Disease

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Disease

• Chapter 9

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Disease Defense and Human Health

• Today in Canada you can expect to live longer
  than your grand-parents.
• Why? living conditions have improved, increased
  public disease/health awareness and scientific
  discoveries such as antibiotics have all
  increased our chances of survival.

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Disease

• Germs are what cause illness and disease
• Disease-causing agents such as the cold virus are
  all around you
• A person's lifestyle, diet, genetic background,
  and environment also have an impact on ones
  health as well

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Causes of Human Disease

• In the past, people thought diseases were caused
  by evil spirits or Gods, but scientist have
  discovered that this may not be true
• Disease is anything that prevents the normal
  functioning of the body
• Scientist such as Louis Pasteur and Robert Koch
  discovered micro-organisms called microbes.
  Microbes that cause disease are known as
  pathogens. Pathogens live everywhere, hence it is
  important to be very clean and have sanitary
  conditions to decrease the chances of disease!
• Poor environmental conditions can also cause
  disease, such as air pollution
• Genetic mutations/changes can also create
  disease, such as muscular dystrophy
• Disease can arise from a combination of factors.
  For example, when finals come around at school,
  the stress, environment, diet, and your lifestyle
  usually causes you to become ill

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Louis Pasteur

• The father of modern microbiology study of
  microorganisms
• First to discover that spoiling of food and wine
  was caused by a microbe, and that microbes could
  be killed by increased temperatures. This
  technique was called pasteurization
• Developed the idea that sterilization and
  sanitary conditions could reduced spoilage
• Developed the first human vaccinations for
  anthrax and rabies
• http//bcs.whfreeman.com/thelifewire/content/chp03
  /0302003.html

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Types of Pathogens

• 1) Bacteria these microbes are found everywhere.
  These are single-celled organisms that you need a
  microscope to observe
• Not all bacteria is bad for humans, some are
  beneficial. For example, the E.Coli bacteria in
  your stomach is used to breakdown food, or the
  bacteria that causes milk to form yogurt.
• Harmful bacteria reproduce quickly and form
  colonies when conditions are good
• Good Conditions for bacteria growth Warm
  temperatures, a lot of moisture, and high food
  availability
• http//www.tulane.edu/dmsander/WWW/Video/pneumo.h
  tml -division of bacteriabacteria reproduce by
  splitting into 2

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• 2) Viruses Like bacteria these are found
  anywhere there are cells to infect
• These are smaller than bacteria, they reproduce
  by taking over cells of the body, and then use
  those cells reproductive units to reproduce
  themselves, then the new viruses attack other
  cells of the body
• Most viruses have to enter the bloodstream some
  how either by having sexual intercourse, sharing
  needles, blood transfusions or moving through the
  birth canal of pregnant mothers

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• 3)Protists single-celled organisms that share
  some characteristics with plants and animals
• amoeba and paramecium
• Malaria, and African sleeping sickness
• Usually found in feces contaminated food, water,
  or soils.
• To prevent the spread of these microbes drink
  sanitary water, wash hands and food regularly

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• 4) Fungi molds, yeast, mushrooms
• Some fungi are parasites and can only live and
  survive on host organism
• Some taste great? mushrooms
• Some cause disease such as athletes foot and
  ringworm

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Communicable and Non-communicable diseases

• Communicable disease These diseases are caused
  by pathogens. The pathogen that causes the
  disease can spared from one organism to another.
  Examples the flu, cold virus, AIDS, etc
• See and COPY table 9.1 from the textbook,
  pg.163 Communicable disease
• Non-communicable disease These are not caused by
  pathogens, thus they can NOT be passed one person
  to another. Examples diabetes, cancer,
  arthritis, depression, etc.

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Who is most likely to get sick?

• As stated before, the average Canadian's lifespan
  has increased. An average female can expect to
  live 81 years, while males can expect to live for
  75 years. But in Africa, the female average is 35
  years and the male average is 33. Why? Living
  conditions
• Canada is a wealthy country that has a lot to
  offer such as health care, clean water/food, and
  disease prevention and awareness, while in Africa
  there is a lot of poverty, unsanitary living
  conditions (water, food, health care), war and
  turmoil, and increased chances to get
  communicable diseases
• Risk Factors that increase your chances of
  getting sick poor diet, drinking unclean water,
  not having a toilet, decreased personal hygiene,
  having sex, smoking, consuming alcohol
• -see Table 9.2-on pg.167.

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The importance of a Clean Environment

• Communicable diseases are mainly caused by
  bacteria and viruses that come into contact with
  food, air, and surfaces that you touch on a daily
  basis
• Clean, sanitary environments kill these unwanted
  micro-organisms
• Special cleaners such as chlorine,
  anti-bacterial soaps, etc. help eliminate
  bacteria and viruses
• When working with food, gloves and washing is
  encouraged to reduce the spread of these microbes
  and food poisoning

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Other Ways to Prevent Disease

• 1) Prevent food poison Food poisoning is due to
  staphylococcus bacteria coming into contact with
  food. To prevent the spread of this bacteria use
  gloves when touching food, wash your hands
  regularly, cover your mouth when coughing, clean
  all cooking utensils, change dishcloths
  regularly, do not use sponges
• 2) Another way is to preserve food

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Food Preservation Techniques

• Food preservation techniques limit the growth of
  pathogens that cause food poisoning.
• Use Table 9.3, on pg.168 to describe the
  following ways to preserve food
• Smoking/drying food
• Caning
• Salting
• Refrigerating
• Freezing
• Chemical additives
• Vacuum packaging
• Irradiating
• Pasteurization

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• 3) Sterilization Using carbolic acids, steam,
  high temperatures, anti-bacterial agents, or
  other ways to clean and remove bacteria from
  utensils
• 4) Aseptic Methods many steps are taking in
  hospitals, healthcare buildings, retirement
  homes, etc to make the equipment and environment
  pathogen free. Some of these methods include
  using sterile bandages/instruments/masks/clothes,
  scrubbing and washing all exposed skin before and
  after surgery, wearing rubber gloves and masks
• Why do you think that these methods so important
  in hospitals and retirement homes?