Nursing Care of Patients With Infections – Core Vocabulary

This set of 75 vocabulary flashcards covers foundational terms and microorganisms, key links in the chain of infection, routes of transmission, host susceptibility factors, and essential nursing interventions and concepts for preventing and managing infections.

Infection

Invasion and multiplication of microorganisms in body tissues causing illness.

Pathogen

Any microorganism (bacteria, virus, fungus, etc.) capable of producing disease.

Chain of Infection

The six-step process (agent, reservoir, portal of exit, transmission, portal of entry, susceptible host) that must occur for infection to develop.

Infectious Agent

The specific microorganism (bug) that starts the chain of infection.

Reservoir

The place where a pathogen lives, grows and multiplies before causing disease.

Animate Reservoir

Living source of pathogens such as people, animals, insects or plants.

Inanimate Reservoir

Non-living source of pathogens such as water, soil, food or medical devices.

Portal of Exit

The path by which a pathogen leaves its reservoir (e.g., cough, stool, wound drainage).

Mode of Transmission

How a pathogen moves from its source to a new host.

Direct Contact Transmission

Spread through immediate physical contact (touching, kissing, sexual contact).

Indirect Contact Transmission

Spread via contaminated object or person-to-object-to-person pathway.

Vehicle-borne Transmission

Spread through a common inanimate object such as food, water, blood or bedding.

Vector-borne Transmission

Spread through a living carrier other than humans (mosquitoes, ticks, fleas, rats).

Airborne Transmission

Spread by tiny particles that remain suspended in the air for long periods and travel distances.

Droplet Transmission

Spread by larger respiratory particles expelled by coughing, sneezing or talking that travel ~3–6 ft.

Portal of Entry

Route through which a pathogen gains access to a new host (respiratory tract, skin break, etc.).

Susceptible Host

Person whose defense mechanisms are weakened, allowing infection to occur.

Immunity

Body’s ability to resist infection through innate and adaptive defenses.

Normal Flora (Microbiota)

Microbes that naturally inhabit body sites (skin, gut) and usually protect against pathogens.

Bacteria

Single-celled prokaryotes; classified by shape, staining and oxygen needs.

Aerobic Bacteria

Bacteria that require oxygen to live and multiply.

Anaerobic Bacteria

Bacteria that grow without oxygen and may be killed by its presence.

Cocci

Spherical bacteria (e.g., Streptococcus).

Bacilli

Rod-shaped bacteria (e.g., E. coli).

Staphylococcus aureus (MSSA/MRSA)

Common skin bacterium; methicillin-sensitive (MSSA) or methicillin-resistant (MRSA) strains can cause severe infections.

Streptococcus

Genus of cocci bacteria; includes strep throat and invasive soft-tissue infections.

Escherichia coli (E. coli)

Gram-negative bacillus often causing urinary tract infections and urosepsis.

Fungi

Yeasts and molds that thrive in warm, dark, moist areas and can cause infections.

Candida albicans

Opportunistic yeast causing thrush and vaginal infections, especially after antibiotics.

Protozoa

Single-celled eukaryotes spread by contaminated water or fecal-oral route causing GI illness.

Fecal-Oral Route

Transmission when organisms in feces reach the mouth (poor hand hygiene, contaminated food/water).

Helminths

Parasitic worms such as ringworm, tapeworm, hookworm that infect skin or GI tract.

Ringworm (Tinea)

Fungal skin infection producing circular, scaly patches; spreads easily in gyms and shared items.

Prions

Infectious protein particles that cause degenerative brain diseases like encephalitis.

Virus

Microscopic acellular agent requiring host cells to replicate; often difficult to treat.

Viral Shedding

Release of new viral particles from host cells, enabling transmission.

HIV

Human immunodeficiency virus; progressive viral infection that attacks immune cells.

COVID-19 (SARS-CoV-2)

Respiratory coronavirus causing global pandemic; spread by airborne and contact routes.

Influenza

Highly contagious respiratory virus; annual vaccination recommended due to antigen changes.

Tuberculosis (TB)

Airborne Mycobacterium infection requiring N95 respirator and negative pressure isolation.

Pertussis (Whooping Cough)

Bordetella infection producing severe cough; prevented by Tdap vaccine.

West Nile Virus

Mosquito-borne flavivirus causing febrile illness or neuroinvasive disease.

Lyme Disease

Tick-borne Borrelia infection marked by bull’s-eye rash and arthritic symptoms.

Malaria

Mosquito-transmitted protozoal infection (Plasmodium) causing cyclical fevers and anemia.

Zika Virus

Mosquito-borne virus linked to birth defects and Guillain-Barré syndrome.

Sepsis

Life-threatening organ dysfunction from a dysregulated response to infection.

Urosepsis

Sepsis originating from a urinary tract infection.

Opportunistic Infection

Infection by ordinarily harmless organisms in immunocompromised hosts.

Hand Hygiene

Most effective, basic method to prevent spread of infection (soap & water or alcohol gel).

Aseptic Technique

Procedures that keep objects and areas free from pathogenic microorganisms during clinical tasks.

Standard Precautions

Minimum infection-control practices applied to all patient care regardless of status.

Transmission-Based Precautions

Extra measures (contact, droplet, airborne) used when specific pathogens are known or suspected.

Personal Protective Equipment (PPE)

Gloves, gowns, masks, eye protection and other barriers worn to reduce exposure.

N95 Respirator

Fit-tested mask filtering ≥95 % of tiny airborne particles; required for TB and COVID-19 care.

Negative Pressure Room

Isolation room that pulls air inward and vents it outside to prevent pathogen escape.

Sterile Technique

Elimination of all microorganisms during invasive procedures (e.g., catheter insertion).

Catheter-Associated Infection

UTI or bloodstream infection linked to indwelling urinary or vascular catheter use.

Central Line-Associated Infection

Bloodstream infection originating from a central venous catheter (PICC, port, midline).

Antimicrobial (Anti-infective) Drugs

Medications that kill or inhibit pathogens (antibiotics, antivirals, antifungals, etc.).

Antibiotic

Drug active against bacteria; selection depends on organism and resistance pattern.

Antiviral

Medication that interferes with viral replication (e.g., remdesivir for COVID-19).

Antifungal

Drug used to treat fungal infections (e.g., fluconazole).

Anthelminthic

Medication used to eliminate parasitic worms.

Immunization (Vaccination)

Administration of antigen to stimulate protective immunity against specific pathogens.

Herd Immunity

Community protection that arises when a high proportion of individuals are immune.

Albumin

Blood protein used as a lab marker of long-term nutritional status (normal ~3.5–5.5 g/dL).

Prealbumin

Short-term plasma protein marker for acute changes in nutrition.

Malnourishment

Deficiency of nutrients, especially protein, that weakens immune defense and healing.

Immunocompromised Patient

Person with weakened immune system due to disease, medication or treatment.

Chronic Disease

Long-term health condition (diabetes, COPD, CKD) that increases infection risk.

Hyperbaric Oxygen Therapy

High-pressure oxygen treatment used to enhance wound healing and combat infection.

Colostrum

Antibody-rich early breast milk that provides newborns passive immunity.

Superfood

Nutrient-dense food (blueberries, sweet potatoes, kale) that supports immune health.

Stress Response

Physiologic changes triggered by stress that can suppress immune function.

Pressure Injury (Pressure Ulcer)

Localized tissue damage from prolonged pressure; open wound increases infection risk.