Campylobacteriosis (campylobacter infection): symptoms, causes and when to get help

Campylobacter is a group of bacteria that infect the gut. The infection they cause is called campylobacteriosis. UKHSA describes it as the most common type of bacterial food poisoning, and an NHS hospital leaflet says it is currently the most common cause of food poisoning in the UK. The NHS website lists campylobacter first among the germs that most often cause food poisoning, ahead of salmonella, E. coli and norovirus.

Most illnesses are caused by one species, Campylobacter jejuni. In UKHSA data for 2024, C. jejuni accounted for 88.4% of the samples where the species was identified. For the person with the illness the practical difference is small: the symptoms and the advice are the same.

The hospital leaflet explains that campylobacter is most often found in cattle, poultry, sheep and goats, and that puppies, kittens and birds can also be a source. You can catch it by eating contaminated food such as chicken that has not been cooked properly, by drinking untreated water or milk, by contact with farm animals or pets with diarrhoea, and by eating foods that have been contaminated by raw meat during storage.

The NHS adds the general ways that food becomes unsafe: not cooked or reheated thoroughly, not stored correctly, left out for too long, handled by someone who is ill or has not washed their hands, or eaten after its use by date. Spread from one person to another is described in the leaflet as uncommon, though careful hand washing remains important.

UKHSA noted that of 9 foodborne outbreaks reported to national surveillance in 2024, 5 were likely associated with liver or products containing poultry liver such as pâté or parfait, a reminder that undercooked liver is a recognised source.

The NHS lists feeling or being sick, diarrhoea, tummy pain, a high temperature and feeling generally unwell as symptoms of food poisoning. For campylobacter specifically, the hospital leaflet says most people have stomach ache, diarrhoea and fever, with vomiting uncommon, and UKHSA says diarrhoea is often bloody.

After swallowing the bacteria the illness can take between 1 and 11 days to appear, but most commonly develops in 2 to 5 days. The NHS says symptoms of food poisoning usually get better within a week. The leaflet notes that diarrhoea can continue for 2 to 3 weeks in some people, even if they have been given antibiotics.

The NHS says the most important thing is to drink lots of fluids to avoid dehydration, taking small sips if you feel sick. It advises staying at home and resting, eating when you feel able, avoiding fatty or spicy food if that helps, and taking paracetamol if you are in discomfort. It says not to give children under 12 medicine to stop diarrhoea and not to give aspirin to children under 16.

A pharmacist can help, particularly if there are signs of dehydration such as dark, smelly pee or peeing less than usual, or if you are an older person or have a weakened immune system. The NHS says they may suggest oral rehydration powder or, for a short time, a medicine such as loperamide, which is not suitable for under 12s.

The NHS says to call 111 if you are worried about a baby under 12 months, if a child under 5 has signs of dehydration, if you or your child keep being sick and cannot keep fluids down, if there is bloody diarrhoea or bleeding from the bottom, or if diarrhoea lasts more than 7 days or vomiting more than 2 days.

It says to call 999 or go to A&E for vomiting blood or vomit that looks like ground coffee, sudden severe tummy ache, a stiff neck with pain looking at bright lights, a sudden severe headache, blue, grey or blotchy skin, severe difficulty breathing, or confusion and not responding as usual.

Campylobacter is confirmed by finding the bacteria in a stool sample, which is how the infection becomes known to hospitals and to UKHSA. The hospital leaflet says that in most cases there is no special treatment beyond drinking plenty of fluid and resting, and that in severe cases patients may be given antibiotics. Doctors decide this case by case; antibiotics are not routinely needed for most people.

The hospital leaflet emphasises personal hygiene, especially hand washing after using the toilet and before preparing food, as the most important way to protect others.

The hospital leaflet gives clear steps: keep cooked and uncooked food separate in your kitchen, cook all food properly especially chicken, do not drink untreated milk or untreated water from rivers and lakes, and wash your hands with soap and water and dry them thoroughly after touching pets or farm animals, before and after handling raw meat and poultry, and after using the toilet. It also suggests extra care with food and water abroad.

Most campylobacter infections are managed through self-care, a pharmacist, NHS 111 or a GP, all of which are NHS routes. Stool testing is normally arranged through the GP or hospital and is free on the NHS. Private testing is available to some people who prefer it, but it is not usually needed for mild illness that is improving.