Warm-up Questions
● What is a Pathogen?
● List the 5 Pathogens.
● Mononucleosis, Common Cold, and Ebola are examples of what?
● Athlete’s Foot, Ringworm, and Jock Itch are example of what?
● Ticks are linked to what type of Pathogen?
Communicable Disease Basics
Objectives
● Describe three ways infectious agents can be transmitted
● Describe at least three ways to decrease risk of infections in public settings
● List three examples of common infectious diseases and how to reduce risk of infection
Chain of Infection
Chain of Infection
● Model used to understand the infection process
● Each link represents step in transmission of infection
● Each link has to be present and in order for an infection to occur
1 - The Infectious Agent-any disease causing microorganism (pathogen)
Infectious agents are:
● Bacterial ● Viral● Fungal ● Parasitic
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● West Nile Virus - when the
mosquito bites and feeds on the bird’s blood
● Hepatitis A - stool● SARS - droplet, contact
4 - The Route of Transmission (Spread)
-the way the pathogen gets from the reservoir to the new host
Transmission:Respiratory Droplets
● From respiratory tract (i.e., nose, mouth) secretions of infected person– E.g. cough, sneeze
● Do not circulate in air for long time or travel far (mostly < 3 feet)
● Many diseases spread by respiratory droplets; e.g. flu, cold, pertussis, SARS
● Can spread germs directly or indirectly
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
Droplets with the infectious agent land on a table, doorknob etc.
Indirect Spread by Droplets
Someone touches contaminated object
Indirect Spread by Droplets
Touch nose, mouth, eyes with contaminated hand
Airborne Transmission
● Germs stay suspended in air on small particles
● Uncommon method of transmission● Only occurs for certain germs, such as
tuberculosis– Less commonly for flu, SARS
Airborne - This Needs to be Breathed in to be Infectious
Other Methods of Transmission
● Food/water/hands contaminated with stool from infected person; e.g., norovirus
● Blood exposures, sexual contact– a.k.a. blood-borne; e.g. HIV, hepatitis B and C
● Vector-borne – E.g. Mosquitoes and West Nile virus, malaria
● Unlikely methods of spread in courtroom
5 - The Portal of Entry
-route through which the pathogen enters its new host
Respiratory System
● Inhale germs
Other Portals of Entry
Sexual contact
Breaks in Protective Skin Barrier
Ingestion
6 - The Susceptible Host
-A person who can get sick when they are exposed to a disease causing pathogen. . I love wesley he penis is huge
How to Break the Chain of Infection
What Is the Purpose of Respiratory Hygiene?
● To reduce the transmission of airborne diseases
Hand Hygiene
● Wash hands frequently with soap and warm water for at least 20 seconds
● Alcohol hand gels
Use gloves where contact with body secretions and excretions is taking place
Cover Your Cough!
Cough Etiquette
● Limit close contact (<3 feet) with coughing clients
● Cover cough/sneeze with tissue
● Offer mask to coughing clients
Keep a clean environment
● Clean contaminated surfaces with commercial germicidal cleanser or wipes
Maintain vaccinations for employees
● Flu shot- every year for age >50 and high-risk groups
● Tetanus shot every 10 years● Hepatitis B for persons who
may contact objects contaminated with blood
● Pneumovax (“pneumonia” vaccine) for age ≥65
● Hepatitis A
What Are Some of the Airborne Diseases of Concern?
● Pertussis● Tuberculosis● Influenza● Common colds
Pertussis (Whooping Cough)● Droplet and contact
transmission● Runny nose and
prolonged severe cough● A bacterial infection ● Most dangerous for
babies● Vaccine preventable for
children aged 7 and under
Tuberculosis
Agent● Caused by bacterium, Mycobacterium
tuberculosis
Reservoir● Humans
TB in King County
Latent TB Infectionvs.
Active TB Disease
Latent TB Infection
● Person infected with TB bacteria● Bacteria kept dormant by person’s
immune system● Not sick or contagious● 10% develop TB disease over life time● Infection detected by TB skin test
TB Skin Test (PPD)
Active TBDisease
● Usually involves lung infection● Cough >3 weeks, fevers, weight loss,
night sweats● Can cause serious illness but is
treatable with antibiotics● Contagious until appropriately treated
Preventing Spread of TB
● Patients with TB disease should delay court appearance until appropriate duration of therapy
● Patients with active TB are no longer contagious after 2-3 weeks of appropriate therapy– should be cleared by doctor
Influenza(Flu)
Agent● Virus
Reservoir● Humans● Animals (e.g. birds, pigs)
– Generally different strains
Flu Transmission:Respiratory Droplets
● Direct: Close contact (<3 feet)– Droplets from cough/sneeze enter mouth,
nose, eyes of susceptible person● Indirect: Contaminated surfaces● Cases peak each winter in U.S.
How Do I Protect Myself From the Flu?
● Flu VaccineRecommended for:➢Persons >50 years old➢Anyone with a chronic illness, such as asthma or
diabetes➢Children age 6-23 months➢Women who will be pregnant during flu season
Habits for Good Health
● Avoid close contact with people who are sick
● Stay home when sick● Cover mouth/nose with tissue when
coughing/sneezing● Avoid touching nose, mouth, eyes● Wash hands often with soap/water or
alcohol rub
What Can You Do to Reduce Your Chances of Getting Sick?
● Encourage coughing clients to wash their hands (or use alcohol hand rub)
● Wash your own hands frequently● Wipe down counters, pens, phones,
computer keyboards, etc. with disinfectant cleaner as needed
● Cough etiquette- cover with tissue● Offer mask to coughing clients
Recommendations
● Staff and clients should have access to:– Hand washing facilities– Tissues – Trash cans for disposing of tissues
● Consider having alcohol
hand rub available
QUESTIONS???