Disease Transmission and Infection Control

1. Disease Transmission and Infection Control Medical Foundations

2. Objectives • Introduce microorganisms • Become familiar with infections and control measures • Introduce the need for standards and precautions • Become familiar with sterile environments

3. Introduction to Microorganisms Pathogenic microorganisms: cause illness, infection, or disease Nonpathogenic microorganisms: help keep a balance in the environment and in the body

4. Microorganism Survival • Most microorganisms that cause disease • Thrive in warm temperatures • How warm is the human body? • Need moisture • How much of the human body is made up of water? • Prefer a dark area to grow in • Need food • Some live on dead tissue (saprophytes), some live on live tissue • Some need oxygen (aerobic), some do not need oxygen (anaerobic)

5. Nonpathogenic Microorganisms “Good” microorganisms are used in a variety of ways: examples? (P. 489) Buttermilk, fermenting alcohol, making bread rise Where do nonpathogenic microorganisms live in your body and what do they do?

6. Types of Pathogens • Bacteria • One celled plants • Classified by shape and arrangement • Causes strep throat, staph infections, syphilis

7. Types of Pathogens • Protozoa • One celled animals • Found in water and soil environments • decayed material and contaminated water • Cause amebic dysentery and malaria

8. Types of Pathogens • Fungi • Simple, low form of plant life • May live on dead matter • Yeasts, molds • Causes athlete’s foot, thrush, vaginitis, and serious lung diseases

9. Types of Pathogens Rickettsiae • Parasitic microorganism • Transmitted to humans through the bite of lice, fleas, ticks, and mites • Responsible for some of the world’s worst epidemics • Rocky Mountain spotted fever • Typhus

10. Types of Pathogens • Viruses • Smallest microorganism, smaller than bacteria • Can only reproduce inside humans cells • Causes common cold, upper respiratory infections, smallpox, chickenpox, measles, mumps, influenza, fever blisters • Also cause HIV which can lead to AIDS

11. Additional Classifications • Endogenous • Originates inside the body • Exogenous • Originates outside the body • Nonsocomial • An infection acquired inside the hospital • Opportunistic • Infections that occur when the body’s immune system is weak

12. How Microorganisms Affect the Body • Production of toxins • Staphylococcus produces enterotoxin that causes food poisoning = fatigue, diarrhea, vomiting • Tetanus bacilli produces a toxin that attacks the central nervous system = damage, possible death • Cell invasion • A protist can enter red blood cells, making them rupture = chills and fever • Allergic reactions • Allergies = runny nose, watery eyes, sneezing

13. Chain of Infection

14. How Microorganisms and Viruses Spread • Direct Contact • Indirect Contact • Airborne • Oral Route • Insects and Pests (Pg. 493)

15. Disease Prevention • Standard Precautions and Transmission-Based Precautions were created to provide guidelines that prevent the spread of microorganisms. • Signs and Symptoms—Which is which? • Infections can be generalized or localized • Affecting all of the body • Affecting one area of the body • Give signs and symptoms of each