1 There are many ways that pathogens
can be spread from one person to
1.1 Droplet infection - when you cough,
sneeze or talk you expel tiny droplets full
of pathogens from your breathing system.
1.2 Direct contact - some diseases are
spread by contact of the skin.
1.3 Contaminated food and drink - eating raw or
undercooked food, or drinking water
containing sewage can spread disease.
1.4 Through a break in your skin - pathogens can enter your
body through cuts, scratches and needle punctures.
2 The main ways of preventing microbes getting
into your body are your skin, your blood and your
3 If pathogens get inside the body they will meet your second line
of defence - the white blood cells.
3.1 Some white blood cells ingest pathogens which
destroy them so they can't make you ill.
3.2 Some white blood cells produce special chemicals called
antibodies. They target particular bacteria or viruses, you need a
antibody for for each pathogen so once they are made once, the
pathogen is remembered and that antibody can be made very
3.3 Some white blood cells produce
antitoxins, they counteract the
toxins released by pathogens.