The continuing challenge of lower respiratory tract infections

antibiotics has markedly changed the management of a wide variety of respi-ratory tract infections, including com-munity-acquired pneumonia (CAP), dur-ing the past half-century. However, despite earlier predictions, these infections have not disappeared as significant clinical problems, and lower respiratory tract in-fections continue to take a major toll in terms of morbidity and mortality throughout the world. One of the factors that could account for the persistence of problematic respi-ratory tract infections is the development of resistance to antimicrobial agents by