A Breakthrough in the Fight Against TB
This blog previously appeared on The Bill and Melinda Gates Foundation website:
On a Friday evening in 1882, Dr. Robert Koch stood before a rapt audience at the Berlin Physiological Society and presented a momentous discovery: the identification of the bacteria that causes tuberculosis. Koch became a household name as news of his discovery spread around the globe. The New York Times reported it as “one of the most impressive and striking achievements of the human mind.”
That evening was March 24, which we now observe as World TB Day, and the method Koch used to identify TB – using dye to make the bacteria visible under a microscope – is still used throughout the developing world. Today we have an opportunity to make a quantum leap in TB diagnosis, and accelerate the fight against TB that Koch helped initiate 129 years ago.
TB is curable, but it still kills 1.7 million people every year. Correctly and rapidly diagnosing the disease is a major stumbling block. The microscopy method, which is the standard for diagnosing the disease in poor countries, has several critical limitations.
As a TB patient at a typical clinic, you will wait days for a diagnosis and may have to return to give multiple samples, a burden especially for poor people and those living in remote areas. Since drug resistance cannot be detected under a microscope, you may be given ineffective drugs as your condition worsens. If you are a person living with HIV/AIDS, the test likely won’t detect your TB. (TB is the leading infectious killer of people with HIV/AIDS). And although researchers don’t fully understand why, if you are a woman with TB you are less likely to be properly diagnosed than a man.
A newly available tool called GeneXpert has the potential to radically alter this picture. About the size of an espresso machine, GeneXpert uses DNA technology to diagnose TB quickly and accurately. It’s more effective in detecting TB in people with HIV/AIDS, and can immediately determine likelihood of drug resistance. With minimal training, a health care worker can deliver these results in about two hours.
Our work in global health should be driven by the simple premise that where you are born should not determine whether you have access to life-saving technology, whether it’s anti-retroviral therapy to treat AIDS, a new vaccine to prevent pneumonia, or a diagnostic to detect TB. Opportunities like GeneXpert can be the nexus of technology and justice if we can seize them through innovative partnerships like the Global Fund to Fight AIDS, Tuberculosis and Malaria. The Global Fund provides two-thirds of all external funding for TB control. It will be critical in financing the equitable roll-out of GeneXpert in poor countries and achieving the scale necessary to drive down costs.
The New York Times said of Dr. Koch’s discovery, “to draw from it its great possible benefits is the work of the future.” There is still work to be done 129 years later – but we have an exciting new tool with which to do it.