1. Understanding Epidemiology Infectious Agents and Preventative Measures

2. What is an Infectious Disease? “Any disease caused by invasion by a pathogen which subsequently grows and multiples in the body.” Pathogen = any disease-causing agent.

3. Categories of Infectious Agents Metazoa Protozoa Fungi Bacteria Viruses Ricketssia Prions

4. Disease Transmission Two types of transmission: 1)Direct o Transmission mechanism in which the infectious agent is transferred directly into the body. o Examples: Touching, kissing, or biting. 2)Indirect o Transmission mechanism in which the infectious agent is transferred to the person by a vector or fomite. o Examples: Airborne, vector-borne, or vehicle- borne.

5. Disease Transmission (Direct) Types of Direct Transmission: ◦ Person-to-Person ◦ Animal-to-Person ◦ Mother-to-Unborn Child ◦ Droplet ◦ Direct Exposure

6. Disease Transmission (Indirect) Types of Indirect Transmission: ◦ Vector-borne ◦ Fomite ◦ Vehicle-borne ◦ Airborne

7. Natural Barriers to Infection Skin Reflexes ◦ Coughing and Sneezing Tears Acidic pH in the stomach Mucous membranes

8. Host Response What is host response? ◦ Reaction of a living system to some material. Why is this relevant to epidemiology? ◦ Leads to clues about the disease. ◦ Leads to effective interventions to help prevent and stop spread of disease.

9. Where Germs are Found Germs live all around us at home, school, and work. Common places to find germs include: ◦ Soil ◦ Air ◦ Water ◦ Food ◦ Animals ◦ People ◦ High-touch surfaces, like doorknobs and telephones

10. Effective Preventative Measures Requires looking at your habits, lifestyles, and surroundings. ◦ Practice good personal hygiene. ◦ Treat all bodily fluids as potentially infectious. ◦ Use protective barriers when exposed to infectious agents. ◦ Maintain a clean home and work environment. ◦ Store and cook foods at the proper temperature.

11. Effective Preventative Measures 80% of all infectious diseases are transmitted by touch. Frequent and proper hand washing is key to preventing the spread of infection.

12. Proper Hand Hygiene

13. Wash your hands after: ◦ Using the restroom. ◦ Changing a diaper. ◦ Coughing, sneezing, or blowing your nose. ◦ Handling a pet. ◦ Preparing or handling uncooked foods. Wash your hands before and after: ◦ Cleaning cuts or abrasions. ◦ Changing bandages. ◦ Changing soiled linens.

14. Proper Hand Hygiene Step 1: Use large amounts of warm, running water and liquid soap to lather hands and wrists. ◦ Scrubs all surfaces of hands and fingers for 15- 20 seconds. ◦ Bar soap can harbor germs that cause infection, so it is important to use liquid soap when possible.

15. Proper Hand Hygiene Step 2: Rinse hands well with clean, running water. ◦ Important to rinse with your hands pointed down to prevent the rinse water from running up your arms. Step 3: Dry with a disposable paper towel.

16. Proper Hand Hygiene Step 4: Shut off faucet using the paper towel as a barrier between your clean hands and the faucet handle. Step 5: Use a skin moisturizing cream regularly to prevent cracks in the skin, which can serve as entry points for germs to cause infection.

17. Proper Hand Hygiene When soap is not available, use an alcohol-based gel (at least 60% alcohol) to sanitize hands. Do not use an alcohol rub when hands are visibly soiled.

18. Resources “Where are Germs Found?” Lysol. http://lysol.org/home-and-family/help- protect-your-family/where-are-germs-found/. “Break the Cycle of Infection – Tips That Will Keep You Healthy.” http://aids.about.com/od/expertadvice/a/infection.htm.