Over the course of the twentieth century, the medical community “appeared to be winning the battle against communicable diseases” with antibiotics and vaccines. Yet, in the last few decades, new infectious diseases and conditions such as Human Immunodeficiency Virus (HIV), Acquired Immunodeficiency Syndrome (AIDS), Severe Acute Respiratory Syndrome (SARS), Ebola, and avian influenza (most notably virus H5N1) have created grave new threats. Although HIV/AIDS is not particularly contagious if appropriate precautions are taken, avian influenza, SARS, and Ebola are believed to be highly contagious, fatal, and sometimes without mechanisms to prevent transmission.