Microscopic Warriors: A Guide to Understanding Microbes and Infections

1. Microscopic Life • Microbiology: study of organisms unable to be seen by naked eye • Pathogens: disease causing organisms • Non-pathogens: do not cause disease • Saprophytes: live on dead organic matter • Opportunistic: non-pathogens which cause disease when a patient has low resistance

2. Classification of Microbescont • Bacteria • Unicellular, plantlike microorganisms • Cause the bulk of all diseases • Identified by shape:

3. Bacteriacont • Bacilli: • Rod-shaped bacteria • Cause whooping cough, diphtheria, TB, tetanus, typhoid fever • Some produce spores: a protective coating surrounding the cell; created under adverse conditions such as high temps or drying; will germinate under better conditions

4. Bacteriacont • Cocci • Spherical shaped bacteria • Diplococci: occurs in pairs; cause gonorrhea & meningitis • Streptococci: occur in chains; cause pneumonia, strep throat; wound infections, boils, scarlet fever • Staphylococci: occur in clusters; cause wound infections, boils, abscesses, acne

5. Bacteriacont • Spirochete • Corkscrew shaped • Causes syphilis & cholera

6. Classification of Microbescont • Protozoa • Simple single-celled organisms • Only a few species cause human disease • Common pathogenic protozoa: • Trichomonas • Malaria • African sleeping sickness

7. Classification of Microbes • Six general groups: algae, fungi, rickettsiae, protozoa, viruses; bacteria • Algae • Simple plants • Most common: seaweed, pond scum • Fungi • Simple plants • Cause: infections of skin & mucous membranes

8. Classification of Microbescont • Viruses • Smallest of all microbes • Grow only within living cells • Use host cell’s energy and biochemical machinery • Not susceptible to antibiotics

9. Classification of Microbescont • Rickettsiae • Parasite-lives within living cells • Transferred by lice, fleas, ticks, mites • Causative agent of Rocky Mountain spotted fever: widespread hemorrhagic rash.

10. Needs of Bacteria • Nutrition: a source of food • Moisture • Temperature: each has a range best suited for that species • Reaction: varying degrees of acidity or alkalinity • Oxygen • Aerobes: grow in presence of oxygen • Anaerobes: grow best without oxygen

11. Needs of Bacteriacont • Osmotic pressure: membrane affected by changes in osmotic pressure • High concentration-cell loses water & shrinks • Low concentration-cell swells • Light: all microbes inhibited/killed by UV rays • Interrelationships: some grow faster when grown with other microbes while some are unable to live together

12. How Microorganisms Cause Infection Production of toxins Allergic reaction Attack and destroy living cells

13. Classifications of Diseases & Infections • Endogenous • Infection/disease originates within body • Exogenous • Infection/disease originates outside body • Nosocomial • Hospital acquired • Opportunistic • Occur when body’s defenses weak • Do not occur with intact immune systems

14. Chain of Infection

15. Chain of Infection • Causative agent • Pathogens such as bacteria or virus

16. Chain of Infection • Reservoir • Place where causative agent can live • Examples: • Human body • Animals • Environment • Fomites

17. Chain of Infection • Portal of Exit • Way for causative agent to escape from reservoir • Pathogens leave body through blood and body fluids

18. Chain of Infection • Means of Transmission • Way pathogen transmitted to another reservoir or host • Direct contact • Physical or sexual • Contact with body secretions • Contaminated hands • Indirect contact • Contaminated food, air, clothing • Contaminated equipment • Airborne • Insects

19. Chain of Infection • Portal of Entry • Way to enter a new reservoir or host • Breaks in skin or mucous membranes • Respiratory, digestive, GU tract, circulatory system

20. Chain of Infection • Susceptible host • Individual who can contact the disease

21. Ending the Chain of Infection • If even one link in the chain is broken, infection will not occur

22. Ending the Chain of Infection • Aseptic techniques directed toward maintaining cleanliness & eliminating or preventing contamination • Common aseptic techniques • Handwashing & personal hygiene • Using gloves • Proper cleaning of equipment • Thorough cleaning of environment

23. Levels of Aseptic Control • Antisepsis • Prevents or inhibits growth of pathogens • Not effective against spores & viruses • Can be used on skin • Examples: alcohol and betadine

24. Levels of Aseptic Control • Disinfection • Process that destroys or kills pathogens • Not always effective against spores & viruses • Used mainly on objects, not people • Examples: bleach and zephirin

25. Levels of Aseptic Control • Sterilization • Process that destroys all microorganisms • Steam under pressure, gas, radiation & chemicals • Autoclave most common equipment used

27. Washing Hands • Major aspect of standard precautions • Hands are perfect media for spread of pathogens • Purposes: • Prevent/control spread of pathogens from person to person • Protect health worker from disease

28. Times hands should be washed When you arrive & when leaving facility Before and after patient contact If hands or other skin surfaces are contaminated with blood/body fluids Before applying &Immediately after removal of gloves Before & after handling specimens

29. Times hands should be washed After contact with soiled/contaminated item After picking something up off floor After personal use of restroom After cough, sneeze or use tissue Before/after contact with your own mucous membranes

30. Principles of Proper Handwashing • Use soap as a cleansing agent because it aids in removal of pathogens through its sudsy action and alkali content • Point fingertips downward while washing hands: • Prevents water from getting on forearm • Water on forearm could run own to contaminate clean hands

31. Principles of Proper Handwashing • Use warm water • Less damaging to skin than hot water • Creates better lather with soap than cold water • Use friction • helps rub off pathogens in oil & dirt from skin surface

32. Principles of Proper Handwashing • Clean all surfaces on the hands: • Palms • Backs/tops of hands • Areas between fingers • Skin folds of knuckles

33. Principles of Proper Handwashing • Clean nails because they harbor dirt and pathogens • Clean with blunt end of cuticle stick • Scrub with a brush to remove dirt or pathogens • Use dry paper towels to turn faucet on and off • Prevents contamination of of hands from pathogens on faucet • Pathogens travel quickly through wet towel • http://www.youtube.com/watch?v=mYiEQaAQFxY&feature=related

35. Observing Universal Precautions

36. Observing Universal Precautions • Introduction: • Three pathogens of major concern: • HBV • HCV • HIV • Federal regulations on Standard Precautions established in 1991 by OSHA

37. Required Regulations • Determine all employees that have exposure to blood & body fluids • Provide hepatitis B vaccine free of charge • Provide PPE: • Gloves • Gowns • Lab coats • Masks • Face shields

38. Required Regulations • Adequate handwashing facilities • Worksite is maintained • Measures for decontamination of surfaces • Disposal of infectious waste materials • Enforce rules of: • No eating or drinking • No smoking • No cosmetics or handling contact lenses • No mouth pipetting or suctioning

39. Required Regulations Provide sharps containers Post signs to areas with occupational exposure Confidential medical evaluation after exposure Provide free training about regulations Make sure all employees use standard precautions at all times

40. Needle Stick Safety & Prevention Act • ID/use effective & safer medical devices • Needles with protective sheaths • Use of needle-less systems • Updated Exposure Control Plan • Input from non-managerial employees • Sharps injury log

41. Standard Precautions Every body fluid should be considered to potentially infectious All patients should be considered to be a source of infection

42. Gloves • Times when gloves should be worn: • Whenever contact with blood/body fluids, mucous membranes, non-intact skin possible • Handling items or surfaces soiled with blood/body fluids • Performing invasive procedures • Performing venipuncture or blood tests

43. Gowns or Aprons • When gowns or aprons should be worn: • During any procedure likely to cause splashing of blood/body fluids • Prevents contamination of clothing or uniforms

44. Masks, Protective Eyewear, Face Shields • Times when should be worn: • During procedures producing droplets of blood/body fluids • Examples: irrigating wounds, suction, dental, deliveries • Prevents exposure of mucous membranes of mouth, nose, eyes

45. Masks, Protective Eyewear, Face Shields • When to change masks: • Used once then discarded • Change every 30 minutes or • If become wet or moist

46. Sharps • Needles: • Never bend or break after use • Never recap or remove after use • Place in sharps container after use • Surgical blades, razors: • Discard in sharps container • Dispose of sharps container according to federal, state, local laws

47. Spills or Splashes of B/BF Wipe up immediately Wear gloves Clean area with disinfectant such as 10% bleach Clean & disinfect contaminated instruments or equipment

48. Mouthpieces or Resuscitation Devices • Purpose: • Used to avoid need for mouth-to-mouth resuscitation

49. Waste & Soiled Linen Disposal • Wear gloves • Place in infectious waste or biohazardous material bags • Soiled linens placed in laundry bags and soaked in a disinfectant prior to laundering

50. Reporting Cuts and Injuries Most agencies require employees to report any cut, injury, needle stick, or splashing of B/BF immediately Agency policy is then followed to deal with the injury of contamination