Infectious Disease

An infectious disease is an illness caused by pathogens or disease-causing microorganisms like viruses, fungi, bacteria, and parasites. Infectious diseases may be spread, directly or indirectly, between people or from animals to people. In history, epidemics of contagious diseases such as leprosy, smallpox, diphtheria, tuberculosis, and meningococcal infections have been documented.

The first recorded smallpox epidemic dates back to 1350 BCE, during the times of the Egyptian