noun, plural: infections
(microbiology) Invasion and multiplication of an infectious agents in body tissues of the host and may lead to clinical symptoms or local cellular injury as a result of competition in metabolism, production of toxins, intracellular replication, or antigen antibody response
(pathology) A disease that is infectious
Infection is the process or the state wherein an infectious agent (such as pathogenic microorganisms, viruses, prions, viroids, nematodes and helminths) invade and multiple in the body tissues of the host. It could result to the manifestation of symptoms and disease when the immune response of the host is activated. It may also be palpable when the infection results in the competition in nutrients and metabolism. The invading microbes and viruses are also capable of producing pyrogens that can incite febrile reaction. Diseases that are communicable (transmissible) are referred to as infectious.
Word origin: Old French infection, from Late Latin infectiō