How FSS aims to protect consumers is laid out in Strategy to Reduce Foodborne Illness in Scotland .Through this strategy, we aim to identify the points in the food chain where contamination can occur and develop interventions which are likely to have the greatest potential for reducing the risks to human health.
Regulations exist to ensure food businesses take appropriate steps to control food safety risks before products are placed on the market. To support food safety management, we apply a ‘farm-to-fork’ approach; to try to ensure contamination is minimised as much as possible during the production and processing of food before it reaches the kitchen. We also promote good food hygiene practices through the development of guidance for Scottish food businesses and caterers; and we also provide consumer guidance. All of our work is supported by research to ensure all of our strategies and interventions are effectively targeted and evidence based.
Main causes of foodborne illness in Scotland
Foodborne illness is most frequently caused by the consumption of food which has become contaminated with harmful microbiological agents, or pathogens, including bacteria and viruses. In Scotland, it is estimated there are 43,000 cases of foodborne illness annually, with 5,800 GP presentations and 500 hospital admissions. FSS works closely with the Food Standards Agency (FSA) and Scottish partners such as Health Protection Scotland (HPS) to target the bacterial and viral pathogens which cause the highest number of cases of foodborne illness.
HPS is responsible for undertaking surveillance of infectious intestinal disease (IID) caused by the key pathogens of interest. This surveillance records the total number of cases of IID which have been acquired through the food chain and other sources such as contaminated water or the environment. Current and historical figures for each pathogen can be accessed through the HPS website.
Campylobacter is the most common form of bacterial foodborne illness in Scotland (a situation which is similar to the UK and most of the developed world). Illness usually lasts around a week and is characterised by diarrhoea, abdominal pain and fever, and, in some cases, nausea and vomiting. For some patients, campylobacter can result in much more serious illness post infection, including irritable bowel syndrome (IBS), reactive arthritis and, in rare cases, Guillain-Barré syndrome – a serious condition of the nervous system. At its worst, campylobacter can kill.
FSS has commissioned research with the University of Aberdeen to improve our understanding of the most important causes of campylobacter in humans in the Scottish population. The results of this research indicate that the types of campylobacter identified in human infection in Scotland are most closely associated to those found in chicken (55-75%), followed by cattle (10%), sheep (10-22%), pigs (0-8%) and wild birds (4-8%).
This research provides evidence that the most important source of infection is chicken, either through the consumption of raw or undercooked chicken or through cross-contamination to other ready to eat foods or surfaces.
FSS has been working closely with FSA and industry to tackle the levels of campylobacter in UK produced chicken to reduce the number of foodborne campylobacter infections. A voluntary slaughterhouse target of less than 10% of poultry leaving processing plants with the highest levels of contamination (>1000 cfu/g) was agreed.Poultry producers, retailers and other stakeholders have worked to identify and implement effective interventions for controlling campylobacter at all stages of the food chain. They have all made significant investments and improvements in their processes and many have achieved the target set to reduce the highest levels of campylobacter contamination. Therefore focus will now move to encouraging and working with smaller retailers and processors who generally do not meet the target levels and have not had the same levels of improvements made to their processing lines.
FSS are also collaborating with other partners in Scotland including HPS and Scottish Government to understand how people in Scotland can become infected with campylobacter through other exposure routes such as the environment and identify ways that they can protect themselves from the risks.
FSS has produced a campylobacter factsheet for caterers and other small businesses.
Shiga toxin-producing E. coli (STEC)
Shiga toxin-producing E. coli is commonly referred to as STEC and is also synonomous with verotoxin producing E. coli (VTEC). There are many different STECs including E. coli O157.
STEC is an important public health challenge in Scotland, as it continues to cause outbreaks of infection, severe illness and, in some cases, death, particularly among the very young. Clinical aspects of infection STEC infection can be asymptomatic, or cause a spectrum of illness ranging from mild diarrhoea, bloody diarrhoea and haemorrhagic colitis. Haemolytic uraemic syndrome (HUS), a consequence of STEC which can lead to kidney failure is more likely in those aged under 16 or over 60 years.
Non-domestic animals, particularly ruminants, are the main reservoir of the organism, which rarely causes disease in livestock. Infection occurs when humans ingest organisms originating from animal faeces, most directly by contact with grazing animals, their environments or contaminated food or water.
Two large outbreaks of E. coli O157 infection (Wishaw 1997 and South Wales 2005) resulted from poor cross-contamination controls by Butchers, which lead to the spread of the pathogen to ready to eat food from contaminated raw meat. Guidance has been published on the steps for food businesses to take in order to control cross-contamination between raw foods that are a potential source of E. coli O157 and ready-to-eat foods. In November 2013, Scottish Government’s VTEC/E. coli O157 Action Plan for Scotland was published, which sets out 86 recommendations designed to tackle STEC/E. coli O157 infection in Scotland. FSS has been working, as a member of the multi-agency action group, to consider ways to disrupt the transmission routes for STEC from source to humans and has sole or joint responsibility for 23 of the recommendations. Good progress has been made on addressing these recommendations through improving STEC controls at primary production, monitoring of contamination at abattoirs, implementation of the cross-contamination guidance and robust enforcement of controls at butchers and caterers across Scotland, communication of food hygiene messages to consumers, and research to improve our understanding of the pathogen and risks in the food chain.
The public health importance of Listeria monocytogenes as a gastro-intestinal pathogen arises not from the number of reported cases, which is relatively low (10-20 cases annually in Scotland) compared with many other pathogens, but rather due to the severity of infection, high mortality, and the fact that it is foodborne. Infection with Listeria monocytogenes causes influenza like illness, septicaemia or a meningo-encephalitis. Pregnant women, newborn infants, the elderly and immunocompromised individuals are most at risk.
Due to the long incubation period for Listeria monocytogenes (up to 90 days) it is difficult to determine the key sources of infection. However, listeria bacteria has been found in a range of chilled ready to eat foods including pre-packed sandwiches, pate, smoked salmon, soft cheeses and cooked sliced meats.
Our work is aimed at reducing the risks of Listeria monocytogenes in the production, storage and handling of chilled ready to eat foods which are most commonly associated with human illness. We have produced an online tool to help smoked fish producers manage the risk of contamination of their product by Listeria monocytogenes, which is often found in the production areas of manufacturers of smoked fish. This initiative aims to help producers of these foods to follow best practice so they can reduce the risk of contamination of their products.
It is also a priority for us to ensure information about risk and avoidance is communicated effectively so listeriosis can be prevented among high-risk groups. We have collaborated with FSA to provide guidance for staff with responsibility for providing food in care settings to allow them to identify and manage the risks that are specific to Listeria in the food supply chain, with the ultimate aim of reducing the risk of vulnerable groups contracting listeriosis in these settings.
Salmonella is the second most commonly reported cause of bacterial infectious intestinal disease in Scotland after campylobacter. Common symptoms include diarrhoea, stomach cramps, nausea, fever and occasionally vomiting. These symptoms usually last 4-7 days and clear up without treatment.
Salmonella can cause illness through a number of routes including contaminated food, environmental exposure, or transmission from infected animals.
During the late 1990s, when vaccination against Salmonella Enteritidis was introduced in the poultry industry, there was a 37% decrease in the number of cases of Salmonella in Scotland, and in following years the numbers have continued to decline annually. However it remains an important pathogen and is responsible for a large number of outbreaks each year, especially from eggs originating from unvaccinated flocks.
EU Regulation requires Member States to take effective measures to detect and control Salmonellas of public health significance in specified animal species at all relevant stages of production. National Control Programmes have been established in the UK to reduce the prevalence of Salmonella in poultry and pigs at primary production level. They cover farm animal species which present a potential risk of transmitting Salmonella and other zoonotic agents to humans.
The virus which is most commonly linked to food is norovirus, which is also known as the ‘winter vomiting disease’, although it can occur at any time of year. Infection usually causes a mild, short lived illness (which lasts 12-60 hours) characterised by sudden onset nausea followed by projectile vomiting and diarrhoea. Dehydration may occur and hospital treatment is sometimes necessary, particularly for the young and elderly.
Norovirus is highly infectious, and person-to-person spread accounts for a high proportion of cases, with outbreaks common in semi-closed settings including carehomes, schools, nurseries, hotels and cruise ships. However, norovirus infection can also occur through contact with contaminated environments or eating food which has been grown in or treated with contaminated water (e.g. shellfish or fresh produce). FSS are currently participating in the EU baseline survey of norovirus in oysters. Additionally, norovirus can be passed on by an infected food handlers and therefore those working in the food industry should adhere to the Fitness to work guidance.
Other causes of foodborne illness
Foodborne illness can also occur following the consumption of food or drink that has become contaminated with either naturally occurring or man-made chemicals. Food Standards Scotland works with FSA and other government agencies to assess the potential food safety risks arising from chemical contaminants and take appropriate action to protect public health.
For more information, see our Contaminants page.