microorganisms are a group of tiny organisms including bacteria viruses protists and fungi all the M don't cause any problem a small group of them do and we call these pathogens which we can Define as microorganisms that can cause disease as the pathogens can spread from person to person the diseases they cause are known as communicable or infectious diseases and they affect both animals and plants over the next three videos we're going to take a Clos look at each of these four types of pathogens and some examples of the particular diseases that they can cause for now though we're going to focus on how these pathogens spread from person to person and what measures we can take to reduce this spread one way they spread is through the air for example many Airborne pathogens like the influenza virus or misles virus can be carried in tiny droplets that we expel when we cough or sneeze another route is to contaminated food and water for example chera is a bacterial disease which is spread by drinking water that's been contaminated by The Diarrhea of somebody already suffering from chora meanwhile Salmonella bacteria is spread by eating contaminated food particularly chicken some pathogens have to be spread by D direct contact though for example athlete spur which is a fungal infection that can make the skin on your feet flake off is often spread by walking barefoot on contaminated surfaces such as in public swimming pools now the only thing better than treating a disease is to stop it from spreading in the first place the common sense way to do this is by being generally hygienic such as washing your hands after you've used the bathroom and before preparing Foods and by cleaning cooking items such as knives and chopping boards in some cases we can kill the vectors of the pathogens which are the organisms that transport the pathogen such as mosquitoes which transport the malaria protests in the case of insect vectors the easiest way to do this is by spreading insecticides which are chemicals which kill insects the best way to prevent a pathogen from spreading though is just to vaccinate everybody because if people can't catch the disease in the first place then they can't pass it on to anyone if all of these methods fail though and somebody does catch a disease then what we can do is isolate or quarantine them we generally tend to do this only if it's a really serious disease that could really harm other people if they get infected so just to quickly recap pathogens can be spread in three ways through the air through contaminated food or water or through direct contact and and to reduce this spread we can do four things we can be hygienic we can kill the vectors we can vaccinate people or we can quarantine people if you haven't heard yet you can find all of our videos on our website Cognito toorgle questions and past papers and we track all of your progress so that you always know what to study next so sign up for free by clicking here or browse our playlist here on YouTube