A study from the University of Adiyaman in Turkey suggests that because of the presence and abundance of 30,0000 known species of fish, the aquatic animals form the largest group in the animal kingdom used for the production of different animal-based foods.
While this makes fish one of the most sought after ingredients in the seafood industry, it has also become one of the protein sources many health organizations are monitoring meticulously because of the risks of contaminants.
Many of their concerns involve food poisoning, which often comes as a result of pathogenic organisms, including Salmonella.
Salmonella is a rod-shaped, gram-negative bacilli that can lead to foodborne illnesses and serious infections. It is a member of the Enterobacteriaceae family of bacteria and is facultatively anaerobic, which means it can grow either with or without oxygen.
Some may think that diarrhea — a primary symptom of many foodborne illnesses such as salmonellosis is a minor health issue — but the World Health Organization describes it as the second leading cause of death among children who are younger than five years old.
Salmonella in fish: It comes with the territory
Aquatic environments and their shorelines are considered to be major reservoirs for Salmonella. Hence, fishery products have been regarded as major sources of pathogens that originate from fish. There are three categories of pathogenic contamination that are often associated with fishery products and fish.
The first is indigenous bacteria, which refers to the type of bacteria that exists as part of the natural microflora of fish. The second, enteric bacteria or non-indigenous bacteria, occurs as a result of fecal contamination. The third is bacteria that is introduced during processing, storage, transportation or preparation for consumption. Salmonella falls under the second group.
The increased run off of organic matter into freshwater bodies such as ponds during rainfall events can also contaminate an aquaculture system with various bacteria and other pathogens. Animal waste, fertilizers, contaminated feed, unsanitary water and other elements of farming are also contributing factors to the prevalence of Salmonella.
Some research, however, shows that fish — except river fish — are not considered a natural habitat of Salmonella. In fact, Benjamin Chapman, a specialist on food safety and associate professor at North Carolina State University, argues that Salmonella in fish can occur as a result of improper handling during preparation or processing.
People who handle the food, in processing facilities or restaurants, probably don’t wash their hands properly every time they should. It is also possible that other meats, which are in the same processing facilities — such as beef or poultry — can cross contaminate fish and fishery products.
How to prevent Salmonella poisoning
As with any other types of meat, the risk of foodborne illnesses is much higher in fish that are raw or undercooked as compared to those that are cooked to the proper temperature to kill pathogens.
The Centers for Disease Control and Prevention recommends using a food thermometer to make sure food is cooked to a safe internal temperature. For fin fish, the CDC’s recommended internal temperature is 145 degrees. Make sure to let the meat rest for about 3 minutes before eating or carving.
Refrigeration is another treatment approach. Freezing fish for 15 hours at minus 35 degrees C, or for a week at minus 20 degrees C is considered an effective way to kill some parasites. But freezing does not kill all pathogens, including listeria monocytogenes, hepatitis A or Vibrio vulnificus.
It is also important that people who catch their own fish carefully select fishing spots that are less prone to pollutants, such as bodies of water that are not contaminated with animal manure.
Food safety measures for people who eat raw fish
Although many studies describe the potential hazards of eating raw meat and fish, including the risk of Salmonella infection, many people still believe in the health benefits of eating raw proteins. Other research suggesting it is beneficial is not uncommon.
Frying fish, for instance, can decrease the level of omega-3 fatty acids such as docosahexaenoic acid (DHA) as well as eicosapentaenoic acid (EPA) which are both healthy and essential for the development of the brain. The same fatty acids also reduce the risk of heart-related illnesses, and some studies found they can even lower the risks of depression.
For these reasons, it is undeniable that raw fish dishes have gained popularity across the globe. Examples include Sushi and Sashimi from Japanese cuisine. Soused herring, a marinated raw herring, is common in the Netherlands. In Latin America, the marinated seafood dish ceviche, which usually consists of raw fish cured in lime juice or lemon, is popular.
For reducing the risks of contaminants and poisoning from raw fish, experts suggest eating only fish which have been frozen. Buy from reputable shops or suppliers, and buy refrigerated fish.
Always inspect your fish by making a visual check, and make sure that it smells fresh. Never keep fresh fish for too long and never leave it out for too long. Always work in a clean kitchen, and wash your hands frequently.
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