1. Infectious Diseases 8th grade science Sept. 19, 2013

2. What are Infectious Diseases? • Infectious diseases are diseases caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another.

3. Infectious Disease Transmission • Physical contact • Contaminated food • Body fluids • Objects • Airborne inhalation • Vector organisms

4. Routes of transmission • Direct • Skin-skin • Herpes type 1 • Mucous-mucous • STI • Across placenta • toxoplasmosis • Through breast milk • HIV • Sneeze-cough • Influenza • Indirect • Food-borne • Salmonella • Water-borne • Hepatitis A • Vector-borne • Malaria • Air-borne • Chickenpox

5. Infection in one person can be transmitted to others Think about the simulation from a few weeks ago!!

6. Factors influencing disease transmission:

7. Epidemic vs. Pandemic • Epidemic is where an infectious disease spreads over a wide geographical area. • Pandemic is where an infectious disease spreads across multiple continents, or even worldwide.

8. Here are a few… * Denotes diseases that are vector based.

9. AIDS

10. AIDS (Acquired Immunodeficiency Syndrome) • Caused by HIV (human immunodeficiency virus) • progressively reduces the effectiveness of the immune system and leaves individuals susceptible to opportunistic infections and tumors. • transmitted through direct contact of a mucous membrane or the bloodstream with a bodily fluid containing HIV, such as blood, semen, vaginal fluid, preseminal fluid, and breast milk. • has not been found to be transmitted through saliva unless there is a cut in your mouth.

11. Malaria

12. Malaria • a mosquito-borne infectious disease of humans caused by eukaryotic protists • It is widespread in tropical and subtropical regions, including much of Subsaharan Africa, Asia and the Americas. • results from the multiplication of malaria parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases progressing to coma, and death.

13. Tuberculosis (TB)

14. Tuberculosis • caused by various strains of mycobacteria • usually attacks the lungs but can also affect other parts of the body. • spread through the air when people who have active MTB infection cough, sneeze, or spit • classic symptoms are a chronic cough with blood-tinged sputum, fever, night sweats, and weight loss