Infection control Flashcards
is a set of 6 intertwined links that allow for communicable diseases to spread.
Each step of the chain is required to effectively transmit infectious illness.
Breaking any one of the 6 links can slow the spread of infectious disease.
Chain of infection
For the infection to escalate to an epidemic means that _______
all components or links are favorable to the pathogenic microbe.
Six Links of the Chain of Infection
Infectious Causative Agent
Reservoir
Exit Pathway/Portal of exit
Mode of transmission
Entry pathway
Susceptible Host
aka _________ are microorganisms that cause disease. Without pathogens, we would not have transmissible, infectious disease.
Ex:
Bacteria, Viruses, Fungi, Parasite
Infectious Causative Agent
Pathogens
serves as a place in the environment where a pathogen lives, replicates and thrives.
Reservoir
Ex:
Human, Animals, Insects, Environment
form of reservoir wherein humans carry the infection
Human Reservoir
are more likely to be recognized. This means that the patient’s contacts and normal activities will normally be restricted
symptomatic infection
Carriers do not display any signs or symptoms of illness. They are asymptomatic but can still spread disease (ex: Typhoid Mary, COVID 19 )
Asymptomatic carriers
Any infectious disease that is naturally transmitted from animal or insect to human is considered a ___________
zoonotic disease
Ex:
Lyme disease (ticks)
Rabies (animals)
Salmonella (raw meats, eggs, and dairy)
Dengue
form of reservoir wherein animals/insects carry the infection
Animal and Insect Reservoir
form of reservoir wherein Environment harbor many infectious diseases
Environmental reservoir
Examples of Environmental reservoir
Ex:
Soil (which acts as a reservoir for Clostridium tetani, the causative agent of tetanus); and
Water (which is a reservoir for Legionella pneumophila, the causative agent of Legionnaire’s disease.)
A way or manner where an infectious agent can leave the reservoir host
This depends entirely on the characteristics of the reservoir.
Exit Pathway/portal of Exit
In humans, the main portals of exit include:
Alimentary: vomiting, diarrhea, saliva
Genitourinary: sexual contact
Respiratory: secretions from coughing, sneezing, or talking
Skin: open wounds
Examples of mode of transmission
Airborne, direct or indirect contact , droplets, vector (insect) and vehicle (food, water or drugs)
way in which pathogen is passed on
Mode of transmission
Is usually considered person-to-person contact.
direct Contact
Examples of direct contact include:
Skin-to-Skin contact (like touching)
Kissing
Sexual contact
Contact with oral secretions
Contact with body lesions
Pathogens that are spread by direct contact include:
Gonorrhea
Mononucleosis
Bacterial Conjunctivitis
COVID-19
Requires a pathogen to be transferred through the air from its reservoir in a droplet of body secretions. These are relatively large and usually will fall from suspension after 3-6 feet of travel. They will rapidly fall on nearby surfaces (tables, door knobs, telephones, elevator buttons, etc.), and may remain viable. The survivability of the pathogen depends on its type.
Droplets
occurs when a droplet from coughing, sneezing or talking carry the pathogen to the hosts body. The transmission is completed by:
Inhaling droplets
Droplets entering the mucous membranes of the face
A host touching droplets that have settled on surfaces and then touching their face (mouth, eyes, nose).
Droplet transmission
3 ways where transmission completed
Inhaling droplets
Droplets entering the mucous membranes of the face
A host touching droplets that have settled on surfaces and then touching their face (mouth, eyes, nose).
Examples of illnesses caused by droplet transmission are:
Strep Throat
Influenza
The common cold
COVID-19
Some pathogens are transmitted directly through blood. These pathogens require that infected blood from the reservoir be directly exposed to the blood of the susceptible host.
This can be accomplished by blood from a needlestick and blood entering mucous membranes or other open wounds.
Blood Borne
Examples of blood-borne pathogens include:
Human Immunodeficiency Virus (HIV)
Hepatitis-B Virus
Hepatitis-C Virus
occurs when pathogens smaller than five microns in size remain suspended in the air long after the infected person has left the area. A host then enters the space where the pathogen is suspended and has the potential to become infected.
Airborne
utilizes insects to transport the pathogen. Insects such as fleas, ticks, and mosquitos are unharmed by the pathogens they potentially carry but can transmit the bacteria or virus when they bite a host.
Vector
Examples of Vectors
Mosquito: West Nile Virus
Fleas: Bubonic Plague (Yersinia pestis)
Ticks: Lyme Disease (Borrelia burgdorferi)
Refers to the way an infectious agent enters a host that is susceptible to infection which includes body orifices.
Entry pathway/Portal of Entry
Examples of Entry Pathway/Portal of entry:
Examples include:
Inhalation
Absorption
Ingestion
Inoculation
Introduction
Someone who is prone to infection due to age, health or immune status. They usually include the elderly, newborn, patients who are immune suppressed.
susceptible Host
Factors of susceptability:
Age
The very young or very old are usually more susceptible.
Health status
Malnourished, dehydrated, or otherwise unhealthy persons are more at risk
Medication usage
Immune suppressing drugs allow pathogens to take hold more freely
inside Laboratory Precautions
Do not eat, drink, smoke or apply cosmetics.
Do not insert or remove contact lenses
Do not bite nails or chew pens
Do not mouth pipet
Assume all patients are infectious
Avoid production of aerosols in centrifuge
exposure control plan for needlestick/other shrap injury:
Carefully remove the shards or foreign object.
Wash the site thoroughly with soap and water for at least 30 seconds.
exposure control plan for Mucous Membrane exposure:
Flush with water or saline for at least 10 minutes.
For the eyes, use eyewash station for flushing.
Remember to remove the contact lenses (if there are any) and make sure to disinfect them.
Report the incident to the immediate supervisor and the provider so that evaluation, treatment and counseling can be provided.
surface decontamination:
use of 1:10 bleach solution or other disinfectants for the specimen collection and processing areas.
Remember to wear gloves and use an absorbent material when cleaning the area to avoid spreading the spills over a wider area.
As a precaution, all non-reusable items contaminated by blood or other body fluids should be placed in biohazard waste containers for proper disposal.
Portal of entry via respiratory tract
inhalation
Portal of entry via mucous membranes (like eyes)
absorption
Portal of entry via the gastrointestinal tract
ingestion
Portal of entry as a result of inoculation injury (vaccine; immunization via introduction of infective material)
inocculation
Portal of entry via insertion of medical devices
introduction
how to break the chain of infection
cleaning disinfection, sterilization
pest control
hand hygiene
PPE
respiratory etiquette
waste disposal
food safety
first aid
immunization
patient education
diagnosis and treatment
