patient care unit 3

healthcare works must know …

• what infectious diseases are

• how they spread

• how they are controlled

microorganisms

grow in or on a host organism & cause disease, known as infections

infection

establishment and growth of a microorganism on or in a host

pathogens

disease producing microorganisms

1. multiply in large numbers and cause an obstruction

2. cause tissue damage

3. can secret organic substances called exotoxins

exotoxins (pathogens)

produce high body temperatures, nausea, vomiting, or shock

bacteria

microscopic, single-celled organisms that may reside in host in a group, or a cluster known as a colony

how are bacteria classified?

morphology - size or shape

• cocci or spheres

• bacilli or rods

• spirals

common bacterial infections encountered today

• streptococcal pharyngitis (strep throat)

• klebsiella pneumoniae infection (bacterial pneumonia)

• clostridium botulinum infection (food poisoning)

virus

cannot live outside a living cell, depends on host to provide missing factors

viral particle (virion) attaches to host & inserts its genome/genetic information into the host

can lay dormant at times known as latent or dormant infection

common viral diseases

• common cold (rhinovirus)

• infectious mononucleosis

• warts (causes by papillomavirus)

fungi

size much larger than bacteria, requires an aerobic environment to live i.

dimorphic

medically important fungi - can grow as yeast or mold; filamentous hyphae

classifications of fungi

• superficial

• cutaneous

• subcutaneous

• systemic

common fungal infections

• athlete’s foot

• ringworm

• tinea nigra

protozoa

larger than bacteria, classified by motility, live on or in other organisms at expense of host, can ingest food particles, and some are equipped with digestive systems

common parasitic infections

• pinworms

• tapeworms

• malaria

what four factors are involved with the spread of infection

1. a host

2. an infectious microorganism

3. a mode of transportation

4. a reservoir

six cycle chain of infection

1. pathogen

2. reservoir

3. portal of exit

4. mode of transmission

5. portal of entry

6. susceptible host

human host

humans provide favorable host environment due to the many organic nutrients & metobolites

different temperatures throughout body, pH, or body fluid for pathogen to grow

microorganisms tend to like …

• warm temperatures

• moisture

• darkness

infectious microorganisms

• bacteria

• viruses

• fungi

• protozoa

mode of transmission

how the pathogen transported outside the body & into the next

mode of transmission - exogenously

from outside the body

• encounter with a microbe in the environment

• can be direct & indirect

mode of transmission - endogenously

from inside the body

• encounter with organisms already inside or on the body; when normal flora of the body is transported to a different area

direct host-to-host

infected individual transmits an infection by any number of methods

• hand holding, coughing, sexual contact

secretions and excretions with infective microbes can remove them from the body & transmit to susceptible person

• phlegm

• aerosols from sneezing/coughing

indirect host-to-host

“direct” with assistance via a vector or fomite

indirect host-to-host - vector

usually an arthropod, takes blood from one host and carries it to the other

• ticks

• some insects

indirect host-to-host - fomite

inanimate object that has been in contact with an infectious organism

• food, water, radiographic equipment

endogenous (inside)

• organisms already in the body or normal flora

• normal flora transported to a different area

• staphylococci on surface of skin can go deeper with a laceration

reservoir

site where an infectious organism can remain alive and from which transmission can occur

types of reservoirs

• people - infected person who does not display the disease symptoms

• animals - cow - ingestion of milk

• insects - if it ingests blood containing pathogens

• inanimate objects - dusty corner, contaminated linen, & food

types of infections

• healthcare associated infections

• communicable

• human immunodeficiency virus (HIV)

• mutidrug-resistant organisms (MDRO) (examples: MRSA, VRE, C, diff)

• tuberculosis

healthcare associated infections (HAI)

infections people acquire while they are receiving treatment in health care setting for another condition

majority of healthcare associated infections

• urinary tract infections (most common)

• surgical site infections

• bloodstream infections

• pneumonia

HAI - nosocomial infection

infections acquired while receiving treatment at the hospital

hospital patients have a greater sensitivity to infection - compromised or immunosuppressed

most common nosocomial infections

• UTI

• surgical site infections

• bloodstream infections

• pneumonia

what % of hospital patients acquire an additional condition while in the hospital?

5%

HAI - iatrogenic infection

infection that is the result of intervention with a physician, given the right condition, it will try to take over

• patient had lung biopsy & developed pneumonia

• improper handwashing by physician between patients

sources of healthcare associated infections (HAI)

• medical personnel

• patient flora

• contaminated healthcare environment

• blood-borne pathogens

• invasive procedures

communicable diseases

disease spread from one person to another through a variety of ways (direct or indirect)

• contact with blood & bodily fluid

• inhaling an airborne virus

• insect bite

examples of communicable diseases

• HIV

• HBV

• influenza

• chicken pox

• malaria

• tuberculosis

• polio

human immunodeficiency virus (HIV) (blood-borne pathogen)

virus that attacks body’s immune system - without treatment can lead to AIDS

no effective cure, but proper treatment can control

how is HIV transmitted

• infected bodily fluids like blood

• sharing needles

• semen

• vaginal fluids

• breast milk

hepatitis B / HBV (blood-borne pathogens)

causes illness that primarily affects the liver, results in swelling, soreness, and loss of normal function in the liver

how is hep B / HBV transmitted

• contaminated needle - biggest for hospital workers

• penetrating injury

• intimate contact

what is the best way to prevent hep B?

the hep B vaccination

• three injections, no risk after receiving vaccine & positive antibody titer, safe & effective

MDRO (multi-drug resistant organism)

bacteria & other microorganisms that have developed resistance to antibiotics

common examples of MDRO (multi-drug resistant organism)

• MRSA - methicillin/oxacillin-resistant Staphylococcus aureus

• VRE - vancomycin-resistant enterococci

• C. Diff - clostridium difficile

• ESBLs - extended-spectrum beta-lactamases (resistant to cephalosporins & monobactams)

• PRSP - penicillin-resistant Streptococcus pneumoniae

• multi-drug resistant tuberculosis (MDR)

MRSA (methicillin-resistant staphylococcus aureus)

staph aureus is easily colonized on skin, assume all patients may be carriers

direct contact or contact with infected objects or surfaces

most susceptible patients of MRSA

• nursing home

• dialysis

• the aged & debilitated

• intensive care

• hospitalized for long periods

effects of MRSA

• decubitus ulcers

• pneumonia

• endocarditis

• bacteremia

• osteomyelitis

• septic thrombophlebitis

VRE (vancomycin-resistant enterococcus)

infections caused by enterococci, typically in hospital patients

• urinary tract, surgical wounds, blood streams

spread direct contact with contaminated hands, surfaces, or equipment

VRE - enterococci

found in normal flora in the GI tract, treated by vancomycin, but sometimes resistant

C. Difficile (clostridium difficile)

spore forming bacterium that releases toxins into the bowel, resistant to disinfectants, easily spread from the hands of healthcare providers, frequent cause of nosocomial infections

tuberculosis (TB)

recurrent, chronic disease affecting the lungs caused by the spore-forming Mycobacterium tuberculosis

treatable disease with antibiotics, primary, latent, and active disease

how do you prevent disease transmission?

take transmission-based precautions

• wash hands

• get immunizations

• get boosters

• follow post-exposure protocols

5 steps of infection prevention

1. stop at the source

2. block the portal of exit

3. interrupt mode of transportation

4. protect portal of entry

5. increase host’s defense

centers for disease control and prevention

mission is centered on preventing and controlling disease and promoting environmental health and heath education in the US

standard precautions

used when performing procedures that may require contact with blood, body fluids, secretions, excretions, mucous membranes, and non-intact skin

standard precautions primary purpose

protect the following against acquiring pathogens that are known or unknown

• healthcare workers

• patients

• anyone in direct contact

• anyone in indirect contact

handwashing

most effective method used to prevent the spread of infection

• before & after performing invasive procedures and after touching bodily fluids, blood, secretions, excretions and contaminated items - even if gloves are worn

gloves

• any time a procedure or contact may include body fluids, blood, secretions, excretions, mucous membranes, non intact skin and contaminated items

• cleaning

• bed pan or urinal assistance

• remove gloves inside out

donning PPE

1. gown

2. mask/respirator

3. goggles/face shield (if applicable)

4. gloves - extend over isolation gown cuffs

doffing PPE

1. gloves inside out

2. goggles/face shield if worn

3. gown

4. mask/respirator

needle recapping

• should be avoided

• 800,000 needle stick injuries & other injuries from sharp objects occur to health care workers annually in the US

• one-handed scoop technique

• must be placed in sharps container

biohazard spills

• gloves & PPE must be worn

• fluoro - must wear PPE when placing certain used instruments into biohazard container & using disinfectant spray

• waste will need to be in red biohazard bag or designated waste container red

red bag

blood & bodily fluids

contaminated items that are saturated or dripping and those caked with dried blood or dried body fluids

cleaning & proper disposal of contaminated waste

• clean with appropriate disinfectant stated by facility

• soak time may be required

• which trash to use is dependent on the saturation & waste

transmission-based precautions (isolation precautions)

RH: environmental and enhanced

• applied when a patient is infected with a pathogenic organism or a communicable disease

• when patient is at risk of becoming infected, such as immunosuppressed

3 types of transmission based precautions (isolation precuations)

1. contact

2. droplet

3. airborne

airborne

pathogenic organisms that remain suspended in the air for long periods on aerosol droplets or dust

airborne treatments

• patients are placed in a negative-pressure isolation room

• health care worker is required to wear N95 respirator

• hand hygiene - alcohol rub or soap & water

examples of airborne

• TB

• chickenpox (varicella)

• measels (rubeola)

droplet

• infected with pathogenic organisms

• pathogens disseminate through large particulate droplets expelled from the patient during coughing, sneezing, or talking

• infects another person through contact with the mouth, nasal mucosa, or conjunctiva

droplet treatments

• healthcare workers should protect themselves by wearing a surgical mask when within 3 feet of the patient

• hand hygiene - alcohol rub or soap & water