Transmission Cycle of Infection

Infection Control Unit

Prepared by: Michael Cruz, RN, MAN

Objectives:

The participants will successfully:

Understand the chain of infection as it applies to infection prevention and control.

Identify evidence-based measures to prevent and control the transmission of infection to self and others.

What do you know about…

Infection control?Why it is important in health care

facilities?

TerminologiesM

icro

org

anis m• Living

organism too small to be seen with naked eye but visible under a microscope.

Path

og

en • A biological

agent that causes disease/infection or illness to its host.

Infe

ctio

n • The invasion and multiplication of microorganisms that are not normally present within the body.

Infectious Agent

Reservoir

Portal of Exit

Mode of Transmissi

on

Portal of Entry

Susceptible Host

CHAIN OF INFECTION

Infectious Agent

Reservoir

Portal of Exit

Mode of Transmissi

on

Portal of Entry

Susceptible Host

CHAIN OF INFECTION

Infectious Agentany disease causing microorganism (pathogen)

Bacteria

Fungi Protozoa

VirusesParasites

Reservoir“habitat” in which the infectious agent lives and multiplies

Human Animal/Insects

EnvironmentalSources

Portal of Exitrefers to the route by which the infectious microorganisms escape the reservoir.

Respiratory Tract

Gastrointestinal Tract

Mucous Membrane

Skin

Mode of Transmissionis the method by which the causative agent moves from one host to another “travels”

AirBorne Droplet Contact Parenteral Vectors

Airborne Transmission

Small-particle residue {<5micron} of evaporated droplets containing microorganisms

Suspended in the air for long periods of time

Dispersed by air currents longer than 3feet

Inhaled by a susceptible host within the same room or over a longer distance

TB

Pulmonary Tuberculosis

Measles

Rubeola

Varicella

Chickenpox

Droplet Transmission

Occurs when respiratory droplets generated via coughing, sneezing or talking contact susceptible mucosal surfaces, such as the eyes, nose or mouth

Large particle droplets (> 5 microns)

Not able to remain suspended in the air thus they are usually dispersed over short distances (< 3 feet /1 meter)

Pertussis Pneumonia Rubella

Influenza Diphtheria

Contact Transmission

Most common route of transmission

Direct contact transmission requires physical contact between an infected person and a susceptible person, and the physical transfer of microorganisms.

Indirect contact transmission involves contact of a susceptible host with a contaminated intermediate object

Diarrhea Skin Infection

Wound Infection MRSA

Parenteral Transmission

Means through the skin, as with cuts or punctures. Parenteral transmission of blood-borne pathogens can occur through

o needle stick injuries,

o human bites,

o cuts,

o abrasions, or

o any break in the skin.

HIV

Hepatitis B&C

Vector borne Transmission

Transmission of a disease by vector occurs when a host is bitten by animals, insects and rodents carrying the infectious agent.

DengueSchistosomiasis

Rabies Leptospirosis

Portal of Entryroute through which the pathogen enters its new host

Non intact skin or Parenteral

Respiratory Tract

Gastro-intestinal Tract

Genitourinary Tact

Mucous Membranes

Susceptible HostA person who gets an infection because he/she is unable to successfully fight the infection

Low Immunit

y

Elderly

Infant Steroids

Infectious Agent

Reservoir

Portal of Exit

Mode of Transmissi

on

Portal of Entry

Susceptible Host

CHAIN OF INFECTION

How to break the chain of infection?

“If one of the links in the chain of infection is broken, then the spread of infection is stopped”

Breaking the chain of infection

• Hand washing • Use of Personal

Protective Equipment

• Respiratory Etiquette

Portal of Exit

• Employee health examinations and screening

• Environmental sanitization

• Disinfection/Sterilization of medical equipment and instruments

• Medical Asepsis • Proper Hygiene

Reservoirs

• Accurate and rapid identification of micro-organisms

• Early recognition of sign and symptoms of infection

Causative Agent

Breaking the chain of infection

• Treatment of Disease

• Recognition of clients at risk

• Immunization • Healthy Lifestyle

(Exercise, Smoking Cessation, Avoid Alcohol Intake, Enough Rest and Sleep etc.)

• Proper Nutrition

Susceptible Host

• Sterile technique or Surgical Asepsis

• Medical Asepsis or Clean Technique

• Proper Disposal of needles or sharps

Portal of Entry

• Hand washing • Rooms with air flow

control • Safe Food handling • Isolation/cohorting• Sterilization of

equipment and supplies

• Medical and Surgical Asepsis

• Use of Personal Protective Equipment

• Proper disposal of contaminated objects

MOT