View clinical trials related to Latent Tuberculosis Infection.
Filter by:The present study was to evaluate the usefulness of a whole-blood interferon-r release assays (IGRAs) as diagnostic tool of the latent tuberculosis infection for healthcare workers.
On a global scale, tuberculosis (TB) is the single most important infectious cause of morbidity and mortality. The World Health Organization has estimated that one-third of the entire world's population carries latent TB infection. A key TB control strategy is therapy of latent TB infection (LTBI). The current standard regimen is 9 months of Isoniazid (9INH). This regimen has excellent efficacy if taken regularly, but its effectiveness is substantially reduced by poor compliance. Serious side effects, such as hepato-toxicity can occur. Three shorter alternatives have been recommended: 6 months INH (6INH), 2 months Rifampin - Pyrazinamide (2RIF-PZA) and 4 months Rifampin (4RIF). The regimen of 6INH is less efficacious than 9INH, while 2RIF-PZA has been largely abandoned because of serious toxicity. Based on some evidence in treatment of LTBI, and extrapolating from extensive experience with treatment of active TB, it is believed that 4RIF has similar efficacy as 9INH. Therefore, the investigators are initiating the first multi-site international randomized trial that will compare the effectiveness of 4RIF and 9INH in preventing active tuberculosis.
It is traditionally considered that the development of Latent Tuberculosis Infection (LTBI) is due to the M. tuberculosis ability to develop a dormancy state within well-structured lesions (granulomas), which can remain in the lung of the host even for life. A new original hypothesis has been developed in the Experimental Tuberculosis Unit based on scientific evidence that take into account the idea that a lesion cannot be held forever, because the host tends to remove any lesion in order to rebuild the original parenchyma, in a healing process. Even if M. tuberculosis can remain in a dormant/non-replicating state for a long period, this is an important but not sufficient factor to explain the LTBI. The Dynamic Hypothesis tries to explain the existence of LTBI in spite of the healing process that could remove it by a constant reinfection of the host's tissue. While the "Static" view defends the induction of active TB after the reactivation of the bacilli from and old lesion; while the "Dynamic" view wants to demonstrate that there is a constant induction of new granulomas. In case one of these new lesions takes place in the upper lobe privileged zone, the possibility to induce a cavity would appear, developing an active Tuberculosis (TB).
Tuberculosis is a current infection during HIV infection. After infectious contact, some patients will develop tuberculosis some will only be infected without symptoms, they have Latent Tuberculosis Infection (LTBI) which can reactivate later.In order to prevent this tuberculosis reactivation, LTBI diagnosis screening is preconised in HIV-infected patients. This diagnosis is made till now by the tuberculin skin test (TST) but this test is not specific of TB. New blood tests (QFTB-G and T-SPOT.TB) specific po MTB infection are now sold but have not been evaluated in immunocompromised HIV-infected patients. The primary endpoint of this study is the evaluation of the theoretic therapeutic impact of the use of IGRAS for diagnosis of LTBI in HIV-infected patients
The overall objective of this study is to assess the feasibility and potential impact of using a targeted testing approach and 2 interferon-gamma release assays (IGRA) to screen for latent tuberculosis (TB) infection (LTBI) among military recruits. The current policy of universal application of the Mantoux tuberculin skin test (TST) to screen for LTBI may result in many TST reactions among recruits who are at low risk for LTBI. The central hypothesis is that targeted testing by use of the questionnaire will reduce unnecessary testing of low-risk recruits without affecting the identification of higher-risk recruits. The secondary hypothesis is that many discordant results between the TST and IGRA may be explained by cross-reactivity to non-tuberculous mycobacteria (NTM) with the TST.
HIV induced altered representation and function of regulatory T cell subsets (NKT and Treg cells) impair the protective T cell response against M.tuberculosis and disrupts LTBI, thus facilitates faster progression and development of severe forms of clinical TB in HIV-TB co-infection.
In populations with high prevalence of latent tuberculosis infection (LTBI), malnutrition (PEM) may influence incident rates of TB. PEM and specific micronutrient deficiencies compromise cell mediated immunity (CMI) and increase susceptibility to, or severity of infections. Vitamin A supplementation significantly reduces all-cause child mortality. The mechanism of the benefits of supplementation on clinical outcomes is largely unknown, but is likely to be related to an influence on the immune system. Vitamin A supplementation promotes lymphogenesis and induces a higher proportion of CD4 naïve T-cells in children. Most cases of LTBI that progress to active disease are vitamin A deficient. Vitamin A deficiency is common in most TB endemic countries. At the MRC, 32% of TBCC contacts were vitamin A deficient. Hypothesis: The investigators plan to test the hypotheses: that supplementation with vitamin A will affect the magnitude and quality of immune responses to mycobacterial antigens and progression to clinical disease.
After exposure to an active case of tuberculosis (TB), close contacts may be infected. They are then considered as having latent tuberculosis infection (LTBI). Detecting LTBI is the main goal of contact tracing procedures after exposure to TB. Until recently, the only test available for detecting LTBI was the tuberculin skin test (TST). More recent tests are now available (Interferon-gamma release assays: IGRA), which are more specific and sensitive than the TST. This study compares the TST and an IGRA in the routine activity of contact tracing in our area.
The aim of this study is to evaluate the safety of a new vaccine against Tuberculosis (RUTI) when administered to healthy adult volunteers, compared to placebo; and determine its safe dosage range. An initial evaluation of immune responses to the vaccine compared to placebo will also be undertaken. In the present Phase I clinical trial, four increasing doses of RUTI will be tested, the groups composed by 6 volunteers each. (Total of 24 volunteers). The escalation to a new dose to test will be done after the safety of the previous dose has been ensured. For each dose of FCMtb to test, each volunteer will be inoculated twice (at day 0 and day 28) with RUTI (4 volunteers) or placebo (2 volunteers) and will be followed-up up to 25 weeks from the first inoculation. The global length of the study will be approximately 15 months.
Background: The TB and HIV epidemics are closely linked in developing countries, where 450,000 children die from HIV annually. TB is a major cause of death in HIV-infected children and is reversing gains made in child survival. The traditional tuberculin skin test (TST) has limited diagnostic accuracy for detecting TB infection. Adult studies suggest that new blood-based diagnostic TB testing offers a quicker, more accurate way to diagnose TB infection. Such diagnostic testing may directly guide clinical management and preventive strategies in immune-suppressed HIV-infected children, who are at high risk of becoming TB diseased following infection. Data regarding the usefulness of these tests in children is currently limited. Objective(s) and Hypothesis(es): The investigators hypothesize that blood-based TB diagnostic testing can accurately identify children with TB infection. In a community with high rates of TB and HIV infection, the following specific aims will be investigated in HIV-infected and uninfected children: 1. assess the agreement between the TST and blood-based diagnostic testing, 2. compare the performance of the TST and blood-based diagnostic testing to a standardized history of TB exposure, 3. measure the impact of age, nutritional and immune status on children's response to blood-based testing, 4. describe factors that might modify children's response to testing over time, and 5) examine the effect of environmental exposures and previous vaccination on the TST, blood-based testing and other measures of immune responses to TB. Potential Impact: The benefits of an accurate, rapid diagnostic test of TB infection in children include 1) timely institution of treatment for TB infection to prevent severe disease and mortality, and 2) preclusion of over diagnosis and treatment. Treatment of childhood TB infection also prevents future contagious adult disease, thus decreasing community transmission. Blood-based diagnostic testing may also be able to identify children that are more likely to become ill following TB infection. Therefore, blood-based diagnostic testing has great potential to improve TB control and the health of HIV-infected and uninfected children, their households and communities.