New detection method for TB provides faster results

A new test, Xpert MTB/RIF, was shown to detect nearly two-thirds of tuberculosis cases identified by current culture tests within a 24-hour period, giving developing countries a tool to give people the help they need faster.

The Xpert test was found to be five times more accurate than examining specimens under a microscope, the first-half of the typical detection process, followed by the culture test. The new test, although less effective than the culture test, is ready in 24 hours, compared to the culture test, which usually takes more than two weeks. The Xpert test was also found to have a 99 percent accuracy rate for tests with negative results.

The Xpert test was found to not only be effective in adult testing, but also in the testing of children. This is significant because since children have a smaller amount of TB bacteria in their systems, it is more difficult to detect an infection in a child.

"The availability of this test in primary care settings can help children get appropriate treatment faster," Lynne M. Mofenson, of the Maternal and Pediatric Infectious Disease Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development that funded the study, said. "Looking at a specimen under the microscope, often used for initial diagnosis of TB in adults, is very inaccurate in children."

Experts have said this new testing method would be ideal for children in countries with limited resources, as the ability to perform a clinical test in a hospital is sometimes not an option.