transmission of disease

• Animals- direct transmission

  -direct contact= kissing, contact with body fluids, microorganisms on hands from faeces, direct skin to skin contact eg: athelet's foot, ring worm

  -inoculation= through a break in the skin, from an animal bite- rabies, through a puncture wound or sharing needles- septicaemia

  -ingestion= contaminated food/drink.
• Animals- indirect transmission

  -formites= inanimate objects such as bedding, socks, cosmetics

  -droplet infection= droplets of saliva, mucus

  -vectors= transmit pathogens from one host to another- malaria.
• Animals- factors affecting transmission

  -overcrowded living conditions

  -poor nutrition

  -compromised immune system

  -poor disposal of waste

  -climate change= new vectors

  -socioeconomic factors
• Plants- direct transmission

  -direct contact= a healthy plant with any part of a diseased plant.
• Plants- indirect transmission

  -soil contamination= pathogens or reproductive spores from protists, fungi in the soil.

  -vectors: wind= pathogens carried by wind

  water= spores swim in surface film of water on leaves.

  animals= insects/birds carry pathogens and spores.

  humans= pathogens transmitted by hands, clothing- ring rot survives on farm machinery.
• Plants- factors affecting transmission

  -plants variety of crops susceptible to disease

  -overcrowding increases likelihood of contact

  -poor mineral nutrition reduces resistance

  -damp, warm conditions increase survival and spreading of pathogens

  -climate change- increased rainfall+ wind promote spread of disease