Campylobacter spp. (mainly C. jejuni and C. coli) are the most commonly isolated bacteria causing food poisoning in the UK, so we culture it as part of the routine investigation of diarrhoea in patients.
The reason we see more cases at this time of year is the
barbeque and the inherent failure of many to cook their meat properly...the usual culprit...chicken. Campylobacter spp. are part of the normal gut flora of most poultry so the uncooked meat is often colonised with these species of bacteria. If the meat is not cooked thoroughly the bacteria
remain on the meat and food poisoning occurs. There have also been outbreaks associated with transfer of Campylobacter spp. from something contaminated (e.g. the contaminated chopping board used to prepare the salad or
the contaminated scissors used to open fruit juice carton).
The incubation period is usually 2-5 days but can be up to 10 days. Patients present with severe diarrhoea, often passing blood and mucus, as well as abdominal pain, vomiting, fever and rigors. Symptoms usually resolve after 2 weeks but can persist for much longer and patients are known to continue to excrete bacteria for as long as 7-8 weeks even if their symptoms resolve.
Patients admitted to healthcare facilities should be isolated in a side-room with their own toilet facilities if possible. Person to person transmission can occur via the faecal-oral
route.
The diagnosis is made by culturing the bacteria from stool
specimens, although patients can often be bacteraemic (have positive blood cultures with Campylobacter spp.)
during the initial acute illness.
Stool culture is time consuming and requires special growth
conditions (specific Campylobacter culture media, incubated at 44oC in micro-aerophilic reduced oxygen concentration). It takes at least 48 hours to get the organism to grow and then a further 48 hours to produce antibiotic sensitivities, if they are required. In this modern era 4 days is a long time to wait when your patient wants to know what is wrong with
them.
There are newer faster methods (less than 24 hours) for
detecting Campylobacter spp. by molecular methods using PCR. These can give faster results and diagnose up to
50% more cases by identifying bacteria which otherwise would fail to grow. However, on the downside they are expensive and they do not give antibiotic sensitivity information.
There is NO SPECIFIC TREATMENT for Campylobacter gastroenteritis. In the vast majority of cases these infections are self-limiting and the patient only requires supportive care with fluids; antibiotics are not indicated and should not be used. Hand hygiene and careful food preparation are the most important ways in controlling infections and outbreaks.
Occasionally immunosuppressed patients or those with severe colitis for other reasons such as inflammatory bowel disease do require antibiotics but increasing resistance due to widespread antibiotic use makes the empirical choices
unreliable. In my practice most isolates are now resistant to Ciprofloxacin and many are becoming resistant to Erythromycin. However if the diagnosis is not Campylobacter spp. antibiotics could make other causes of gastroenteritis much more severe e.g. Clostridium difficile associated diarrhoea. Therefore hold off antibiotics until results are available. Even bacteraemic patients get better
without antibiotics.
So what do you need to do when Campylobacter gastroenteritis is diagnosed in one of your patients?
- Reassure them that it will eventually settle down (even though this may take up to 7-8 weeks)
- Explain to them how they might have caught the infection so to avoid another episode on the next sunny weekend!
- Notify Public Health England about the case so they can make sure there is no risk to the health of others
- Recommend good hand hygiene and careful avoidance of cross infection
And finally, be careful yourselves when preparing and cooking meat, especially chicken and other poultry. You really don’t want Campylobacter spp. or to become the next patient…