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]

Update on the epidemiology of pulmonary nontuberculous mycobacterial infections.

Semin Respir Crit Care Med. 2013 Feb;34(1):87-94

Authors: Kendall BA, Winthrop KL

Abstract
For decades, the incidence of pulmonary nontuberculous mycobacteria (NTM) has been reported to be increasing, yet formal epidemiological evaluation of this notion has been lacking until recently. Defining the epidemiology of NTM has been more challenging than with Mycobacterium tuberculosis (MTB). Unlike MTB, NTM are soil and water organisms, and infection is thought to be acquired from the environment rather than transmitted from person-to-person, with very rare exceptions. Due to their nearly ubiquitous presence in municipal water supplies, exposure to NTM is common. Further, NTM can colonize the respiratory tract without causing disease. NTM disease is not reportable to public health authorities; therefore, epidemiological and surveillance data are not readily available. Nonetheless, the prevalence of pulmonary NTM disease has increased dramatically in the United States and globally over the past 3 decades. Mycobacterium avium complex (MAC) accounts for the majority of NTM infections worldwide, but there is significant regional variability of various species. Additionally, novel species have been implicated in several countries in NTM pulmonary disease.

PMID: 23460008 [PubMed - in process]

Management of Nontuberculous Mycobacterial (NTM) Lung Disease.

Semin Respir Crit Care Med. 2013 Feb;34(1):135-42

Authors: Philley JV, Griffith DE

Abstract
Nontuberculous mycobacterial (NTM) lung diseases present formidable obstacles to successful management, especially when compared with tuberculosis, beginning with diagnosis and extending through treatment. Factors peculiar to NTM disease such as extensive microbial resistance mechanisms and difficult to interpret, even misleading, in vitro drug susceptibility patterns are just two of the multiple and frustrating clinical management challenges. More conventional problems such as drug-drug interactions, medication side-effects, and nonadherence with therapy add further impediments to successful outcomes. In spite of these difficulties, the majority of NTM lung disease patients are still treated successfully. Because the prevalence of NTM is rising, it is increasingly necessary for clinicians to understand those unique aspects of NTM lung disease diagnosis and treatment that differ from tuberculosis and that contribute to limited treatment options.

PMID: 23460013 [PubMed - in process]

Management of extrapulmonary nontuberculous mycobacterial infections.

Semin Respir Crit Care Med. 2013 Feb;34(1):143-50

Authors: Kasperbauer S, Huitt G

Abstract
Nontuberculous mycobacteria represent a vast group of environmental organisms that have the potential to cause disease in humans. Unlike tuberculosis, these organisms are not known to be transmitted from human to human. The most common clinical presentation is pulmonary disease. Approximately 10% of infections manifest as extrapulmonary disease. The portals of entry are the respiratory tract, gastrointestinal tract, or direct inoculation via trauma or an invasive procedure. Like tuberculosis, the nontuberculous mycobacteria have the potential to infect any organ system given the opportunity in an immunocompromised host. The spectrum of disease is extensive ranging from self-limited furunculosis to life-threatening disseminated infection. Common extrapulmonary manifestations include lymphadenitis, disseminated disease, skin, soft tissue, and bone infection. Less common manifestations include keratitis, catheter-related bloodstream infections, septic arthritis, central nervous system infection, and peritonitis. The incidence of extrapulmonary infections is unknown. Outbreaks have been reported due to inadequate disinfection of surgical equipment or contamination of injected solutions or medications. A high index of suspicion is required when patients present with subacute or chronic complaints of extrapulmonary infection. This review addresses the management of the common extrapulmonary nontuberculous infections.

PMID: 23460014 [PubMed - in process]