Featured Research

from universities, journals, and other organizations

New approach of resistant tuberculosis

Date:
August 10, 2012
Source:
Institute of Tropical Medicine Antwerp
Summary:
Scientists have breathed new life into a forgotten technique and so succeeded in detecting resistant tuberculosis in circumstances where so far this was hardly feasible. Tuberculosis bacilli that have become resistant against our major antibiotics are a serious threat to world health.

Result of a FDA-test under the microscope: the fluorescent lines are living tuberculosis bacilli, on a background of cellular debris from human sputum.
Credit: © ITG

Scientists of the Antwerp Institute of Tropical Medicine have breathed new life into a forgotten technique and so succeeded in detecting resistant tuberculosis in circumstances where so far this was hardly feasible. Tuberculosis bacilli that have become resistant against our major antibiotics are a serious threat to world health.

Related Articles


If we do not take efficient and fast action, 'multiresistant tuberculosis' may become a worldwide epidemic, wiping out all medical achievements of the last decades.

A century ago tuberculosis was a lugubrious word, more terrifying than 'cancer' is today. And rightly so. Over the nineteenth and twentieth century it took a billion lives -- more than the world population in 1800. Only in the nineteen fifties it became possible to push the disease back, with newly developed antibiotics. Countless sanatoria in Switzerland were closed one after the other and converted into hotels. Today almost nobody in the industrialized world still grasps the gruesome nature of 'consumption disease'. The treatment was so successful that the World Health Organization (WHO) in 1960 decided to eradicate tuberculosis once and for all. It almost worked.

But Mycobacterium tuberculosis is a tough adversary, demanding a treatment with several antibiotics simultaneously during months on end. Hardly feasible in developing countries. The numerous erratic or halted treatments led to growing numbers of bacilli that were resistant to several antibiotics. In the early eighties the death toll first stagnated and then got up again. The arrival of AIDS in the same period made things worse, because an infection with the one makes you more susceptible to the other.

Today we witness a growing number of 'multiresistant' tuberculosis, withstanding our best medicines, and only treatable with a costly and long cure of toxic drugs. Unfeasible in developing countries. According to WHO estimations, of the 5 million or so multiresistant cases of the last decade, only one percent had access to treatment. In 1991, a tuberculosis bug in New York was found to be resistant to 11 antibiotics. Cases have been reported where each and every antibiotic was useless. So far, these 'omniresistant' bacilli each time perished with their host before they could spread. So far, that is.

In 2012 on average 1 in 30 of new TB cases worldwide was multiresistant, with peaks of 1 in 3. With patients relapsing after a first cure, on average 1 in 5 was multiresistant, with peaks up to 65%. The highest numbers were all registered in the former Soviet Union. Without active measures the numbers will only rise.

If we want to prevent an epidemic of difficult to treat tuberculosis, then resistant cases, which do not react to the normal treatment, need to be recognized as early as possible, and immediately treated with second-line antibiotics that still work. But the laboratory tests to identify resistant TB bugs are cumbersome -- the WHO estimates that in 2009 only 11% of multiresistant cases were discovered.

Checking smears under the microscope still is the recommended technique for TB screening, but it cannot differentiate between living and dead bacilli. So you do not know if you are looking at the cadavers of a successful treatment, or at resistant survivors. Only if the numbers after a long wait still don't fall, you know you are dealing with a resistant strain. But all that time the patient has remained contagious.

With high-tech PCR technology one can immediately ascertain if the bacillus is from a resistant strain, but in practice and certainly in resource-limited countries this is unfeasible. It also is impossible to cultivate every sample and then bombard it with every possible antibiotic to survey which ones still work for that individual patient.

Armand Van Deun and colleagues therefore gave a new application to a forgotten technique: vital staining with fluorescein diacetate (FDA). It only stains living TB bacilli, so one immediately sees those bacilli escaping treatment. The scientists improved the detection of the luminous bacilli by replacing the classical fluorescence microscope with its LED counterpart. Together with colleagues in Bangladesh they tested the approach in the field for four years. This was made possible by a grant from the Damien Foundation -- another possible sponsor had fobbed them off because their technique was too unknown.

But their approach works, also in a poor country. If after treatment the FDA-test was negative, in 95% of cases more elaborate tests didn't find active bacilli in the patient's sputum either. And if the test was positive, you could bet your boots that you had found a resistant bacillus.

This simple test allows, also in resource-limited labs, to detect a high number of resistant TB bacilli that otherwise would have been discovered too late or not at all. The scientists report in the International Journal of Tuberculosis and Lung Disease that three times more patients could directly switch to the correct second-line treatment without losing time on a regimen ineffective against their resistant bacilli. On top of that, the technique can cut in half the number of cases where doctors start a re-treatment 'just to stay on the safe side', because it ascertains that the bacilli detected by the classical microscopy in fact are dead ones, which do not require further treatment.


Story Source:

The above story is based on materials provided by Institute of Tropical Medicine Antwerp. Note: Materials may be edited for content and length.


Cite This Page:

Institute of Tropical Medicine Antwerp. "New approach of resistant tuberculosis." ScienceDaily. ScienceDaily, 10 August 2012. <www.sciencedaily.com/releases/2012/08/120810112731.htm>.
Institute of Tropical Medicine Antwerp. (2012, August 10). New approach of resistant tuberculosis. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2012/08/120810112731.htm
Institute of Tropical Medicine Antwerp. "New approach of resistant tuberculosis." ScienceDaily. www.sciencedaily.com/releases/2012/08/120810112731.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins