Seafood Hygiene/Food preservation Flashcards
What is included in “seafood”?
Fresh or saltwater finfish, crustaceans, all mollusks, other forms of aquatic life - gator, frogs, aquatic turtles, sea urchin etc
_____ officially makes regulations for seafood, but regulations are limited in effectiveness
FDA
Many plants “fly under the radar”
What health safety process is required for all US seafood plants?
HACCP
Who handles the voluntary seafood inspection program (VSIP)?
Dep. of commerce - National Oceanic and Atmospheric Administration (NOAA)
What is the goal of VSIP?
The focus is on inspection for QUALITY and sanitation
certification program for international export
HACCP training and assistance is also offered
*products from processing plants in the inspection program will be stamped
What is one of the biggest problems with seafood that can lead to illness?
DETERIORATION
- extremely perishable
- autolytic spoilage
- bacterial spoilage
- Rancidity
What health risks are associated with consuming seafood?
infectious dzs, parasites, natural toxins,chemical contaminants
T/F: Since catfish is seafood, it is regulated by the FDA
FALSE
Although it is seafood, it is regulated under the USDA
What causes the most illnesses associated with seafood consumption?
Toxins from bacteria (not necessarily the bacteria itself)
What bacteria is often is most often involved with seafood consumption illness? often occurs when eating raw fish or shellfish from warmer coastal waters
Vibriosis (Vibrio vulnificus + parahaemolyticus)
These are “halophilic” bacteria - require salt
**This can also be contracted through skin wounds in warm coastal waters
What viruses are associated with seafood consumption illnesses?
Hepatitis A and Norovirus
What parasites are associated with seafood consumption illnesses?
Tapeworms: Diphyllobothrium spps (D. latum)
Nematodes: Anisakis spp, Gnathostoma spinigerum, Capillaria philippinensis
Trematodes: Liver flukes, lung flukes (paragonimus spp), Intestinal flukes (many species - 3 genra)
What is the MOT of vibriosis?
Vehicle: raw, improperly cooked seafood/oysters
Direct: Infection of wounds while walking or swimming in contaminated water
What clinical signs are associated with vibriosis?
Dhr, cramps, vomiting, fever
- incubation 4-96 hours
- more common in the summer when the waters are warm
What actions can be taken to prevent vibiosis?
- proper handling and storage of seafood
- cook seafood
**close waters for fishing and swimming when vibrio is present
Who are the intermediate hosts for Diphyllbothrium latum?
Fish like trout, perch, salmon, and pike
- fish that travel between fresh and salt water are more susceptible
- when small fish are eaten by larger fish -the larvae migrates into the muscle of the larger fish
Who are the definitive hosts of D. latum?
Many mammal species: humans, canids, felids, etc
What clinical signs may be present in a human with D. latum?
Minor bloating and anemia
What is the MOT to humans of D. latum?
Vehicle: raw infected fresh water or anadromous fish: ceviche, sushi, pickled herring
**Scandinavia, Russia, Baltics, Pacific Northwest, Japan
How do you prevent D. latum infections?
COOK or freeze fish (blast freeze for 15 hours or freeze for 7 days )
What is the life cycle of Anisakis spp? (nematode) How are humans infected?
Intermediate hosts: crustaceans eaten by fish or squid
Definitive hosts: Marine mammals, humans –> adult worms live burrowed into the stomach lining
MOT: humans eat raw infected fish - ceviche, sushi, pickled herring (salmon, herring, halibot, cod, squid, etc)
What clinical signs are associated with human infections of Anisakis spps?
Tingling in throat, cough up or pull out a worm
Invades stomach wall –> acute abdominal pain, nausea, vomiting, dhr, can mimic Crohn’s or stomach cancer
**FYI - prevention is the same as D. Latum - cook or freeze fish
T/F: Humans infected with Anisakis spps usually have a large worm load
FALSE
**usually only one worm per person
How are humans infected with fish-borne trematodes?
Ingestions of variable trematode metacercariae
source = FRESH water fish, mollusks, or crabs
Who are the intermediate and definitive hosts of fish borne trematodes?
Intermediate = snails or mollusks are the first stage –> they are consumed by freshwater fish and then encyst in the muscle (second stage)
Definitive: Humans and other mammals
*eggs passed into water in human or mammal feces
What is the MOT of fish borne flukes to humans and what clinical signs are associated with infections?
Vehicle: raw/undercooked infected fresh water fish, crayfish, crustaceans, salted or smoked fish
Clinical signs: related to liver damage by flukes - leading to cirrhosis +/- carcinoma
Where are fish borne trematode infections most common?
Asia and eastern Europe
What actions can be taken to prevent fish borne trematode infections?
Target reservoirs - treat infected hosts—> people, pigs, dogs, cats, etc
Target vehicle - prevent fecal contamination of water, proper sewage tx and management, cook or freeze fresh water fish and seafood, don’t feed uncooked table scraps containing seafood to animals
Who is the intermediate hose of Paragonimus spps of lung flukes?
snail –> crab or crayfish
MOT = raw or under cooked freshwater crab or crayfish
What clinical signs are associated with Paragonimus infections in humans?
Cough, chest pain, fever, coughing up blood
**most resolve without tx, but occasionally enter the CNS causing meningitis
**Asia, Africa, and Latin America = 21 million infected
**Prevention is similar to other fish borne flukes
Who are the hosts of fish borne intestinal flukes?
Definitive hosts: people and other mammals
Intermediate= Snail –> fresh or brackish water fish, bivalves, mollusks, oysters
How do people get fish borne intestinal flukes and what are the clinical signs associated with infections?
MOT = raw or undercooked fresh or brackish water fish, bivalves, mollusks, oysters
Clinical signs: Abdominal pain, dhr, lethargy, weight loss, fever, malabsorption
**most common in Africa (Egypt), Middle East, Asia, Latin America
**Prevention is similar to other fishborne flukes
What is the pathogenesis of Scrombrotoxin aka Histamine Fish Poisoning?
Toxin is produced during spoilage due to poor storage (warm temperatures)
Bacterial enxymes convert to histidine in/on fish to histamine
T/F: Freezing/cooking fish will kill the bacteria that causes scrombrotoxin, making it safe to consume
FALSE
Cooking/freezing will KILL the bacteria - but once the toxin is present - there is no removing it
What is the MOT and clinical signs of Histamine Fish Poisoning?
Vehicle = tuna, mackerel, bonito, mahi mahi, marlin, bluefish
Clinical signs = Sudden onset (2mins - 2hrs) burning, swelling of the mouth, nausea, vomiting, dhr, headache, cramps, pruritis, rash
*usually self limiting
How do you prevent Histamine Fish Poisoning?
Proper handling of fish –> chilling after catching and during storage
What is the toxin that causes Pufferfish poisoning?
Tetrodotoxin
- pufferfish - contain lethal amounts of toxin in liver, ovaries, and skin –> preparation of this fish should be done by someone properly trained
- this fish is eaten raw as sashimi
What clinical signs are seen with pufferfish poisoning?
Vasopressor and neurotoxin caused muscle paralysis –> victim is fully conscious and dies of asphyxiation - usually within 20 mins
What toxin is associated with consuming predatory reef fish? What clinical signs are seen in infections?
Ciguatera poisoning
Nausea, vomiting, dhr, colic (resolves in 1-2days)
- sometimes neuro signs
- severe cases = bradycardia, shock, resp. distress/paralysis, coma
**Hawaii and Florida and tropics world wide
How do you prevent ciguatera poisoning?
This is difficult since fish appear healthy. Close fishing waters prn
Avoid eating large predatory reef fish
What organism produces the toxin responsible for Paralytic Shellfish poisoning (PSP) and also causes “red tides”?
dinoflagellate
*these will produce toxins that will accumulate in mussels, cockles, clams, scallops, oysters, crabs, and lobsters
What are the clinical signs of PSP? How is infection prevented?
Clinical signs - symptoms 15min-10hours after consumption
Ataxia, dizziness, incoherence, rash, fever, and respiratory paralysis and death
**one heavily contaminated clam can kill
*prevention = close waters with red tide, check with local health department before collecting shellfish
Neurotoxic shellfish poisoning occurs due to a neurotoxin produced by a ______. Toxins will accumulate in ______, ______, and _______.
dinoflagellate
oysters, clams, mussels
What are clinical signs of neurotoxin shellfish poisoning?
Symptoms begin 1-3hrs post consumption
Numbeness, tingling in the mouth, arms, and legs, incoordination, and gastrointestinal upset
Recovery in 1-2 days
*gulf of Mexico, Atlantic coast of Southern US
Amnesic shellfish poisoning is caused by a ____ ____ produced by a ________
domoic acid produced by a diatom (phytoplankton or algae)
Toxins accumulate in oysters, clams, and muscles
What are symptoms of Amnesic shellfish poisoning?
Occur within 24 hrs of consumption
GI symptoms, dizziness, headache, disorientation and permanent, short term memory loss, dementia, occasionally death
**East and west coast of northern US and Canada
