Seminars in respiratory and critical care medicine
-
The nontuberculous mycobacteria (NTM) are typically environmental organisms residing in soil and water. Although generally of low pathogenicity to humans, NTM can cause a wide array of clinical diseases; pulmonary disease is most frequent, followed by lymphadenitis in children, skin disease by M. marinum (particularly in fish tank fanciers), and other extrapulmonary or disseminated infections in severely immunocompromised patients. Of the >140 NTM species reported in the literature, 25 species have been strongly associated with NTM diseases; the remainder are environmental organisms rarely encountered in clinical samples. ⋯ Because of limited sensitivity and specificity of symptoms, radiology, and direct microscopy of clinical samples, culture remains the gold standard. Yet culture is time consuming and demands the use of multiple media types and incubation temperatures to optimize the yield. Outside of reference centers, such elaborate culture algorithms are scarce.
-
Semin Respir Crit Care Med · Feb 2013
Ecology of nontuberculous mycobacteria--where do human infections come from?
Nontuberculous mycobacteria (NTM) are environmental, opportunistic human pathogens whose reservoirs include peat-rich potting soil and drinking water in buildings and households. In fact, humans are likely surrounded by NTM. ⋯ These include avoiding inhalation of dusts from peat-rich potting soil and aerosols from showers, hot tubs, and humidifiers. A riskanalysis of the presence of NTM in drinking water has not been initiated because the virulence of independent isolates of even single NTM species (e.g., Mycobacterium avium) is quite broad, and virulence determinants have not been identified.
-
The identification of phenotypes of asthma has a long history, but previous classifications have not identified clinically important differences in pathology, natural history, or treatment response. Progress has accelerated recently, fueled by the development of new techniques to assess airway disease, particularly noninvasive techniques to assess airway inflammation. ⋯ There has been increasing interest in the application of mathematical techniques such as factor analysis and cluster analysis to organize and group large amounts of interrelated data in an unbiased way. This article discusses attempts to do this in asthma and speculates on the clinical implications of this new information.
-
Semin Respir Crit Care Med · Dec 2012
Asthma: vocal cord dysfunction (VCD) and other dysfunctional breathing disorders.
Vocal cord dysfunction (VCD) and dysfunctional breathing (DB) disorders may mimic or coexist with asthma, leading to overtreatment with corticosteroids with consequent morbidity. Iatrogenic complications can be averted by early and correct diagnosis. VCD, also termed paradoxical vocal fold motion disorder (PVFMD), is characterized by intermittent paradoxical adduction of the vocal cords, mainly during inspiration, leading to airflow obstruction and dyspnea. ⋯ The pathophysiology of DB is poorly understood, but psychological or physiological stress may precipitate episodes in some patients. Treatment requires a multidisciplinary approach (including speech therapy and psychological support). Prognosis is usually good.