Communicable/Infectious Diseases

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Communicable/Infectious Diseases

• Unit 8
• Page 484

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Immune System P. 485

• Lymphocytes- white blood cells that help the
  body fight pathogens
• Two Types
• B Cells- produce antibodies
• T Cells- signal B-cells to produce
  antibodies

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Immunity P.485

• - the bodys resistance to disease-causing
  agents.
• Active- resistance to disease due to the presence
  of antibodies
• Passive- introducing antibodies into a persons
  blood stream
• Vaccine- weakened disease that is introduced into
  the body to give immunity (make antibodies)

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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.

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What to know about types of pathogens P. 487

• Bacteria- microscopic, single celled org. that
  cause disease.
• Fungi(yeast mold)- simple org., cant make own
  food (ex Athletes foot, ringworm)
• Viruses
• Protozoa- single celled org., can produce toxins
  that cause disease.
• Helminith(worms)- not micro org., cause disease
  in human body by infecting intestines, muscles,
  rectum (ex Round worms or Trichinosis)

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• Microbes- tiny organisms that can not be seen by
  the naked eye.

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Bacteria

• multiplies in moist, dark, warm, nutrient-rich
  body tissue.
• (can also live and multiply outside the body)
• microscopic, single celled organisms that can
  cause disease.
• Tetanus, Tuberculosis(492) Lyme disease,
  Strep Throat, Syphilis and Gonorrhea are all
  caused by bacteria.

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Viruses

• Viruses are not cells! Viruses cause diseases by
  invading cells forcing them to reproduce viruses.
  Some remain in the body for life. Can live
  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.

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How Pathogens are SpreadP.488
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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.

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Defense Against InfectionP.485

• First Line of Defense- Structural
• 1. Skin (unbroken)
• 2. Mucous Membranes in the mouth, nose and
  bronchial tubes.
• 3.Cilia
• 4. Digestive Juices (stomach acids)
• 5. Tears

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• 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.
• Immunity- Last Line of Defense
• T-cells lymphocytes recognize invaders and
  activate B-cells
• B-cells responsible for producing antibodies
  that destroy invading germs.
• Inborn Immunity- temporary immunity that an
  infant has. (acquired from mothers antibodies)

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Bacterial STDsP.499

• Chlamydia-
• PID- Pelvic Inflammatory Disease
• Syphilis- chancre appears, if it goes away
  doesn't mean STD is gone, its dormant.
• Spirochete- bacteria that causes syphilis
• Gonorrhea-
• Gonococcus- bacteria that causes gonorrhea
• Bacterial STDs are curable with antibiotic

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Viral STDsP.502

• Herpes I- blisters or sores appear on or around
  the mouth
• 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
• Parasites
• Pubic Lice-
• Trichomoniasis-

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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 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 so low due to HIV.

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Ways of Transmission P. 506

• List the 7 ways-
• -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 in this day and age)
• Ways HIV is not transmitted

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How HIV Takes Over the BodyP.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.

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Early Signs of HIV

• Tiredness
• Skin rashes
• Night sweats
• Loss of weight
• Diarrhea
• Sore throat fever

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Incubation Period

• Word given for the time period when you turn from
  HIV- to HIV
• It may 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

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Tests P. 512

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

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AIDSAcquired Immune Deficiency Syndrome

• - the last and deadly stage of HIV is AIDS. 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.

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Avoiding STDs HIV

• P. 508