Perspective

Outbreaks of resistant pathogens are the most visible consequences of antibiotic practices that fail to keep mutant pathogen subpopulations small. Because resistant pathogens spread by the same routes as susceptible ones, we already know what to do: interrupt transmission. But often that must be done without our first-line antibiotics, which makes the task more difficult and expensive. Over the years we have made progress in the community through sanitation, vaccines, and vector control. However, that progress is countered by our increasing population density. Moreover, our populations now contain large numbers of persons whose bodies do not fight infections effectively. Among these are the elderly, transplant patients, and persons with im....