NORWEGIAN FERMENTED FISH AS POSSIBLE SOURCE OF FOODBORNE BOTULISM – IS THE RISK OF CONTRACTING BOTULISM FROM FERMENTED FISH STILL RELEVANT?

Abstract

Foodborne illnesses represent a substantial cause for disease among the population. The Norwegian fermented fish is a traditional way of conserving fish during winter. If wrongly prepared or stored, fish contaminated with Clostridium botulinum may be contaminated with neurotoxin due to favorable conditions for the anaerobic bacterium. The classical form of botulism is due to ingestion of preformed neurotoxin in food that has been contaminated with spores. Hygiene is one of the main preventive factors in order to decrease contamination of the fish with unwanted bacteria, including C. botulinum. Norwegian fermented fish („rakfisk“) is made with attention to key steps and strategies to prevent contamination by bacteria, with C. botulinum especially. The temperature and salt concentration are some of the most important hurdles in order to prevent unwanted microbial growth. The hurdle principle refers to a combination of obstacles which are placed to have a safe end-product. Botulism is a rare disease in Norway, but it does occur. As such it is still relevant when discussing „rakfisk“, especially if it is homemade. Clinicians should be aware of botulism and „rakfisk“ could provide an important diagnostic clue when the condition is suspected.