MICROBES AND DISEASE
The normal result of an interaction between a micro-organism that is not a commensal and man is INFECTION. Infection is the invasion or colonisation of the body by pathogenic organisms. DISEASE results when this results in a change of the state of health.
Pathogens can cause us harm in a number of ways.
- They multiply in the body, using food and oxygen meant for healthy cells.
- They make toxins which damage healthy cells.
Our body has defences against these microbes. Our white blood cells roam the blood stream looking for anything foreign, which should not be in the body. When they encounter something foreign (like a bacterium) they make special chemicals called antibodies. These antibodies stick to the surface of the invading microbes immobilising them. The antibodies also act as markers for white blood cells called phagocytes which engulf and destroy the microbes. The antibodies remain in the blood to deal swiftly with any further invasions by the same microbe. This means that the second time a microbe enters the body, it can be destroyed so quickly that you do not even realise you've been infected. This is known as immunity.
FOOD HYGIENE
Glass of water
Clean water is one of the most important things in life. If it is not clean, water can carry harmful germs, including bacteria and fungi. That's why waterworks, which look after our water for us, have careful cleaning and control systems built in. They make sure the water is clean before it ever gets to us.
Never drink from still rivers, lakes or ponds, or drink water from containers outside - it may have germs that can make you very ill. If in doubt, boil it out!
Raw meat
Raw (uncooked) meat often carries harmful bacteria such as Salmonella or E. coli. But cooking kills bacteria, so meat is safe to eat when it is thoroughly cooked (when the inside of meat is not pink).
When you touch raw meat it's important to use separate utensils, such as knives and spoons, and to wash your hands afterwards. You should also make sure that surfaces are hygienically clean before and after raw meat touches them.
This way you won't pass bacteria from raw meat to other things Symptoms include stomach pain, diarrhoea and vomiting. It takes up to 48 hours to develop and generally lasts only 2 to 3 days. However, in young children and the elderly, the illness can be much more severe.
Main sources are undercooked meat and poultry, untreated milk and raw or undercooked eggs.
Raw fruit and vegetables
Raw vegetables can carry germs which come from the soil and manure on farms. Fruit which is brought to our country from another country can sometimes carry unusual germs.
That's why it's always best to wash fruit and veg before eating it.
Vermin
Vermin such as rats and mice can carry germs which they can pass on to food and surfaces. They can also carry germs from one place to another, e.g. from drains or bins with rotting food.
To stop this happening we need to keep food in safe places and stored in containers which vermin can't sneak into!
Insects
Insects such as cockroaches and flies can carry germs to food and surfaces from drains, the garden and things which are rotting.
The best way to keep insects away is to keep the home clean and keep food covered - most insects like coming into the house looking for dirt, even the tiniest crumbs of food. So store food in containers or in the fridge.
Hands
Every time we touch things our hands pick up germs. They can then get into your body through food, or if you touch your mouth, nose, eyes, or if you have cuts.
That's why it's important to wash your hands before you eat, after going to the toilet, and after playing outside or with animals. It's also good to cover any cuts you have to keep them clean until the skin is better.
A meal
Germs can get into food in many different ways: from our hands, dirty plates, knives and forks or from surfaces such as tables.
But to be safe, simply wash your hands before touching food and eating, and make sure dishes and cutlery are clean.
People
We all carry germs in our body, for example in our mouths, our stomachs and our throats and noses. We can pass them on to other people by sneezing, coughing, touching - or sometimes even by kissing.
Keeping clean - and having good manners! - are the best way to stop germs spreading. Remember:
1. wash hands after going to the loo
2. hide sneezes and coughs in a handkerchief
3. avoid kisses and cuddles if you're ill.
Food Safety - Read the LabelInfection, Detection, Protection