There cannot be many people who are not familiar with salmonella food poisoning. This may be a type of food poisoning which you yourself have experienced or know of others who have suffered from it.

And ‘suffer’is the right word when it comes to describing this very unpleasant form of food poisoning.

The technical name for this type of food poisoning is ‘salmonellosis’which occurs as a result of consuming food infected by these bacteria. This bacteria is not one but rather a group of bacteria which are known to cause food poisoning.

The salmonella bacterium is rod shaped in appearance which is able to move quickly and freely. It is found within poultry especially chicken which has not been undercooked, raw eggs or food which has not been prepared properly. It also thrives in unclean kitchens and areas where there is poor hygiene.

These bacteria can survive for a long period of time in both dry and wet conditions and as a result of this is often found in water which has been contaminated by bird and reptile faeces.

Types of salmonella bacteria

There are numerous types of salmonella bacteria but there is one type in particular which is responsible for causing food poisoning.

This is the Salmonella Enteritidis bacteria.

These bacteria enter the digestive system and once there, they attack the cells within the lining of the intestines which then causes this infection.

Foods which contain the salmonella bacteria

Eggs or any product which contains raw egg, for example mayonnaise is likely to contain salmonella bacteria. Other examples include:

  • Poultry, e.g. chicken
  • Meat
  • Unpasteurised milk
  • Salad dressings
  • Cream based desserts and cakes

More than 20 years ago the UK experienced uproar over the claims that salmonella could be found in both chicken and eggs which caused a drop in sales of both of these food products.

It also damaged the reputation of a politician who, as health minister at the time, made these claims.

There are fewer risks now but according to the Food Standards Agency there were an increase in the number of cases of salmonella poisoning in 2009.

(Source: Food Standards Agency: Nov 2009)

However, measures have been put in place to reduce this risk which includes a national testing programme. This is an effective way of doing so but it is important to realise that there is no guarantee of a salmonella free chicken or egg.

Outbreaks do still happen, especially in places such as nursing homes or social events where groups of people are congregated together. This is why it is important to practise good hygiene and food safety to prevent the risk of this happening.

Who is likely to get salmonella food poisoning?

The elderly, children and people who have a compromised immune system, e.g. have HIV, are at high risk of contracting this type of food poisoning.

The main reason for this is that it is a highly infectious illness which spreads via person to person contact. This is why it often occurs in nursing and residential care homes, hospitals and nurseries.

This is a very common form of food poisoning.

Causes of salmonella food poisoning

It is caused by the salmonella bacteria which live in the digestive systems of poultry, farm animals and household pets.

This means that there are a wide range of food products, e.g. chicken, which are likely to be contaminated by the salmonella bacteria.

Normally salmonella bacteria are destroyed during cooking at temperatures of more than 66 degree Celsius: or are prevented from reproducing themselves if stored at temperatures lower than 4 degrees Celsius.

But, if food is not cooked at the correct temperatures such as those mentioned above, or are left out overnight instead of being kept in a fridge then contamination will occur.

So, if you eat food which has been contaminated then you will develop salmonella poisoning. This also happens if you eat unwashed fruit and vegetables or shellfish which have been swimming in contaminated waters.

Apart from food another source of infection is household pets. Dogs and cats can both become infected with salmonella or act as carriers for these bacteria. Stroking or touching an infected pet will enable the bacteria to transfer to you.

If, for instance you stroke or pat a dog which is harbouring these bacteria then they will pass from the dog, through your hands and into your mouth. The bacteria will then pass through your digestive system and into your intestines where they will cause an infection.

Symptoms of salmonella food poisoning

Symptoms develop within 12 to 72 hours after eating contaminated food. The period of time before these symptoms appear is called the ‘incubation period’.

These symptoms include:

  • Nausea
  • Vomiting
  • Stomach cramps
  • Diarrhoea
  • Fever
  • Chills
  • Muscle aches
  • Loss of appetite

This illness usually lasts between 5 to 7 days.

Most cases are mild but severe cases or complications can develop which may require medical treatment.

A major side effect of this is dehydration. Dehydration occurs if someone has lost an excessive amount of fluid due to vomiting and/or diarrhoea. A mild case of dehydration can be treated at home by drinking plenty of fluids but a severe case will require fluids via an intravenous drip in hospital.

This is particularly the case if the person affected is a young child or an elderly person.

Treatment for salmonella food poisoning

If your symptoms are relatively mild then they can be dealt with at home. This involves getting plenty of rest and drinking lots of fluids. Make sure that any fluids you drink contain electrolytes to replace any vitamins and minerals lost as a result of your illness.

Painkillers such as ibuprofen can help to ease any headaches or muscle pains.

If your case requires medical treatment then your GP may prescribe antibiotics to help clear the infection. Your GP will also ask you about the types of foods you have recently eaten and whether you have been abroad as well as your medical history.

He or she will examine you, check your blood pressure, pulse and temperature and may also you for a sample of faeces to check for signs of the salmonella bacteria. This sample is sent away to a laboratory for analysis and confirmation of this diagnosis.

Seek medical advice if your symptoms persist, worsen, you have an underlying condition or you suspect that you have contracted food poisoning from outside the UK.

Plus contact your GP if you think that your food poisoning has been caused by eating out at a restaurant or a meal from a fast food outlet. He/she has to report this via a large database of identified cases in case it is part of a wider outbreak.

Find out more in our reporting food poisoning section.

Preventing the spread of salmonella food poisoning

What is important is to prevent the spread of this illness to other people. This means taking a few precautions such as washing your hands every time you go to the bathroom, avoiding handling any food until you are fully recovered and using separate towels, bedding and sheets.

If your job involves handling food then inform your employer of your illness and stay home from work until you are completely recovered.

This similarly applies if your job involves working with children or the elderly.

Complications of salmonella food poisoning

These tend to be uncommon but if they do happen are more likely to develop in people who are considered a ‘high risk’.

These complications include:

  • Dehydration
  • Irritable bowel syndrome (IBS)
  • Lactose intolerance
  • Persistent bouts of diarrhoea
  • Infection spreads to other parts of your body
  • Reactive arthritis

These are discussed in more detail in our complications of food poisoning section.

Preventing salmonella food poisoning

It is possible to prevent this type of food poisoning by following a few easy steps. These are:

  • Keep kitchen surfaces and areas clean and tidy
  • Avoid cross contamination: this means separating raw and cooked foods.
  • Wash your hands each time you handle food. Do this before and after.
  • Follow cooking instructions carefully. Check that meat and poultry are cooked through.
  • Store food at the correct temperature within the fridge.

Finally, be aware that pets such as tortoises, snakes, lizards and turtles are known carriers of the salmonella bacteria. Owning one of these increases your risk of this infection as well as posing a risk to any children you may have who are less than one year old.

Food Poisoning Guide

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