Simple test for tuberculosis infection a step closer
Press Release: 14 September 2006
Scientists have devised a new way of detecting tuberculosis (TB) infection. They look for certain indicators of infection, known as unique biomarkers, in serum blood samples. The test is 94% accurate and will be further developed into a simple serum test for use in the developing world.
The current TB diagnosis method involves careful examination of sputum using a microscope. Away from a clinic in rural areas in developing countries, this test has only 40-60% accuracy. Sputum culture, which takes between 2 - 6 weeks to produce a result, is not routinely carried out in countries with a high prevalence of TB but improves rates of diagnosis.
The research by scientists at the Medical Research Council National Institute for Medical Research (NIMR) and at St George's Hospital, University of London, is published today in The Lancet.
The research team has identified a serum molecular signature unique to TB. The TB serum signature was detected using a mass spectrometer and statistical methods were used to uncover complex patterns known as biomarkers, within samples from people infected with TB. They then used this signature to work out a simpler way to diagnose TB infection.
Dr. Delmiro Fernandez-Reyes of NIMR said: "Current developments in mass spectrometry together with new statistical methods for pattern discovery are allowing us to identify biomarkers of infection. Our work opens the door to further research into translating these findings to fast and reliable methods of detecting active TB infection that could have a major impact in global health. We currently apply similar approaches to malaria diagnosis.'
The key to reducing death rates in patients with TB, and to stopping transmission in poor countries, is to diagnose and start treatment at the time a patient first visits a clinic.
Professor Sanjeev Krishna of the Centre for Infection at St George's Hospital, University of London said: "We are putting forward a fresh approach to an ancient problem. I think it is going to be very exciting to make this work in clinics where a test for TB is desperately needed. The next stage will be to use the biomarkers we have identified to develop a cheap, accurate and rapid diagnostic test that can be used easily and quickly out in the field."
For further information or to arrange an interview with Dr Fernandez-Reyes please contact the MRC Press Office on 0207 637 6011, press.office@headoffice.mrc.ac.uk or out of hours on 07818 428 297.
Notes to editors
In the UK alone there are 7,000 new cases of TB reported each year. This number is rising and resistance to treatment is currently emerging. Large cities in the developed world, like London, are particularly affected by the increased numbers of people who visit or arrive looking for work. Tuberculosis (TB) is the number one cause of death by infection in the world today killing about two million people a year. Despite current emergence of resistance, most deaths from TB are preventable by early diagnosis and treatment.
The Medical Research Council (MRC) is funded by the UK tax-payer. It aims to improve human health. The research it supports and the scientists it trains meet the needs of the health services, the pharmaceutical and other health-related industries and universities. The MRC has funded work which has led to some of the most significant discoveries and achievements in medicine in the UK.
