DISTINGUISHING MYCOBACTERIA - A ROLE FOR PCR AND IMMUNODIAGNOSIS

Conventional diagnosis of mycobacterial infections takes several weeks , which is a hindrance to effective treatment for the patient and a hi ndrance to infection control in the population as a whole. Improved, m ore rapid, near-patient methods for the diagnosis of mycobacterial inf ections are needed. The last two decades of research in identification of mycobacterial genetic sequences and the antigens derived from them have been one of the driving forces in the search for alternative spe cies specific tests. The different approaches dan be classified into m olecular methods which investigate infections at the genetic level and immunological methods which either investigate the host response to i nfection or mycobacterial components circulating in the host. Examples of these contrasting approaches are discussed with emphasis on the po lymerase chain reaction and skin testing for the diagnosis of tubercul osis.