Infectious agents comprise a vast and diverse group of pathogens—including bacteria, viruses, fungi, protozoa, helminths, and prions—that are responsible for a wide spectrum of diseases. These agents ...

Infectious diseases shape health care in complex ways, impacting research, treatment and public health — locally and globally. The capability of infectious agents to rapidly adapt to host defenses is ...

The term modes of transmission refer to how an infectious agent, also called a pathogen, can be transferred from one person, object, or animal, to another. Viruses, bacteria, parasites, or fungi can ...

The belief that infectious agents may cause certain chronic diseases can be traced to the mid-19th century, when cancer was studied as a possible infectious disease. This effort met with little ...