Resistance to antimicrobial drugs--a worldwide calamity.

The introduction of penicillin 50 years ago was followed by an extraordinary period of discovery, exuberant use, and predictable obsolescence. Resistant bacterial strains have emerged and have spread throughout the world because of the remarkable genetic plasticity of the microorganisms, heavy selective pressures of use, and the mobility of the world population. New and more expensive drugs have appeared almost in the nick of time, but it is doubtful that they will keep pace. The problem of resistance to antimicrobial drugs is particularly troublesome in developing countries. The underlying problems are largely economic and societal, and no ready solutions are available. An urgent need exists for more appropriate selection and use of antimicrobial drugs in the developed as well as in developing countries. The focus in developing countries should be on the availability of safe and effective drugs and on the enforcement of more responsible national drug policies. These issues must be addressed by the collective action of governments, the pharmaceutical industry, health care providers, and consumers. The developed countries have an important stake in the ways in which antibiotics are used in developing countries because resistant microorganisms do not recognize national boundaries.