Infection Control Part 1 (RADS 210)

Infectious diseases are caused by

microscopic germs (bacteria or viruses) that get into the body and cause illness

Infectious germs are referred to as

infectious pathogens or agents

Contagious

infectious diseases that spread from person to person

Types of infectious pathogens (agents)

1. bacteria

2. viruses

3. fungi

4. parasites

5. prions

Bacteria (Agents)

gram-positive, aerobes or anaerobes

Fungi (Agents)

yeasts and molds, aerobes

Virus (Agents)

smallest germ of all microorganisms known to produce disease

Prion (Agent)

infectious protein in brain cells, malform and convert to disease

-leads to dementia

Parasite (Agent)

An organism that feeds/ lives on a living host

ex. tapeworms or botflies

nosocomial infection

infectious acquired in a hospital, nursing home, or other health care setting

-not covered by insurance

Most common site for nosocomial infections

urinary tract (UTI)

example of nosocomial infection

infections contracted at birth by infants of infected mothers

Iatrogenic infection

A nosocomial infection that results from a particular treatment or therapeutic procedure

ex. chemotherapy causing nausea, vomiting, hair loss

community acquired infection

A person who enters a health care facility with an infection

-was acquired in group setting

Normal Flora

microorganisms that everyone has in their bodies at all times

Exogenous nosocomial infection

an infection caused by microorganisms that are not normal flora

Endogenous nosocomial infection

when a person acquires an infection in the health care setting as a result of an overgrowth of normal flora

Factors that encourage nosocomial infections

-Environment

-Therapeutic regimen

-Equipment

-Contamination during medical procedures

Environment Examples that encourage nosocomial infections

-air contaminated with infectious agents

-other pts with infectious diseases

-visitors

-contaminated food

-contaminated instruments

-hospital personnel

Therapeutic Regimen Examples that encourage nosocomial infections

-Immunosuppressive/ cytotoxic drugs- causes drop in pts resistance

-Antimicrobial therapy alters normal flora

-Cytoxic- toxic to living cells

Equipment Examples that encourage nosocomial infections

instruments that have not been adequately cleaned and sterilized

Contamination during medical procedures examples that encourage nosocomial infections

microbes transmitted during dressing changes catheter insertion or any invasive procedure

communicable disease

diseases that are considered to be infectious include or contagious

-can be transmitted to other people

Communicable disease examples

HIV, AIDS, TB, Hepatitis, Chicken Pox, Measles, Mumps, Covid 19

multidrug-resistant organisms (MDROs)

-Methicillin-resistant Staphylococcus aureus (MRSA)

-Vancomycin-resistant Enterococcus (VRE)

-Vancomycin-resistant Staphylococcus aureus (VRSA)

-Bacteremia & Fungemia

-C. Difficile

-Extended-spectrum beta-lactamase (EBSL)

Methicillin-resistant Staphylococcus aureus (MRSA)

direct contact or contact with infected surface

Vancomycin-resistant Enterococcus (VRE)

enterococcus is part of normal flora of GI tract. thought to be the second most causative microbe for nosocomial infections

Bacteremia & Fungemia

when both are located in bloodstreat by way of Vascular Access Device (VAD)

C. Difficile

frequent cause of nosocomial infection. spore forming bacteria that causes pseudomembranous colitis, which can result in sepsis

Extended-spectrum beta-lactamase (EBSL)

an enzyme produced by some bacteria.

Ex of bacteria. Escherichia Coli (E. Coli)

Infectious pathogens

Contagious disease causing agents

Elements needed to transmit infection (Cycle of Infection)

1. Infectious Angent

2. Enviroment where Pathogenic microbes can live and multiply (Resevoir/Host)

3. Portal of Exit from reservoir

4. Means of Transmission

5. Portal of entry into new host

Pathogenicity

organisms ability to cause disease

virulence

organisms ability to grow and multiply with speed (faster it can infect someone)

Invasiveness

organisms ability to enter tissues

Specificity

organisms attraction to a particular host

Environment where pathogenic microbes can live and multiply examples. (2nd part of the cycle of infection)

-Human Being

-Animal

-Plant

-Water

-Food

-Earth

-Any combination of organic material that supprt the life of the pathogen

Portal of exit from reservoir examples (3rd part of cycle of infection)

-nose (sneeze)

-mouth (cough)

-urinary tract

-intestines

-open wound

Means of transmission examples. (4th part of cycle of infection)

-direct/indirect contact

-droplet

-vehicle

-vector (bug)

-airborne route

how is it getting out of the body

direct contact

when the person with the disease is touched by hands, kissing, sexual intercourse, sharing needles

Indirect Contact

touching objects (fomites) contaminated by an infected person

ex. dressings, instruments, clothing, dishes, fomite

fomite

inanimate object

Droplet

coming in contact with infectious secretions from conjunctiva (eyes), nose (sneezing), mouth (coughing)

-comes from sneezes, coughs, or talking

Vehicle

route of transmission that includes the following that are contaminated with infectious organism

-food, water, drugs, blood

Vector

insect or animal carriers of disease transmitted by stinging or biting the human host

ex. mosquitoes (west nile virus & encephalitis virus

rabies (saliva of animals)

Infected Tick- lyme disease

Airborne Route

residue from evaporated droplets of diseased microorganisms suspended in air for LONG periods of time; the residue is infectious if inhaled by the susceptible host

Portal of Entry Into New Host examples (5th and art of cycle of infection)

ingestion, inhalation, injection, across mucous membranes, and across the placenta

Persons susceptible to infection

poorly nourished & fatigued

Which persons are at greatest risk of infection?

those with chronic diseases

ex. cancer & diabetes mellitus