Diagnostic standards and classification of tuberculosis in adults and children

A joint statement of the American Thoracic Society and the CDC, this article provides a framework for and an understanding of the diagnostic approaches to tuberculosis (TB) infection/disease and to present a classification scheme that facilitates management of all persons to whom diagnostic tests have been applied. The specific objectives of this revision of the Diagnostic Standards are to define diagnostic strategies for high- and low-risk patient populations based on current knowledge of TB epidemiology and information on newer technology and to provide a classification scheme for TB that is based on pathogenesis. Definitions of TB disease and latent infection have been selected that (1) aid in an accurate diagnosis; (2) coincide with the appropriate response of the health care team, whether it be no response, treatment of latent infection, or treatment of disease; (3) provide the most useful information that correlates with the prognosis; (4) provide the necessary information of appropriate public health action; and (5) provide a uniform, functional, and practical means of reporting. Because TB, even after it has been treated adequately, remains a pertinent and lifelong part of a person's medical history, previous as well as current disease is included in the classification. This edition of the Diagnostic Standards has been prepared as a practical guide and statement of principles for all persons involved in the care of patients with TB. References have been included to guide the reader to texts and journal articles for more detailed information on each topic. Section headings are (I) Epidemiology, (II) Transmission of Mycobacterium Tuberculosis, (III) Pathogenesis of Tuberculosis, (IV) Clinical Manifestations of Tuberculosis, (V) Diagnostic Microbiology, (VI) Tuberculin Skin Test, (VII) Classification of Persons Exposed to and/or Infected with Mycobacterium Tuberculosis, and (VIII) Reporting of Tuberculosis.I. Epidemiology -- II. Transmission of Mycobacterium Tuberculosis -- III. Pathogenesis of Tuberculosis -- IV. Clinical Manifestations of Tuberculosis -- V. Diagnostic Microbiology -- VI. Tuberculin Skin Test -- VII. Classification of Persons Exposed to and/or Infected with Mycobacterium Tuberculosis -- VIII. Reporting of Tuberculosis.This official statement of the American Thoracic Society and the Centers for Disease Control and Prevention was adopted by the ATS Board of Directors, July 1999. This statement was endorsed by the Council of the Infectious Disease Society of America, September 1999.Reprinted from American journal of respiratory and critical care medicine, Vol. 161, 2000.Also available on the World Wide Web (accessed 06/18/2010),Includes bibliographic references (p. 1392-1395)

Prescribing cycle training intensity from the six-minute walk test for patients with COPD

Background: Cycle training intensity for patients with chronic obstructive pulmonary disease (COPD) is normally based on an incremental cycle test. Such tests are expensive and not readily available to clinicians. The six-minute walk test (6MWT) has been proposed as an alternative to an incremental cycle test for this purpose, based on the findings of previous research that the peak oxygen consumption (VO2peak) for the incremental cycle test and the 6MWT was equivalent in participants with COPD. A regression equation relating distance walked on the 6MWT and peak work rate (Wpeak) on the incremental cycle test has been described. The aim of this study is to measure the physiological responses to constant load cycle exercise performed at an intensity of 60% Wpeak determined from the 6MWT in participants with stable COPD. Methods/Design: This study is a prospective, repeated measures design. Thirty-five participants with stable COPD and mild to severe lung disease will be recruited from referrals to pulmonary rehabilitation. Subjects with co-morbidities limiting exercise performance will be excluded. Two 6MWTs will be performed. The better 6MWT will be used to calculate Wpeak for cycle exercise from a regression equation. After 30 minutes rest, subjects will perform ten minutes of constantload cycle exercise at 60% of the calculated Wpeak. During all exercise, cardiorespiratory and metabolic data (Cosmed K4b2), dyspnoea and rate of perceived exertion (RPE) will be recorded. The VO2 measured at the end of cycle exercise will be compared to VO2peak of the 6MWT (VO2bike/ VO2walk). Pearson's correlation coefficient will be calculated for the relationship between VO2bike and VO2walk. A one-way analysis of variance (ANOVA), with Bonferroni correction, will be performed to determine whether the ratio of VO2bike/VO2walk is affected by disease severity. Discussion: This novel study will measure the physiological responses to cycle exercise, in terms of VO2peak, performed at an intensity determined from the 6MWT in participants with COPD. Positive findings will enable clinicians to more precisely prescribe cycle training intensity by utilising a simple, reliable and inexpensive 6MWT, thus providing a better standard of care for patients with COPD referred to pulmonary rehabilitation

Sequential Bilateral Lung Resection in a Patient with Mycobacterium Abscessus Lung Disease Refractory to Medical Treatment

Mycobacterium abscessus (M. abscessus) is the second most common nontuberculous mycobacteria (NTM) in South Korea. Nevertheless, the diagnosis and treatment of M. abscessus lung disease can be problematic. Surgical resection has been tried for patients with localized M. abscessus lung disease refractory to medical treatment. Here, we report on a 25-year-old woman with M. abscessus lung disease who had been diagnosed and treated three times for pulmonary tuberculosis. She was initially diagnosed as having M. intracellulare lung disease; however, M. abscessus was isolated after several months of medication. She had multiple bronchiectatic and cavitary lesions bilaterally, and M. abscessus was repeatedly isolated from her sputa despite prolonged treatment with clarithromycin, ethambutol, moxifloxacin, and amikacin. She improved only after sequential bilateral lung resection. Based on the experience with this patient, we suggest that, if medical treatment fails, surgical resection of a diseased lung should be considered even in patients with bilateral lesions

New methodology for specific inhalation challenges with occupational agents

<p>Abstract</p> <p>Background</p> <p>Inhalation challenges are used for diagnosing occupational asthma (OA). The initial methodology consisted of a "realistic" exposure without monitoring nor controlling exposure. Our aim was to design an equipment, called the GenaSIC, that allows the generation of various agents regardless of the formulation and to assess the feasibility of its use in patients investigated for OA.</p> <p>Results</p> <p>GenaSIC can generate lactose, flour, malt, isocyanates, formaldehyde and N-butyl acetate with precise and fairly stable concentrations. Using N-butyl-acetate as a control agent and real time measurement, we show that normal breathing has a negligible effect on the concentration. We exposed forty-four different subjects to a control agent and/or to a suspected occupational agent. Nineteen of the subjects were only exposed to N-butyl acetate as a control agent without experiencing any significant irritant effect (no significant changes in spirometry thereafter). Eight subjects who were exposed to both N-butyl acetate and formaldehyde did not show significant reactions. Seven subjects were exposed to dry particles (flour in six instances, malt in the other) and five showed immediate asthmatic reactions which changes in FEV1 from 20% to a maximum of 28%. Finally, ten subjects were exposed to isocyanates, four of whom showed a positive reaction, including one subject with immediate maximum changes in FEV1 of 22%.</p> <p>Conclusion</p> <p>GenaSIC offers the possibility of reliable and safe exposures to dry particles, formaldehyde and isocyanates in the investigation of OA.</p

Policy Implications of Genetic Information on Regulation under the Clean Air Act: The Case of Particulate Matter and Asthmatics

The U.S. Clean Air Act (CAA) explicitly guarantees the protection of sensitive human subpopulations from adverse health effects associated with air pollution exposure. Identified subpopulations, such as asthmatics, may carry multiple genetic susceptibilities to disease onset and progression and thus qualify for special protection under the CAA. Scientific advances accelerated as a result of the ground-breaking Human Genome Project enable the quantification of genetic information that underlies such human variability in susceptibility and the cellular mechanisms of disease. In epidemiology and regulatory toxicology, genetic information can more clearly elucidate human susceptibility essential to risk assessment, such as in support of air quality regulation. In an effort to encourage the incorporation of genomic information in regulation, the U.S. Environmental Protection Agency (EPA) has issued an Interim Policy on Genomics. Additional research strategy and policy documents from the National Academy of Science, the U.S. EPA, and the U.S. Department of Health and Human Services further promote the expansion of asthma genetics research for human health risk assessment. Through a review of these government documents, we find opportunities for the inclusion of genetic information in the regulation of air pollutants. In addition, we identify sources of information in recent scientific research on asthma genetics relevant to regulatory standard setting. We conclude with recommendations on how to integrate these approaches for the improvement of regulatory health science and the prerequisites for inclusion of genetic information in decision making

The incidence of interstitial lung disease 1995–2005: a Danish nationwide population-based study

<p>Abstract</p> <p>Background</p> <p>Current data on incidence of interstitial lung diseases (ILDs) are sparse and concerns about an increasing trend have been raised. We examined incidence rates (IRs) of ILDs and changes in IRs between 1995 and 2005.</p> <p>Methods</p> <p>All persons with a first-time hospital discharge or outpatient diagnosis of ILD were identified through the Danish National Registry of Patients, which covers all Danish hospitals. Crude and age-standardised IRs were computed for ILD overall, as well as stratified by ILD subcategories.</p> <p>Results</p> <p>A total of 21,765 patients with ILD were identified. Between 1995 and 1998 the overall standardised IR of ILD decreased from 27.14 (95% CI 25.82–28.46) per 100,000 person-years to 19.36 (95% CI 18.26–20.46) per 100,000 person-years. After 1998 the IR increased considerably, peaking at 34.34 (95% CI 32.84–35.85) per 100,000 person-years in 2002. Subsequently there was a slight decrease. The highest IR was observed in the non-specific category "Respiratory disorders in diseases classified elsewhere". By ILD subcategory, the greatest average increase during the study period was observed in "Respiratory disorders in diseases classified elsewhere".</p> <p>Conclusion</p> <p>The incidence rate of ILD in Denmark increased during the study period, most pronounced for ILDs associated with systemic diseases.</p

Ambient and Microenvironmental Particles and Exhaled Nitric Oxide Before and After a Group Bus Trip

OBJECTIVES: Airborne particles have been linked to pulmonary oxidative stress and inflammation. Because these effects may be particularly great for traffic-related particles, we examined associations between particle exposures and exhaled nitric oxide (FE(NO)) in a study of 44 senior citizens, which involved repeated trips aboard a diesel bus. METHODS: Samples of FE(NO) collected before and after the trips were regressed against microenvironmental and ambient particle concentrations using mixed models controlling for subject, day, trip, vitamins, collection device, mold, pollen, room air nitric oxide, apparent temperature, and time to analysis. Although ambient concentrations were collected at a fixed location, continuous group-level personal samples characterized microenvironmental exposures throughout facility and trip periods. RESULTS: In pre-trip samples, both microenvironmental and ambient exposures to fine particles were positively associated with FE(NO). For example, an interquartile increase of 4 μg/m(3) in the daily microenvironmental PM(2.5) concentration was associated with a 13% [95% confidence interval (CI), 2–24%) increase in FE(NO). After the trips, however, FE(NO) concentrations were associated pre-dominantly with microenvironmental exposures, with significant associations for concentrations measured throughout the whole day. Associations with exposures during the trip also were strong and statistically significant with a 24% (95% CI, 15–34%) increase in FE(NO) predicted per interquartile increase of 9 μg/m(3) in PM(2.5). Although pre-trip findings were generally robust, our post-trip findings were sensitive to several influential days. CONCLUSIONS: Fine particle exposures resulted in increased levels of FE(NO) in elderly adults, suggestive of increased airway inflammation. These associations were best assessed by microenvironmental exposure measurements during periods of high personal particle exposures