New Rapid TB Test Gains WHO Endorsement
The World Health Organization (WHO) has given its backing to a new molecular test for tuberculosis (TB) which can rapidly diagnose the disease.
The rapid molecular test for sputum (Xpert MTB/RIF; Cepheid) can detect TB in the span of 2 hours rather than the 4 to 8 weeks needed for TB culture methods which is considered the gold standard or the 2-3 days a Mantoux skin test takes.
"This new test represents a major milestone for global TB diagnosis and care. It also represents new hope for the millions of people who are at the highest risk of TB and drug-resistant disease." said Dr Mario Raviglione, Director of WHO's Stop TB Department. "We have the scientific evidence, we have defined the policy, and now we aim to support implementation for impact in countries."
WHO's endorsement of the rapid test, a fully automated NAAT (nucleic acid amplification test), follows 18 months of rigorous assessment of its field effectiveness in the early diagnosis of TB. Evidence to date indicates that implementation of this test could result in a three-fold increase in the diagnosis of patients with drug-resistant TB and a doubling in the number of HIV-associated TB cases diagnosed in areas with high rates of TB and HIV.
This new rapid test can be used outside conventional laboratories and give a diagnosis ‘while you wait.' It also benefits from being fully automated and therefore easy and safe to use.
WHO is now calling for the fully automated NAAT to be rolled out under clearly defined conditions and as part of national plans for TB and MDR-TB care and control.
A major concern in the assessment process was affordability. Co-developer FIND (the Foundation for Innovative and New Diagnostics) has negotiated with the manufacturer, Cepheid, for a 75% reduction in the price for countries most affected by TB, compared to the current market price. Preferential pricing will be granted to 116 low- and middle- income countries where TB is endemic, with additional reduction in price once there is significant volume of demand.
"There has been a strong commitment to remove any obstacles, including financial barriers, that could prevent the successful roll-out of this new technology," said Dr Giorgio Roscigno, FIND's Chief Executive Officer. "For the first time in TB control, we are enabling access to state-of-the-art technology simultaneously in low, middle and high income countries. The technology also allows testing of other diseases, which should further increase efficiency."
Though there have been major improvements in TB care and control, tuberculosis killed an estimated 1.7 million people in 2009 and 9.4 million people developed active TB last year.
Tuberculosis is caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal.
TB is spread through the air from one person to another. The TB bacteria are put into the air when a person with active TB disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.
TB is NOT spread by shaking someone’s hand, sharing food or drink, touching bed linens or toilet seats, sharing toothbrushes, or kissing.