Promising new TB test is important step, but simpler one still needed

A new test for tuberculosis that became available in 2010 will make diagnosing a curable disease that kills nearly two million people every year much faster, easier and more precise.

At present, confirming that a person has TB usually involves a 130-year-old test to examine the phlegm patients cough up under a microscope. But this method fails to detect TB in about half of all cases – particularly in people living with HIV. And for the growing number of people with drug-resistant forms of the disease, it can take up to three months to get an accurate result – by which time many will have died.  The new test will cut this time down to less than two hours, will show if the strain of TB is resistant to one of the most common medicines used to treat the disease, and will greatly improve the ability to diagnose TB in people living with HIV.

This test represents an important breakthrough, and should be used widely in HIV and TB treatment programmes.  

But a simpler and cheaper test is still needed: the new test remains a sophisticated piece of machinery that requires access to electricity and complex maintenance.  Even at discounted prices, the machine costs US$17,000 and each test device costs $17.  This means it is too expensive to have in every clinic and can not be used in the most remote settings.  

MSF was involved in testing this new diagnostic in its project in Khayelitsha, South Africa, and will purchase machines for its TB and HIV projects.  But MSF will also continue to push for the development of a fast, simple, affordable diagnostic test that delivers results on the spot, and does not require sophisticated laboratory equipment.  However, the development of such a ‘point-of-care’ test likely remains several years away.

Dr. Francis VARAINE, MSF TB Coordinator “Until we have a simple, reliable test, many TB patients will keep falling through the net and die untreated.”