Here's another one to add to the tally of drawbacks of life-saving antibiotics: according to a recent article in the American Journal of Infection Control, the burden of Clostridium difficile (C. diff) in US health settings is significantly higher than previously estimated. "Thirteen in every 1,000 inpatients has C. diff -- 20 times more than previous estimates" (see attached image for variance in prevelence by state).

When a physician decides what to prescribe a patient, the expectation that antibiotic treatment will provide some benefit to the patient often outweighs the concern that this use will contribute to the shared problem of antibiotic resistance.