BACKGROUND To investigate how the risk of active tuberculosis disease is influenced by time since original infection and to determine whether the risk of reactivation of tuberculosis increases or decreases with age. METHODS Cohort analysis of data for the separate ten year birth cohorts of 1876-1885 to 1959-1968 obtained from Statistics Norway and the National Tuberculosis Registry. These dat...

The majority of healthy individuals exposed to Mycobacterium tuberculosis will not develop disease and identifying what constitutes "protective immunity" is one of the holy grails of M. tuberculosis immunology. It is known that IFN-gamma is essential for protection, but it is also apparent that IFN-gamma levels alone do not explain the immunity/susceptibility dichotomy. The controversy regardin...

A key challenge to greater progress in tuberculosis (TB) control is the reservoir of latent TB infection (LTBI), which represents a huge long-lived reservoir of potential TB disease. In parts of Africa, as many as 50% of 15-year-olds and 77%-89% of adults have evidence of LTBI. A second key challenge to TB control is the human immunodeficiency virus (HIV)-associated TB epidemic, and Africa alon...

BACKGROUND Tuberculosis is epidemic among workers in South African gold mines. We evaluated an intervention to interrupt tuberculosis transmission by means of mass screening that was linked to treatment for active disease or latent infection. METHODS In a cluster-randomized study, we designated 15 clusters with 78,744 miners as either intervention clusters (40,981 miners in 8 clusters) or con...

Latent infection with Mycobacterium tuberculosis (LTBI) is defined by the presence of M. tuberculosis-specific immunity in the absence of active tuberculosis. LTBI is detected using interferon-c release assays (IGRAs) or the tuberculin-skin-test (TST). In clinical practice, IGRAs and the TSTs have failed to distinguish between active tuberculosis and LTBI and their predictive value to identify ...

Restriction fragment length polymorphism analysis with IS6110 and DR-r probes was used to study 69 Mycobacterium tuberculosis isolates obtained from Israeli patients and new immigrants from the former Soviet Union and Ethiopia. DNA fingerprinting identified unique patterns for almost all isolates, indicating that most patients were infected with a unique strain imported from their country of or...

BACKGROUND The 2050 Millennium Development Goals (MDG) for tuberculosis (TB) aim for elimination of TB as a public health issue. We used a mathematical modelling approach to evaluate the feasibility of this target in a low-prevalence setting with immigration-related strategies directed at latent tuberculosis. METHODS We used a stochastic individual-based model to simulate tuberculosis disease...

BACKGROUND Untreated latent TB infection (LTBI) is a significant risk factor for active pulmonary tuberculosis, hence predisposing to adverse pregnancy outcomes and mother to child transmission. The prevalence of latent tuberculosis in pregnancy and its association, if any, with various socio-demographic, obstetric and clinical characteristics was evaluated. METHODS Northern Tanzania was chos...

The aims of the present study were to identify risk factors associated with latent tuberculosis (TB), examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent i...

The cross-immunity between tuberculosis and leprosy is unknown. The aim of this pilot study was to evaluate the occurrence of Mycobacterium tuberculosis and M. leprae infection in Marshallese adult volunteers in Springdale, Arkansas, U.S.A., a population that experiences high rates of leprosy and tuberculosis. We used immunodiagnostic testing for tuberculosis and leprosy infection and found sig...