Principles of Infection Control: Understanding Disease Transmission and Prevention

1. Chapter 13 Infection Control

2. 13:1 Principles of Infection Control • Understanding is essential to all health care workers • Provide a basic knowledge of how disease is transmitted • Main emphasis on prevention of disease transmission

3. Microorganisms or Microbes • Small living organisms • Not visible to the naked eye • Microscope must be used to see them • Found everywhere in the environment • Found on and in the human body • Many are part of normal flora of body • May be beneficial (continues)

4. Microorganisms or Microbes(continued) • Called nonpathogens when not harmful to the body • Some cause infections and disease • Called pathogens (germs) when able to harm the body (continues)

5. Microorganisms or Microbes(continued) • Most prefer warm environments • Most prefer darkness • Need source of food and moisture • Need for oxygen varies • Human body is ideal supplier of all the requirements

6. Microbe Classifications • Bacteria • Protozoa • Fungi • Rickettsiae • Viruses

7. Bacteria • Simple, one-celled organisms • Multiply rapidly • Classified by shape and arrangement (continues)

8. Bacteria(continued) • Cocci are round or spherical in shape • Diplococci—in pairs • Streptococci—in chains • Staphylococci—clusters or groups • Examples of diseases (continues)

9. Bacteria(continued) • Bacilli are rod shaped • Occur singly, in pairs, or in chains • May have flagella • Ability to form spores • Examples of diseases (continues)

10. Bacteria(continued) • Spirilla are spiral or corkscrew shaped • Includes comma-shaped vibrio and corkscrew spirochete • Diseases include syphilis and cholera

11. Antibiotics • Antibiotics are used to kill bacteria • Some strains of bacteria have become antibiotic-resistant • When antibiotic-resistant, the antibiotic is no longer effective against the bacteria

12. Protozoa • One-celled, animal-like organism • Found in decayed materials and contaminated water • May have flagella for movement • Some are pathogenic • Examples of diseases

13. Fungi • Simple, plant-like organisms • Live on dead organic matter • Yeast and molds • Can be pathogenic • Examples of diseases • Antibiotics do not kill • Antifungal medications

14. Rickettsiae • Parasitic microorganisms • Cannot live outside the cells of another living organism • Transmitted to humans by the bites of insects (e.g., fleas, lice, ticks, mites) • Examples of diseases • Antibiotics are effective against many of them

15. Viruses • Smallest microorganisms • Must use electron microscope to see • Must be inside another living cell to reproduce • Spread by blood and body secretions • Very difficult to kill • Cause many diseases (continues)

16. Viruses(continued) • Viruses infecting animals can mutate to infect humans • Examples include: • Severe acute respiratory syndrome (SARS) • West Nile Virus (WNV) • Monkeypox • Ebola and Marburg • H5N1

17. Virus—Hepatitis B • Also called serum hepatitis • Caused by HBV • Transmitted by blood serum and body secretions • Affects the liver • Vaccine available for protection • Vaccine is expensive (continues)

18. Virus—Hepatitis B(continued) • Vaccine given in a series of three injections • By law, employers must provide vaccine at no cost to employees with occupational exposure to blood or other body secretions • If employee refuses, written statement must be signed documenting refusal

19. Hepatitis C • Caused by HVC • Transmitted by blood and blood-containing body fluids • Many infected individuals are asymptomatic • Others have mild symptoms • Can cause severe liver damage (continues)

20. Hepatitis C (continued) • Currently, no vaccine ready for use • Vaccine is in development stage • Extremely difficult to destroy HVC • Can survive and remain active for several days in dried blood • Health care workers must follow precautions to protect against virus

21. Acquired Immune Deficiency Syndrome (AIDS) • Caused by the Human Immunodeficiency Virus (HIV) • Suppresses the immune system • Individual becomes susceptible to cancers and infections that would not affect a healthy person • No cure presently and no vaccine • Take precautions for prevention

22. Helminths • Multicellular parasites otherwise known as worms or flukes • Are transmitted: • By eating contaminated food • Being bitten by infected insects • When worms enter the skin

23. How Pathogens Cause Infection and Disease • Some produce poisons called toxins • Some cause an allergic reaction • Others attach and destroy the living cells they invade

24. Classifications of Diseases and Infections • Endogenous • Exogenous • Nosocomial • Opportunistic

25. Endogenous • Originates within the body • Examples: metabolic disorders, congenital abnormalities, tumors, and infections caused by microorganisms within the body

26. Exogenous • Originates outside the body • Examples: radiation, chemical agents, trauma, electric shock, and temperature extremes

27. Nosocomial • Acquired in a health care facility • Usually present in facilities and carried by health care workers to the patient • Many are antibiotic-resistant • Can cause serious and even life-threatening infections (continues)

28. Nosocomial(continued) • Examples are staphylococcus, pseudomonas, and enterococci • Infection-control programs are used in facilities to prevent and deal with nosocomial infections

29. Opportunistic • Infections that occur when the body’s defenses are down • Usually do not occur in normal immune system • Examples: Kaposi’s sarcoma (rare type of cancer) and Pneumocystiscarinii pneumonia in individuals with AIDS

30. Chain of Infection • Present for disease to occur and spread from one individual to another • Causative agent • Reservoir • Portal of exit • Mode of transmission • Portal of entry • Susceptible host

31. Common Body Defenses • Mucous membranes • Cilia • Coughing and sneezing • HCL in the stomach • Tears • Fever • Inflammation response • Immune response

32. Ending the Chain of Infection • Eliminate any step in the chain and infection is stopped • Follow practices to interrupt or break the chain • Remember, pathogens are everywhere • Prevention is a continuous process

33. Aseptic Techniques • Asepsis: absence of disease-producing microorganisms • Contaminated: any object or area that may contain pathogens • Major aim: maintaining cleanliness and eliminating or preventing every aspect of contamination

34. Common Aseptic Techniques • Thorough handwashing • Good personal hygiene • Disposable gloves • Cleaning instruments and equipment • Proper cleaning of environment

35. Levels of Aseptic Control • Antisepsis—used on the skin • Disinfection—used mainly on objects • Sterilization—use of steam under pressure, gas, radiation, and chemicals on objects

36. Summary • Important for health care workers to know and use proper aseptic techniques at all times • Prevents spread and transmission of disease

37. 13:2 Bioterrorism • Bioterrorism: use of microorganisms or biologic agents for warfare • Infecting humans, animals, or plants • Have been used over time by different nations not only in war but also on innocent people

38. Biologic Agents • Microorganisms with characteristics suitable for bioterrorism: • Inexpensive, available, easily produced, spreads quickly • Maintains its survival • Brings death or disability • Travels from person to person • Difficult to prevent/treat (continues)

39. Biologic Agents(continued) • High priority agents include: • Smallpox: contagious and infectious disease, result of the Variola virus • Anthrax: infectious disease caused by Bacillus anthracis • Plague: infectious disease from the bacteria Yersinia pestis (continues)

40. Biologic Agents(continued) • Botulism: paralytic illness resulting from a nerve toxin from the bacteria Clostridium botulinum • Tularemia: infectious disease from the bacteria Fracisella tularensis • Filoviruses: infectious diseases causing severe hemorrhagic fever known as Ebolavirus and Marburgvirus

41. Preparing for Bioterrorism • Bioterrorism attack would result in a public health emergency • Would have impact on health care facilities • Social disorder would ensue • Comprehensive plan (continues)

42. Preparing for Bioterrorism(continued) • Bioterrorism Act 2002 passed by Congress and signed into law • Involves local, regional, state, and national government and includes: • Early detection by communities • Public to be notified • Infection control and education • Funding available (continues)

43. Preparing for Bioterrorism(continued) • Guidelines and restrictions • Nationwide immunizations • Protection of food/water supplies • Trained personnel available • Emergency management controls • Investigation of potential threats • Preparation of health care facilities • Efficiency of communication

44. Summary • All health care workers need to be aware of bioterrorism • Attack could occur at any time • Being prepared and properly trained will result in saving many lives

45. 13:3 Washing Hands • Major aspect of standard precautions • Most important aseptic technique • Hands are perfect media for the spread of pathogens

46. Purpose of Handwashing • Prevent and control spread of pathogens • Protect the health care worker from disease and illness

47. Recommendations for Handwashing • Regular handwashing with plain soap and water • Antiseptic handwashing with antimicrobial soap and water • Antiseptic hand rub with alcohol-based cleaner (waterless)

48. When to Wash Hands • On arrival at facility • Immediately before leaving facility • Before and after every patient contact • After contact with patient’s skin • Before moving from a contaminated site to a clean site (continues)

49. When to Wash Hands(continued) • Anytime the hands become contaminated during a procedure • Before applying gloves • Immediately after removing gloves • When gloves are torn or punctured • Before and after handling specimens • After contact with any soiled or contaminated item (continues)

50. When to Wash Hands(continued) • After picking up any item off the floor • After personal use of the bathroom • Following a cough, sneeze, or using a tissue • Before and after any contact with mouth or mucous membranes