Here are some interesting words: "infection", "bacteria", "virus", "microbe", "antibiotics" and "antibiotic resistance".
If anything destroys the human race before climate change, it might well be antibiotic resistance. This is in the UK news at the moment, because when we leave the European Union we will probably have to make a new trade deal with the US, where standards for food production are much lower. One of the problems, besides chlorinated chickens and hormone-injected cows, is the use of antibiotics. So I thought we could look at some relevant vocabulary.
Here we go...
Infections (illnesses caused by the body being invaded by organisms) are mainly caused by two types of microbe (tiny organism): bacteria and viruses.
"Bacteria" is the plural, by the way; the singular is "bacterium" but it's almost never used.
Viral infections range from AIDS to flu and the common cold. Bacterial infections include tuberculosis and tetanus, as well as most types of food poisoning. On the other hand, many bacteria cause no harm, and some are essential. In fact we need lots of bacteria in our gut to help us digest food.
Just to confuse matters, some infections can be caused by either bacteria or viruses, including pneumonia and diarrhoea.
Antibiotics are medicines designed to kill bacteria. As the name suggests, they don't work on viruses. Antibiotics changed the world, saving us from many diseases that once would have killed us. Like pretty much all medicines, they can have negative side effects. One of these is that they can damage the good bacteria in your gut, often causing diarrhoea.
But that's not the scary thing. Bacteria can evolve* quickly and learn how not to be killed by an antibiotic. This is called antibiotic resistance. It means that, unless there's a major advance in science, at some point in the near future, antibiotics will probably stop working.
One of the things that encourages antibiotic resistance is the misuse of antibiotics. Giving them to animals or people that don't actually need them gives the bacteria lots of opportunities to evolve and develop their antibiotic resistance. And that's really scary.
*"Evolve": develop over successive generations. For example, humans evolved from apes. Can also be used to mean "develop" in a more general sense.
