We estimated the rate of reactivation tuberculosis (TB) in the United States, overall and by population subgroup, using data on TB cases and Mycobacterium tuberculosis isolate genotyping reported to ...the Centers for Disease Control and Prevention during 2006-2008. The rate of reactivation TB was defined as the number of non-genotypically clustered TB cases divided by the number of person-years at risk for reactivation due to prevalent latent TB infection (LTBI). LTBI was ascertained from tuberculin skin tests given during the 1999-2000 National Health and Nutrition Examination Survey. Clustering of TB cases was determined using TB genotyping data collected by the Centers for Disease Control and Prevention and analyzed via spatial scan statistic. Of the 39,920 TB cases reported during 2006-2008, 79.7% were attributed to reactivation. The overall rate of reactivation TB among persons with LTBI was estimated as 0.084 (95% confidence interval (CI): 0.083, 0.085) cases per 100 person-years. Rates among persons with and without human immunodeficiency virus coinfection were 1.82 (95% CI: 1.74, 1.89) and 0.073 (95% CI: 0.070, 0.075) cases per 100 person-years, respectively. The rate of reactivation TB among persons with LTBI was higher among foreign-born persons (0.098 cases/100 person-years; 95% CI: 0.096, 0.10) than among persons born in the United States (0.082 cases/100 person-years; 95% CI: 0.080, 0.083). Differences in rates of TB reactivation across subgroups support current recommendations for targeted testing and treatment of LTBI.
Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis ...(TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone.
This article reviews recommended strategies for screening and treatment of latent tuberculosis in the United States, with attention to the role of interferon-γ–release assays in screening and of ...shorter treatment regimens (as compared with a 9-month course of isoniazid).
Foreword
This
Journal
feature begins with a case vignette highlighting a common clinical problem. Evidence supporting various strategies is then presented, followed by a review of formal guidelines, when they exist. The article ends with the authors' clinical recommendations.
Stage
A healthy 43-year-old woman presents for a pre-employment physical examination. She is originally from Ghana and came to the United States 18 months ago. Her employer, a hospital, requires a tuberculosis test. She reports having no known exposure to tuberculosis and no cough, fevers, or weight loss. Her physical examination is unremarkable. What screening test would you recommend, and how would you decide whether treatment is needed?
The Clinical Problem
More than 80% of cases of tuberculosis in the United States are the result of reactivated latent infection,
1
,
2
and nearly all these cases could be prevented by the . . .
Background. The risk of progression to active tuberculosis is greatest in the several years following initial infection. The extent to which latent tuberculosis infection reduces the risk of ...progressive disease following reexposure and reinfection is not known. Indirect estimates from population models have been highly variable. Methods. We reviewed prospective cohort studies of persons exposed to individuals with infectious tuberculosis that were published prior to the widespread treatment of latent tuberculosis to estimate the incidence of tuberculosis among individuals with latent tuberculosis infection (LTBI group) and without latent tuberculosis (uninfected; UI group). We calculated the incidence rate ratio (IRR) of tuberculosis disease following infection between these 2 groups. We then adjusted incidence for expected reactivation, proportion of each group that was infected, and median time of observation following infection during the study. Results. We identified 18 publications reporting tuberculosis incidence among 23 paired cohorts of individuals with and without latent infection (total N = 19 886). The weighted mean adjusted incidence rate of tuberculosis in the LTBI and UI groups attributable to reinfection was 13.5 per 1000 person-years (95% confidence interval CI: 5.0—26.2 per 1000 person-years) and that attributable to primary infection was 60.1 per 1000 person-years (95% CI: 38.6—87.4 per 1000 person-years). The adjusted IRR for tuberculosis in the LTBI group compared with the UI group was 0.21 (95% CI: .14—.30). Conclusions. Individuals with latent tuberculosis had 79% lower risk of progressive tuberculosis after reinfection than uninfected individuals. The risk reduction estimated in this study is greater than most previous estimates made through population models.
To improve the effectiveness of tuberculosis (TB) control programs in the United States by identifying cost-effective priorities for screening for latent tuberculosis infection (LTBI).
To estimate ...the cost-effectiveness of LTBI screening using the tuberculin skin test (TST)and interferon-g release assays (IGRAs).
A Markov model of screening for LTBI with TST and IGRA in risk-groups considered in current LTBI screening guidelines.
In all risk-groups, TST and IGRA screening resulted in increased mean life expectancy, ranging from 0.03–0.24 life-months per person screened. IGRA screening resulted in greater life expectancy gains than TST. Screening always cost more than not screening, but IGRA was cost-saving compared with TST in some groups. Four patterns of cost-effectiveness emerged, related to four risk categories. (1) Individuals at highest risk of TB reactivation (close contacts and those infected with HIV): the incremental cost-effectiveness ratio (ICER) of IGRA compared with TST was less than $100,000 per quality-adjusted life year (QALY) gained. (2) The foreign-born: IGRA was cost-saving compared with TST and cost-effective compared with no screening (ICER ,$100,000 per QALY gained). (3) Vulnerable populations (e.g., homeless, drug user, or former prisoner): the ICER of TST screening was approximately $100,000–$150,000 per QALY gained, but IGRA was not cost-effective. (4) Medical comorbidities (e.g., diabetes): the ICER of screening with TST or IGRA was greater than $100,000 per QALY.
LTBI screening guidelines could make progress toward TB elimination by prioritizing screening for close contacts, those infected with HIV, and the foreign-born regardless of time living in the United States. For these groups, IGRA screening was more cost-effective than TST screening.
Undernutrition impairs immunity to Mycobacterium tuberculosis and is a risk factor for tuberculosis disease (TB). We aim to investigate if severe undernutrition affects the tuberculin skin test (TST) ...response among household contacts (HHCs) of pulmonary TB cases.
We analyzed data from HHCs (> five years) of pulmonary TB cases in Southern India. Undernutrition was defined as per World Health Organization based on body mass index (BMI) for adults (undernutrition 16-18.4 and severe undernutrition <16 kg/m2) and BMI relative to the mean for children (undernutrition 2SD-3SD and severe undernutrition < 3SDs below mean). Univariate and multivariate models of TST positivity (> five mm) were calculated using logistic regression with generalized estimating equations.
Among 1189 HHCs, 342 were children (age 5-17 years) and 847 were adults. Prevalence of TST positivity in well-nourished, undernourished and severely undernourished children was 135/251 (53.8%), 32/68 (47.1%), and 7/23 (30.4%) respectively; among adults, prevalence of TST positivity was 304/708 (42.9%), 43/112 (38.4%) and 12/26 (46.2%), respectively. Severe undernutrition in children was associated with decreased odds of TST positivity (adjusted odds ratio 0.3; 95%CI 0.1-0.9).
Severe undernutrition in children was associated with decreased odds of TST positivity. False-negative TSTs may result from undernutrition; caution is warranted when interpreting negative results in undernourished populations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Tuberculosis (TB) is a risk factor for chronic obstructive pulmonary disease (COPD), but COPD is also a predictor of TB. The excess life-years lost to COPD caused by TB can potentially be ...saved by screening for and treating TB infection. We examined the number of life-years that could be saved by preventing TB and TB-attributable COPD. We compared the observed (no intervention) and counterfactual microsimulation models constructed from observed rates in the Danish National Patient Registry (covering all Danish hospitals between 1995 and 2014). In the Danish population of TB and COPD-naive individuals (n = 5,206,922), 27,783 persons (0.5%) developed TB. Among those who developed TB, 14,438 (52.0%) developed TB with COPD. Preventing TB saved 186,469 life-years overall. The excess number of life-years lost to TB alone was 7.07 years per person, and the additional number of life-years lost among persons who developed COPD after TB was 4.86 years per person. The life-years lost to TB-associated COPD are substantial, even in regions where TB can be expected to be identified and treated promptly. Prevention of TB could prevent a substantial amount of COPD-related morbidity; the benefit of screening and treatment for TB infection is underestimated by considering morbidity from TB alone.
Background: Treatment of latent TB infection (LTBI) is essential for preventing TB in North America, but acceptance and completion of
this treatment have not been systematically assessed.
Methods: We ...performed a retrospective, randomized two-stage cross-sectional survey of treatment and completion of LTBI at public and
private clinics in 19 regions of the United States and Canada in 2002.
Results: At 32 clinics that both performed tuberculin skin testing and offered treatment, 123 (17.1%; 95% CI, 14.5%-20.0%) of 720
subjects tested and offered treatment declined. Employees at health-care facilities were more likely to decline (odds ratio
OR, 4.74; 95% CI, 1.75-12.9; P = .003), whereas those in contact with a patient with TB were less likely to decline (OR, 0.19; 95% CI, 0.07-0.50; P = .001). At 68 clinics starting treatment regardless of where skin testing was performed, 1,045 (52.7%; 95% CI, 48.5%-56.8%)
of 1,994 people starting treatment failed to complete the recommended course. Risk factors for failure to complete included
starting the 9-month isoniazid regimen (OR, 2.08; 95% CI, 1.23-3.57), residence in a congregate setting (nursing home, shelter,
or jail; OR, 2.94; 95% CI, 1.58-5.56), injection drug use (OR, 2.13; 95% CI, 1.04-4.35), age ⥠15 years (OR, 1.49; 95% CI,
1.14-1.94), and employment at a health-care facility (1.37; 95% CI, 1.00-1.85).
Conclusions: Fewer than half of the people starting treatment of LTBI completed therapy. Shorter regimens and interventions targeting
residents of congregate settings, injection drug users, and employees of health-care facilities are needed to increase completion.
Lange et al discuss the study by V. De Jager and colleagues on the early bactericidal activity of different concentrations of meropenem plus clavulanate. Tuberculosis is the leading cause of ...bacterial infectious diseases death worldwide. Over the past decade, the number of patients identified with rifampicin-resistant tuberculosis (RR-TB) or multidrug-resistant tuberculosis (MDR-TB; RR-TB plus isoniazid-resistant tuberculosis) has increased by approximately 20% annually. MDR/RR-TB is related to long treatment duration, incurs high treatment costs, and generally leads to poor treatment outcome. Unfortunately, the effect was only modest, and the treatment was poorly tolerated. Moreover, the intravenous route of administration of meropenem is operationally not feasible in most countries where MDR/RR-TB is prevalent.
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