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