At the beginning of the 20th century, infectious disease was the primary cause of death in the United States. With the introductions of antibiotics for the treatment of infection and vaccines to prevent disease, the public began to believe protection was lasting.

In fact, despite advances in medical research during the 20th century, infectious diseases remained among the leading causes of death worldwide for three reasons: 1) emergence of new infectious diseases; 2) re-emerging diseases defined as diseases that have reappeared after a significant decline or the re-emergence of old infectious diseases; and 3) persistence of intractable infectious diseases (Siegel et al., 2006).

Antibiotics are no longer the one-step answer to cure. Today there is growing alarm concerning multi-drug-resistant organisms such as Methicillin-Resistant Staphylococcus Aureus (MRSA) (Siegel et al., 2006). The Institute of Medicine emphasized, “The evolution of drug resistance is an inevitable consequence of genetics and natural selection when drugs are used against microbial pathogens” (Institute of Medicine, 2004). To prevent the spread of diseases such as MRSA and prepare for the next evolving disease, the Centers for Disease Control and Prevention (CDC) recommends health care professionals use antimicrobials wisely.