Infection: The colonizationand multiplication of a microbe in
or on the tissues of a host. Infecting Microbes seek
to use the host's resources to reproduce, often
resulting in disease.
Disease: Any deviation from a condition of good
health & well-being
Infectious Disease:
A disease condition caused by the presence or growth of infectious
microorganisms or parasites
DEFINITIONS
3.
• Caused bymicroorganisms
like viruses, bacteria,
parasites and fungi.
• Invasion by and
multiplication of pathogenic
in a bodily part or tissue,
which may produce
subsequent tissue injury
and progress to manifested
disease through cellular or
toxic mechanisms.
INFECTION
4.
Links in theChain
Transmitted through a chain (six links)
1. Pathogen - disease causing microorganism
2. Reservoir - natural environment of the pathogen:
Person, animal or environmental
component
3. Portal of Exit
4. Means of transmission
• Direct transmission
• Indirect transmission
5. Portal of entry
• Penetration of the skin
• Inhalation
• Ingestion
6. New host
6 Links - Chain of Infection
1. Locate, removereservoir host
2. Block portal exit of microbes from reservoir
3. Know mode(s) of transmission of specific infections
4. Block portals of entry
5. Cleaning
6. Sterilization
7. Disinfectants
8. Antiseptics
Steps to Minimize Risk of Infection
8.
Standard Precautions (UniversalPrecautions)
1. Hand Hygiene (Handwashing and Alcohol-
Based Hand Rub)
2. Use of Personal Protective Equipment
(PPE):
Gloves
Masks
Gowns
Face shields/goggles
3. Respiratory Hygiene/Cough Etiquette
4. Safe Injection Practices
5. Safe Handling of Potentially Contaminated
Equipment or Surfaces
Standard Precautions
(Universal Precautions)
Donning– the process of putting on PPE.
Step Procedure Rationale
1 Perform hand
hygiene
Reduces microorganisms on
hands before touching clean
PPE.
2
Put on gown
(coverall or
apron)
Fully covers torso, arms, and
part of the legs to protect
skin/clothing.
3
Put on mask or
respirator
Protects mouth and nose
from droplet or airborne
transmission. Ensure proper
fit.
4
Put on goggles or
face shield
Protects eyes from splashes
or droplets.
5
Put on gloves
(last)
Gloves should cover the
cuffs of the gown for full
protection.
13.
Standard Precautions
(Universal Precautions)
Doffing– the process of safely removing PPE to avoid contamination.
Step Procedure Rationale
1 Remove gloves
Grasp the outside of one
glove with the opposite
gloved hand, peel off. Hold in
gloved hand, slide ungloved
finger under the wrist of the
remaining glove, peel off.
2 Remove gown
Untie the gown, pull away
from the body (touch only
inside), fold/roll it inside out,
and discard properly.
3
Remove goggles
or face shield
Remove by headband or ear
pieces without touching the
front.
4
Remove mask or
respirator
Remove from the straps
(bottom first), without
touching the front. Discard in
appropriate bin.
5
Perform hand
hygiene again
Final cleaning step to remove
any contamination during
removal process.
14.
Standard Precautions
(Universal Precautions)
3.Safe Handling of Sharps and Needles
What Are Sharps?
Sharps are medical devices with sharp points or edges that can puncture or cut the
skin.
Examples:
Needles
Syringes
Lancets (used for blood glucose testing)
Scalpels
Broken glass from medicine vials
15.
Standard Precautions
(Universal Precautions)
3.Safe Handling of Sharps and Needles
Safe Practice Description Rationale
Use Puncture-proof Sharps
Containers
Do Not Recap Used Needles
Dispose Immediately After Use
Keep Sharps Containers Close
and Upright
Do Not Overfill the Container
Use One-hand Scoop
Technique (only if recapping is
absolutely necessary)
Do Not Reach into Sharps
Container
✅
✅
✅
✅
✅
Use rigid, leak-proof, clearly labeled
containers with secure lids.
Prevents accidental puncture or
spills; allows safe disposal.
Never attempt to recap, bend, or break
needles after use.
Major cause of accidental needle-
stick injuries.
Place sharps directly into container at
point-of-care.
Avoids leaving used needles on
beds, trays, or carts.
Must be within arm’s reach during
procedures.
Reduces the need to walk around
with exposed sharps.
Replace when ¾ full (or as indicated).
Prevents overflow and accidental
injury.
Safer method to avoid using two
hands.
Reduces risk of contact with needle.
Never try to retrieve items from it. Risk of injury and infection.
Standard Precautions
(Universal Precautions)
5.Environmental Cleaning and Disinfection
Cleaning: The physical removal of dirt, dust, and organic matter using water, soap/detergent,
and scrubbing.
Disinfection: The process of eliminating most pathogenic microorganisms (except bacterial
spores) on inanimate objects using chemical agents.
Sterilization: Complete destruction of all microorganisms including spores.
Importance in Caregiving
1. Prevents spread of infections
(especially in high-risk patients like
the elderly or infants).
2. Reduces contamination of care areas
and equipment.
3. Maintains a safe and healthy
environment for both caregiver and
client.
18.
Transmission-Based Precautions
Additionalprecautions used for specific types of infections.
1. Contact Precautions
Used for infections spread by direct or indirect contact with the patient or their
environment.
MRSA, diarrhea, wounds
2. Droplet Precautions
Used for diseases spread through large respiratory droplets that travel up to 1
meter (3 feet).
Influenza, COVID-19
3. Airborne Precautions
Used for infections spread via tiny airborne particles that remain suspended in the
air.
Tuberculosis, measles
Caregiver Responsibilities
1. Recognize which precautions apply to each patient.
2. Don and doff PPE appropriately before and after care.
3. Educate patient and family on the importance of isolation.
4. Ensure signage is posted, PPE is available, and waste is disposed of properly.
19.
Transmission-Based Precautions
1. ContactPrecautions
Precaution Measures:
1. Wear gloves and gown upon entering
the patient’s room.
2. Use dedicated or disposable
equipment (e.g., thermometer, BP
cuff).
3. Limit transport of patient unless
necessary; cover infected areas if
moved.
4. Disinfect surfaces and equipment
after every use.
20.
Transmission-Based Precautions
2. DropletPrecautions
Precaution Measures:
1. Wear a surgical mask within 1
meter of the patient.
2. Provide a mask to the patient when
outside the room.
3. Encourage respiratory
hygiene/cough etiquette.
4. Place patient in a single room if
possible; otherwise, cohort with
same illness.
21.
Transmission-Based Precautions
3. AirbornePrecautions
Precaution Measures:
1. Use N95 respirator or higher-
level mask.
2. Place patient in a Negative
Pressure Isolation Room (AIIR)
if available.
3. Keep the room door closed at
all times.
4. Limit patient movement; if
transport is necessary, the
patient must wear a surgical
mask.
22.
• Latency Period
-the INCUBATION PERIOD of an infectious disease, BEFORE
symptoms appear.
- the interval between exposure to an infectious organism (stimulus)
and the clinical appearance of disease (response).
• Incubation Period
- the time between infection and onset of symptoms
Time Parameters Of
Interaction
1. Epidemiology
Epidemiology isthe study and analysis of the
distribution (who, when, and where) and determinants of
health and disease conditions in defined populations.
2. Communicable Disease
A disease that can be transmitted from one individual to
another
3. Contagious Disease
A communicable disease that is easily spread from one
individual to another
4. Non communicable Disease
A disease that is not transmitted from one individual to
another
DEFINITIONS
26.
1. ENDEMIC -Disease constantly present in particular
area or in a certain percentage of a population
2. EPIDEMIC - spreads rapidly, involves many persons in an
area at a time (E.g. - meningococcal meningitis, Influenza)
3. PANDEMIC - spreads many areas in world involves large
number within short period (E.g. - Cholera, Enterovirus)
Definitions: Epidemiological
Terms
27.
ACUTE INFECTION VS.CHRONIC INFECTION
Acute Infection
• An infection characterized by sudden onset, rapid
progression, and often with severe symptoms
• However, there is a balance between production and
degradation of molecules e.g. collagen, extracellular matrix
Classification Of Infection
28.
Chronic Infection
• Aninfection characterized by delayed onset and slow
progression of healing process
• Why? – the healing process doesn’t occur orderly as by stages
and at the possible duration of the healing period (take more
than 3 months - years)
• E.g. Wound remain in the inflammatory state for longer time.
Classification Of Infection