1. Communicable Disease Basics

2. 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

3. Chain of Infection

4. 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

5. 1 - The Infectious Agent
-any disease causing microorganism (pathogen)

6. Infectious agents are:
Bacterial
Viral
Fungal
Parasitic

7. 2 - The Reservoir
-Where a microorganism normally lives and reproduces

8. Examples of reservoirs:
Humans
Animals
Water
Food

9. 3 - The Portal of Exit
-route of escape of the pathogen from the reservoir.

10. 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

11. 4 - The Route of Transmission (Spread)
-the way the pathogen gets from the reservoir to the new host

12. 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

13. Agent is coughed or sneezed out into the air
Droplet Transmission
Agent is coughed or sneezed out into the air
and floats on droplets

14. 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

15. Indirect Spread by Droplets
Droplets with the infectious
agent land on a table,
doorknob etc.

16. Indirect Spread by Droplets
Someone touches contaminated object

17. Indirect Spread by Droplets
Touch nose, mouth, eyes with
contaminated hand

18. 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

19. Airborne - This Needs to be Breathed in to be Infectious

20. 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

21. 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

22. What Do You Need to Do?
Make sure that you have available for staff and patient use an adequate supply of:
surgical masks
tissues
alcohol hand rub
trash cans with foot pedals to lift lid for disposing of tissues/masks

23. 5 - The Portal of Entry
-route through which the pathogen enters its new host

24. Respiratory System
Inhale germs

25. Breaks in Protective Skin Barrier
Other Portals of Entry
Sexual contact
Ingestion
Breaks in Protective Skin Barrier

26. 6 - The Susceptible Host
-A person who can get sick when they are exposed to a disease causing pathogen

27. How to Break the Chain of Infection

28. What Is the Purpose of Respiratory Hygiene?
To reduce the transmission of airborne diseases

29. Hand Hygiene
Wash hands frequently with soap and warm water for at least 20 seconds
Alcohol hand gels

30. Use gloves where contact with body secretions and excretions is taking place

31. Cover Your Cough!

32. Cough Etiquette Limit close contact (<3 feet) with coughing clients
Cover cough/sneeze with tissue
Offer mask to coughing clients

33. Keep a clean environment
Clean contaminated surfaces with commercial germicidal cleanser or wipes

34. 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
NOTE: MORE DETAILS ON FLU RECS LATER

35. What Are Some of the Airborne Diseases of Concern?
Pertussis
Tuberculosis
Influenza
Common colds

36. 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

37. Tuberculosis Agent Caused by bacterium, Mycobacterium tuberculosis
Reservoir
Humans

38. TB in King County

39. Latent TB Infection vs. Active TB Disease

40. 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

41. TB Skin Test (PPD)

42. Active TB Disease 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

43. 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

44. Influenza (Flu) Agent Virus Reservoir Humans
Animals (e.g. birds, pigs)
Generally different strains

45. 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.

46. How Do I Protect Myself From the Flu?
Flu Vaccine
Recommended 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

47. 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

48. 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

49. Recommendations Staff and clients should have access to:
Hand washing facilities
Tissues
Trash cans for disposing of tissues
Consider having alcohol
hand rub available

50. QUESTIONS???