What is the definition of disease?
Any deviation from or interruption of the normal structure or function of any part, organ, or system of the body.
Caused by microorganisms and characterized by tissue damage with symptoms.
What is infection?
Establishment and growth of a microorganism on or in a host, resulting in injury to the host.
Caused by pathogenic organisms.
What are the three functions of pathogens?
- Multiply and cause obstructions
- Cause tissue damage
- Secrete organic exotoxins
List the four basic types of pathogens.
- Bacteria
- Viruses
- Fungi
- Parasitic protozoa
What are the characteristics of bacteria?
- Microscopic, single-celled organisms
- Prokaryotes—lack nuclei and membrane-bound organelles
- Reside in host as a colony
- Classified as cocci, bacilli, and spirals
What is the gram staining technique used for?
To classify bacteria.
What are the two forms of fungi?
- Yeast
- Molds
What are the classifications of diseases caused by fungi?
- Superficial
- Cutaneous
- Subcutaneous
- Systemic
How are parasitic protozoa classified by motility?
- Ameboid
- Flagellum
- Cilia
- Sporozoans
What are the steps involved in the establishment of an infectious disease?
- Encounter
- Entry
- Spread
- Multiplication
- Damage
- Outcome
What are the two types of entry for infectious organisms?
- Ingression
- Penetration
What are the two forms of damage caused by microbes?
- Direct
- Indirect
What are the three possible outcomes of an infectious disease state?
- Host gains control and eliminates the agent
- Infectious agent overcomes host’s immunities
- Host and agent live in a symbiotic state
What are the links in the chain of infection?
- Host
- Infectious microorganism
- Mode of transportation
- Reservoir
What are the two avenues of disease transmission?
- Exogenous
- Endogenous
Define health care-associated infections.
Infection acquired while in the care of a medical provider.
What factors encourage nosocomial infections?
- Environment
- Therapeutic regimen
- Equipment
- Contamination during medical procedures
What are the two types of blood-borne pathogens of concern in hospitals?
- HIV (human immunodeficiency virus)
- HBV (hepatitis B virus)
What does HIV specifically infect?
CD4+ T cells
What is the primary effect of HBV?
Affects the liver, resulting in swelling, soreness, and loss of normal liver function.
What are the internal defense mechanisms of the body?
- Mechanical barriers
- Chemical processes
- Cellular processes
What are standard precautions?
Features of both body fluid precautions and body substance isolation used during procedures involving blood and body fluids.
What are the three common types of transmission-based precautions?
- Airborne
- Droplet
- Contact
What is asepsis?
Freedom from infection.
