Infection Disease Vocabulary Study Guide - Unit 3.1

Vocabulary flashcards covering types of pathogens, infectious disease concepts, the chain of infection, types of immunity, bacterial colony morphology, Gram staining, bacterial shapes and arrangements, and infection prevention methods.

Nosocomial Infection

An infection acquired in a hospital that was not present or developing when the patient was admitted. It is a type of healthcare-associated infection.

Outbreak

More cases of a disease than expected in a particular place or group during a specific time.

Epidemic

An increase in disease cases above what is normally expected in a population or region. An outbreak generally refers to a more limited area.

Pandemic

An epidemic that spreads across multiple countries or continents and affects many people. The term describes spread, not severity.

Antibiotic Resistance

The ability of bacteria to survive or grow despite an antibiotic that would normally kill them or stop their growth. The bacteria become resistant, not the person.

Disease

A condition that disrupts the normal structure or function of the body. Diseases may be infectious or noninfectious.

Infectious

Caused by a pathogen. Not all infectious diseases spread directly from person to person.

Host

A living organism in or on which a pathogen or parasite lives.

Pathogen

A biological agent that can cause disease.

Virus

An infectious agent containing genetic material inside a protein coat, sometimes with an outer envelope. It can reproduce only inside a living host cell.

Helminth

A parasitic worm, such as a tapeworm, roundworm, or fluke.

Prion

An infectious, misfolded protein that causes other proteins to misfold and can lead to serious brain disease.

Bacteria

Single-celled organisms that lack a nucleus. Many are harmless or helpful, but some cause disease.

Fungus

An organism, such as a yeast or mold, whose cells contain a nucleus. Some fungi cause infections, such as athlete's foot.

Protists

A diverse group of organisms whose cells contain a nucleus; many are single-celled. Some are parasites that cause diseases, such as malaria.

Chain of Infection

A model showing how infections spread through six links: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. Breaking a link can help prevent infection.

Reservoir

The usual place where a pathogen lives and multiplies, such as a person, animal, soil, or water.

Portal of Exit

The route a pathogen uses to leave its reservoir, such as through respiratory secretions, blood, or feces.

Mode of Transmission

The way a pathogen spreads, such as through direct contact, contaminated objects, respiratory particles, food, water, or insect bites.

Portal of Entry

The route a pathogen uses to enter a host, such as the respiratory tract, digestive tract, or broken skin.

Innate Immunity

The defenses you are born with, that respond quickly to broad types of threats. Examples include skin, mucus, inflammation, and certain immune cells.

Acquired Immunity

Protection against specific pathogens that develops through an immune response or comes from receiving antibodies. Also called adaptive immunity in many classroom contexts.

Naturally Acquired Immunity

Protection gained without a medical intervention. It can be active, after infection, or passive, through antibodies passed from a mother to her baby during pregnancy or through breast milk.

Artificially Acquired Immunity

Protection gained through a medical intervention. It can be active, through vaccination, or passive, through receiving prepared antibodies.

Form

The overall shape of a colony when viewed from above, such as circular or irregular.

Elevation

The height or profile of a colony when viewed from the side, such as flat, raised, or convex.

Margin

The outer edge of a colony, such as smooth, wavy, or lobed.

Colony

A visible mass of microorganisms growing on a solid medium, usually arising from one cell or a small group of cells.

Gram Stain

A laboratory staining method that helps classify bacteria by differences in their cell envelopes. It also reveals cell shape and arrangement.

Gram Positive

Describes bacteria that usually appear purple after Gram staining because their thick peptidoglycan cell wall retains the primary stain complex.

Gram Negative

Describes bacteria that usually appear pink or red after Gram staining. They have a thin peptidoglycan layer and an outer membrane.

Coccus

A spherical or round bacterial cell. The plural is cocci.

Bacillus

A rod-shaped bacterial cell. The plural is bacilli.

Spirillum

A rigid, spiral-shaped bacterial cell. The plural is spirilla.

Diplo-

A prefix meaning bacterial cells are arranged in pairs.

Strepto-

A prefix meaning bacterial cells are arranged in chains.

Staphylo-

A prefix meaning bacterial cells are arranged in grape-like clusters, usually referring to cocci.

Urinary Tract Infection (UTI)

An infection in any part of the urinary system, including the urethra, bladder, ureters, or kidneys. Most UTIs are caused by bacteria.

PPE

Personal protective equipment: items such as gloves, gowns, masks, and eye protection that reduce exposure to infectious materials and other hazards.

Hand Hygiene

Cleaning the hands with soap and water or an alcohol-based hand sanitizer to reduce the spread of pathogens.