Colorado State University LogoNearly two billion people across the world seem to carry the pathogen which causes tuberculosis (TB). Moreover, most of them seem to be unaware that they are infected. This is because some 90 percent of people with TB are noted to have ‘latent’ infections. Apparently, they have no symptoms due to which they can’t spread the disease to others. However, the bug appears to remain latent in their lungs, often for years.

Currently, a group of researchers at Colorado State University (CSU) seem to have established a sensitive novel technology to use light in order to detect traces of TB bacteria in fluids. Moreover, this technology may be responsible for extensive use in the developing world, where most cases of TB occur.

Identifying latent TB infections is believed to be an important public health problem because those 10 percent of people who go on to develop full-blown ‘active’ TB may in turn, infect another 10 to 15 people each year on average. Such smoldering spread is known to be one of the reasons why TB remains the seventh-leading cause of death worldwide. It was estimated to kill more than 1.5 million people every year.

Diego Krapf and CSU Professor stated that what is missing from the public health tool chest appears to be a technique which could be used to broadly detect TB in those places where it is most prevalent.

It was observed that Krapf, along with CSU graduate student, Barbara Smith and their colleagues have developed a technique which can considerately detect different molecular markers. These markers may possibly indicate a TB infection that would be economical to use and easy to administer as compared to a common pregnancy test. These features could perhaps make it ideal for use in the developing world.

It was noted that the Colorado researchers imagine a device which would only require someone to smear a drop of blood or urine on a glass slide, insert it into a machine and read a simple display that would indicate whether that person is infected or not.

Lead researcher, Diego Krapf claimed that such a device could easily be built with an available off-the-shelf technology. Furthermore, it may be simpler as contrast to the internal workings of a typical DVD player.

This device is known rely on specialized surface chemistry that avoids protein adsorption, apart from those molecules which require to be detected. Subsequently, the presence of these molecules appears to be recorded by fluorescence with the help of a red diode laser.

After having been detected, TB infections seem to be usually treatable with an extensive course of antibiotics. Also, one of the basic strategies behind the World Health Organization’s current efforts appears to control the spread of the disease worldwide. This control may be possible only after having found the infected people thereby providing them with antibiotics which they need.

Presently, finding people who are infected seems to be difficult. However, doctors can spot suspected cases through chest X-rays, which may reveal evidence of infection in the lungs. Otherwise, they can turn to a century-old technique called a sputum smear. Supposedly, in this technique, a sample of coughed fluid is stained and examined under a microscope for indications of the infection.

Nevertheless, it would be better if doctors may able to grow cultures of TB bacteria from lung fluid. Allegedly, this would let doctors definitively know that a person is infected. However, these tests may be unable to detect latent TB infections, because people who are latently infected may not have sufficient bacteria in their lungs to detect. For people with latent infections, other tests appear to exist, but they have their problems too.

Krapf said that a simple skin test exists, but it is merely sensitive enough to detect about half of all cases. Further more sophisticated methods which rely upon detecting specific markers in the blood seem to be more sensitive. However, they require special facilities and training that could be far too expensive for extensive use in the developing world.

Krapf along with his colleagues have been able to demonstrate the likelihood of detecting markers of TB infections at great sensitivity in saline solutions. Additionally, they were able to detect a single molecular marker of a TB infection in solution.

They have not yet built a functioning device that could identify hidden TB infections in blood or urine samples. Besides, they have not yet tested the technology on samples gathered in the field. Before any such detector is available for use in the field, it would have to be severely tested in clinical trials.

Going in that course, the team plans to conduct a survey of blood and urine samples from people infected with TB bacteria. Supposedly, this will assist them in concluding how sensitive they need to make any detector and which markers are the best to test.

The CSU development might one day play a role in curbing the spread of TB. Also, the findings of the research may one day assist health care workers in recognizing people who are latently infected.

The research findings will be soon presented at the Optical Society’s (OSA) Annual Meeting, Frontiers in Optics (FiO), in San Jose, California.