1. Preventing the spread of disease

3. Disease: Any condition that interferes with the proper functioning of the body or mind. Example: Cancer and Alzheimers

4. Communicable Disease
A disease that can be passed to a person from another person, animal, or object.
Example: Common Cold
The agents that cause communicable diseases are called pathogens.
Pathogens: Can only be seen through a microscope.
These are also called germs.
When pathogens enter your body they can cause infections.

5. Infections:
A condition that occurs when pathogens enter the body, multiply, and cause harm.
Example: Strep Throat

6. Pathogens: Four Common Pathogens
Viruses
Bacteria
Fungi
Protozoa

7. Viruses Smallest pathogens Cause common diseases
Can not be treated and cured with antibiotics
Examples: Colds, influenza, chicken pox, measles, mononucleosis, herpes, HIV/AIDS, fever, polio, rabies, viral pneumonia.

8. Bacteria Tiny one-celled organism.
Some bacteria can be helpful. The bacteria that lives in your digestive tract helps to digest food.
Others are harmful.
Can be cured and treated by antibiotics.
Examples: pink eye, pertussis (whooping cough), strep throat, tuberculosis, Lyme disease, ear infections and bacterial pneumonia.

9. Fungi Are more complex than bacteria but can’t make their own food.
They feed on organic material.
They thrive in warm moist environments.
Examples: Ring worm, and Athletes foot.

10. Protozoa One-celled organisms that are more complex than bacteria.
Example: Malaria
If an infected mosquito bites a person, the protozoa transfers into the body through the skin.

11. How are pathogens spread?
Direct contact with others. Can be spread directly from one person to another.
Example: You can get a virus or bacteria by shaking hands, kissing. Or sexual contact.
Indirect contact with others. Pathogens can enter the body through using utensils or drinking glasses from an infected person.
Example: You can get viruses and bacteria by using contaminated needles, body piercings, and drug injection.

12. How are pathogens spread?
Contact with contaminated food and water. Food borne illnesses come from pathogens in food.
Example: Food that is improperly stored or undercooked provide an environment where pathogens can multiply.
Contact with animals or insects. A vector is an organism, such as an insect, that transmits pathogens.
example: A tick can spread Lyme disease by a bite, and a mosquito can cause West Nile Virus through their salvia.

13. How to keep pathogens from spreading
There is no way to completely avoid pathogens.
Good hygiene can help you protect yourself.
Avoid close contact with people who have a communicable diseases.
Eat nutritious food, get enough physical activity and rest.
Do not share personal hygiene items.
Wash your hands.
Use proper food safety when cooking.
Avoid touching your mouth, nose, and eyes. Do not bite your nails.

14. Why do you think it is important for teens to practice good personal hygiene?
Brendan is coughing and sneezing at school. What should Brendan do to help prevent the spread of pathogens?

15. The Body’s Defense Against Infection
Pathogens are everywhere. Most bacteria and viruses never get the chance to make you sick. Your body has natural barriers between you and pathogens.
You have 5 major barriers to pathogens.
Immune system: A combination of body defenses made up of cells, tissues, and organs that fight off pathogens and disease.
Your immune system has two main responses: nonspecific and specific response. These responses provide immunity.
Immunity: Your body’s ability to resist the germs that cause a particular disease.

16. Five Major Barriers
Tears: Tears contain chemicals that kill pathogens. Tears carry foreign material away from the eyes. They cover and protect the eyes.
Mucous Membranes: Soft skin that lines the nose, mouth, eyes, and other body openings.
Saliva: Contains chemicals that kill pathogens trying to enter through your mouth. It washes germs off your teeth.
Skin: Provides a tough outer protection that keeps pathogens out. If you get cut they can get through the barrier.
Stomach Acid: Gastric Juices are produced by the stomach lining. It kills the pathogens that get past your saliva and mucous membranes of your mouth.

17. Nonspecific Immune Response
Inflammation: The body’s response to injury or disease, resulting in a condition of swelling, pain, heat, and redness.
The brain sends signals telling white blood cells to rush to the affected area and destroy the pathogens. The circulation will slow down in that area.
With inflammation, the immune system is stimulated. The pathogens will try to multiply. The body may produce a fever to help stop the pathogens from multiplying. A fever will also signal the body to produce more white blood cells to destroy the pathogen.

18. Specific Immune response
If the pathogen escapes the nonspecific response, the body will then send out a customized specific response. Our immune system can recognize if it has already had a battle with a pathogen. Once it creates a specific response certain cells are sent in to attack the pathogen.
This results is a much quicker response than the first response.

19. The Lymphatic System
This system is a secondary circulatory system that helps fight pathogens and maintains its fluid balance.
Lymphocytes: White blood cells in the lymphatic system. Two types of lymphocytes. B cells and T cells.
B Cells: Form in bone marrow.
T Cells: Develop in the thymus gland.
Macrophages: Surround foreign substances and destroy them. They help the lymphocytes recognize the invader and prepare for future attacks.

20. Immunity Antigen: Any substance released by invading pathogens.
Antibodies: Proteins that attach to antigens, keeping them from harming the body.
If the same type of pathogens invade the body again, these antibodies are ready to attack.

21. Immunity Everyone born with a natural immunity.
These immunities only last a few months.
Then a baby’s own immune system fights off pathogens.
Immunity can also develop from a vaccine.
Vaccine: A preparation of dead or weakened pathogens that causes the immune system to produce antibodies.
Example: polio, measles, chicken pox.

22. How do you think your immune system reacts to a vaccination?
How do vaccines help protect the health of the community?