Transcript Lecture 2

Infection
Prevention & Control
Note for the Exam
•This lecture was given Dec 2. It differs in some
areas from the version in the notes.
•The source for the exam questions is the posted
notes version, although the same area may have
been covered in this lecture.
•These notes are provided for you to have a
complete set from the course and as a source of
information for the future. They also complement
the previously posted notes on Infection Control
and may be useful to augment your understanding
of important issues in Infection Control.
Learning Objectives
The learner will:
•Define healthcare acquired infection (nosocomial)
•List 5 types of healthcare acquired infections
•Differentiate between infection & colonization
•Identify sources of healthcare acquired infection
•List 7 host risk factors
•Name 4 main routes of transmission
Learning Objectives
The learner will:
•Describe methods to prevent transmission
•Define antibiotic resistant bacteria
•Discuss control measures for communicable
diseases
•Identify the single most effective tool to prevent
healthcare acquired infection.
The Theme
Infection
Entry into & multiplication of an infectious
agent (pathogen) in the tissues of the host
resulting in tissue damage/injurious effects.
Subclinical – unapparent
Clinical – apparent
Colonization
The presence of microorganisms in or
on a host with growth & multiplication
but without tissue invasion or
damage.
Nosocomial Infection
•A result of hospitalization
•Not present or incubating at time of
admission
Nosocomial Infection
•May be exogenous
– acquired from the environment, other
patients or caregivers
•May be endogenous
– from patients’ own organisms
Nosocomial Infections
•UTI – urinary tract infection
•SSI – surgical site infection
•Pneumonia
•Bacteremia
•Infectious diarrhea - CDAD
Exogenous Risk Factors
UTI
•Urinary catheterization
– Indwelling
– In/out catheterization
•Contaminated drainage systems
•Hands of care givers
Exogenous Risk Factors
SSI
•Shave prep
•Length of procedure
•Contaminated surgical instruments
•Nares & oropharynx of OR personnel
•Contaminated solutions, antiseptics,
dressings
•Hands of personnel
Exogenous Risk Factors
Pneumonia
•Intubation
•Respiratory therapy equipment
•Respiratory tract instrumentation
•Hands of caregivers
Exogenous Risk Factors
Bacteremia
•Intravascular access devices
•Contaminated IV solutions
•Contaminated multi-dose vials
•Hands of caregivers
Exogenous Risk Factors
CDAD
•Spore former
•Contaminated environment
•Antibiotic use
•Hands of care givers
Endogenous Risk Factors
•Prolonged hospitalization
•Immunosuppression
•Co-morbidities
– Diabetes
– Malignancy
– Renal insufficiency
– Aspiration
•Poor nutritional status
•Altered GI flora
•Obesity
•Immobility
•Extensive burns or wounds
•Trauma
•Age
Chain of Infection
Chain of Infection - Links
Infectious Agent
– Agent capable of causing disease
– Bacteria, viruses, fungi, & parasites
Reservoir
– Place in which the infectious agent can survive but
may or may not multiply.
– Humans, animals, & the environment.
• Patients
• Healthcare personnel & healthcare equipment &
environment
Chain of Infection - Links
Portal of Exit
– Path by which the infectious agent leaves the reservoir
Mode of Transmission
– Method by which the organism reaches a susceptible
host
Chain of Infection - Links
Portal of Entry
– Means by which the an infectious agent enters the
susceptible host
– Similar to portal of exit
Susceptible Host
Modes of Transmission
1. Contact
– Direct
– Indirect
– Droplet
2. Airborne
3. Vehicle
4. Vectors
Infection Prevention
•Modifiable risk factors (exogenous)
•Routine practices
•Barrier precautions
•Hand hygiene
Routine Practices
(Health Canada,1999)
•Hand washing/ hand antisepsis
•Gloves
•Gowns
•Masks & eye protection/face shields
•Accommodation
•Patient care equipment
•Environmental control
Additional Precautions
Respiratory Isolation
Airborne spread
•Single room
•Special ventilation
•Particulate respirator (N-95)
•Varicella (chicken pox),TB
Droplet spread
•Surgical mask within 3 feet
•Influenza, mumps, pertussis (whooping cough)
Additional Precautions
Contact Spread
•Low infective dose
•May be transmitted from intact skin
•Potential for widespread environmental
contamination
Strict Isolation
Contact Measures
Enteric Measures
Hand Hygiene
The single most important measure to prevent
the transmission of infection.
Improved hand hygiene practices have been
associated with reduced healthcare-associated
infection rates.
•Frequency
•Technique
Hand Hygiene – Resident Flora
•Survive and multiply on skin
•Inhabit deeper layers
– Coagulase negative staphylococci
– Diphtheroids
– Staphylococcus aureus
– Streptococci sp.
– Candida sp.
Hand Hygiene – Transient Flora
•Colonize the superficial layers of the skin
•Unable to multiply on skin
•Usually have a short life span
•May include highly pathogenic organisms
•Frequently associated with infection
•Easily removed
•High incidence in HCW
•Hands without healthy skin are more susceptible
to becoming colonized with transient bacteria.
Hand Hygiene
Before:
– beginning your work day
– every patient contact
– donning sterile gloves
– inserting invasive devices
– handling/preparing medications
– feeding a patient
– leaving the workplace/eating
Hand Hygiene
After:
•Patient contact (even with patient’s intact skin)
•Removing gloves
•Contact with contaminated objects and equipment
•Blowing nose/coughing/trips to the washroom
Hands that are visibly soiled need to be
washed with soap & water.
Antibiotic Resistant Bacteria
•Not new – first documented in the 50’s
•An outcome of evolution
•Bacteria devised mechanisms to survive
•Overuse & misuse of antibiotics contributed to the problem
Results
•Multiply resistant strains
•Lack of effective antibiotics
•Transmissions from patient to patient (via hands of HCW &
equipment)
•Endemic in our institutions
Antibiotic Resistant Bacteria
Control Measures
•Prevent patient to patient transmissions
•Prevent hospital environmental reservoirs
•Judicious antibiotic use
•Research & future drug development