microorganisms in relation to human health: chapter 2

Routes of contamination

• food and drinking water

  • foodborne infection

    • food is contaminated with microorganisms → multiply in the body → infect the intestinal wall

    • prevention: during preparation → heat the food above 75°c/167 F

    • example: salmonella, cholera

  • food poisoning

    • food is contaminated with toxins that could be coming from bacteria who leave the toxins after contamination

    • example: Botulism → botulin which is produced by the bacteria Clostridium botulinum → affects the nervous system

• Inhaled air

  • aerosol = a suspension of fine solid or liquid particles in a gas

    • can contain microorganisms

    • example: influenza, TBC (tuberculosis)

• other ways

  • via cracks mucous membrane

    • example: HIV, STDs

    • prevention: a condom

  • via contaminated needles

    • via the vein, into the bloodstream

    • example: reused drug needles (a needle to inject drugs → blood goes in the syringe and needle HIV spreads through the blood) → HIV, HBV (Hepatitis B Virus), HCV (Hepatitis C virus)

  • via skin wounds

    • microorganisms come into the skin barrier

    • example: tetanus → caused by the bacteria Clostridium tetani → in the earth or old metal

  • via bit and stab wounds

    • microorganisms come into the skin barrier

    • example: rabies → bitten by an infected animal like dogs, foxes, bats, cats,

      malaria → bitten by a female mosquito who carries the disease

      sleeping sickness or African trypanosomiasis → bitten by the Tsetse fly

      Lyme disease → bitten by ticks who carry the bacteria Borrelia burgdorferi