Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Blood-based TB test matches up to old skin test in study among health workers in India


In a head-to-head matchup between a new blood-based tuberculosis (TB) test and the traditional tuberculin skin test, researchers from the University of California, Berkeley, and the Mahatma Gandhi Institute of Medical Sciences in India found that the two methods of detecting latent TB infection are equally good.

The results of the study, to be published in a special June 8 theme issue on tuberculosis in the Journal of the American Medical Association, mean that switching to the more expensive blood test may not be necessary for people in India.

"Our study is the first time this blood test has been evaluated in India, where TB is highly endemic," said Dr. Madhukar Pai, a post-doctoral fellow in epidemiology at UC Berkeley’s School of Public Health and lead author of the paper. "It’s also the largest study of its kind among health care workers, a group that is at high risk for occupational TB."

There are about 9 million new cases of TB each year, and a large proportion of the disease burden is in developing countries. Most people infected with TB contain the infection, and it remains latent. In some individuals, the infection progresses to active disease.

The tuberculin skin test, in which the skin is pricked with antigens from Mycobacterium tuberculosis, had stood alone for more than 100 years as the method for detecting latent TB infection.

However, many health professionals consider the skin test crude, said Pai, because it is unable to clearly distinguish between people who have received a vaccine against TB from those who have a true infection. Moreover, the skin test requires the patient to return three days after the skin prick so that a health worker can measure the resulting bump on the skin.

Having a test that allows health care officials to confirm a true TB infection is important because a positive test can lead to a six-month treatment of daily anti-TB drugs for the patient.

Pai said the development of a more advanced assay that uses specific TB antigens to detect levels of interferon-gamma, a protein released by the immune cells of people infected with tuberculosis, was greeted with a measure of excitement among health officials.

The test, called QuantiFERON-TB-Gold, has been approved by the U.S. Food and Drug Administration. Unlike the skin test, the interferon-gamma test requires only one visit by the patient, and its results do not rely upon the subjective interpretation of a health worker.

However, the new test requires special lab facilities, making it more expensive than the old skin test. The skin test, in turn, involves more personnel time because it requires health care workers to deal with a patient twice. "The new test may turn out to be more cost-effective in developed nations like the United States where labor costs are higher," said Pai.

For this study, researchers analyzed the results of 726 health care workers from the Mahatma Gandhi Institute, a rural hospital in Sevagram, India, that treats about 300 tuberculosis patients a year. The workers were tested with both the traditional TB skin test and the interferon-gamma assay.

About half of the workers tested positive for latent TB infection. The researchers found a high level of agreement - 81.4 percent - between the two tests. Surprisingly, previous TB vaccination had little impact on the results of either test.

Pai notes that other studies in North America and Europe have shown that the interferon-gamma test outperformed the skin test. "It’s important to keep both tests on the menu so that health professionals can choose what’s best for their target population," said Pai. "For high-burden, low-resource countries such as India, the skin test might still have value."

Sarah Yang | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>