Infectious

Infectious diseases are disorders caused by organisms – such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They are usually harmless or even helpful. But under certain conditions, some organisms can cause disease.
Some infectious diseases can be transmitted from person to person. Some are transmitted by insects or other animals or by consuming contaminated food, water or being exposed to the organisms in the environment.
General signs and symptoms common to a number of infectious diseases include: