1. The Cycle of Infection

2. Infection and Disease Classifications 4 types- 1.Endogenous- it originates w/in 2.Exogenous- it originates outside the body 3.Nosocomial- the infection is one that is acquired by an individual in a health care facility which are transmitted by health care workers to the patient. 4.Opportunistic- means the infections are those that occur when the body defenses are weak.

3. Also classified as Aerobic or Anaerobic Aerobic- means the organism requires oxygen to live Anaerobic- means it lives and reproduces in the absence of oxygen.

4. The Chain of Infection Infectious Agent

5. The Chain of Infection Reservoir Host Infectious Agent

6. The Chain of Infection Reservoir Host Portal of Exit Infectious Agent

7. The Chain of Infection Reservoir Host Portal of Exit Mode of Transmission Infectious Agent

8. The Chain of Infection Reservoir Host Portal of Exit Mode of Transmission Portal of Entry Infectious Agent

9. The Chain of Infection Reservoir Host Portal of Exit Mode of Transmission Portal of Entry Susceptible Host Infectious Agent

10. As healthcare professionals, it is important to understand two things about infection As healthcare professionals, it is important to understand two things about infection:

11. 1.the various ways infection can be transmitted 2. the ways the infection chain can be broken

12. There are six links in the chain of infection :

13. 1st - The Infectious Agent -any disease-causing microorganism (pathogen)

14. 2nd - The Reservoir Host -the organism in which the infectious microbes reside

15. Hosts that do not show any outward signs or symptoms of a disease but are still capable of transmitting the disease are known as carriers. What are “Carrier Hosts”

16. 3rd - The Portal of Exit -route of escape of the pathogen from the reservoir. Examples: respiratory secretions, blood exposure, breaks in skin

17. 4th - The Route of Transmission -method by which the pathogen gets from the reservoir to the new host

18. Transmission may occur through: direct contact

19. air

20. insects

21. 5th - The Portal of Entry -route through which the pathogen enters its new host

22. Respiratory System inhalation

23. Gastrointestinal System ingestion

24. Urinary & Reproductive Tracts Sexual contact

25. Breaks in Protective Skin Barrier

26. 6th - TheSusceptible Host 6th - The Susceptible Host -the organism that accepts the pathogen The support of pathogen life & its reproduction depend on the degree of the host’s resistance.

27. Organisms with strong immune systems are better able to fend off pathogens.

28. Organisms with weakened immune systems are more vulnerable to the support & reproduction of pathogens.

29. -The essential part of patient care & self-protection. How to interrupt the chain of infection:

30. 1. Pathogen Identification -identification of infectious agent & appropriate treatment

31. 2. Asepsis & Hygiene -potential hosts & carriers must practice asepsis & maintain proper personal hygiene

32. 3. Control Portals of Exit -healthcare personnel must practice standard precautions:

33. 4. Prevent a Route of Transmission -prevent direct or indirect contact by: 1.Proper handwashing 2.Disinfection & sterilization techniques 3.Isolation of infected patients 4.Not working when contagious

34. (Control body secretions & wash hands according to protocol.)

35. 5. Protect Portal of Entry -Health professionals must make sure that ports of entry are not subjected to pathogens. (nose, mouth, eyes, urinary tract, open wounds, etc.)

36. 6. Recognition of Susceptible Host -health professionals must recognize & protect high-risk patients

37. Cancer Patients AIDS Patients Transplant Patients Infant & Elderly Patients

38. Remember--breaking the chain of infection is the responsibility of each health professional.

39. Microorganisms and Disease A. Microorganism: an organism that is too small to be seen by the human eye  1. Fungi: simple plants such as molds and yeasts, some of which cause disease  2. Protozoa: the only group of microorganisms classified as an animal  3. Virus: microorganisms that are so small they cannot be seen with an ordinary light microscope. They are not destroyed by antibiotics.

40. 4. Bacteria: microorganisms first seen under the microscope by Antoni van Leeuwenhoek in 1693. The classification is determined by the shape of the bacteria and whether it grows with or without oxygen. Only a few bacteria, such as staphylococcus and streptococcus cause disease.  a. Aerobic bacteria: live and multiply in the presence of oxygen  b. Anaerobic bacteria: live and multiply without oxygen  c. Cocci: round bacteria  Staphylococci: round bacteria in clusters like grapes; cause boils, impetigo, and osteomyelitis  Streptococci: round bacteria arranged in chains; cause rheumatic fever, streptococcal pneumonia, and scarlet fever  Diplococci: round bacteria arranged in pairs; cause gonorrhea and meningitis  d. Bacilla: rod shaped bacteria  e. Spirilla: shaped like spirals  5. Rickettsiae: smaller than bacteria, barely visible under light microscope; cause typhus, Rocky Mountain spotted fever

41. B. Pathogen: a disease causing microorganism

42. Asepsis is the absence of infection A. Medical asepsis: practices and techniques that are designed to protect individuals from the spread of disease  1. Antiseptic: substances that inhibit the growth of bacteria. Some of these substances can be used on the skin.  2. Disinfectant: substances or practices that cannot be used on the skin. This includes chemicals and boiling.  3. Sterile: absence of all microorganisms B. Surgical asepsis: the use of sterile technique to handle equipment, maintain sterile fields, change dressings and dispose of contaminated materials without introducing harmful microorganisms

43. Epidemiology-tracing the occurrence of health related events in society A. Epidemiologist is a person who specializes in the study of outbreaks of diseases within a population group  1. Endemic: refers to the ongoing presence of a disease within a population, group, or area. For example, the common cold is always present within a population.  2. Epidemic: is a sudden and widespread outbreak of a disease within a population, group or area. For example a sudden wide spread outbreak of measles is an epidemic.  3. Pandemic: refers to an outbreak of a disease occurring over a large geographic area, possibly worldwide. For example, AIDS is pandemic.