Challenges

Challenges - History tells the story of things past. The future of TB must concern all of us now. Whatever the past may have taught us, we face a future challenged by rising TB incidence in much of the world. That HIV infection fosters the spread of TB and that multidrugresistant disease is an increasing problem add to the challenges and call for new initiatives. New drugs and a better vaccine are needed. The spread of TB is now being approached with new tools made possible by genetic typing of mycobacteria. What we learned by contact tracing has been augmented with new knowledge, for now it is possible to connect sources and targets of air-borne tubercle bacilli with great certainty. The contacts are not always obvious, and often are buried in the forgotten past. 

CFP-10 ESAT-6

ESAT-6 CFP-10

New approaches to the diagnosis of TB are being made possible by new knowledge of the antigens of mycobacteria. There is a vast panoply of these proteins; some are limited to specific species or trains, while others are widespread among members of the genus. ESAT-6, for example, is an antigen that has been lost from BCG, so it is possible to use the presence or absence of immune recognition of it to distinguish BCG infections from true tuberculous infection. Immunization has served since the time of Edward Jenner as a major weapon in the battle against infectious diseases. However, BCG has fallen short of initial hopes for controlling TB. As more is learned about the immunopathogenesis of TB, it is becoming more possible to target candidate vaccines against specific components of the tubercle bacillus, perhaps increasing protective efficacy. New vaccines are currently in development; field trials to assess their efficacy will pose large challenges.

Drug discovery efforts have long neglected TB, but this has changed in recent years. New agents targeting new microbial receptors are being produced by pharmacologists now alerted to the challenges of multidrug-resistant TB. Research workers – immunologists, epidemiologists, microbiologists, pharmacologists, molecular biologists, experimental pathologists – are attacking these challenges. One can hope that expanding knowledge emanating from their laboratories will produce new and unanticipated tools for control of the ‘Captain among these Men of Death’.