Extrait

Background and study aims Tuberculosis (TB) is a common, infectious condition caused by a bacterial infection. It is generally spread by breathing in tiny droplets released into the air by an infected person coughing or sneezing. TB usually affects the lungs (pulmonary TB), but it can also affect other areas of the body such as the bones, brain and kidneys. Controlling the spread of TB is founded on the basis of early diagnosis (confirmed under a microscope) and treatment and ensuring patients complete the full course of treatment needed to cure the disease. Often the first way of testing for TB is to take a sample of sputum (mixture of saliva and mucous that has been coughed up) and examining it under a microscope for signs of TB bacteria (smear microscopy). This is around 50-60% accurate however, and so further tests are needed to confirm diagnosis and start treatment. Experience of TB screening among hard to reach groups and other TB patients by the pan London Find&Treat TB outreach service has shown that the current service offered in the UK rarely achieves same day diagnosis in patients who have a positive TB smear. This could mean that many patients who need follow up can do not receive it, especially amongst hard to reach groups, and the risk of an outbreak increases. Patients with negative smears often have to wait several weeks for their results before starting treatment, and there is further delay in the availability of drug sensitivity tests (tests to show how effective a particular treatment will be on the TB bacteria) to inform clinical management. The use of PCR based molecular technologies allows a high proportion of smear negative cases (later confirmed by culture) to be diagnosed within 48 hours. In addition these technologies enable identification of mutations specific to rifampicin drug resistance (a key marker of multidrug resistance). The study aims to determine the effects of a rapid diagnostic service alongside the pan London mobile X-ray screening (MXU) for TB in best possible management of suspected TB cases in hard to reach groups. Who can participate? Patients aged 16 years and over who have a chest x-ray result suggesting they have pulmonary TB identified through MXU screening at hostels for homeless people and drug and alcohol services across London. What does the study involve? Participants are randomly allocated to one of two groups. Those in the first group provide a sputum sample for immediate analysis using by staff working on the MXU. An additional sample is also submitted for routine smear microscopy and culture (growing in a petri-dish) in the local hospital laboratory. Patients with a positive test result are referred immediately to a local hospital for clinical assessment, isolation and to start TB treatment. Patients with a negative test result but who still show signs of TB are also referred. Patients with a negative test result without these symptoms are followed up in the community with two further sputum samples (including 1 early morning specimen for microscopy and culture) and clinic referral if these tests are positive. Patients with three negative microscopy and culture results are offered a repeat chest X-ray on the MXU three months from the initial X-ray and travel expenses are provided as necessary. Those in the second group are managed as per standard practice. This involves being accompanied directly to a hospital and a sputum sample will be collected for routine analysis in a hospital laboratory. Further investigations at the clinic will include collection of additional samples for microscopy and culture. What are the possible benefits and risks of participating? Participants may benefit from early detection of TB, meaning that treatment can be started earlier and the risk of spreading TB to others is reduced. There are no notable risks involved with participating. Where is the study run from? Royal Free Hospital (London) When is the study starting and how long is it expected to run for? March 2012 to December 2016 Who is funding the study? National Institute for Health Research (UK) Who is the main contact? Professor Andrew Hayward [email protected]

Critère d'inclusion

• Specialty: Respiratory disorders, Primary sub-specialty: Respiratory disorders

Liens

• isrctn
• ictrp