Concept of Asepsis

Microbiology
Unit-IV

Muhammad Iqbal
Lecturer
KMU
 Objectives
At the end, the students will be able to:
•Define key terms.
•Identify the six components of chain of infection.
•Explain examples of ways that infection may occur
•Describe factors that increase the risk of infection in
various settings.
•Discuss the role of health care personnel in infection
control.
Chain of Infection
 Chain of Infection

• Model used to understand the infection

process
• Each link represents step in transmission of
infection
• Each link represents step in transmission of
infection
1 - The Infectious Agent
-Any disease-causing microorganism (Bacteria,
Virus, Fungus, etc.)
2 - The Reservoir
-Where a microorganism normally lives and
reproduces

Examples of reservoirs:
Humans, Animals, Water, Food
3 - The Portal of Exit
Route of escape of the pathogen from the reservoir
Examples of portals of exit:
Flu or cold --- mucous secretions
Hepatitis A --- Oro-fecal

4 - The Route of Transmission (Spread)

The way the pathogen gets from the reservoir to the new
host
Examples of rout of transmission
From respiratory tract (nose, mouth) secretions of infected
person. E.g. cough, sneeze
 Droplet Transmission

Agent is coughed or sneezed out into the air

and floats on droplets
 Direct Spread by Droplets

• Close contact with infected person (<3 ft)

• Infected person coughs, sneezes, talks, sings
• Droplets land directly on mucous membranes
(eyes, nose, mouth) of susceptible person
Indirect Spread by Droplets

Someone touches
contaminated object
5 - The Portal of Entry
The Route through which the pathogen enters its new host

Examples:
Sexual
Inhale germs contact

Ingestion
Breaks in Protective Skin Barrier
6 - The Susceptible Host
A person who can get sick when exposed to a
disease causing pathogen
 Example of How Infection Occurs
• Example of common cold
• Any infection follows the same steps as that of chain
of infection starting from infectious agent to
susceptible host.
• A flu virus is deposited into the front of the nasal
passages by contaminated fingers or by droplets
from coughs and sneezes.
• Small doses of virus (1-30 particles) are sufficient to
produce infection.
• The virus is then transported to the back of the nose
and onto the adenoid area.
Role of Health Care Personnel in Infection
Control
 Learning Objectives
At the end of this, the learners will be able to:
•Recognize patient safety as an important nursing
responsibility in health care systems.
•Apply required knowledge in preventing and/or
minimizing infection.
•Perform appropriate behaviors required to prevent
health care associated infections.
•Demonstrate required competence to provide
patients with safe care.
 Introduction to Patient Safety

• Definition: Patient safety is a discipline in the

health care sector that applies safety science
methods toward the goal of achieving a
trustworthy system of health care delivery.
• Patient safety is also an attribute of health care
systems; it minimizes the incidence and impact of
adverse events and maximizes recovery from
health problems.
 Introduction to Patient Safety Cont…

• Adverse medical events are widespread and

preventable.
• Much unnecessary harm is caused by health-
care errors and system failures.
– Ex. 1: Hospital acquired infections from poor hand-
washing.
– Ex. 2: Complications from administering wrong
medication.
 Goal of Patient Safety

• Prevent and/or minimize the adverse events

and eliminate preventable harm in health
care.
• All health care professionals including nurses
are responsible for ensuring patient safety
 Global Infection Problems
According to WHO (2005),
• On average, 8.7% of hospital patients suffer health
care-associated infections (HAI).
• In developed countries: 5-10%
• In developing countries:
– Risk of HAI: 2-20 times higher
– HAI may affect more than 25% of patients
• At any one time, over 1.4 million people worldwide
suffer from infections acquired while in hospital.
 Health Care-Associated Infections (HAI)

According to WHO:
• HAI is also called “nosocomial”.
• HAI is defined as:
– an infection acquired in hospital by a patient who was
admitted for a reason other than that infection.
– an infection occurring in a patient in a hospital or
other health-care facility in whom the infection was
not present or incubating at the time of admission.
– How would you come to know this ????
 Impacts of Nosocomial Infections (HAI)

HAI can:
• Increase patients’ suffering.
• Lead to permanent disability.
• Lead to death.
• Prolong hospital stay.
• Increase need for a higher level of care.
• Increase the costs to patients and hospitals.
 Preventing infections

Requires health care providers who have:

– Knowledge of common infections and their
vectors
– An attitude of cooperation and commitment
– Skills necessary to provide safe care
– Use universal precautions
 Required Knowledge
• Knowledge of the extent of the problem;
• Knowledge of the main causes, modes of
transmission, and types of infections.
 Required Attitudes

Being an effective team player.

Commitment to preventing HAIs

 Required Skills
• Apply universal precautions*
• Use personal protection methods
• Know what to do if exposed
• Encourage others to use universal precautions
• Report breaks in technique that increase
patient risks
• Observe patients for signs and symptoms of
infection
 Universal precautions
• "Universal precautions," as defined by CDC,
are a set of precautions designed to prevent
transmission of pathogens when providing first
aid or health care.
• Under universal precautions, blood and certain
body fluids of all patients are considered
potentially infectious.
• Retrieved from CDC web site
http://www.cdc.gov/ncidod/dhqp/bp_universal_precautions.html
 One more important thing!

Protect Yourself
Be sure you have been immunized against
certain infectious diseases.
 Main Sources of Infection
• Person to person via hands of health-care
providers, patients, and visitors
• Personal clothing and equipment (e.g.
Stethoscopes, flashlights etc.)
• Environmental contamination
• Airborne transmission
• Hospital staff who are carriers
 Main Routes for infections
• The following four types of infections account for
more than 80% of all health care-associated
infections:
• Urinary tract infections (UTI)
– Catheter-associated UTIs are the most frequent,
accounting for about 35% of all HAI.
• Surgical infections: about 20% of all HAI
• Bloodstream infections associated with the use
of an intravascular device: about 15% of all HAI
• Pneumonia associated with ventilators: about
15% of HAI
 Four Ways to Prevent HAI
1. Maintain cleanliness of the hospital.
2. Personal attention to hand washing before and
after every contact with a patient or object.
3. Use personal protective equipment whenever
indicated.
4. Use and dispose of sharps safely.
 Prevention through Hand-washing
• Hand washing: the single most important
intervention before and after patient contact.
• Required knowledge and skills:
– How to clean hands
– Rationale for choice of clean hand practice
– Techniques for hand hygiene
– Protect hands from contaminants
– Promote adherence to hand hygiene guidelines

Remember medical and surgical hand wash

 Five moments for hand hygiene
• Before patient contact
• Before an aseptic task
• After body fluid exposure even if wearing
gloves!
• After patient contact
• After contact with patient surroundings
Your 5 moments for HAND HYGIENE
 Resources for Correct Hand washing
Procedures

• Your Five Moments for Hand Hygiene

• http://www.who.int/gpsc/tools/5momentsHandHygiene_A3.pdf
• How to handrub? How to handwash?
• http://www.who.int/gpsc/tools/GPSC-HandRub-Wash.pdf
Personal Protective Equipment (PPE)

• Gloves, gown, goggles, apron, and face mask

• Health care workers should wear a face mask,
eye protection and a gown if there is the
potential for blood or other bodily fluids to
splash.
 PPE-----Gloves
Gloves must be worn for:
• all invasive procedures
• contact with sterile sites
• contact with non-intact skin or mucous membranes
• all activities assessed as having a risk of exposure to
blood, bodily fluids, secretions and excretions, and
handling sharps or contaminated instruments.
Hands should be washed before and after gloving
 PPE----Face Mask
• Mask should be worn
– if an airborne infection is suspected or confirmed
– to protect an immune compromised patient.
 Safe Use and Disposal of Sharps
• Keep handling to a minimum
• Do not recap needles; bend or break after use
• Discard each needle into a sharps container at
the point of use
• Do not overload a bin if it is full
• Do not leave a sharp bin in the reach of children
 Required Performance
Nursing students need to:
• apply universal precautions
• be immunized against Hepatitis B
• use personal protection methods
• know what to do if exposed
• encourage others to use universal precautions
Act to Minimize Spread of Infection

Before contact with each and every patient:

– clean hands before touching a patient
– clean hands before an aseptic task
Act to Minimize Spread of Infection

After contact with each and every patient:

– clean hands after any risk of exposure to
body fluids
– clean hands after actual patient contact
– clean hands after contact with patient
surroundings
Encourage Others to Participate in
Infection Control

Students may routinely observe staff who:

– apply inadequate technique in hand-washing
– fail to wash hands
– routinely violate correct infection control
procedures
 Summary
• Know the main guidelines in each of the clinical
environments you are assigned.
• Accept responsibility for minimizing opportunities
for infection transmission.
• Let staff know if supplies are inadequate or
depleted.
• Educate patients and families/visitors about clean
hands and infection transmission.
• Ensure patients’ safety
 References
• World Health Organization. (2010). WHO Patient Safety Curriculum
Guide for Medical Schools.
• World Health Organization. (2010). Topic 1: What is patient safety?
• World Health Organization. (2010). Topic 9: Minimizing infection
through improved infection control.
• Emanuel, L., Berwick, D., Conway, J., Combes, J., Hatlie, M.,
Leape, L., Reason, J., Schyve, P., Vincent, C., & Walton, M.
(2008). What exactly is patient safety? Advances in Patient Safety,
Vol. 1: Assessment. Retrieved from
http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?
book=aps2v1&part=advances-emanuel-berwick_110
• Burke, J. P. (2003). Infection control — A problem for patient
safety. The New England Journal of Medicine, 348, p. 651-656.
 Further study guide lines
• http://www.who.int/patientsafety/
education/curriculum/en/index.html