Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Rewriting Life

An Easier Test for TB

A study suggests that an electronic nose could sniff out tuberculosis in a urine sample.

Electronic noses, which detect chemicals in the air, have shown promise as a tool for diagnosing disease. A recent study in Analytical Chemistry offers a first step toward developing an electronic nose to detect tuberculosis (TB) infection in a urine sample, which could be especially useful in poor countries.

Many diseases affect the chemical components of patients’ breath and bodily fluids in characteristic ways, and scientists have been trying to exploit these chemical fingerprints as a disease-detection method. Electronic noses, which pair chemical sensors with a pattern-recognition system, are being developed to spot bacterial infections and lung cancer.

Treating TB in developing countries is hampered by diagnostic tests that are invasive and time-consuming and require technical skill and laboratory equipment. An inexpensive, fast, and simple test would be a boon. Several research groups have begun investigating electronic-nose technologies for TB diagnosis, primarily with samples of sputum, the mucus that lines the lower respiratory tract. However, a study led by Virander Chauhan and Ranjan Nanda from the International Centre for Genetic Engineering and Biotechnology in New Delhi, India, has taken a new approach by studying urine, which can be collected without stressing a patient, is not infectious, and can be stored more easily and for longer periods of time.

The researchers collected urine samples from more than 100 newly diagnosed TB patients in New Delhi. They analyzed molecules from the urine that evaporate quickly in the air, called volatile organic compounds (VOCs), using gas chromatography and mass spectrometry, which give a detailed readout of chemical components and their concentrations. Using this method to hunt for patterns, they identified several VOCs that occurred in significantly different concentrations in infected individuals. Using this signature, they were able to predict TB infection in another group of patients with nearly 99 percent accuracy.

This method could also be used to distinguish TB from other lung diseases. And, Nanda says, although the current study focused on diagnosing the disease, it may also be possible to use an electronic nose to monitor the extent of the infection as patients undergo treatment.

Hossam Haick, a chemical engineer at the Technion-Israel Institute of Technology who is researching sensors for biomarkers, says that these initial results show promise, but more studies on larger numbers of patients will be needed to validate the results. He adds that although the research demonstrates the feasibility of a urine test for TB, a simple, quick test is still a ways off, because the method used to identify the VOC signatures is expensive and time-consuming. The next step is to develop a small, inexpensive, and easy-to-use device that can detect the TB-specific VOCs accurately. Nanda says that this “is going to be a hugely complex job” and that his team is currently investigating appropriate sensor technologies.

Become an MIT Technology Review Insider for in-depth analysis and unparalleled perspective.

Subscribe today

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

More from Rewriting Life

Reprogramming our bodies to make us healthier.

Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    What's Included

    Unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

    Bimonthly print magazine (6 issues per year)

    Bimonthly digital/PDF edition

    Access to the magazine PDF archive—thousands of articles going back to 1899 at your fingertips

    Special interest publications

    Discount to MIT Technology Review events

    Special discounts to select partner offerings

    Ad-free web experience

/
You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.