1. Chapter 28: Infectious Diseases p. 619
Lesson 1:
What Causes Infectious Diseases? P. 620

2. Health Terms p. 620 Infectious diseases Parasites Virus Transmission
Immunity
Mucous membranes
Phagocytosis
Neutrophils
antibodies

3. Causes of Infectious Diseases
Every infectious disease is caused by a pathogen.
Pathogens invade the body and attack it’s cells and tissues.
Most pathogens are parasites.

4. Bacteria Single-celled microorganism Can live almost anywhere
Some produce poisons that are harmful to human cells
Abundant in the air, soil and water
Upon entering the body, they multiply rapidly through cell-division
Division can take place every 20min.
1 bacterium can be 4 billion in just 15 and 1/2 hours
Usually body’s immune system does not allow this

5. Viruses Viruses very specific in the cells it invades
Smallest infectious agent
HIV is one of the deadliest known viruses; it causes AIDS
Are not living cells
Invade all known forms of life
Viruses very specific in the cells it invades
Upon entering the body, it attaches to a cell and injects its genetic material in that cell. The virus then makes copies that repeat the process
Usually killed by immune system

6. Rickettsias Organisms that resemble small bacteria
Act like viruses in that they need to invade the cells of another life form
Most are found in the intestinal tract of insects
Rickettsias are passes to human or animal by bites or feces deposits on the skin
Typhus
Rocky Mountain Spotted Fever

7. Protozoans Fungi Single-celled Simple organisms
Larger than bacteria
Most are harmless
About 30 types causes disease in humans
Most common in tropical areas that have poor sanitation
Fungi
Simple organisms
Prefer dark, damp environments
Most invade deep tissues of hair, nails and skin causing infections of the scalp and feet
Examples are ringworm and athletes’s foot

8. How Infectious Diseases Spread
People
Direct contact - when an uninfected person comes in to physical contact with an infected person.
Sexually Transmitted Diseases (STD’s) are spread this way
Pregnant women may transmit infection to an unborn child

9. How Infectious Diseases Spread cont’d
People cont’d
Indirect contact- Pathogens spread through the air or other means of transmission other than direct contact.
Pathogens can be spread through touching contaminated objects.(Desk, utensils, glasses or needles)
Pathogens can be spread through the environment. (Food, water, soil, and even the air)

10. How Infectious Diseases Spread cont’d
Animals
may spread infectious diseases such as Malaria or Rabies.

11. How Your Body Defends Against Infectious Disease
How does your body remain health?
Immunity
Your immune system fights millions of pathogens each day
thus keeping your body mostly free of infection.
Nonspecific Resistance- Inborn, or general, defenses against infection
When nonspecific, the body responds the same way to every foreign substance
4 types:

12. Nonspecific Resistance
The Immune Response
Nonspecific Resistance
Physical barriers
Skin first line of defense against invading pathogens, the main barrier
Mucous membrane/mucous
Cil

13. The Immune Response cont’d
Nonspecific Resistance cont’d
Chemical Barriers
Enzymes in tears
Acidic digestive juices
Body Cells
White Blood Cells (WBC)
Phagocytes
Neutrophils - chief phagocytes

14. The Immune Response cont’d
Nonspecific Resistance cont’d
Inflammatory response
“Red Alert” stage, increased blood flow.
Symptoms include heat, redness and swelling
Once pathogens are destroyed, tissues return to normal.

15. Specific Resistance
Immune system mounts specific attacks against particular types of pathogens.
Lymphocytes- Type of white blood cell that fights pathogens.
Two main types of lymphocytes are B cells and T cells.

16. Specific Resistance cont’d
B cells- Enlarge and multiply, eventually turning into antibodies. If you encounter the same specific pathogen again, the antibodies are still there to fight.
T Cells- Two main types.
Killer T cells - multiply by the presence of abnormal body cells; they then fight to kills the abnormal cells
Helper T cells - aid the activity of the B and Killer T cells.

17. Specific Resistance cont’d
When you fail to take in adequate nutrients, you can jeopardize the immune system. This is why those with poor eating habits tend to get more sick.

18. Chapter 28: Infectious Diseases p. 619
Lesson 2:
Common Infectious Diseases
p. 627

19. Health Terms Pneumonia Tuberculosis (TB) Strep throat Vaccine
Immunization
Rubella

20. Respiratory Infections
Infections of the breathing passages, most of these are caused by a virus or a bacteria.
Common Cold - viral infection, inflammation of the mucous membranes lining the nose and throat.
Mostly contracted by breathing in virus
sneezed or coughed by an infected person,
or rubbing the eyes or nose with fingers that picked up the virus
by direct contact or indirect contact
There is no cure, but most clear up in a week or so. The best treatment is rest, proper nutrition, and drinking plenty of fluids.

21. Respiratory Infections cont’d
Influenza (The Flu)- viral infection, spread and treated the same way as cold.
Major breakouts generally occur in the winter.
Secondary bacterial infection may accompany the flu
which can develop in to pneumonia (A serious inflammation of the lungs)
Secondary infections need antibiotic treatment

22. Respiratory Infections cont’d
Tuberculosis (TB)- Highly contagious bacterial infection that most often affects the lungs.
Spread by airborne droplets produced by coughing or sneezing.
Main symptoms include coughing, chest pains, shortness of breath, fever, sweating, and weight loss.

23. Respiratory Infections cont’d
Strep Throat - A bacterial infection of the throat.
Spread through droplets coughed or sneezed in the air.
Symptoms include sore throat, fever, general feeling of sickness and enlarged lymph nodes in the neck.
If left untreated can lead to serious complications.
Strep can be cured with antibiotics.

24. Infectious Diseases of the Nervous System
Encephalitis
Inflammation of the brain
Often caused by a virus carried by a mosquito
No known cure
Can be caused by herpes simplex virus
If can be cures with an antiviral

25. Infectious Diseases of the Nervous System cont’d
Meningitis
An inflammation of the membranes that cover the brain and spinal cord
Viral illness is mild
Bacterial is life-threatening
Poliomyelitis (Polio)
Viral
1950 to scientists developed a vaccine

26. Measles viral Fever Total body rash Can cause encephalitis
Vaccine - part of the MMR series

27. Mononucleosis “Mono” “Kissing Disease” 3-6 weeks for recovery
Usually spread through direct contact
3-6 weeks for recovery

28. Hepatitis Inflammation of the liver
Can result in permanent damage
Common symptom is yellowing skin and eyes
Appear weeks after exposure
Lasts weeks

29. Hepatitis cont’d 3 Types of Hepatitis: Hepatitis A Hepatitis B
The virus is contracted by eating or drinking foods contaminated with the virus; food in contact with feses
Hepatitis B
Found in body fluids
Spread via blood and sexual contact
Can cause liver damage

30. VACCINE FOR HEPATITIS B
Hepatitis cont’d
Hepatitis C
Found in blood
Can cause liver cancer
NO CURE
VACCINE FOR HEPATITIS B

31. Chapter 28: Infectious Diseases p. 619
Lesson 3:
Preventing Infectious Diseases
p. 632

32. Health Terms
Active immunity
Passive immunity

33. The body’s natural resistance to many pathogens 2 Types:
IMMUNITY
The body’s natural resistance to many pathogens 2 Types:

34. IMMUNITY cont’d
Active immunity - the body develops specific, long term antibodies to fight pathogens.
ie Chicken Pox virus enters and your body produces antibodies to kill that virus
Passive Immunity - infant acquires immunity through its mother while in womb and shortly after birth

35. Additional help to establish immunity against specific pathogens
Immunization
Additional help to establish immunity against specific pathogens

36. Immunization cont’d Passive immunization Active Immunization
Blood is taken from an infected person who has developed antibodies
An extract of that blood is injected into the person needing immunity help
Active Immunization
Also know as a vaccine
3 types:

37. 3 Types of Active Immunization:
Immunization cont’d
3 Types of Active Immunization:
Live-virus vaccine
Made from weakened viruses
Help the person to produce antibodies and not get sick
Measles, rubella, & oral polio

38. Immunization cont’d Killed-virus vaccine Made from killed viruses
Helps a person to produce antibodies and not get sick
Less powerful than Live-Virus vaccine
Thus boosters are needed
Cholera, typhoid fever, rabies and injected polio

39. Immunization cont’d Toxoid
Made with chemically treated bacteria toxins
These toxoids stimulate production of antibodies

40. Why do you think immunizations are important in the school setting?
Immunization for All
Why do you think immunizations are important in the school setting?

41. Common Sense Measures Keep your body healthy Bathe or shower every day
Good nutrition
Adequate slee
Exercise
Bathe or shower every day
Avoid sharing eating & drinking utensils
Wash your hands after using the restroom or changing diapers

42. Common Sense Measures cont’d
Wash your hands before handling food
Avoid giving your illness to others
Cover your mouth & nose when sneezing/coughing
Use tissues only once and dispose
Avoid contact with those who are sick

43. Test Review
Rickettsias resemble bacteria and are able to reproduce only by invading the cells of another life form.
Chief type of white blood cells involved in phagocytosis are neutrophils
TB is caused by a bacteria
B cells produce antibodies against pathogens
When they encounter a pathogen, B cells turn into plasma cells.
Meningitis is an inflammation of the membranes that cover the brain and spinal cord.

44. A live-virus vaccine is a type of vaccine made from a weakened virus.
Hepatitis is an inflammation of the liver usually caused by a viral infection in which the skin and the whites of the eyes turn yellow.
Know ALL of your vocabulary!!!
Page
Directions- Write the answer, then take the answer and use it in a sentence that you either made up or found in the book. Sentences should show knowledge of the def.