The widespread introduction of antibiotics was one of the greatest medical accomplishments of the twentieth century, but our success in treating infectious diseases has led to a new public health challenge - the emergence and proliferation of microorganisms resistant to standard antibacterial therapy. Unfortunately, legal and market structures in the United States have created a substantial gap between the private and social value of antibiotics, leading to problematic supply and demand incentives and increasingly resistant infections. Both hospitals and community settings report growing resistance problems.

Multidrug resistant bacteria are a grave public health concern because they put patients at risk for serious illness and possibly death, and they place increased demand on already strained health care resources. Patients with resistant infections can lead to increased inpatient hospital costs, outpatient treatment costs, and long-term care spending. Life in a post-antibiotic era would be remarkably different and less healthy.

Leading academic groups, public health organizations, and governments have recently become more vocal about the problem of drug-resistant infections. The Infectious Diseases Society of America (IDSA) reported that "[i]nfections that were once easily curable with antibiotics are becoming difficult, even impossible, to treat, and an increasing number of people are suffering severe illness - or dying - as a result."