Perspective

A central reason for antibiotic overuse with human patients is the perception that the cost to the individual is small. However, the cumulative cost to the community is quite large. Philosophers call this situation the “tragedy of the commons.” Curbing the urge to use antibiotics is difficult, because even doctors have that impulse. Physicians fear that they will fail to treat a treatable infection. However, cases are beginning to appear in which patient outcome is improved by using fewer rather than more antibiotics, and it is clear that commensal populations become resistant.¹⁴⁷ Such information enables doctors to conserve antibiotics while still meeting their primary obligation to the individual patient. Black market pharmacies, production of low-potency low-cost compounds, and self-medication still loom as major obstacles to lowering antibiotic use by consumers. Financial considerations drive agricultural use. We feed low doses of antibiotics to animals as “growth promoters,” we treat overcrowded animals to bring them to market, and we spray antibiotics on crops to control bacterial and fungal pathogens. Nevertheless, an awareness of antibiotic resistance problems is developing. An example of this awareness surfaced in mid-2008. A major U.S. chicken producer thought that it was important to say that its chicken....²²⁸ At a different level are ecological effects from agricultural and hospital waste water. They are less clearly defined, but the principle is clear: Antibiotic exposure inside the selection window, regardless of the source, leads to antibiotic-resistant bacteria. Some of those bacteria are human pathogens, whereas others serve as starting points for movement of resistance genes into pathogens, as pointed out in Chapter 6, “Movement of Resistance Genes Among Pathogens.” We can reduce each type of antibiotic use.