1. Communicable/ Infectious Diseases
Unit 8
P. 484

2. Immune System
Lymphocytes: White blood cells that help the body fight pathogens
Two Types:
B Cells: produce antibodies
T Cells: Signal B cells to produce antibodies

3. Immunity P. 485 The body’s resistance to disease-causing agents.
Active: Resistance to disease due to the presence of antibodies
Passive: Introducing antibodies into a person’s blood stream
Vaccine: Weakened disease that is introduced into the body to give immunity (make antibodies)

4. Communicable/ Infectious Diseases P. 487
An illness caused by pathogens that can be spread from one living thing to another.
Pathogens: Microbes which can cause infectious diseases.
Contagious: Having the ability to be transmitted.
Epidemiology: The study of the source & the spread of diseases.

5. What to know about types of pathogens P.487
Bacteria: Microscopic, single celled org., that cause disease.
Fungi (yeast & mold): Simple org., can’t make own food (ex: Athlete’s foot, ringworm)
Viruses
Protozoa: Single celled org., can produce toxins that cause disease. Most are harmless.
Helminith (worms): Not micro org., cause disease in human body by infecting intestines, muscles, rectum (ex: round worms or Trichinosins)
Microbes: tiny organisms that can’t be seen by the naked eye

6. Viruses
Viruses are not cells! Viruses cause disease by invading cells forcing them to reproduce viruses. Some remain in the body for life. Can life outside the body for a short time but must multiply inside.
*Smallest disease causing pathogen
Examples: rabies, polio, common cold, hepatitis, mumps, chicken pox, shingles, and warts.

7. How Pathogens are Spread P.488
May be spread from person to person through direct contact (shaking hands, intimate kissing, sexual intercourse, receiving a transfusion of the person’s blood, touching ulcers or sores, of handling bodily fluids like blood or urine)
May be spread in the air by coughing or sneezing
Contact with contaminated objects (needles)
Handling or being bitten by an infected insect
Contaminated food or water, not washing hands

8. Possible Causative Factors
Host: person who is ill & is carrying the virus.
Environment: where the host lives.
Time: season of the year.
Agent: germ which caused the illness.
Susceptible: having a high chance of getting disease.
Relapse: recurrence of symptoms of disease after a period of improvement.

9. Defense Against Infection P.485
First line of defense: Structural
Skin (unbroken)
Mucous Membranes in the mouth, nose, and bronchial tubes
Cilia
Digestive juices (stomach acids)
Tears

10. Second line of defense – Cellular
White Blood Cells
Phagocytes eat up invaders
Lymph Nodes- gland like structures that serve as filters to screen out bacteria
Last line of defense- Immunity
T-Cells: lymphocytes recognize invaders and active B-Cells
B-Cells: responsible for producing antibodies that destroy invading germs
Inborn Immunity: temporary immunity that an infant has (acquired from mother’s antibodies)

11. Bacterial STD’s
Chlamydia: painful urination and unusual discharge from penis or vagina
PID: Pelvic Inflammatory disease (Infection of the internal female reproductive sys.)
Syphilis: chancre appears, if it goes away doesn’t mean STD is gone, its dormant.
Spirochete: bacteria that causes syphilis
Gonorrhea: infects linings of the male and female genital and urinary tracts
Gonococcus- bacteria that causes gonorrhea
*Bacterial STD’s are curable with antibiotics

12. Viral STD’s P.502
Herpes I: blisters or sores appear on or around the mouth, only transmissible when sores are present
Herpes II: causes blisters to appear in genital region
HPV: wart in genital area
(can cause cervical cancer in females)
Hepatitis (A,B,C,D,E): viral infection of the liver
*Drugs that help produce antibodies: Vaccines*
Parasites:
Pubic Lice
Trichomoniasis

13. HIV P.504
Transmissible virus that attacks T-cells of the immune system and causes immune deficiency.
-The virus that causes AIDS. Some people who become infected with HIV become ill and die within six months. Others may remain in good health and show no signs for six to ten years.
Opportunistic Infections: Infections like pneumonia or cancer, that actually kill the person because immune system is low due to HIV

14. Ways of Transmission (P.506)
-Contact with infected blood, semen, or vaginal secretions.
-Injection of infected blood or blood products
-Infected mother to baby (Breast Milk)
High Risk Behaviors: Anal intercourse, injecting needles with multiple users, vaginal intercourse.
Other Risky Behaviors: Oral sex, receiving blood (not too probable anymore)
*Ways HIV is NOT transmitted (kissing, hugging, coughing, bathroom facilities, insect bites, sharing towels, prepared or served foods, swimming, sports equipment)

15. How HIV Takes Over the Body P.505
The virus destroys the T-Cells & disables their function of signaling the B-Cells to produce antibodies. With the immune system so low, the T cells are not able to fight off other microorganisms & cancer cells. The HIV cells multiply.

16. Early Signs of HIV Tiredness Skin rashes Night Sweats Loss of Weight
Diarrhea
Sore throat & fever

17. Incubation Period
Word given for the time period when you turn from HIV- to HIV+
It make take 6 weeks to 6 months before HIV antibodies will show up in the blood. Most people develop antibodies in 6-12 weeks.
Treatment Drugs: slows down the germs ability to reproduce. P.510
Cure: None

18. Tests P.512
ELISA: blood test that identifies whether a person has HIV antibodies.
If negative- retest in 6 months, if positive-another ELISA test is done to confirm.
Western Blot Test: this is also an antibody test done to confirm the results of the ELISA test.

19. AIDS The last and deadly stage of HIV.
When a person has 200 T-Cells or less they are considered to have AIDS. After symptoms marking the beginning of AIDS development, most people die within two years & the rest within five years.

20. Avoiding STD’s & HIV P.508 Abstain from sex until marriage
Change you behavior and be tested for STD’s and HIV if you have becomes sexually active
Have a monogamous marriage
Choose a drug-free lifestyle
Change your behavior if you use drugs
Avoid sharing needles for tattoos or to pierce body parts
Follow universal precautions