Campylobacter

Campylobacter are germs (campylobacter bacteria) that can cause an unpleasant bout of food poisoning. One of the most common strains in the group is Campylobacter jejuni. When eating or drinking something containing the campylobacter germs it cause illness, usually with gastroenteritis, an infection of the guts.

By far the commonest causes of gastroenteritis are viruses. Bacterial gastroenteritis is much less common but campylobacter is the commonest bacterial cause in the UK.

Campylobacter symptoms

The typical symptoms of campylobacter include:

• Feeling sick (nausea).

• Having diarrhoea (it can sometimes be bloody).

• Vomiting.

• Having crampy stomach pains and a high temperature (fever).

• Possible dehydration.

Symptoms tend to come on within 2-5 days of eating the contaminated food or of being in contact with the contaminated animal. However, sometimes the time period before symptoms appear (known as the 'incubation period') can be as short as one day or as long as 11 days.

In most people, symptoms are relatively mild and improve within 2-3 days. About 9 in 10 affected people recover from the illness within one week. However, sometimes symptoms can be more severe and/or complications can occur. If symptoms are severe, dehydration can occur.

Diarrhoea and vomiting may cause dehydration. Medical advice should be sought urgently if suspecting dehydration in a child. Children, especially babies and children under 2 years old, can become severely dehydrated quickly. Mild dehydration is common and is usually easily reversed by drinking fluids.

For more information on dehydration symptoms in children and adults, see our separate leaflet called Dehydration.

Campylobacter treatment

Most people with campylobacter do not need any specific treatment. The symptoms usually improve in a few days as the immune system has time to clear the infection. People with campylobacter can usually manage at home. Very occasionally, admission to hospital is needed if symptoms are severe, or if complications develop. This is most common in the very young (children under 2 years of age), the very elderly or frail, or people with other conditions such as severe kidney disease.

The following are commonly advised until symptoms ease:

Fluids to prevent dehydration

Plenty of fluids should be encouraged. If there is no vomiting then increasing the volumes and frequency is advised. If there is vomiting then small but frequent amounts of fluid is advised (as described above). The aim is to prevent dehydration. However, fizzy drinks or large amounts of concentrated fruit juices are best avoided as these can make diarrhoea worse.

Babies under 6 months old are at increased risk of dehydration. Medical advice should be sought if they develop gastroenteritis. Breast-feeds or bottle-feeds should be encouraged as normal. Demand for feeds may increase. It may be advised to give extra fluids (either water or rehydration drinks) in between feeds.

Rehydration drinks may be advised for people at increased risk of dehydration (see above for who this may be). They are made from sachets available over-the-counter from pharmacies and on prescription.

Rehydration drinks provide a perfect balance of water, salts and sugar. The small amount of sugar and salt helps the water to be absorbed better from the gut (intestines) into the body.

What about food?

• It is advised to eat as normally as possible once any dehydration has been treated. Correcting any dehydration is the first priority.

• Be guided by appetite - small meals of dry, bland food is usually recommended eg, plain pasta, plain toast, plain rice.

• Breast-fed babies should continue to be breast-fed if they will take it. This will sometimes be in addition to extra rehydration drinks.

• Bottle-fed babies should be fed with their normal full-strength feeds if they will take it. Again, this may be in addition to extra rehydration drinks.

Do I need any medication?

Diarrhoea medicines are not usually necessary. Medicines to stop diarrhoea should never be given to children under 12 years old. They can sound attractive remedies but are unsafe to give to children, due to possible serious complications.

A medicine called loperamide may occasionally be advised but should usually be avoided. Loperamide works by slowing down the gut's activity and it can reduce the number of episodes of diarrhoea but it can cause the symptoms to last for longer.

Paracetamol can be useful to ease some of the symptoms such as high temperature or headache. Ibuprofen can be useful for the same symptoms if there is no vomiting or abdominal pain.

Antibiotic treatment is not usually needed for people with mild symptoms, as infection usually resolves without treatment. If symptoms are severe (high fever, severe or bloody diarrhoea) or if the person has a poor immune system (eg, taking steroids, or using chemotherapy to treat cancer), an antibiotic called clarithromycin may be used (but should be started within 3 days of the onset of symptoms).

Racecadotril is licensed as an addition to rehydration to treat the symptoms of uncomplicated acute diarrhoea in adults and children over 3 months.

How do you get campylobacter?

Like other infectious diseases of the gut, campylobacter germs (bacteria) are commonly acquired from food. They can be found in:

• Raw meat, particularly raw or undercooked poultry such as chicken, turkey, etc.

• Raw unpasteurised milk.

• Mushrooms.

• Shellfish.

• Drinking contaminated water.

• Pets (including cats and dogs) and other animals infected with campylobacter.

Drinking contaminated water whilst travelling is a common cause of campylobacter infection.

For more information on this situation, see the separate leaflet called Traveller's diarrhoea. Campylobacter is one of many possible germs which cause traveller's diarrhoea.

When should I seek medical advice?

In gastroenteritis from any cause (including possible food poisoning caused by campylobacter), medical advice should be sought in the following situations:

• If the affected child is under the age of 6 months.

• If there is a suspicion that dehydration (a lack of fluid in the body) is developing (see earlier).

• If vomiting a lot and unable to keep any fluids down (It is best to try very small volumes of fluid - for example, in a child over 2 years old,10 ml at a time every 10 minutes or in an adult, 25ml at a time every 5 minutes. If even this amount of fluid cannot be kept down then medical attention should be sought).

• If there is drowsiness or confusion.

• If there is blood in diarrhoea or vomit.

• If there is severe tummy (abdominal) pain.

• If the infection was caught abroad.

• If there are very severe symptoms or if the condition is becoming worse.

• If the fever is not settling with time or with paracetamol.

• If symptoms are not settling (for example, vomiting for more than 2 days, or diarrhoea that does not start to settle after 4 days. Diarrhoea often continues slightly longer than this but the episodes should be less violent, less frequent and becoming more solid).

• If there are any other unusual symptoms such as a rash.

• If there is an underlying medical condition such as diabetes or kidney disease and symptoms are not settling quickly.

• If there is a weaker immune system, either due to medication such as chemotherapy or a condition such as AIDS.

• If there is a suspicion that food poisoning may have been contracted from eating restaurant or takeaway food.

How common is campylobacter?

Campylobacter germs (bacteria) are the most common bacteria causing food poisoning in the UK. Public Health England reports that in England and Wales the number of cases increased from 52,381 in 2016 to 56,729 in 2017. The numbers in 2018 and 2019 were very similar to those in 2017. There are probably many more cases which are not tested.

Who gets campylobacter?

Campylobacter food poisoning can affect anyone of any age. It may be more common in:

• People who travel to developing countries where sanitation and food hygiene may be less strict.

• People working with farm animals.

• People who work in the meat industry.

How is campylobacter diagnosed?

Many people will recognise food poisoning from the typical symptoms. If symptoms are mild, there is not usually any need to seek medical advice or receive specific medical treatment. Therefore campylobacter infection may not be 'confirmed'.

However, in some circumstances, medical advice may need to be sought for food poisoning (see above about when to seek medical advice).

Usually people with gastroenteritis will be advised to stay at home and do not need examination. If examination is advised (for example, in young children or the very elderly), checks will be done for signs of dehydration and often checks of the temperature, pulse and blood pressure as well as the tummy (abdomen) to look for any tenderness.

The clinician may request a stool (faeces) sample to test for bacteria. This is not usually requested until the 7th day of illness if diarrhoea is still ongoing. The sample of your stool is sent to the laboratory for testing. Campylobacter is confirmed if the germ (bacterium) is found in your stool sample.

A stool sample is not always needed. It is likely to be suggested in certain situations, such as:

• Recent travel abroad.

• Being severely unwell.

• Having blood or pus in your stools (faeces).

• If the diarrhoea is not settling after a week.

• Having recently been in hospital or having had recent antibiotic treatment.

• Having another medical condition, particularly one which affects the immune system.

• Having a job that involves handling food.

The reason a stool sample is not always needed is that in most cases the diarrhoeal illness will be due to a virus which will not show in a test. Even with a bacterial cause, knowing which bacteria is causing the illness does not necessarily mean that treatment is necessary. Most cases of campylobacter get better on their own even before the stool test result is back.

Are there any complications?

Complications are uncommon in the UK. They are more likely in the very young or in the elderly. They are also more likely there is an ongoing (chronic) condition such as diabetes or if the immune system is not working normally. (for example, if taking long-term steroid medication or if having chemotherapy treatment for cancer.)

Possible complications include the following:

• Salt (electrolyte) imbalance and lack of fluid (dehydration). This is the most common complication. It occurs if the salts and water that are lost in the diarrhoea or vomit are not replaced by you drinking adequate fluids. If managing to drink plenty of fluids then dehydration is unlikely to occur or is only likely to be mild and will soon recover when drinking. Severe dehydration can lead to a drop in blood pressure which can cause reduced blood flow to the vital organs. If dehydration is not treated, it is possible for kidneys to be damaged. Some people who become severely dehydrated need fluid to be given directly into a vein which requires admission to hospital. People who are very young, elderly or pregnant are more at risk of dehydration.

• Reactive complications. Rarely, other parts of the body can 'react' to an infection that occurs in the gut (intestines). This can cause symptoms such as joint inflammation (reactive arthritis), skin inflammation and eye inflammation (either conjunctivitis or uveitis).

• Spread of infection to other parts of your body such as the bloodstream, liver or pancreas gland can occur; however, this is rare.

• Persistent diarrhoea syndromes may rarely develop - for example:

  • Irritable bowel syndrome is sometimes triggered by a bout of food poisoning.

  • Lactose intolerance can sometimes occur for a period of time after food poisoning. This is known as 'secondary' or 'acquired' lactose intolerance. This is more common in children. A child's gut lining can be damaged by the episode of gastroenteritis. This leads to lack of a chemical (enzyme) called lactase that is needed to help the body digest a sugar (lactose) that is in milk. Lactose intolerance leads to bloating, tummy (abdominal) pain, wind and watery stools after drinking milk. The condition gets better over time as the gut lining heals.

• Guillain-Barré syndrome may rarely be triggered by campylobacter infection. This is a condition that affects the nerves throughout the body and limbs, causing weakness and sensory problems. See the separate leaflet called Guillain-Barré syndrome for more details.

• Reduced effectiveness of some medicines. During any episode of food poisoning, medications may not be absorbed as well from the gut and may not be as effective. This is particularly important for medicines such as those for epilepsy, diabetes and contraception.

Can campylobacter be prevented?

The Foods Standards Agency in the UK has identified the '4 Cs' to help prevent food poisoning, including food poisoning caused by campylobacter:

Cleanliness

• Keeping work surfaces and utensils clean.

• Washing and drying hands regularly but especially after going to the toilet, before preparing food, after handling raw food and before touching 'ready-to-eat' food.

• Regularly cleaning toilets with disinfectant.

• Wearing gloves when handling a child's potty.

• Not preparing food for others if suffering from diarrhoea or vomiting.

• Covering sores or cuts on hands with a waterproof plaster before touching food.

• Changing dishcloths and tea towels regularly.

• Washing hands after touching pets or animals, after visiting farms and after gardening.

Cooking

• Making sure that food is cooked thoroughly, especially meat. This will kill germs (bacteria). Food should be cooked right through and be piping hot in the middle.

• If reheating food, it needs to be cooked right through and be piping hot in the middle.

• Not reheating food more than once.

It is also advised to drink only pasteurised or boiled milk and avoid drinking water thought to be unsafe (including avoiding drinks containing ice cubes that may have been made from unsafe water).

Chilling

• Food that needs to be chilled or refrigerated, should be. If food is left out of the fridge, bacteria may multiply to levels that can cause food poisoning.

• A fridge needs to be kept between 0°C and 5°C.

• Leftover food should be cooled quickly and then refrigerated. Taking it out of the cooking pot and putting it into a shallow container can speed up the cooling process.

Cross-contamination

This occurs when bacteria pass from foods (commonly raw foods) to other foods. It can occur if foods touch directly, if one food drips on to another, or if hands, utensils or equipment - such as knives or cutting boards - touch one food and then another. This can be avoided by:

• Washing hands after touching raw foods.

• Separating raw and cooked or 'ready-to-eat' foods.

• Keeping raw meat in a sealable container at the bottom of the fridge.

• Not using the same surface or chopping board for preparing raw and ready-to-eat foods.

• Making sure that knives and utensils are cleaned after preparing raw foods.

Time off work

It is important to stay off work, school, college, etc until at least 48 hours after the last episode of diarrhoea or being sick (vomiting). Contact with other people should be avoided as far as possible during this time.

If someone is working with food and develops diarrhoea or vomiting, they must inform their employer and immediately leave the food-handling area. If campylobacter is confirmed, they should inform their employer and stay away from work until at least 48 hours after the last episode of diarrhoea or vomiting.

Someone who has campylobacter infection and works with vulnerable groups of people such as the elderly, the unwell or the young, should inform their employer.