The consequences of tuberculosis on human society are immense. Tuberculosis remains a major cause of morbidity and mortality in many countries and a significant public health problem worldwide. Active tuberculosis is diagnosed by detecting Mycobacterium tuberculosis complex bacilli in specimens from the respiratory tract (pulmonary TB) or in specimens from other bodily sites (extra pulmonary TB). Rapid diagnostic tools are urgently needed to interrupt the transmission of tuberculosis and multidrug-resistant tuberculosis. Laboratory confirmation of TB and drug resistance is critical to ensure that people with TB signs and symptoms are correctly diagnosed and have access to the correct treatment as soon as possible.
There have been many advances in methodology for tuberculosis diagnosis and earlier diagnosis is of value clinically, and through the early institution of appropriate drug therapy is of public-health benefit. Although many new molecular diagnostic methods have been developed, acid fast bacilli smear microscopy (positive in only half of TB patients) and culture on Lowenstein-Jensen medium (results take weeks to obtain) are still the “gold standards” for the diagnosis of active TB and, especially in low-resource countries.
At present many of new techniques are only economically viable in the developed nations, it is to be hoped that recent advances will lead to the development of novel diagnostic strategies applicable to use in developing nations, where the burden of tuberculosis is greatest and effective intervention most urgently required.