Though tuberculosis has been largely eradicated in much of the developed world, the disease still poses a grave danger on most of the globe. In fact, the World Health Organization reports that tuberculosis is the second-deadliest infectious disease, after HIV/AIDS, causing 8.7 million cases and 1.4 million deaths in 2011.
Part of the reason that tuberculosis is so deadly is that it can take weeks to receive a tuberculosis diagnosis, meaning that treatment is delayed and carriers of the bacteria can spread the disease to others. A new study published in the Journal of Breath Research has found that a recently developed breath test may cut down the time of a tuberculosis test from weeks to minutes.
Study author Jane Hill, from the University of Vermont explained in a statement that current methods for tuberculosis tests take so long because "[traditional] methods employed to diagnose bacterial infections of the lung require the collection of a sample that is then used to grow bacteria. The isolated colony of bacteria is then biochemically tested to classify it and to see how resistant it is to antibiotics. This whole process can take days for some of the common bacteria and even weeks for the causative agent for tuberculosis. Breath analysis would reduce the time-to-diagnosis to just minutes."
The study was conducted on mice. One group of mice was infected with the Pseudomonas aeruginosa and Staphylococcus aureus bacteria, both of which are common in acute and chronic lung infections. After 24 hours, both sets of mice were tested by analyzing the volatile organic compounds (VOCs) present in the mice's breath. This analysis occurred using a technique named secondary electrospray ionization mass spectrometry (SESI-MS), which can detect VOCs down to parts per million.
The researchers found that technique was able to detect which mice were infected and which mice were not. The study could lead to the development of a breath test for tuberculosis in humans. Researchers are interested in breath-testing methods because of the low time needed and the minimal invasiveness.