1. Communicable Diseases
Chapter 8

2. What are communicable diseases?
Pathogens - living organisms or particles that can cause disease
Communicable disease - a disease caused by pathogens that can be spread from person to person
Can you think of any communicable diseases?

3. Types of pathogens
Viruses – Microscopic particles that can reproduce inside living cells
Examples: the common cold, the flu, Hepatits A, B, and C
Bacteria – one-celled organisms that live almost everywhere on Earth
Most bacteria are harmless but some can cause diseases such as: strep throat, gonorrhea, tuberculosis, Lyme disease, and anthrax

4. Types of pathogens Cont’d
Fungi – living organisms that have some characteristics of plant cells but cannot make their own food
Causes diseases such as: athlete’s foot and ring worm
Protozoa – one-celled organisms that are larger and more complex than bacteria
Examples: malaria and toxoplasmosis

5. How pathogens enter the body
Direct Contact – touching, kissing, or other close contact with a person who carries a pathogen
Indirect contact – contact with objects used by a person who has a pathogen
Using a needle that has infected blood on it
Inhaling air, eating food, or drinking liquid that carries pathogens
Being bitten by an animal or insect that carries pathogens

6. BRAINSTORM
Think about your typical day spent here at GVMS. Brainstorm and list TEN things you might touch during the day that you could infect if you were sick. 6.

7. Your body’s defense
Immune system – organs, tissues and cells that destroy pathogens

8. First line of defense Mucus traps pathogens from entering the body
Cilia – tiny hairs inside air passages that trap some pathogens that exit the body when you exhale or sneeze

9. Second line of defense Stomach acid Fever White blood cells
Antibodies – protein substances in blood that can find, weaken or destroy certain pathogens

10. Third line of defense Immunity – resistance to a particular disease
Vaccine – dead or weakened pathogens given for immunity
Common childhood vaccines:
Polio
Pertussis
Measles
Chicken Pox
Diptheria
Tetanus

11. Avoiding communicable diseases
Wash your hands before and after preparing food and after using the bathroom
Cover your mouth when you sneeze or cough with a tissue or your sleeve
Don’t share personal items