenosynovitis in the levofloxacin arm (18.2%). Although the clinical course was favorable in all cases, tenosynovitis persisted for 7 weeks in some patients. No patients treated with isoniazid, developed tenosynovitis. Only 32.2% of patients randomized to isoniazid (10/31) and 54.5% of patients randomized to levofloxacin (18/33, P = .094) completed prophylaxis. No patient developed tuberculosis during the study follow-up (median 270 days).

CONCLUSIONS

Levofloxacin prophylaxis of tuberculosis in liver transplant candidates is associated with a high incidence of tenosynovitis that limits its potential utility.

Relative Versus Absolute Noncontagiousness of Respiratory Tuberculosis on Treatment

Objective:

To assess the validity of current estimates of the noncontagiousness of sputum smear-positive respiratory tuberculosis (TB) on treatment.

Design:

A descriptive analysis of the mycobacteriologic response to treatment.

Setting:

A TB inpatient unit of a Canadian hospital.

Patients:

Thirty-two HIV-seronegative patients with moderate to advanced sputum smear-positive respiratory TB were treated with uninterrupted, directly observed, weight-adjusted isoniazid, rifampin, and pyrazinamide. Each patient's initial isolate was drug susceptible and each patient's sputum mycobacteriology was systematically followed until 3 consecutive sputum smears were negative on 3 separate days.

Results:

The time to smear conversion varied remarkably (range, 8 to 115 days; average, 46 days) and was influenced by sputum sampling frequency. Only 3 patients (9.4%) had smear conversions by 14 days and only 8 (25%) had smear conversions by 21 days, the average time it took for drug susceptibility test results to become available. During the first 21 days of treatment, the semiquantitative sputum smear score decreased rapidly and the time to detection of positive cultures doubled. Within the time to smear conversion, virtually all smear-positive specimens (98%) were culture positive and only 34% of the patients had culture conversions (ie, 3 consecutive negative cultures).

Conclusion:

Current estimates of the noncontagiousness of sputum smear-positive respiratory TB on treatment (for 14 days, for 21 days, or until smear conversion) are estimates of relative noncontagiousness. They do not signal absolute noncontagiousness (culture conversion). Semiquantitative smear and time-to-detection data suggest that respiratory isolation beyond 21 days of optimal treatment should be selective.

A 10-year population based study of 'opt-out' HIV testing of tuberculosis patients in Alberta, Canada: national implications

INTRODUCTION

Compliance with the recommendation that all tuberculosis (TB) patients be tested for human immunodeficiency virus (HIV) has not yet been achieved in Canada or globally.

METHODS

The experience of "opt-out" HIV testing of TB patients in the Province of Alberta, Canada is described over a 10-year period, 2003-2012. Testing rates are reported before and after the introduction of the "opt-out" approach. Risk factors for HIV seropositivity are described and demographic, clinical and laboratory characteristics of TB patients who were newly diagnosed versus previously diagnosed with HIV are compared. Genotypic clusters, defined as groups of two or more cases whose isolates of Mycobacterium tuberculosis had identical DNA fingerprints over the 10-year period or within 2 years of one another, were analyzed for their ability to predict HIV co-infection.

RESULTS

HIV testing rates were 26% before and 90% after the introduction of "opt-out" testing. During the "opt-out" testing years those <15 or >64 years of age at diagnosis were less likely to have been tested. In those tested the prevalence of HIV was 5.6%. In the age group 15-64 years, risk factors for HIV were: age (35-64 years), Canadian-born Aboriginal or foreign-born sub-Saharan African origin, and combined respiratory and non-respiratory disease. Compared to TB patients previously known to be HIV positive, TB patients newly discovered to be HIV positive had more advanced HIV disease (lower CD4 counts; higher viral loads) at diagnosis. Large cluster size was associated with Aboriginal ancestry. Cluster size predicted HIV co-infection in Aboriginal peoples when clusters included all cases reported over 10 years but not when clusters included cases reported within 2 years of one another.

CONCLUSION

"Opt-out" HIV testing of TB patients is effective and well received. Universal HIV testing of TB patients (>80% of patients tested) has immediate (patients) and longer-term (TB/HIV program planning) benefits.

Tuberculosis

Tuberculosis remains a serious health problem worldwide, particularly affecting the poorest in both high-income and developing countries. It was declared a global emergency by the World Health Organization in 1993. Central nervous system (CNS) tuberculosis is caused by mycobacteria belonging to the Mycobacterium tuberculosis complex, and is acquired through inhalation of aerosolized droplet nuclei. Meningitis represents the most frequent and severe form of CNS tuberculosis. Parenchymal CNS involvement can occur in the form of tuberculoma or, more rarely, abscess. Also, damage of the spinal cord, roots, and spine can occur in the form of spinal meningitis, radiculomyelitis, spondylitis, or spinal cord infarction. Diagnosis remains a challenge due to the slow growth of the organisms and the low yield of cerebrospinal fluid cultures, as well as the frequent absence of evidence of infection elsewhere. This results in frequent empirical therapy, based on a combination of four drugs (isoniazid, rifampicin, pyrazinamide and ethambutol) for 2 months, followed by 10 additional months with two drugs (isoniazid and rifampicin) to a total duration of 12 months. Shorter regimens have also been successful, but there have been few controlled trials in patients with extrapulmonary disease. Corticoid therapy seems to be associated with a reduced risk of death, and is usually indicated. Evidence of multidrug resistance requires variable combinations of first- and second-line drugs; fortunately, resistance does not seem to represent a serious threat for CNS tuberculosis at present, but still requires the utmost vigilance.

Novel magnetic resonance imaging scoring system for diagnosis of spinal tuberculosis: A preliminary report

Background:

There exists a lot of ambiguity in the preoperative diagnosis of the various vertebral lesions. Mostly in these patients tuberculosis of spine (TB) is suspected due to endemicity of the disease in the Indian subcontinent. However, no definite guidelines are available to diagnose tuberculous (TB) vertebral lesions in the current literature.

Study Design:

This prospective study was conducted in the Department of Neurosurgery, Nizam's Institute of Medical Sciences, from August 2009 to March 2012.

Aim of the Study:

To formulate non invasive methods to diagnose tuberculous vertebral lesions confidently so that the dependency on histopathologic diagnosis can be reduced.

Material and Methods:

Spinal MRI images of 45 patients suspected of having tuberculosis aetiology were included in the study prospectively.

Results:

A total of 64 patients were analysed and 19 patients were excluded due to lack of regular follow up or histological proof. The patients were divided into two groups; those with TB of the spine and those with some other condition affecting the spine (non TB spine) based on the final diagnosis. Of the 45 patients males were 30 (66.6%) and females were 15 (33.3%). There was no significant difference in the mean age of presentation. For TB patients this was 41 ± 15.56 years and in Non TB was 43 ± 18.27 years. All patients presented with backache in either group. There was epiphyseal involvement (100%), disc height reduction (71.42%) and pedicle destruction (42.82%) in plain X-rays in the TB group. Lumbar spine was the most common affected region in our study (26.31% in non TB and 34.6% in TB group of patients). Significant P value and the Odds Ratio was found for T1 hypo intensity, T2 hyper intensity, epiphyseal involvement, disc involvement, pedicle involvement, anterior subligamentous extension, paraspinal extension and no spinous process involvement (eight parameters). The eight parameters were tested among both the groups and it was noted that scores ≥ 6 favored a tuberculous pathology whereas ≤4 were suggestive of non tuberculous etiology.

Conclusions:

The eight point MRI criteria of the vertebral lesions are likely to enhance the diagnostic ability of tuberculous and non tuberculous pathologies thereby reducing the dependency on histopathologic diagnosis or invasive method for early initiation of therapy.

Concomitant acromioclavicular and miliary tuberculosis

A 48-year-old man was being treated unsuccessfully for miliary tuberculosis for 5 months until he presented with acromioclavicular joint swelling. Imaging of the shoulder revealed destruction of the acromioclavicular joint and the patient was brought to the operating theatre and underwent the excision of the distal end of the clavicle, synovectomy and drainage of the abscess. Surgery was followed by prompt clinical, functional and radiological improvement. Histopathology confirmed the diagnosis of acromioclavicular tuberculosis. Resistance to appropriate antituberculous treatment in patients with miliary tuberculosis can sometimes be a result of undiagnosed extrapulmonary site of infection.

Chemoprophylaxis with isoniazid in liver transplant recipients

A patient receiving a liver graft needs to be treated with immunosuppressive drugs to avoid rejection. These kinds of drugs predispose the patient to the reactivation of latent infections such as tuberculosis (TB). Therefore, it is necessary to establish treatment regimens to prevent this. We retrospectively analyzed all consecutive patients undergoing liver transplantation (LT) at our center between January 1, 2000 and December 31, 2010. Latent tuberculosis infections (LTBIs) were diagnosed with positive tuberculin skin test results. After LT, infected patients were treated with isoniazid for 6 months; the treatment began soon after transplantation, and the patients were followed until the end of the study. During this period, 53 patients had LTBI data. All these patients were treated with isoniazid after LT. The median observation period after LT was 52 months (range = 12-129 months). No cases of TB reactivation were reported during follow-up. Only 4 patients presented alterations in liver enzymes related to this treatment, and they showed clear improvement after the treatment was stopped. None of these patients showed severe graft dysfunction. In conclusion, preventive isoniazid appears to be a safe drug for use in LTBI patients after LT. The treatment may be established just after LT without important graft dysfunction or severe consequences for the patient.

Synergistic interactions of methanolic extract of Acacia mearnsii De Wild. with antibiotics against bacteria of clinical relevance

With the emergence of multidrug-resistant organisms, combining medicinal plants with synthetic or orthodox medicines against resistant bacteria becomes necessary. In this study, interactions between methanolic extract of Acacia mearnsii and eight antibiotics were investigated by agar diffusion and checkerboard assays. The minimum inhibitory concentrations (MICs) of all the antibiotics ranged between 0.020 and 500 μg/mL while that of the crude extract varied between 0.156 and 1.25 mg/mL. The agar diffusion assay showed that extract-kanamycin combination had zones of inhibition ≥20 ± 1.0 mm in all the bacteria tested (100%), followed by extract-chloramphenicol (90%) > extract-ciprofloxacin = extract-tetracycline (70%) > extract-amoxicillin (60%) > extract-nalidixic acid (50%) > extract-erythromycin (40%) > extract-metronidazole (20%). The checkerboard showed synergistic interaction (61.25%), additivity/indifference (23.75%) and antagonistic (15%) effects. The synergistic interaction was most expressed by combining the extract with tetracycline, metronidazole, amoxicillin, ciprofloxacin, chloramphenicol and nalidixic acid against E. coli (ATCC 25922), erythromycin, metronidazole, amoxicillin, chloramphenicol and kanamycin against S. aureus (ATCC 6538), erythromycin, tetracycline, amoxicillin, nalidixic acid and chloramphenicol against B. subtilis KZN, erythromycin, metronidazole and amoxicillin against E. faecalis KZN, erythromycin, tetracycline, nalidixic acid and chloramphenicol against K. pneumoniae (ATCC 10031), erythromycin, tetracycline, metronidazole and chloramphenicol against P. vulgaris (ATCC 6830), erythromycin, tetracycline, amoxicillin and chloramphenicol against S. sonnei (ATCC 29930), metronidazole, amoxicillin and chloramphenicol against E. faecalis (ATCC 29212) and ciprofloxacin and chloramphenicol against Proteus vulgaris KZN. The synergistic interactions indicated that the bactericidal potentials of the antibacterial agents were improved and combining natural products with antibiotic could be potential sources for resistance-modifying agents useful against infectious multi-drug resistant bacteria.

Tobacco consumption is a reversible risk factor associated with reduced successful treatment outcomes of anti-tuberculosis therapy

OBJECTIVE

The aim of this study was to evaluate the reversible factors that could possibly affect outcomes of anti-tuberculosis (anti-TB) treatment.

METHODS

A retrospective observational nested case-control study was performed to evaluate the association of patient and clinical factors with anti-TB therapy outcomes as defined by the World Health Organization (WHO).

RESULTS

To examine the impact of a variety of factors on the outcomes of anti-TB treatment, a total of 302 TB patients were included in the study. Univariate analysis revealed that age, gender, concurrent hypertension, asthma/chronic obstructive pulmonary disease, or liver disease, worsened baseline blood urea nitrogen or creatinine, ethambutol <800 mg/day, hepatitis or adverse skin reactions during therapy, smoking history, and current tobacco consumption were significant factors in decreasing both the cure rate and treatment completion rate. However, multivariate regression showed that only age, current daily tobacco consumption, baseline liver disease, and ethambutol dosage were independent factors. A high level of tobacco consumption (>20 cigarettes per day) was significantly associated with a decreased odds of cure or treatment completion (odds ratio 0.23, 95% confidence interval 0.05-0.98, p=0.047).

CONCLUSIONS

As smoking significantly inhibits the effectiveness of TB treatment, the integration of smoking cessation into TB treatment programs is strongly advocated to reduce the dual global burden of smoking and TB.

Re-examining treatment of latent tuberculosis infection

In April 2000, the American Thoracic Society published guidelines for targeted tuberculin testing and the treatment of latent tuberculosis infection (LTBI) (1). These guidelines are a joint statement of the American Thoracic Society and the Centers for Disease Control and Prevention, and were endorsed by both the Infectious Diseases Society of America and the American Academy of Pediatrics. Similar recommendations were published by the Infectious Diseases Society of America in its guidelines for the treatment of tuberculosis (TB) (2). These updated guidelines were developed in recognition of the importance of treating LTBI as one component of eliminating TB in the United States - a goal reiterated in 1999 by the Advisory Council for the Elimination of Tuberculosis (3) - but also realizing the differing risks and benefits of treatment for patients based on their individual risks of developing active disease or drug toxicity (4). The 2000 edition of theCanadian Tuberculosis Standardsprovided similar recommendations for the treatment of LTBI (formerly known as chemoprophylaxis) and reminded us of the two major Canadian TB elimination initiatives: the National Tuberculosis Elimination Strategy (Medical Services Branch, 1992), with the aim of eliminating TB in First Nations people by 2010, and the National Consensus Conference on Tuberculosis (Health Canada, 1997), with an interim goal of a 5% reduction in the number of TB cases each year in Canada (5). Given the recent publication of the American guidelines and the updatedCanadian Tuberculosis Standards(Fifth Edition), it was considered timely to remind readers of the evidence supporting the use of antituberculous chemotherapy in the treatment of latent infection.

Intraocular tuberculosis

Intraocular manifestations of tuberculosis (TB) are rare, but TB infection is common worldwide, especially in developing economies, and in immigrant populations and immunocompromised patients in developed nations. The current review focuses on the clinical characteristics and diagnostic modalities useful in the diagnosis of intraocular TB. Specifically, IFN-gamma Release Assays (IGRAs), antigen-detection assays, and polymerase chain reactions will be discussed. Clinical management of TB patients includes counseling and testing for HIV infection. The use of corticosteroids along with anti-tuberculous medications and special therapeutic considerations in immunocompromised patients are discussed.

The feasibility of using an 'opt-out' approach to achieve universal HIV testing of tuberculosis patients in Alberta

OBJECTIVE

Universal HIV testing of tuberculosis (TB) patients, defined as testing greater than 80% of incident cases, has been recommended but not achieved in Canada. The objectives of this study were: i) to assess the success of an 'opt-out' approach, whereby HIV testing is routine unless the patient specifically chooses otherwise, and ii) to determine the risk factors for HIV in patients tested before and after this approach was implemented.

METHODS

TB and HIV databases in the province of Alberta were cross-matched before HAART (highly active anti-retroviral therapy) was available (1991-1997), after HAART but before 'opt-out' testing was implemented (1998-2002), and after 'opt-out' testing was implemented (2003-2006), and the HIV status of TB patients in each time period was described. The demographic and clinical characteristics of HIV-positive and -negative TB patients aged 15-64 years were compared.

RESULTS

HIV testing of TB patients increased from 11.5% before HAART, to 44.9% after HAART but before 'opt-out' testing, to 81.9% after 'opt-out' testing was implemented. Between 1991 and 2006, 50 TB patients were diagnosed with HIV co-infection, all in the age group 15-64 years. Among TB patients aged 15-64 years who were HIV tested, those testing positive were significantly less likely to be female and to have respiratory TB and significantly more likely to have both respiratory and non-respiratory TB. The prevalence of HIV positivity in HIV-tested TB patients aged 15-64 years was 7.4% in 2003-2006.

CONCLUSION

Universal HIV testing of TB patients is achievable through 'opt-out' HIV testing.

[Consensus document for the management of tuberculosis in solid organ transplant recipients]

The relevance of tuberculosis in solid organ transplant recipients stems from the difficulties in the diagnosis, which delay the start of treatment, and the associated toxicity of pharmacological therapy. These facts are responsible for the large number of clinical complications and the high mortality in this population. This Consensus Document from GESITRA (Spanish Transplantation Infection Study Group) defines the indications for prophylaxis of latent tuberculosis infection in patients undergoing solid organ transplantation, in particular those with a high risk of pharmacological toxicity, as is the case of liver transplant recipients. This Consensus Document also establishes recommendations for the choice of drugs to use and duration of treatment for tuberculosis in solid organ transplant recipients, with special mention of vigilance for the development of pharmacological interactions between rifampin and immunosuppressive drugs (cyclosporine, tacrolimus, rapamycin, and steroids).

Guía de práctica clínica de la Sociedad Andaluza de Enfermedades Infecciosas (SAEI) sobre el tratamiento de la tuberculosis

The therapeutic scheme for initial pulmonary tuberculosis recommended by the SAEI is as follows: Initial phase, isoniazid, rifampin and pyrazinamide given daily for 2 months. In HIV(+) patients and immigrants from areas with a rate of primary resistance to isoniazid > 4%, ethambutol should be added until susceptibility studies are available. Second phase (continuation phase): rifampin and isoniazid, given daily or intermittently for 4 months in the general population. HIV(+) patients (< or = 200 CD4) and culture-positive patients after 2 months of treatment should receive a 7-month continuation phase. A 6-month regimen is recommended for extrapulmonary tuberculosis, with the exception of tuberculous meningitis, which should be treated for a minimum of 12 months and bone/joint tuberculosis, treated for a minimum of 9 months. Treatment regimens for multidrug resistant tuberculosis are based on expert opinion. These would include a combination of still-useful first-line drugs, injectable agents, and alternative agents, such as quinolones. Patients who present a special risk of transmitting the disease or of non-adherence should be treated with directly observed therapy.

Contact investigation of a case of active tuberculosis in the community

BACKGROUND

Ashtabula County, Ohio, has been a low-risk county for tuberculosis (TB) based on the Centers for Disease Control and Prevention guidelines. The Ashtabula County TB clinic is provided through the Ashtabula County Health Department. Over the past 10 years, there has been an annual average of one to 2 active cases of TB seen and treated at the county TB clinic. CONTACT INVESTIGATION: In 2005, over a period of 3 months there were 6 cases of active TB identified in Ashtabula County. Contact investigation and follow-up were complicated by the fact that the suspected source case likely had active disease for more than 4 years and had some medical procedures performed at health care facilities in another county. This person was unaware of having TB and was identified through contact investigation by the county health department staff and sent for testing. The investigation was complicated further because the index case did not reveal contact with the suspected source case, although this was confirmed later through investigation. Contact investigation involved Ashtabula County and notification of other counties in Ohio. The Ohio Department of Health also was notified.

DISCUSSION

Following identification of each case of active TB, contacts were identified through interviews with the clients, physicians, and health care facilities where clients were treated. Initially in Ashtabula County, 97 people were reviewed for follow-up, and 87 people were skin tested for TB. There were 7 conversions.

CONCLUSION

Although the overall incidence of TB has declined in the United States, increased awareness of TB, appropriate diagnostic work-up, treatment, and control measures among health care professionals in low-incidence areas is increasingly important. Contact investigation of a case of TB requires diligence and effective communication.

Preparation and in Vivo Evaluation of a Dry Powder for Inhalation of Capreomycin

PURPOSE

To develop an aerosol system for efficient local lung delivery of a tuberculostatic drug.

METHODS

The antibiotic, capreomycin sulfate, was spray dried to form a dry powder aerosol. The chemical content and physical properties of resulting particles were assessed under various storage conditions. Plasma concentrations of capreomycin after insufflation into guinea pigs were evaluated at three doses, and compared to IV and IM administration of a capreomycin solution.

RESULTS

Dry powder aerosols containing capreomycin were formulated to enable efficient delivery of large drug masses to the lungs of guinea pigs. Aerosols loaded with 73% CS were shown to possess good aerosolization properties and physical-chemical stability for up to 3 months at room temperature. Upon insufflation into guinea pigs, the amount of CS reaching the bloodstream was significantly lower compared to IV or IM administration, but resulted in a significantly longer drug half-life.

CONCLUSIONS

The results indicate that large doses of capreomycin in dry powder form can be efficiently delivered to the lungs of guinea pigs, which may result in high local drug exposure but significantly reduced systemic exposure as suggested by plasma concentrations in the present studies. These systems have considerable potential to provide more effective therapy for MDR-TB.

Leprosy and tuberculosis: an insight-review

A quick glance at this review article provides an insight into the common and different features of M. leprae and M. tuberculosis and the diseases caused by these organisms. Table I provides the popular names, history, stigma, description of the disease, clinical features, classification and the types of disease manifestations, who are affected, Signs and Symptoms, Clinical examination, treatment regimens, reactions, relapses, immunity, infectiousness, risk groups, deformities, sequelae, transmission, prevention, complications, vaccination, laboratory studies, days of importance for both the diseases. Table II provides information regarding the causative organisms, M. leprae and M. tuberculosis, their size, genome, protein coding region, lost genes, pseudogenes, classification, predilection, incubation period, ecology, cell structure, metabolism, resistance, bacterial index, growth in vitro, experimental animals, etc. Table III provides figures of M. leprae and M. tuberculosis, their genome, Lepromin and Tuberculin testing, Global scenario, Indian scenario, colonies of M. leprae and M. tuberculosis, drugs for treatment of tuberculosis and leprosy (MDT blister pack), and so on.

[Tuberculosis treatment in 2007]

Treatment principles have changed little over the past 30 years and most patients with tuberculosis should receive isoniazid, rifampin, pyrazinamide and ethambutol during the first two months (initial phase), and isoniazid and rifampin during 4 months thereafter (continuation phase). Thorough guidelines were elaborated by the Conseil Supérieur d'Hygiène Publique de France in 2003 and were widely publicized since, including in the journal "Médecine et Maladies Infectieuses". However, this general review is largely justified by the amount of data accumulated over recent years, including: i) resistant-tuberculosis epidemiology (rising incidence of multi-resistant tuberculosis in Eastern Europe, the emergence of ''extensively drug-resistant tuberculosis''); ii) latent tuberculosis standard of care (new diagnostic tests; chemoprophylaxis and workout guidelines before initiating TNF inhibitors); iii) corticosteroids in neuromeningeal tuberculosis; iv) new therapeutic options for multi-resistant tuberculosis (moxifloxacin, linezolid); v) tuberculosis treatment in HIV-infected patients; vi) discrepancies between guidelines and practices in France.

Variations of care quality for infectious pulmonary tuberculosis in Taiwan: a population based cohort study

Background

Effective and efficient care is required to prevent the spread of infectious pulmonary tuberculosis (PTB). We attempted to compare care quality among different healthcare institutions in Southern Taiwan.

Methods

This study conducted population-based retrospective cohort design. One tuberculosis sanatorium, 2 medical centers, 11 regional hospitals, and 15 district hospitals and primary practitioners in the study area had reported tuberculosis cases, registered from January 1 to June 30 2003. Those cases with sputum positive PTB were followed 15 months after anti-tuberculosis treatment initiation. Meanwhile, Level of conformance with diagnostic guidelines, efficiency of diagnostic and treatment process, and treatment were measured as main outcome. Association was investigated using Chi-square tests, Kruskal Wallis tests, Mann-Whiteney U tests, and multiple logistic regression analysis to evaluate outcome differences among different levels of institutions.

Results

The analyses included 421 patients. In comparison with patients receiving treatment at medical centers, regional hospitals, and district hospitals/primary practitioners, patients at the Chest Specialty Hospital were more likely to provide at least three sputum specimens (74.1% vs. 48.2%, 36.8%, and 50.0%), shorter workdays examining sputum smears (2.4 ± 2.4 days vs. 2.6 ± 2.1, 4.5 ± 3.1, and 3.5 ± 2.6 days), shorter interval between the first consultation and treatment (10.1 ± 18.3 days vs. 31.0 ± 53.6, 31.2 ± 70.4, and 25.4 ± 37.6 days), and a higher successful treatment rate (92.6% vs. 65.2%, 63.9%, and 68.0%). Furthermore, after adjusting age and gender, the patients treated by the pulmonologists and treated at Chest Specialty Hospital had significantly more successful treatment rate, of which odds ratios were 1.74 and 4.58 respectively.

Conclusion

Differences in care quality exist among different types of healthcare institutions and among individual physicians. The implementation of practice guidelines should contribute to an improvement in the care quality of the treatment and diagnosis of PTB.

[Controversies in the treatment of extrapulmonary tuberculosis]

Tuberculosis (TB) can spread to any tissue or organ of the body by way of hematogenous or lymphatic dissemination or contiguity. However, pulmonary TB is the most common presentation and the only form of the disease of epidemiologic importance. Consequently, the literature on the various forms of extrapulmonary TB (EPTB) is scant, and most of the published authors are specialists in specific extrapulmonary forms. As a result, in most of the major areas of study of EPTB, recommendations similar to those for pulmonary TB or others based on little or no evidence have been accepted. This lack of evidence is of particular concern in the case of treatment guidelines. The present article reviews important work that has given rise to current treatment guidelines. While most of these guidelines reveal the lack of evidence available on this subject, it can, nevertheless, be concluded that a 6-month treatment regimen similar to that used in patients with pulmonary TB may be sufficient to treat all forms of EPTB, including meningeal disease. The role of steroids and surgery in the treatment of TB affecting different sites is also discussed. Other topics dealt with are the considerations that should be taken into account and the treatment modifications necessary in patients infected with the human immunodeficiency virus.

Bacterial pericarditis: diagnosis and management

Bacterial pericarditis occurs by direct infection during trauma, thoracic surgery, or catheter drainage, by spread from an intrathoracic, myocardial, or subdiaphragmatic focus, and by hematogenous dissemination. The frequent causes are Staphylococcus and Streptococcus (rheumatic pancarditis), Haemophilus, and M. tuberculosis. In AIDS pericarditis, the incidence of bacterial infection is much higher than in the general population, with a high proportion of Mycobacterium avium-intracellulare infection. Purulent pericarditis is the most serious manifestation of bacterial pericarditis, characterized by gross pus in the pericardium or microscopically purulent effusion. It is an acute, fulminant illness with fever in virtually all patients. Chest pain is uncommon. Purulent pericarditis is always fatal if untreated. The mortality rate in treated patients is 40%, and death is mostly due to cardiac tamponade, systemic toxicity, cardiac decompensation, and constriction. Tuberculous infection may present as acute pericarditis, cardiac tamponade, silent (often large) relapsing pericardial effusion, effusive-constrictive pericarditis, toxic symptoms with persistent fever, and acute, subacute, or chronic constriction. The mortality in untreated patients approaches 85%. Urgent pericardial drainage, combined with intravenous antibacterial therapy (e.g. vancomycin 1g twice daily, ceftriaxone 1-2g twice daily, and ciprofloxacin 400 mg/day) is mandatory in purulent pericarditis. Irrigation with urokinase or streptokinase, using large catheters, may liquify the purulent exudate, but open surgical drainage is preferable. The initial treatment of tuberculous pericarditis should include isoniazid 300 mg/day, rifampin 600 mg/day, pyrazinamide 15-30 mg/kg/day, and ethambutol 15-25 mg/kg/day. Prednisone 1-2 mg/kg/day is given for 5-7 days and progressively reduced to discontinuation in 6-8 weeks. Drug sensitivity testing is essential. Pericardiectomy is reserved for recurrent effusions or continued elevation of central venous pressure after 4-6 weeks of antituberculous and corticosteroid therapy.

Tuberculosis in children: an update

TB is a common and serious global infection that is spread exclusively from person to person. The initial infection in most healthy people leads to LTBI 95% of the time, but untreated individuals have a 5% to 10% lifetime risk for reactivating their infection to develop highly infectious cavitary pulmonary TB or extrapulmonary disease. Following primary infection progressive disease is more likely to develop in children younger than 5 years old or those who are immunocompromised, particularly those with HIV infection. The diagnosis of TB in most of the world depends on the presence of a clinical illness typical for TB in concert with radiographic changes, the presence of AFB in sputum, or a positive TST. Newer methods of in vitro stimulation of T lymphocytes from TB-infected people to produce interferon may be more accurate than a TST but have yet to be well studied in children. Treatment of children with LTBI is generally 9 months of daily isoniazid unless the child has been in contact with an adult with known isoniazid-resistant TB. For active TB, children generally are treated for 6 months with an initial 2 months of isoniazid, rifampin, and pyrazinamide. Where exposure to an isoniazid-resistant strain is likely, ethambutol is added. After 2 months, pyrazinamide is discontinued unless the patient has been confirmed to have been infected with a resistant strain of M. tuberculosis. BCG, rarely used in the United States, is still considered important to prevent meningitis and miliary disease in very young children in areas of the world with a high prevalence of TB.

American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: Controlling Tuberculosis in the United States

During 1993-2003, incidence of tuberculosis (TB) in the United States decreased 44% and is now occurring at a historic low level (14,874 cases in 2003). The Advisory Council for the Elimination of Tuberculosis has called for a renewed commitment to eliminating TB in the United States, and the Institute of Medicine has published a detailed plan for achieving that goal. In this statement, the American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC), and the Infectious Diseases Society of America (IDSA) propose recommendations to improve the control and prevention of TB in the United States and to progress toward its elimination. This statement is one in a series issued periodically by the sponsoring organizations to guide the diagnosis, treatment, control, and prevention of TB. This statement supersedes the previous statement by ATS and CDC, which was also supported by IDSA and the American Academy of Pediatrics (AAP). This statement was drafted, after an evidence-based review of the subject, by a panel of representatives of the three sponsoring organizations. AAP, the National Tuberculosis Controllers Association, and the Canadian Thoracic Society were also represented on the panel. This statement integrates recent scientific advances with current epidemiologic data, other recent guidelines from this series, and other sources into a coherent and practical approach to the control of TB in the United States. Although drafted to apply to TB-control activities in the United States, this statement might be of use in other countries in which persons with TB generally have access to medical and public health services and resources necessary to make a precise diagnosis of the disease; achieve curative medical treatment; and otherwise provide substantial science-based protection of the population against TB. This statement is aimed at all persons who advocate, plan, and work at controlling and preventing TB in the United States, including persons who formulate public health policy and make decisions about allocation of resources for disease control and health maintenance and directors and staff members of state, county, and local public health agencies throughout the United States charged with control of TB. The audience also includes the full range of medical practitioners, organizations, and institutions involved in the health care of persons in the United States who are at risk for TB.

La tuberculose péritonéale : une entité toujours présente. À propos de quatre observations

INTRODUCTION

Tuberculous peritonitis, a major problem in developing country, occurs preferentially in immigrant population and in patients with acquired immune deficiency syndrome (AIDS). Although rare in France, it did not disappear and epidemiological, clinical and therapeutic approach deserve to be reminded.

EXEGESIS

We reported 4 patients (immigrants in two cases), occurred in caucasian and African persons (one with AIDS). Disease was characterized by fever, abdominal pain, anorexia, weight loss and ascites. Biological and radiological were unconclusive. Cell count analysis from ascitic fluid show a lymphocytic predominance with negative direct smear for Ziehl-Neelsen strain. Tuberculous peritonitis was established with combined visual and histological diagnosic laparoscopic examination.

CONCLUSION

These observations have the interest to underline that tuberculous peritonitis must be evoked in case of lymphocytic ascitis. We believe an aggressive diagnostic approach, particulary with peritoneal biopsy, is warranted for the diagnosis of tuberculous peritonitis. Validity of PCR amplification is ascitic fluid still needs to be established.

Minimum inhibitory concentrations of herbal essential oils and monolaurin for gram-positive and gram-negative bacteria

New, safe antimicrobial agents are needed to prevent and overcome severe bacterial, viral, and fungal infections. Based on our previous experience and that of others, we postulated that herbal essential oils, such as those of origanum, and monolaurin offer such possibilities. We examined in vitro the cidal and/or static effects of oil of origanum, several other essential oils, and monolaurin on Staphylococcus aureus, Bacillus anthracis Sterne, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, and Mycobacterium terrae. Origanum proved cidal to all tested organisms with the exception of B. anthracis Sterne in which it was static. Monolaurin was cidal to S. aureus and M. terrae but not to E. coli and K. pneumoniae. Unlike the other two gram-negative organisms, H. pylori were extremely sensitive to monolaurin. Similar to origanum, monolaurin was static to B. anthracis Sterne. Because of their longstanding safety record, origanum and/or monolaurin, alone or combined with antibiotics, might prove useful in the prevention and treatment of severe bacterial infections, especially those that are difficult to treat and/or are antibiotic resistant.

Tuberculosis prevention and control in long-term-care facilities for older adults

In the United States, older adults comprise 22% of cases of tuberculous disease but only 12% of the population. Most cases of tuberculosis (TB) occur in community dwellers, but attack rates are highest among frail residents of long-term-care facilities. The detection and treatment of latent TB infection and TB disease can pose special challenges in older adults. Rapid recognition of possible disease, diagnosis, and implementation of airborne precautions are essential to prevent spread. It is the intent of this evidence-based guideline to assist healthcare providers in the prevention and control of TB, specifically in skilled nursing facilities for the elderly.