The trouble with Campylobacter
26th November 2014
The anticipated publication by the Food Standards Agency (FSA) of specific retailer’s levels of Campylobacter bacteria on chicken meat tomorrow has brought the issue back to the forefront of consumers’ minds.
Campylobacter is the most frequent cause of bacterial foodborne illness in the UK, with the number of cases reaching up to half a million a year. It is commonly found within the gut of poultry, in particular chicken. As chicken is now the most popular choice of meat for UK consumers, the problem is a major health and consumer issue, with a huge economic cost to healthcare, and lost time at work. However it is not a particularly hardy bug. It will not survive in low temperatures and is easily killed by heating above 50oC.
Campylobacter has evolved to colonise the gut of chickens, where it can reside happily and not cause any outward symptoms or disease within the bird. It becomes a problem to us when chicken meat is contaminated during slaughter, and when the bacteria are present in chicken livers used for pate.
Due to the rise in incidences of foodborne Campylobacter infection, and the increasing consumption of poultry, reducing Campylobacter within chickens is currently a major focus of collaborative research between the Food Standards Agency, the poultry and food manufacturing industry and academic institutions. The FSA’s figures show that Campylobacter is an industry wide issue with no one processor or retailer being responsible, so a collaborative approach is vital and essential.
The Food Safety Centre at the Institute of Food Research (IFR) is contributing on many levels. It is working with the FSA to identify characteristics within strains of colonising Campylobacter, with the poultry industry to determine the effects of processing on the Campylobacter strains, and with fellow academics to develop more sophisticated genetic techniques to allow easier tracking and identification of strains. IFR is strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), who, along with Defra and the FSA are co-funding initiatives to study Campylobacter in the food chain, from field to plate. By tackling the problem collaboratively, any solutions will be quicker and easier to implement, and we will see reductions in the amount of Campylobacter reaching consumers.
More about Campylobacter
What is Campylobacter?
Campylobacter is a group of bacteria which are commonly found in the intestines of many animals and especially birds. In many of these animals and birds it is relatively harmless, and although it may cause underlying disease in some birds and animals, this is unlikely to show on the outside. Hence it is difficult to impossible to screen birds or animals for Campylobacter just on their outside appearance or signs of illness.
So, what’s the problem then?
While birds and animals generally do not develop disease, this is different for humans, especially in the Western world. In countries like the UK it is by far the most common cause of diarrhoeal illness caused by bacteria, with more than a quarter of a million cases annually. The problem is not limited to the UK: in Europe it is estimated that there are between 2 and 20 million cases annually. This is a very important public health problem, but also an economic problem due to days of work lost, cost to the NHS and effects on the export of food.
What are the symptoms of Campylobacter infection?
In Western countries like the UK, the problems usually start about 1-3 days after eating the contaminated food, and typical signs are (severe) abdominal pain and diarrhoea, with fever and generalized malaise and nausea. Vomiting is not a common symptom. In developing countries infection often presents as milder diarrhoea and asymptomatic colonization is common.
Symptoms often resolve within a few days, but in a minority of cases there are possible serious complications which can develop months later. These include reactive arthritis affecting ankles, knees and wrists, and more seriously paralytic diseases such as Guillain-Barre syndrome, which can lead to death or lifelong mobility problems.
Why hasn’t Campylobacter been more widely heard of?
Although the symptoms of the diarrhoeal illness are very unpleasant, they are not specific and usually resolve without treatment. This means many people do not go to their GP. Also infections occur throughout the year, rather than in outbreaks, and as Campylobacter does not commonly kill people, it does not make the headlines as much. This is changing though as Campylobacter is in the news a lot recently, as it is an issue the FSA is trying to address in order to reduce its social and economic impact. How do the bacteria cause these problems?
Although Campylobacter can be picked up from many sources, in the UK contaminated poultry meat, especially chicken, is seen as the major source, as the bacteria’s main habitat is the intestines of poultry. During processing, intestinal contents can get onto the meat, and the bacteria may somehow survive the handling and storage, through as yet unexplained mechanisms, to reach the consumer. If this meat is then not properly cooked, or kitchen hygiene is not rigorously applied (see below), the Campylobacter can cause sickness. When ingested through contaminated food, the Campylobacter bacteria quickly move to the lining of the intestine, and disrupt this lining, leading to diarrhoea. Besides the activity of the bacteria, the human immune system wants to destroy the invading bacteria, and while it is often successful, this again causes a lot of damage in the intestine with bloody diarrhoea, cramps and pain as consequence, and this can lead to the complications like arthritis, paralytic disease and inflammatory bowel disease.
How can I prevent getting Campylobacter?
It will always be important to be aware of the possibility of Campylobacter on the meat, as even with all the best efforts, we are unlikely to ever be able to eradicate 100% of Campylobacter.
It is vitally important is to apply kitchen hygiene rigorously.
- Wash and clean all chopping boards, utensils and surfaces used for preparing poultry meat, or use separate ones for raw meat. Also wash your hands with soap and warm water afterwards.
- Don’t wash the chicken or turkey, as this is likely to spread the bacteria onto other kitchen surfaces.
- Make sure the meat is cooked throughout, so that no pink meat remains, and the juices run clear.
- Store your chicken at the bottom of the fridge, to prevent juices dripping on other food. It has been suggested that freezing the poultry meat aids safety, as this will lower the number of bacteria on the meat. Campylobacter may also be present on the packaging, so double-bag your chicken to reduce the risk of contamination.
- When going to restaurants and fast food outlets, check the food hygiene rating of the outlet.
Is organic or free-range poultry meat free of Campylobacter?
No, these can contain similar levels of Campylobacter, and should not be treated differently.
Why doesn’t the government or the industry do something about it?
They are doing something about it. This is a problem without quick fixes or easy solutions, and all partners involved (government/regulators, producers, retailers, other food industry, consumers and scientists) want to solve it. Solutions need to be long-term, economically viable and robust. While all partners are doing everything within their power to look for these solutions, consumers can play their part by protecting themselves, thereby solving the problem together.