[New diagnostic tests for tuberculosis in southern countries: from theory to practice in southern countries]

Tuberculosis (TB) is responsible of 1.7 millions of deaths per year worldwide. In high burden countries sputum smear-microscopy diagnoses only half of the cases of pulmonary TB. It is unlikely that a new test will replace smear-microscopy in peripheral services in the short term.

Between 2007 and 2009 WHO recommended the introduction of seven new tests or diagnostic approaches for high burden countries, for peripheral laboratories : 1) the optimisation of smear-microscopy using the revised smear-positive case definitions; 2) examination of two specimens instead of three; 3) examination of two specimens collected on the same day; 4) the use of light-emitting diode based fluorescence microscopy and for reference laboratories: 5) the use of liquid medium culture; 6) the use of rapid antigenic identification tests; 7) the rapid detection of rifampicin resistance.

The recent development of a fully automated nucleic acid amplification test for both TB detection and detection of rifampicin resistance will soon improve the diagnosis of TB in HIV infected patients outside reference laboratories in high burden countries.

Despite the recent advances in TB diagnosis, there is need for more research to develop point of care tests that do not depend on sputum specimens, that are practicable at peripheral units and that are highly sensitive in HIV infected patients and children.