The UK’s Health Protection Agency (HPA) has announced, in a press release, that it has developed a highly sensitive test for tuberculosis that takes just one hour to diagnose the presence of Mycobacterium tuberculosis.
The standard test for TB (sputum microscopy) takes eight weeks to produce a result and its accuracy levels vary widely. Tests developed during the last few years can produce results within 24 hours but have various disadvantages. The new HPA test uses a uses real-time polymerase chain reaction (PCR) - a technique used in molecular biology to amplify copies of a piece of DNA and generate millions of copies of that particular DNA sequence, enabling more DNA to be tested.
Dr Cath Arnold, head of HPA’s genomic services unit says: “We’re excited to have developed this new test because it means we can potentially diagnose someone at a TB clinic within an hour and start them immediately on the treatment they need. This new test could really have an impact where it is most needed”. (A BBC report on the test includes a podcost of a short interview with Dr Arnold.)
Tests in other UK labs will be conducted over the coming year. Full details of the test have not yet been made available and its development has not as yet been reported in a peer-reviewed journal. A key issue will be the likely cost. The need for such a test is greatest in developing countries but for it to be used widely in the South it must be affordable.
Other TB tests are also under development. These include a two-hour test developed with the support of the Foundation for Innovative New Diagnostics (FIND) which has been evaluated in a study  recently published in the New England Journal of Medicine.
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