Treatment of latent tuberculosis infection.

Semin Respir Crit Care Med. 2013 Feb;34(1):67-86

Authors: Vernon A

Abstract
Latent tuberculosis infection (LTBI) refers to a circumstance in which viable Mycobacterium tuberculosis (MTB) bacilli are present in an individual but symptoms and signs of active disease are lacking, and the bacilli are relatively inactive metabolically. In favorable circumstances, some of these inactive bacilli resume greater metabolic activity and replication, leading to the development of active tuberculosis disease. Treatment of this condition (TLTBI) is designed to prevent (soon, or in the distant future) this progression from asymptomatic infection to symptomatic, potentially lethal, active disease. This narrative review draws upon recent reviews of LTBI and seeks particularly to include recently published or presented data that are not included in those prior reviews. Adverse effects of treatment are considered, as are the special circumstances of human immunodeficiency virus-related LTBI, drug resistance, and use of TLTBI in the context of tumor necrosis factor alpha (TNF-α) inhibition. The review describes the main studies underpinning Centers for Disease Control and Prevention recommendations on use of the new 3-month isoniazid-rifapentine regimen and points to evolving data that may support future modification of those recommendations.

PMID: 23460007 [PubMed - in process]

Nontuberculous mycobacteria in patients with cystic fibrosis.

Semin Respir Crit Care Med. 2013 Feb;34(1):124-34

Authors: Leung JM, Olivier KN

Abstract
As a result of their underlying lung disease, patients with cystic fibrosis (CF) have a higher risk of developing nontuberculous mycobacteria (NTM) infections compared with the general population. Although NTM may be present intermittently in low amounts in the airways of CF patients without an apparent clinical effect, progressive respiratory decline due to NTM disease may also occur. Identifying this latter group of patients can be challenging for clinicians because the usual symptoms exhibited by infected individuals without CF may be difficult to distinguish from the baseline respiratory dysfunction of a patient with CF. The distinction, however, is of utmost importance because those patients with clinical worsening may benefit considerably from antimycobacterial treatment. For CF patients under evaluation for lung transplantation, NTM can play a critical role in determining overall outcomes, and treatment in the pre- and post-transplant period may be vital to success. A general approach to NTM in CF thus involves surveillance to detect NTM, careful monitoring for associated clinical decline, and consideration of treatment given for those with an otherwise unexplained deterioration. In this review, the epidemiology and clinical course of NTM in CF is described with an algorithm for management proposed.

PMID: 23460012 [PubMed - in process]

Management of multidrug resistant tuberculosis.

Semin Respir Crit Care Med. 2013 Feb;34(1):44-59

Authors: Daley CL, Caminero JA

Abstract
Drug-resistant strains of Mycobacterium tuberculosis have emerged as a major threat to global tuberculosis control. Despite the availability of curative antituberculosis therapy for nearly half a century, inappropriate and inadequate treatment has allowed M. tuberculosis to acquire resistance to our most important antituberculosis drugs. The epidemic of drug-resistant tuberculosis has spread quickly in some areas due to the convergence of resistant strains of M. tuberculosis in high-risk patients (e.g., those with human immunodeficiency virus/acquired immunodeficiency syndrome) and high-risk environments (e.g., hospitals and prisons). The World Health Organization (WHO) estimates that there were 650,000 cases of multidrug resistant tuberculosis (MDR-TB) in 2010, defined as strains that are resistant to at least isoniazid (INH) and rifampicin (RIF). Globally, WHO estimates that 3.7% of new tuberculosis cases and 20% of re-treatment cases have MDR-TB. By the end of 2012, 84 countries had reported at least one case of extensively drug resistant strains (XDR-TB), which are MDR-TB strains that have acquired additional resistance to fluoroquinolones and at least one second-line injectable. Recently, cases of "totally drug resistant" tuberculosis have been reported. It is estimated that only 10% of all MDR-TB cases are currently receiving therapy and only 2% are receiving quality-assured drugs. This article reviews the management of MDR and XDR-TB and highlights the updated 2011 WHO guidelines on the programmatic management of drug-resistant tuberculosis.

PMID: 23460005 [PubMed - in process]