Common Communicable Diseases

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Common Communicable Diseases

• A communicable disease is a disease caused by a
  pathogen (a disease-causing organism) that can be
  transmitted to another person. The common cold,
  for example, is caused by pathogens. A
  noncommunicable disease is a disease which cannot
  be transmitted from one person to another, such
  as heart disease.

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Disease-Causing Pathogens

1. Viruses- are the smallest pathogens, programmed
   to infect only certain body cells. When a virus
   enters a cell, it directs the cell to make more
   viruses. Some viral diseases are the common cold,
   measles, chicken pox, influenza, and herpes.
2. Bacteria- are single-celled microorganisms. There
   are more than 1000 kinds of bacteria, but only
   about 100 are known to cause disease. Some
   bacterial diseases are strep throat,
   tuberculosis, syphilis, gonorrhea, and Lyme
   disease.

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Disease-Causing Pathogens (cont.)

• 3. Rickettsia- are pathogens that grow inside
  living cells and resemble bacteria (but are much
  smaller than bacteria). Two diseases they cause
  are Rocky Mountain spotted fever and typhus.
• 4. Fungi- are single-celled or multicellular
  plantlike organisms, such as yeast and molds.
  Fungi can cause diseases of the skin, mucous
  membranes, and lungs. Athletes foot, ringworm,
  jock itch, and nail infections are examples of
  diseases caused by fungi.

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Disease-Causing Pathogens (cont.)

• 5. Protozoa- are tiny, single-celled parasites.
  Some disease caused by protozoa are malaria,
  African sleeping sickness, and dysentery. Giardia
  is a protozoan that might infect people who drink
  impure water. Giardiasis is a disease that causes
  intestinal pain and diarrhea.

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How Pathogens Are Spread

• 1. Direct Contact- Examples include kissing,
  sexual intercourse, blood transfusions, open
  sores, touching infected body fluids.
• 2. Contact with pathogens in the air- When an
  infected person coughs or sneezes, pathogens are
  released into the air. When inhaled by another
  person, that person may become infected.

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How Pathogens Are Spread (cont.)

• 3. Contact with contaminated objects- A person
  can become infected by using objects touched by
  an infected person, such as a toothbrush, pen or
  pencil, eating utensil, or clothing.
• 4. Through contact with animals and insects- A
  person can become infected when bitten by an
  animal or insect. An insect can pick up a
  pathogen when it lands on sewage and deposit it
  on food. People might eat the food and become
  infected.

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How Pathogens Are Spread (cont.)

• 5. Contact with contaminated food or water- As
  you well know, pathogens may be found in either
  food or water. That is why it is so important to
  wash your hands before handling food. Water is
  purified before it gets to your tap for the same
  reason- to kill pathogens which could cause
  disease. Chlorine and fluoride are used for this
  purpose.

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How The Body Defends Itself Against Pathogens

• Your body has several ways to protect itself from
  pathogens
• Skin- Unbroken skin prevents pathogens from
  entering the body. The outer layer of skin (the
  dead cells), is removed when you bathe. In this
  way, bathing rids the body of pathogens.
• Tears, Saliva, and Perspiration- All of these
  contain chemicals that kill pathogens.

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How The Body Defends Itself Against Pathogens
(cont.)

• 3. Mucous Membranes- Mucous found in the nose and
  throat trap and destroy pathogens.
• 4. Stomach acids- Some pathogens are destroyed by
  saliva when they enter the mouth. The pathogens
  that make it to the stomach are killed by stomach
  acids.
• 5. Fever- Since many pathogens cannot live in a
  high temperature environment, running a fever is
  helpful in fighting certain infections.

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How The Body Defends Itself Against Pathogens
(cont.)

• 6. The Immune System- Is the body system that
  contains cells and organs that fight disease.
  T-Cells are white blood cells that regulate the
  action of the immune system. Phagocytes are white
  blood cells that surround and kill pathogens by
  ingesting them. B-Cells are cells that produce
  antibodies. An antibody is a protein that helps
  fight infection.

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Active Immunity

• Immunity is resistance to disease. Active
  immunity is a resistance to disease due to the
  production of antibodies. You develop active
  immunity from having a disease or from receiving
  a vaccine. A vaccine consists of dead or weakened
  pathogens that are introduced to the body in
  order to give a person more immunity.

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Passive Immunity

• Passive immunity is the immunity that results
  from introducing antibodies into the bloodstream.
  The antibodies might be from another persons
  blood. This type of immunity is short term. It is
  used when the risk of developing a disease is
  immediate.

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Reducing The Risk Of Communicable Diseases

1. Avoid being with people who are ill.
2. Stay home from school when you are ill.
3. Practice abstinence.
4. Do not touch sores on another persons body.
5. Use universal precautions when exposed to another
   persons body fluids.
6. Cover your mouth and nose when sneezing or
   coughing.

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Reducing The Risk Of Communicable Diseases (cont.)

• 7. Do not share personal items such as towels,
  toothbrushes, and eating utensils.
• 8. Do not share a needle for ear or body
  piercing.
• 9. Check with your physician if bitten by an
  animal.
• 10. Keep animals and insects away from foods.

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Reducing The Risk Of Communicable Diseases (cont.)

• 11. Wash your hands with soap and water after
  using the restroom, and especially before eating.
• 12. Keep fingers and hands away from the nose,
  eyes, and mouth.
• 13. Follow precautions to prevent foodborne
  illness.
• 14. Get appropriate vaccines.