All about Food Poisoning and what you should know!

imageLast weekend I was unfortunately struck down for the third time in five years with a rather nasty episode of food poisoning. I have to say that I have become accustomed and even expect the occasional bout of food poisoning as after all, my life revolves around eating out in various restaurants, pubs and bars and then writing about and reviewing the overall experience. I guess it could even be considered an occupational hazard of the “freelance” food writer and blogger. The thing is, it should NEVER happen and is a result of poor food or personal hygiene.

This latest bout tested positive as Bacillus cereus and having eaten rice on that dreaded Thursday night, that all adds up to suggest reheated rice (probably many times) or rice that had been stored far longer than it should have been. By 4am Friday morning it all started, but I won’t subject you to the hours that followed, but suffice it to say, I was pretty ill until Sunday. So the purpose of this blog is to offer some basic information of the common bugs out there and what you can do if you are unfortunate to encounter a bout of food poisoning in a restaurant near you anytime in the future…

There are many different types of food poisoning. The most common are Campylobacter and Salmonella and unfortunately the numbers of people affected by Campylobacter is increasing year after year. Cases of Salmonella have declined due to immunisation of animals.

The young and the elderly are particularly at risk and those people whose job involves handling food, working with children or nursing may pass the infection onto others.
imageSo what are the commonest types of food poisoning and how do we become infected?


Sources – undercooked poultry and meat, untreated milk or ‘milk pecked’ by birds, untreated water, contact with domestic animals and shellfish.

Symptoms – severe diarrhoea sometimes containing blood and abdominal pain

Spread – Via food (undercooked or via cross contamination, water or from animals.

Incubation period (the time it takes from eating the suspected food until symptoms begin) is 1-10 days, most usually 2-5 days

Duration of illness – 2 days – 1 week

Control – Through cooking of poultry and meat, prevention of cross-contamination, pasteurisation of milk, water treatment and precautions when cleaning up after pets.


There are many different types of Salmonella, including typhi and paratyphi both known as enteric fever.

Sources – food such as raw eggs, undercooked poultry and meat, unpasteurised milk, infected food handlers and other people and animals.

Symptoms – diarrhoea, high fever, severe abdominal pain, vomiting.

Spread – Food-borne, due to inadequate cooking and/or cross-contamination made worse by poor handling/storage techniques. Sometimes directly from infected animals. Human to human contact from cases with diarrhoea.

Incubation period (the time it takes from eating the suspected food until symptoms begin) – usually 12-48 hours, occasionally up to 4 days.

Duration of illness – Up to 3 weeks. You may be a carrier for up to 12 weeks or longer after your symptoms have subsided.

Control – through cooking of poultry, meat and eggs. Good personal hygiene.

Reduction of risk of cross-contamination, good temperature control.

Bacillus cereus

Sources: Food – cereal products, rice, spices, dried foods, milk and dairy products.

Environmental – soil, dust, sediments


a) nausea, vomiting and stomach cramps. Diarrhoea may occur later

b) Acute diarrhoea and abdominal pain

Spread: Food: Contaminated cooked food, particularly rice and pasta dishes, dried foods and dairy products

Environment: soil, dust and sediments

Incubation period (the time it takes from eating the suspected food until symptoms begin)

1- 5 hours

8-16 hours

Duration of illness

Usually no longer than 24-36 hours


Correct cooking to minimise spore germination and multiplication. Cooked food should be held hot at 630C before consumption. Left over rice should be cooled quickly and placed in the fridge.

Ecoli – there are 2 types, one being carried by humans and Ecoli O157 caused by undercooked meat or unpasteurised/contaminated milk.

Sources: Humans

Symptoms: Diarrhoea with blood

Spread: Water, human contact via the faecal-oral route.

Incubation period (the time it takes from eating the suspected food until symptoms begin)

10 –18 hours

Duration of illness

2 weeks

Control: Good standards of personal hygiene, through cooking of food

Ecoli O157

Sources: Under cooked beef, contaminated/unpasteurised milk

Symptoms: Range from mild diarrhoea to more serious bloody diarrhoea and can cause kidney damage.

Spread: By food, water and humans via the faecal-oral route

Incubation period (the time it takes from eating the suspected food until symptoms begin)

12 – 60 hours

Duration of illness: Variable

Control: Through cooking of meat until piping hot or juices run clear. Avoid cross-contamination of food

Clostridium Botulinum

Sources: Environment, soil, marine sediments, intestinal tracts of fish and animals

Symptoms: Diarrhoea and vomiting followed by constipation, double vision, dry mouth, difficulty in swallowing, weakness of limbs, paralysis and respiratory failure

Spread: Raw, undercooked or under-processed foods.

Incubation period (the time it takes from eating the suspected food until symptoms begin)

2 hours – 5 days. Usually 12 – 36 hours

Duration of illness: Up to 6-8 months

Control: Food processing technology

Clostridium Perfringens

Sources: Faeces of animals and man, soil, sewage, dust, feeds of animal origin

Symptoms: Diarrhoea and abdominal pain

Spread: Contaminated bulk cooked meat and poultry dishes which have been left at ambient temperature during cooling and storage.

Incubation period (the time it takes from eating the suspected food until symptoms begin)

8 – 18 hours

Duration of illness: 24 hours

Control: Adequate cooling, storage and re-heating of food
imageThe other causes of food poisoning which are unfortunately becoming commonplace are;

Viruses: Some viruses, such as norovirus or rotavirus, can contaminate food and cause food poisoning.

Parasites: These are another type of microbe (germ). Examples include cryptosporidium, Entamoeba histolytica and giardia parasites. Food poisoning caused by parasites is more common in the developing world.

In the UK, the most common parasite that can cause food poisoning is toxoplasma. This is a parasite that lives in the gut of a number of animals, including cats. Food poisoning can occur if food or water is contaminated with the faeces of infected cats, or if raw or undercooked meat from another animal carrying the parasite is eaten. The infection is known as toxoplasmosis. Symptoms of this type of food poisoning include swollen lymph glands and sometimes a skin rash.

Toxins (poisons) and chemicals: Toxins can be produced by bacteria that contaminate the food. For example, the bacterium Staphylococcus aureus can contaminate ice cream and its toxins can lead to food poisoning.
imageSo what should you do to treat your symptoms?

In most cases, food poisoning can be treated at home without seeking medical advice.
It is very important that you do not become dehydrated because it will make you feel worse and slow down your recovery.

Dehydration is a risk because you will lose fluid through vomiting and diarrhoea. You should try to drink as much water as possible, even if you’re only able to sip it, particularly after you pass diarrhoea.

Oral rehydration salts (ORS)

Oral rehydration salts (ORS) are recommended for people vulnerable to the effects of dehydration, such as the elderly and those with a pre-existing health condition.
ORS are available in sachets from pharmacies. You dissolve them in water to drink and they help replace salt, glucose and other important minerals your body loses through dehydration.

If you have a kidney condition, some types of oral rehydration salts may not be suitable for you. Ask your pharmacist or GP for further advice about this.

Other self care advice

To cope with your symptoms and speed up your recovery you should also;

eat when you feel up to it (the gut sometimes needs time to recover and food may cause diarrhoea even if you feel better)

stick to foods that are easily digested, such as toast, crackers, bananas and rice until you begin to feel better. Avoid alcohol, cigarettes, caffeine and spicy and fatty foods because they will make you feel worse.

Further treatment

Visit your GP or accident and emergency (A&E) department if you are severely dehydrated – for example, if you have sunken eyes and you are unable to urinate.

Your GP may admit you to hospital so that you can be given fluids and nutrients through a tube inserted into a vein (intravenously).

Antibiotics may be prescribed if test results show the source of your food poisoning was bacterial, and your symptoms are severe or last longer than 3-4 days.

Antibiotic tablets are usually used, although you may be given injections if your symptoms are severe or if you are having problems keeping tablets down.

You have to trust the people who handle your food and serve it to you, so take some time out and research before visiting an establishment. Read any reviews that might be available and check out the food rating scores from the local council and just remember, that drunken kebab or box of fried chicken might just cost you more than a few quid!image


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