Infection Control

I. Vocabulary

Microorganism (microbe) Small, living organism that is not visible

to the naked eye Pathogen

Microbe that causes infection and disease

Nonpathogen Microbes that are beneficial for certain

body processes

Example

E. coli can be beneficial in one system, but pathogenic in another

II. What do microorganisms need?

Warm environment (body temp) Darkness Source of food and moisture Aerobic-need oxygen,

Anaerobic-do not need oxygen

The body is a perfect place for microorganisms to live and reproduce!

III. BACTERIA-One celled organisms

Cocci Round shape

Diplococci: Bacteria in pairs Gonorrhea, meningitis, pneumonia

Streptococci: Bacteria in chains Strep throat, rheumatic fever

Staphlococci: Bacteria in clusters or groups Pus-producing Boils, Urinary tract infections, wound infections,

toxic shock

BACTERIA-One celled organisms

Bacilli: Rod-shaped bacteria Occur singly, in pairs, or in chains Flagella (tail to move with) Form spores which are hard to kill Diseases:

Tuberculosis, tetanus, whopping cough, botulism, diptheria, typhoid

BACTERIA-One celled organisms

Spirilla-Spiral or corkscrew shape Diseases include syphilis and cholera

Protozoa

One-celled animal-like organisms Found in decayed materials, animal

feces, insect bites, and contaminated water

Many have flagella to swim Diseases:

Malaria, amebic dysentery, African sleeping sickness

V. Fungi

Plantlike organisms Live on dead organic matter YEASTS and MOLD Diseases:

Ringworm, athlete’s foot, yeast vaginitis, thrush

VI. Rickettsiae

Parasitic microorganisms Can’t live outside their host Found in fleas, lice, ticks, mites Transmitted to humans by bites Diseases:

Typhus fever, Rocky Mountain spotted fever

VII. Viruses Smallest microorganisms Can’t reproduce unless inside a cell Spread by blood and body secretions NOT AFFECTED BY ANTIBIOTICS Mutate quickly Diseases:

Cold, mumps, measles, chicken pox, herpes, warts, influenza, polio, west nile virus, SARS, HIV, H5N1 (avian bird flu)

Important Viruses-Hepatitis B

HBV virus Transmitted by blood, serum, or other

body secretions Affects liver Vaccine is available (3 shots)

Important Viruses-Hepatitis C HCV virus Transmitted by blood and blood-

containing body fluids (can remain active in dried blood for several days)

No symptoms or mild symptoms like flu

Can cause severe liver problems Difficult to kill

Important Viruses-AIDS

Aquired Immune Deficiency Syndrome

Supresses immune system Can’t fight off cancers and infections

that a healthy person easily fights No cure, no vaccine (in development)

VIII.Helminths-Parasitic organisms

Worms and flukes Humans ingest eggs or larvae in

contaminated food (some penetrate skin)

Examples: Hookworms-attach to small intestine, can

get to heart and lungs Tapeworm-attaches to small intestine,

crawls out anus

IX. Types of Infection

Pathogen produces toxin (poison) Cause allergic reaction Attack and destroy living cells they

invade

Types of Infection

Endogenous: infection or disease originates within the body

Exogenous: Infection or disease originates outside the body

Nosocomial: Acquired by an individual in a health care facility

Opportunistic: Occur when the body’s defenses are weak

X. Chain of Infection Causative Agent: pathogen Reservoir: Place to live Portal of Exit: A way to escape the reservoir

(feces, urine, mucus, etc) Mode of transmission:

Direct contact, Indirect contact Portal of Entry: A way to get into new host Susceptible host

XI. Body Defenses Mucous membranes Cilia Coughing and sneezing Hydrochloric acid Tears in eyes Fever Inflammation Immune response

X. Aseptic Techniques-Vocabulary

Asepsis: Absence of disease-producing pathogens

Sterile: Free from all organisms (pathogenic or nonpathogenic)

Contaminated: Pathogens present

Aseptic Techniques Antisepsis: Antiseptics prevent or inhibit

growth of pathogens (not effective against spores & viruses)

Disinfection: Process that destroys or kills pathogenic organism (not effective against spores & viruses) Can irritate or damage skin, used on objects

Sterilization: Process to destroy all pathogens (includes spores & viruses)

XII. Common Aseptic Techniques

Handwashing Good personal hygiene Use of disposable gloves when

contacting body secretions Proper cleaning of instruments