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60 Cards in this Set
- Front
- Back
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foodborne illness outbreaks 1990-2003
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other - 40%
seafood - 20% produce - 12% poultry - 11% beef - 10% eggs - 7% |
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marine toxins
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-naturally occuring chemicals that contaminate certain seafood
-seafood contaminated with these chemicals usually looks, smells and tastes normal -disease can result if humans consume contaminated seafood |
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disease caused by marine toxins (in order of incidence in the US)
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-scombrotoxic fish poisoning
-ciguatera fish poisoning -paralytic shellfish poisoning -neurotoxic shellfish poisoning -amnesic shellfish poisoning |
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marine toxins that have occured in florida:
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-Methyl Mercury poisoning ***
-Neurotoxic shellfish poisoning *** -Ciguatera fish poisoning *** -Scombrotoxic fish poisoning *** |
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another name for scombrotoxic fish poisoning
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scombroid or histamine fish poisoning
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scombrotoxic fish poisoning (SFP)
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-caused by bacterial spoilage of certain finish (tuna, mackerel, and bonito)
-these fish contain relatively large amounts of histidine in their muscles which cause disease -rarely occurs in other fish -results from improper handling of fish (time/temp abuse) -bacteria within the fish convert histidine into histamine -cooking, canning or freezing does not reduce the toxic effect |
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tuna, mackerel and bonito belong to...
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Scombridae family of fish
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what enzyme catalyzes this rxn: histidine ---> histamine
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decarboxylase
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Scombrotoxic fish poisoning symptoms
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-start 2 mins to 2 hours after eating the fish
-usually last a few hours -common symptoms: rash, diarrhea, flushing, sweating, headache, vomiting, burning/tingling or swelling of mouth, ab pain, or metallic taste |
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Scombrotoxic fish poisoning symptoms may be more severe in:
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patients taking certain medications that retard the breakdown of histamine by their liver (ex. isoniazide and doxycycline)
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Scombrotoxic fish poisoning treatment
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-not necessary
-in certain cases: antihistamines or epinephrines may be required |
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How to reduce Scombrotoxic fish poisoning
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-rapidly chilling catch to prevent histamine formation
-bleeding and gutting the fish can assist rapid cooling -if done carefully, gutting can remove source of bacteria |
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Ciguatera is
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a form of human poisoning caused by the consumption of subtropical and tropical marine finfish which have accumulated naturally occurring toxins (ciguatoxin) through their diet
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Ciguatera fish poisoning (CFP)
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-Ciguatoxin is produced by microscopic sea plants called dinoflagellates
-Ex. Gambierdiscus toxicus -As many as 50,000 cases are reported globally annually |
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Foods associated with ciguatera poisoning
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-Groupers, barracudas, snappers, jacks, mackerel, and triggerfish
-These toxins become progressively concentrated as they move up the food chain from small fish to large predatory fish that eat them |
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Nature of CFP disease
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-Ciguatera poisoning is usually self-limiting (subside within several days from onset)
-Poisoning occur within 6 hours after eating toxic fish |
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CFP symptoms
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-Symptoms include a combination of gastrointestinal, neurological, and cardiovascular disorders
-In some cases neurological symptoms persist from weeks to months and even years |
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How to prevent ciguatera poisoning
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-Consume less coral reef fish
-Avoid eating the head, viscera, skin, and roe of coral reef fish which usually have higher concentration of toxin -when eating coral reef fish, avoid consuming alcohol, peanuts or beans as they may aggravate ciguatera poisoning. |
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Paralytic Shellfish Poisoning (PSP) is:
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-Caused by a different dinoflagellate with a different toxin
-These dinoflagellates have a red-brown color, and can grow to such numbers that they cause red streaks (red tides) to appear in the ocean |
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PSP toxins:
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-This toxin is known to concentrate within certain shellfish that typically live in the colder coastal waters of the Pacific states and New England
-20 toxins responsible for paralytic shellfish poisonings (PSP) and are all derivatives of saxitoxin |
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PSP associated foods
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Mussels, cockles, clams, scallops, oysters, crabs, and lobsters
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PSP onset
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-Symptoms begin anywhere from 15 minutes to 10 hours after eating the contaminated shellfish, although usually within 2 hours
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PSP symptoms
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-numbness or tingling of the face, arms, and legs which is followed by headache, dizziness, nausea, and muscular incoordination
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PSP complications
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-muscle paralysis and respiratory failure which may cause death in 2 to 25 hours if respiratory support is not provided
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How to prevent PSP
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-Harvesters of shellfish should check with authorities concerning the harvesting status of the beds. Should only harvest from officially open and regulated beds.
-Call the Biotoxin Hotline at 1-800-562-5632 -Individuals should not buy or accept shellfish from unlicensed vendors or friends when they are not certain of the area of harvesting or on-going monitoring results |
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Neurotoxic shellfish poisoning (NSP) is caused by:
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Caused by a third type of dinoflagellate that produces another toxin (brevetoxins)
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brevetoxins are:
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a group of 10 natural neurotoxins produced by the marine dinoflagellate, Karenia brevis
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Karenia brevis is
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naturally occurring in the Gulf of Mexico, Caribbean Sea and along New Zealand coasts
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NSP toxin regularly produces blooms along which coasts?
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Florida and Texas (known as the Florida Red Tide)
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K. brevis name after
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biologist Karen Steidinger FL FWC scientist(retired)
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K. brevis was in which newspaper and when?
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Tampa Times article
2006 |
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NSP/K. brevis associated foods:
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Shellfish (such as clams, oysters, whelks, mussels, conch, coquinas, and other filter-feeding mollusks)
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NSP disease onset
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Symptoms begin 1 to 3 hours after eating the contaminated shellfish
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NSP symptoms
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-Symptoms include numbness, tingling in the mouth, arms and legs, incoordination, and gastrointestinal upset
-Symptoms usually last for 2 to 3 days -Death is rare |
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Amnesic shellfish poisoning (ASP) history
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-an event occurred in Canada in 1987 where 150 people felt sick after eating mussels contaminated with an unknown toxin
-19 hospitalizations, and 4 deaths (elderly) -symptoms observed in many of the sick included memory loss |
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ASP chemical toxin is
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domoic acid
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domoic acid is
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an amino acid produced by some species of phytoplankton
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how does domoic acid affect fish/humans?
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domoic acid gets bio-concentrated by shellfish and enters the human food chain when shellfish is consumed by human
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ASP associated foods
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Cockles, crabs, furrow shell, mussels, razor clams and scallops
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onset of ASP disease
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occurs 24 hrs after eating contaminated shellfish
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ASP symptoms
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gastrointestinal upset, dizziness, headache, disorientation, and permanent short-term memory loss
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complications
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seizures, focal weakness or paralysis, and may result in death
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Mercury
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mineral that exists naturally in the environment
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mercury in the air
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Thousands of tons are released into the air each year through pollution and waste
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where does mercury bioaccumulate and what happens?
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-streams and oceans
-it is converted into the poisonous organic compound methylmercury (MeHg) through bacteria action |
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mercury and fish?
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fish absorb and accumulate MeHg as they feed in these waters
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levels of MeHg in fish depending on size:
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Levels of MeHg tend to be higher in larger predatory fish such as shark and swordfish that feed on smaller fishes in these waters
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Who's at risk for mercury poisoning?
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-every one
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according to CDC reports, people more sensitive to mercury are:
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-pregnant and nursing
-children under age of six (esp up to age of 3) -ppl with impaired kidney function -those with very sensitive immune responses to metal |
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why are pregnant and nursing women more sensitive to mercury?
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-MeHG easily crosses the placenta and accumulates in the blood and tissues of the developing fetus
-it can be passed to newborns through breast milk |
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mercury poisoning symptoms of toxicity
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-Include paraesthesia (a pricking, tingling or creeping sensation on the skin)
-Depression -Blurred vision -Prenatal and infant exposure can effect attention span, language, visual-spatial skills, memory, and coordination |
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The national academy of sciences:
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estimates nearly 60,000 children each year are born at risk for neurological problems due to methylmercury exposure in the womb
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When did the FDA/EPA revise their consumery advisory for mercury?
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2012
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FDA/EPA recommends to not eat:
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Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.
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what are five common fish that are ow in mercury?
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shrimp, canned light tuna, salmon, pollock, and catfish.
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common;y eaten fish high in mercury
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albacore (white) tuna which has more mercury than canned light tuna
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how many ounces of fish are you allowed to eat a week?
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12 ounce (2 average meals)
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any restrictions on locally caught fish?
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only eat 6oz a week, don't eat any other fish that same week and check local advisories about the safety of fish in the area
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Polychlorinated biphenyls (PCBs) are:
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mixtures of synthetic and organic toxic chemicals developed and used as fire retardants, insulators, and plasticizers in electrical devises mostly
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In 1976, Congress passed the Toxic Substances Control Act (TSCA), which banned:
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the production of PCBs because of troubling health effects discovered in workers that come in contact with PCB
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