Inexpensive test may diagnose TB in 30 minutes

Written by PTI | Washington | Updated: Jul 4 2014, 22:45pm hrs
HealthScientists are developing a portable, battery-powered device that could provide the fastest tuberculosis.(Reuters)
Scientists are developing a portable, battery-powered device that could provide the fastest tuberculosis diagnosis yet, taking less than half an hour to detect the bacteria.

Currently, a method called GeneXpert, can accurately

detect Mycobacterium tuberculosis DNA within a couple of

hours, but it requires specialised equipment and trained

personnel, making it impractical for rural areas or developing


Chemist Jianghong Rao of Stanford and microbiologist

Jeffrey Cirillo of Texas A&M Health Science Center in Bryan

have developed a chemical called CDG-3, which glows when it is

broken down by an M tuberculosis enzyme called BlaC.

The researchers found that they could detect as few as

ten bacteria in a millilitre sample, '' reported.

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 per cent of

those in which infections were not visible.

When tested in people without TB, the CDG-3 probe

diagnosed them correctly 73 per cent of the time.

Rao and Cirillo are now working with diagnostics company

GBDbio in Temple, Texas, to develop a portable,

battery-powered device that measures the fluorescence coming

from CDG-3 as it is broken down.

Chief executive Michael Norman said that the company

hopes to have the device completed and on the market in 2015.

He expects that a single test will cost about USD 5, and

will take less than 30 minutes to deliver a diagnosis.