A disease that is caused by a microorganism, such as a bacterium, virus, or parasite, that is not normally found in the body and is capable of causing infection. Some, but not all, infectious diseases are contagious, meaning they can spread from person to person. Other infectious diseases can spread from animals or insects to humans, but not from person to person. HIV is both infectious and contagious.
See Related Term(s): Contagious Disease
National Institute of Allergy and Infectious Diseases (NIAID) (En español)
A federal agency that supports basic and applied research to prevent, diagnose, and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted infections. The Institute also supports medical research studies on tuberculosis (TB), malaria, autoimmune disorders, asthma, allergies, and illnesses from potential bioterrorism agents.