Consumer eating habits have changed over the years with an increased demand for ready to eat (RTE) raw or undercooked fish products, such as sushi or sashimi, gravlax, raw herring and ceviche. This dietary trend has led to a noticeable increase in reported parasitic infections in Western countries. Knowing the hazards and implementing practical control measures can help a food business comply with the law and protect consumers.
Signs and Symptoms
Anisakiasis is a disease caused by the consumption of raw or undercooked fish contaminated with parasitic nematodes (worms) that attach to the wall of the oesophagus, stomach or intestine1. Many cases happen in countries where raw fish is commonly eaten, especially Holland, Scandinavia, Korea and Japan. Infections are mostly associated with fish contaminated by the Anisakis simplex species and are a problem in wild fish such as salmon, herring, cod and monkfish2.
Signs and symptoms of anisakiasis are nausea, abdominal pain, vomiting, diarrhoea, abdominal distention, blood and mucus in stool, and mild fever2. Allergic reactions can also occur in people previously infected by a live Anisakis worm because they can develop a hyposensitivity to the parasite3. Typical symptoms include urticaria, reddening and blistering of the skin and in extreme cases anaphylactic shock3.
Effective control measures must be identified, implemented and maintained to prevent the risk of illness caused by anisakis.
Your approved supplier is legally required to visually inspect fish and must not sell any contaminated with parasites2. But a visual examination is not enough to protect consumers if the product is intended to be eaten raw or when a cooking/smoking process fails to achieve a core temperature of 60OC for 1 minute2. Legislation intervenes with a legal requirement for all food businesses to freeze fish if a previous process has not destroyed the parasite. There are legal critical limits for ensuring all parts of the product have reached a specified temperature over a set period: -20OC for not less than 24 hours or -35OC for not less than 15 hours2. Suppliers are legally required to provide information with the consignment on the type on freezing process the fish product has undergone. If the product has not been frozen and intended to be consumed raw or undercooked, then the caterer will have to carry out the legally specified freezing process2.
Although, there are exemptions for farmed salmon, or a fish product supported by epidemiological data to demonstrate that it does not present a health hazard in relation to parasites2. Scientific evidence produced by European Food Standards Agency (EFSA) shows farmed salmon contaminated with fish parasites is a low risk2. But primary producers of farmed fish must still prove embryos have been exclusively reared in an environment free from parasites and can verify fishery products do not present a hazard to health with regards to parasites.
Documentation and Records
The scope of the food safety management system must consider the risk of anisakiasis if fish is to be served raw or undercooked. The hazard analysis and codex decision tree will document and determine its significance and identify appropriate controls measures at critical control points. Established critical limits will need to be validated and monitored at appropriate frequencies. Written procedures, trained food handlers and accurate monitoring records will also demonstrate due diligence.
The risks of parasites in food are reviewed on all our food safety, food allergen management and HACCP courses. Percipio Training run open courses in Milton Keynes and London. We can also deliver an onsite course at your premises or chosen venue anywhere in the UK. Contact us now to discuss your exact requirements for training.
1. Centers for Disease Control and Prevention (2012). Anisakiasis FAQs. [Online]. Available at: https://www.cdc.gov/parasites/anisakiasis/faqs.html ( Accessed on 27/08/2019)
2. Food Standards Agency (2018). Freezing fish and fishery products: How to freeze fish and fishery products that are intended to be eaten raw or lightly cooked in food businesses and restaurants. [ Online]. Available at: https://www.food.gov.uk/business-guidance/freezing-fish-and-fishery-products Accessed 27/08/2019)
3. Choi SJ, Lee JC, Kim MJ, Hur GY, Shin SY, Park HS. The clinical characteristics of Anisakis allergy in Korea. Korean J Intern Med. 2009;24(2):160–163. doi:10.3904/kjim.2009.24.2.160