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

08.06.2005


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:
http://www.berkeley.edu

More articles from Studies and Analyses:

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>