Changing Pathogens

-If you are given a antibiotic, the bacteria which have made you ill are almost killed. The ones that are left are the ones which have a natural mutation, which means they are not affected by the antibiotic. They are resistant to it 

-Antibiotic-resistant bacteria:

-If antibiotics are used too often, or you don't take the full course of medicine prescribed by your doctor, more of the resistant bacteria survive 

-If they go on to make someone else ill, they will not be killed by the original antibiotic. They are resistant to that antibiotic, this resistancw is the result of a process of natural selection 

-As more types of bacteria become resistant to more antibiotics, diseases caused by bacteria are becoming harder to treat 

-To prevent more resistant strains of bacteria appearing it is important not to over-use antibiotics. It's only best to use them when you really need them. It is also very important people finish their course of medicine every time 

-As a result of natural selection hospitals often contain a number of bacteria which are not affected by most commonly used antibiotics 

-This is what happened with MRSA (the bacterium methicillin resistant staphylococcus aureus)

-Ways to control the spread of antibiotic-resistant bacteria:

• Docotors, nurses and other medical staff wash their hands between patients 
• Visitors wash their hands as they come in and leave the hospital
• Look after patients infected with the bacteria in insolation from other patients 
• Keep hospitals clean 
• Medical staff wear either disposable clothing or clothing which is regualrly sterilised 

-Mutation of bacteria caused new diseases to form, and because no-one is immune to them, they can cause widespread illness

-Flu is caused by a virus which mutates easily, so new strains appear which can fool your immune system. These new strains are usually quite similar to the old 'flu' but just occasionally a very different form of 'flu' virus appears 

-These usually cause a flu epidemic (in one country) or even a pandecmic (across several countries). In 1918-19 a new strand of flu emerged which spread rapidly around the world and killed betweeen 20 and 40 million people 

-Animals such as chickens and pigs get flu-like diseases too. Sometimes an animal virus will mutate itself so it can infect people. 

-Scientists are trying to produce different vaccines to protect us agaisnt new and dangerous forms of the disease 

-Countries have plans to restrict travel and put people in isolation if there's a flu outbreak