There are more than 500,000 cases of recorded food poisoning a year in the UK according to the Food Standards Agency (FSA), and those are just the ones we know about. Researchers estimate the true figure could be upwards of a million. Often people may have the symptoms of food poisoning but don't seek any medical treatment or, if they do go to their GP, are not tested to see what particular microorganism (or pathogen) has made them so unwell.
What is food poisoning?
You get food poisoning after eating contaminated food. Unfortunately you can't tell by looking at it that food is contaminated. In most cases the food is contaminated by bacteria or a virus. It's the reason why good standards of food preparation and cooking are so important.
Food poisoning symptoms
Symptoms depend on what bug was responsible for contaminating your food and usually begin 1 to 2 days after you've eaten the contaminated food. However, symptoms can start within hours or even several weeks later.
The main symptoms are:
People who've eaten contaminated food usually get better within a few days. They should rest and make sure they have plenty of fluids to prevent dehydration.
Types of food poisoning - bacterial
You're more likely to need hospital care with salmonella than any other type of food poisoning. According to the Food Standards Agency there are around 2,500 admissions to hospital a year in the UK due to salmonella food poisoning. Salmonella is the name for a group of bacteria which can be found in raw meat and poultry.
It spreads by eating food contaminated by poo from infected people or animals. Vegetables, fruit and shellfish can be contaminated by contact with manure in soil or sewage in water.
Salmonella is killed by cooking and pasteurisation.
Listeria is found in soil, water and some animals, including poultry and cattle. The bacteria can be in a number of uncooked foods, such as meats and vegetables. It can also be present in unpasteurised milk or foods made from unpasteurised milk as well as in processed foods such as soft cheeses, cooked sliced meats and pre-packaged sandwiches because it can live in the processing plants.
Listeria is unusual because it can grow even in the cold temperature of the fridge. It's killed by cooking and pasteurisation.
Its full name is Escherichia coli. It's a bacteria found in the digestive system of humans and many other animals. Many strains of E.coli are harmless but some produce a poison or toxin.
You can contract it from swimming in contaminated water and from farm animals, particularly cows, sheep and goats. You can also get it from undercooked meat, unpasteurised foods and eating unwashed vegetables that have come into contact with manure from infected cattle.