RADTC100: Ch. 17 - Infection Control

Eukaryotes

Organisms whose cells have a *true nucleus*.

Nosocomial

Pertaining to or *originating in the hospital*; said of an infection *not present or incubating before admittance* to the hospital but generally developing 72 hours after admittance.

Standard Precautions

Precautions to *prevent the transmission of disease by body fluids* and substances.

Surgical Asepsis

Procedure used to *prevent contamination by microbes and endospores* before, during, or after surgery using sterile technique.

Bacteria

Prokaryotic, ubiquitous, single-celled organisms.

Iatrogenic

Resulting from the activities of physicians.

Outcome

Results in any of three outcomes. 1. *Host gains control* of the infectious agent and eliminates it. 2. *Infectious agent overcomes* host's immunities to cause disease. 3. Host and infectious agent compromise and live in a sort of *symbiotic state*.

Categorize the four basic infectious agents along with their unique characteristics

See the next 4 cards.

Remember that direct transmission requires...

Some sort of contact, like holding hands.

Cyst

Stage in the life cycle of certain parasites during which they are enclosed in a protective wall. (protozoa form cysts)

Describe the basic premises of standard precautions.

Standard precautions incorporate the features of both *body fluid precautions and body substance isolation*. Standard precautions should be used when performing *procedures that may require contact with blood, body fluids, secretions, excretions, mucous membranes, and nonintact skin*. Also *soiled and contaminated* items. All patients should be *regarded as potentially infectious*. - Hand washing - Gloving - Personal protective equipment (PPE) - Needle recapping - Biospills

Protozoa

Subkingdom compromising the *simplest organisms of the animal kingdom*, consisting of unicellular organisms that range in size from submicroscopic to macroscopic; most are free living, but some lead commensalistic, mutualistic, or parasitic existences.

Chemotherapy

Treatment of disease by chemical agents.

The best method of preventing the spread of aerosol infections is by:

a. the patient wearing a mask.

A person is bitten by a mosquito and develops an infection. This type of transmission is known as

a. vector.

A health care working is accidentally punctured with a contaminated needle. This type of transmission is known as:

b. fomite.

The common cold is an example of an infection by a:

b. virus.

An infectious microbe can gain entrance into the human body by:

c. ingression and penetration. (remember that ingression does not involve deep-tissue penetration. Instead, these microorganisms adhere to the surface of the cell and excrete toxins that cause a distressed state within the system)

Microorganisms that cause infectious diseases can be classified as:

c. pathogenic.

Hand washing employs which of the following methods of infection control?

d. chemical and physical.

An outpatient develops a staphylococcal infection after a surgical procedure. This type of transmission is known as:

d. more than one of the above, but not all. I think nosocomial and fomite.

The term that best describes the absolute removal of all life forms is:

d. sterilization.

List the chemical and physical methods of asepsis.

*Chemical* - Disinfectants: Chemicals that *alter the environment* of the microbe. May or may not entail the removal of bacterial endospores. If the disinfectant is applied *topically, it is termed antiseptic*. Can be either *bacteriostatic* (stop growth), or *bacteriocidal* (kill). Common disinfectants are *hologens chlorine and iodine, alcohol, hydrogen peroxide, and ammonium-containing detergents*. *Physical*: - Sterilization - Autoclave (moist heat and pressure) - Oven (dry heat) - Pasteurization (heating followed by rapid cooling) - UV light - Gloves, gowns, masks, etc.

Disinfectants

*Chemicals* used to free an environment from pathogenic organisms or to render such organisms inert, especially as applied to the *treatment of inanimate materials to reduce or eliminate infectious organisms*.

Sterilization

*Complete destruction or elimination of all living microorganisms*, accomplished by *physical* methods (dry or moist head), *chemical* agents (ethylene oxide, formaldehyde, alcohol), *radiation* (ultraviolet, cathode), or *mechanical* methods (filtration).

Explain the constituents of microbial control within the host.

*Internal Mechanisms:* - Mechanical Barriers (skin) - Chemical Processes (sebaceous, sweat, mucus, tears, and urine) - Cellular Processes (phagocytes) *External Mechanisms:* - Normal Microbial Flora (varies in every person) - Physical Methods (hand washing) - Chemotherapeutic Agents (bactercidal with the ability to kill and bacteriostatic, which inhibit growth, but do not cause killing) - Immunizations (vaccines)

Infection

*Invasion and multiplication* of microorganisms in body tissue that may be clinically inapparent or may result in local cellular injury as a result of *competitive metabolism, toxins, intracellular replication, or antigen-antibody response*.

Contrast medical and surgical asepsis.

*Medical*: Involves the *reduction in numbers of infectious agents, which in turn decreases the probability of infection* but does not necessarily reduce it to zero. The microbes are not eliminated, however. Instead, their environment is altered so that it is not conductive to growth and reproduction. *Surgical*: Prevent contamination of microbes and endospores *before, during, and after surgery* using sterile technique. The absolute killing of all life forms (*sterilization*).

Flora

*Microbial community* found on or in a *healthy* person.

Fomite

*Object*, such as a book, wooden object, or article of clothing, that is not in itself harmful but is able to harbor pathogenic microorganisms and thus *may serve as an agent of transmission of an infection*.

Medical Asepsis

*Reduction in numbers of infectious agents*, which, in turn, decreases the probability of infection but *does not necessarily reduce it to zero*.

Immunity

*Security* against a *particular* disease.

Vaccine

*Suspension of attenuated or killed microorganisms* (bacteria, viruses, or rickettsiae) administered for the *prevention, improvement, or treatment* of infectious disease.

All of the following are types of indirect transmission EXCEPT:

*d. touching*. (a. fomite; b. vector; c. aerosol)

Relate types of transmission-based precautions with appropriate clinical situations.

- *Airborne*: TB, varicella (chicken pox), and rubeola (measles). Patients should be placed in *negative isolation room*. Health care professionals should wear *respiratory protection* when entering. - *Droplet*: Rubella, mumps, influenza, and adenovirus. Patient should be placed in *private rooms* or with another person with same disease. Health care professionals should *wear surgical mask within 3 feet of patient*. - *Contact*: Virulent pathogens that spread. Staphyloccocus aureus, hepatitis A. Patient will be housed in *private room* or with another patient with same disease. Health care practitioner should use *contact precaution technique*.

Discuss the four factors involved in the spread of disease and the chain of infection.

- *Host*: Usually humans. - *Infectious microorganism*: bacteria, viruses, fungi, and protozoa. - *Mode of transportation*: Air, Droplet, Contact (hand holding, sexually), Exogenous (acquired from organisms outside of the body) or Endogenous (acquired from organisms already present inside of the body), Vector (like a mosquito), Fomite (inanimate object). - *Reservoir*: A person who serves as a reservoir is called a carrier. They are infected, but do not display symptoms (like Typhoid Mary).

Describe the various sources of health care-associated infection.

- *Nosocomial infections*: Occurring in the hospital. - *Iatrogenic infections*: Caused by a physician. - *Compromised patients*: Greater sensitivity to infection. Example are transplant or chemo patients. - *Medical personnel*: Carrying microbes in hair, sneezing, etc. - *Patient flora*: When a person is immunocompromised, their normal flora like streptococci living in the nasopharnynx can become harmful. - *Blood-borne pathogens (BBPs)*: HIV and HBV

Entry

- Access to the organism through a *portal of entry*. - Entry may be one of two types: *ingression or penetration*.

Damage

- Damage can be either *direct or indirect*. - A microbe can induce a host response that also *causes tissue and cell death* through activation of the *host's inflammatory and immune responses*.

Explain the steps involved in the establishment of an infectious disease.

- Encounter. - Entry. - Spread. - Multiplication. - Damage. - Outcome. (EESMDO - Elephants Eat Spicy Meals During October. The elephants are zombie elephants with infectious disease)

Fungi

- Eukaryotic protists (has nucleus and membrane-bound organelles). - Size much larger than bacteria. - Medically important fungi are called dimorphic. - Two forms: yeast and mold. - Diseases caused by fungi can be of four different classifications.

Encounter

- Involves the infectious organism *coming in contact* with the host. - Each encounter *varies according to the host and microorganism*. - *Congenital infections* = when a microorganism is able to pass through the placenta and infect the unborn child. - During the human life span, the body comes in contact with new organisms; *some are quickly eliminated*, and others that *colonize* either become *part of the microbes normally found* in the body or *cause disease*.

Viruses

- Microscopic, single celled. - Cannot live outside a living cell. Lack components for own survival. - Carry their own DNA or RNA, but never both. - Viral particle (viron) attaches to host cell, inserts its own genetic information, and then redirects host cell to produce new viruses. - Not affected by antibiotics. - Size of virus vary from 20 to 250 nanometers. - Direct observation of a virus is possible only though electron microscope. - May lie dormant for extended periods of time and then manifest in illness.

Bacteria

- Microscopic, single-celled. - Prokaryotes (lack nuclei). - Reside in colonies. - Classified as cocci, spheres, bacilli, rods, and spirals. - Gram staining technique to classify bacteria. - Contains both DNA and RNA. - Produces endospores (dormant and highly resistant to external environment)

Parasitic Protozoa

- Organisms are neither plant nor animal. - Larger than bacteria. - Eukaryotic. - Classified by their motility. - Live on or in other organisms at expense of host. - Usually have motile functionality. - Can ingest food particles, and some are equipped with digestive systems.

HBV

- Primarily *affects liver*, resulting in swelling, soreness, and loss of normal function of liver. - Symptoms: weakness, fatigue, anorexia, nausea, abdominal pain, fever, and headache. - Leads to yellow skin color (*jaundice*). - Some patients are asymptomatic. - Blood will test positive 2-6 weeks after symptoms develop. - Patients can recover in 6-8 weeks, but blood tests will always show they were exposed.

Spread

- The *propagation* of the infectious organism. - Requires *overcoming body's immune* defenses. - Degree of spreading is a *function of the logistics* of both the host and the microbe.

Multiplication

- The growth in microbe numbers as a *function of mitosis*. - Many infectious agents *undergo great multiplication before their impact is recognized* by the host. - *Incubation* period.

HIV

- Virus specifically *infects immune system* in host. - Responsible for acquired immunodeficiency syndrome (*AIDS*). - Symptoms: weight loss, muscle and joint pain, glandular pain and swelling, night sweats. - May be *asymptomatic* after exposure to HIV for as long as *10 years*. - May *take up to 1 year* for results of blood test to become *positive for HIV antibodies*.

Demonstrate the medically aseptic hand-washing technique.

1. Approach the sink. Use either foot pedal or paper towel to turn it on. 2. Wet hands thoroughly with water. Keep hands lower than elbows. 3. Apply soap. 4. Use a firm, vigorous, rotary motion. Begin at the wrist and work toward the fingertips. Rub palms, back of hands, between fingers, and under nails. 5. Rinse and allow water to run down hands. 6. Repeat entire process to cleanse from the elbow to the fingertips. 7. Turn off water. Use paper towel or foot pedal. 8. Dry from elbow to fingertips, never returning to an area.

Demonstrate the contact precautions technique.

1. Determine the correct number of cassettes needed. Place each cassette into a protective bag. 2. Move the portable machine to the isolated room. 3. Locate the isolation supplies in the room. 4. Remove all ornamentation (including watch, rings, earrings) and place them in pocket. 5. Put on a lead apron. 6. Wash your hands as described previously. 7. Booties! (not mentioned) 8. Put on a clean gown, making sure it is sufficiently long. Pick up the gown from the inside near the armhole openings and gently shake it open. Put one arm in and then the other. First tie the neck strings, then the waist. 9. Put on mask, then cap. 10. Have assistant put on gown, gloves, and cap. 11. Enter isolated area and explain to patient who you are what you're doing. 12. Check their wristband (not mentioned). 13. Position the cassette. 14. Have your assistant manipulate the machine and make exposure. 15. Remove the cassette from behind patient. Fold edge of protective bag back, never touching the inside. Have your assistant remove the cassette, never touching the outside. Throw covering away. Have your assistant remove portable from room. 16. Remove in the order: booties, gown (waist tie, then neck tie. be sure to roll gown away from you), gloves, cap, and mask. 17. Wash hands.

Reservoir

Alternative or passive host or *carrier that harbors pathogenic organisms, without injury to itself*, and serves as a source from which other individuals can be infected.

Host

Animal or plant that harbors or *nourishes* another organism.

Viruses

Any of a group of *minute infectious agents* not resolved in the light microscope, with certain exceptions (e.g., poxvirus), and characterized by a *lack of independent metabolism and by the ability to replicate only within living host cells*.

Vector

Carrier, especially an animal (usually an arthropod), that transfers an infective agent from one host to another.

Prokaryotes

Cellular organisms that *lack a true nucleus*.

Viron

Complete *viral particle* found extracellularly and capable of surviving in crystalline form and infecting a living cell; comprises the *nucleoid* (genetic material) and the *capsid*; also called viral particle.

Diseases

Deviations from or *interruptions of the normal structure or function of any, organ, or system* (or combination thereof) of the body that are exhibited by a *characteristic set of symptoms and signs* and whose cause, *pathologic mechanism*, and prognosis may be known or unknown.

Pathogens

Disease-producing microorganisms.

Asepsis

Freedom from infection.

Fungi

General term used to denote a group of *eukaryotic protists* -- including mushrooms, yeasts, rusts, molds, and smuts -- that are characterized by the *absence of chlorophyll* and by the presence of a *rigid cell wall*.

Health Care-Associated infection (HAI)

Infection that patients acquire while they are receiving treatment for another health care issue.

Microorganisms

Microscopic organisms; those of medical interest include *bacteria, viruses, fungi, and protozoa*.

Dimorphic

Occurring in two distinct forms. (as with fungi - they can be in the form of yeast or hyphae)