acute: (of an illness) having a rapid onset, usually sudden and severe

etiology: The cause, set of causes, or manner of causation of a disease or condition.

prion: A misfolded protein that can induce misfolding of normal variants of the same protein and trigger cellular death.

antibiotic: A chemical substance produced by a living organism that is detrimental to other microorganisms.

fungus: A group of single-celled or multicellular eukaryotic organisms that feed on organic matter such as other microorganisms or organic debris.

prognosis: The expected course and outcome of a disease or condition.

antiseptic: A substance that stops or slows down the growth of microorganisms.

helminth: A parasitic worm, especially an intestinal worm.

protozoa: A group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris.

arthropod: Invertebrates in the phylum Arthropoda, possessing an exoskeleton with a cuticle made of chitin, a body with differentiated segments, and paired jointed appendages.

host: A person who receives or entertains guests socially, commercially, or officially; or an organism that harbors a parasite, mutual partner, or commensal partner.

sign: An objective evidence of disease especially as observed and interpreted by the physician rather than by the patient or lay observer.

asepsis: The state of being free from disease-causing contaminants or preventing contact with microorganisms. Infection: The process by which an infectious agent invades and multiplies in the body tissues.

sterilization: The process of making something free from bacteria or other living microorganisms.

bacteria: Single-celled microorganisms that can exist either as independent (free-living) organisms or as parasites (dependent on another organism for life).

microbiome: The combined genetic material of the microorganisms in a particular environment.

symptom: A physical or mental feature which is regarded as indicating a condition of disease, particularly such a feature that is apparent to the patient.

chronic: (of an illness) persisting for a long time or constantly recurring.

microorganism: A microscopic organism, especially a bacterium, virus, or fungus.

syndrome: A group of symptoms which consistently occur together, or a condition characterized by a set of associated symptoms.

diagnosis: The identification of the nature of an illness or other problem by examination of the symptoms.

nosocomial infection: An infection that is contracted from the environment or staff of a healthcare facility.

systemic: Relating to a system, especially as opposed to a particular part.

disease: A disorder of structure or function in a human, animal, or plant, especially one that produces specific symptoms or that affects a specific location.

opportunistic infection: An infection caused by pathogens that take advantage of an opportunity not normally available, such as a host with a weakened immune system, an altered microbiota, or breached integumentary barriers.

therapy: Treatment intended to relieve or heal a disorder.

disinfectant: A chemical liquid that destroys bacteria.

pandemic: (of a disease) prevalent over a whole country or the world.

toxin: An antigenic poison or venom of plant or animal origin, especially one produced by or derived from microorganisms and causing disease when present at low concentration in the body.

endemic: (of a disease or condition) regularly found among particular people or in a certain area.

parasite: An organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other’s expense.

vector: An organism, typically a biting insect or tick, that transmits a disease or parasite from one animal or plant to another.

endospore: A resistant asexual spore that develops inside some bacteria cells.

pathogen: A bacterium, virus, or other microorganism that can cause disease.

virulence: The severity or harmfulness of a disease or poison.

epidemic: A widespread occurrence of an infectious disease in a community at a particular time.

pathophysiology: The disordered physiological processes associated with disease or injury.

virus: An infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host