Cheap portable device to diagnose TB faster

Washington: Researchers have developed a cheap enzyme-based method that can diagnose tuberculosis (TB) more accurately and faster than available devices.

This inexpensive portable diagnosis system can cut the time it takes to spot TB bacteria from weeks or months to less than half an hour.

Chemist Jianghong Rao of Stanford University and microbiologist Jeffrey Cirillo of Texas A&M University developed a chemical called CDG-3 that glows when it is broken down by an mycobacterium tuberculosis (TB bacteria) enzyme called BlaC.

The researchers found they could detect as few as 10 TB bacteria in a millilitre sample.

They then tested the method on 50 sputum samples from people in Texas.

It correctly identified all the samples that contained M tuberculosis visible under a microscope, and 80 percent of those in which infections were not visible.

When tested in people without TB, the CDG-3 probe diagnosed them correctly 73 percent of the time.

Rao and Cirillo are now working to develop a portable, battery-powered device that measures the fluorescence coming from CDG-3 as it is broken down.

The device is expected to hit the market in 2015.

A single test will cost about $5 (Rs.295) and will take less than 30 minutes to deliver a diagnosis, said the paper published in the journal Angewandte Chemie.