To Be or not TB

New tuberculosis diagnosis methods are more convenient and just as effective

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) In low-income nations, healthcare costs are soaring and many people infected with tuberculosis (TB) are left without any treatment options.

Infectious disease specialists from Liverpool, U.K., have completed two TB testing studies, which they hope will bring less costly methods of diagnosing the infectious lung disease to third world countries. One study suggests that most patients with TB can be identified on one patient visit and the other offers faster results. Both tests offer the same integrity in diagnosis and are cheaper than current testing protocols.

"Less costly TB tests are fast and just as effective."

Study co-authors, Luis E. Cuevas and Mohammed Yassin, report that this new diagnostic method is very exciting because the majority of patients are only required to have one doctor visit to get a positive or negative diagnosis. The plan is to reduce costs and improve diagnosis in low and middle-income countries. A single-visit diagnosis is especially beneficial to the poor.

The first study included 6,627 patients from Ethiopia, Nepal, Nigeria and Yemen who had been coughing for two weeks or more.

For one year, participating clinics alternated specimen-collection methods on a weekly basis. The results indicate that collecting two sputum samples one hour apart followed by a morning collection the next day could identify as many positive patients as the currently recommended "spot-morning-spot" method in which patients provide a specimen during their initial clinic visit and a morning-after specimen from home. At the second, morning-after clinic visit, the patient gives one more specimen.  Additionally, the study confirmed that most smear-positive patients are identified with only the first two samples, making the third sample arguably optional.

The second study included nearly 2,400 patients and showed that a quicker lab test, which is a variant form of smear microscopy, could identify more people with TB than the standard smear microscopy test. However, this quicker lab test may also have more false positives, resulting in antibiotic treatment for people who don't need it.

These study results are published in PLoS Medicine July 2011.

Reviewed by: 
Review Date: 
July 8, 2011
Last Updated:
July 22, 2011