FISH POISONING

FISH POISONING1Fish poisoningDefinition ofFISH POISONINGAcute illness resulting from the consumption of fish:

a: illness due to eating fish that normally contain neurotoxins in their flesh

b: illness due to eating stale fish:(1): a histamine intoxication(2): a bacterial food poisoning*SAMFish poisoningThe same rules about food safety and preparation apply to fish as with any other food product. If fish is left out on a work surface for any period of time then it will decay (or go off) very quickly.Raw and cooked fish must not come into contact with each other due to the risk of cross contamination. This means using separate utensils and chopping boards for raw and cooked fish and wiping them down after use.Fish needs to be cooked thoroughly and at the correct temperature.One exception to this is sushi. Sushi is a popular Japanese dish which consists of raw fish, e.g. salmon, rolled in rice and seaweed. This is available in restaurants and as ready prepared packs in supermarkets.Generally, this is safe to eat as long as the fish used has been cooked or if raw, has been frozen beforehand in order to kill off any parasites.

*JOSHCauses of fish poisoningThis type of food poisoning is caused by fish which has been contaminated by:ParasitesToxinsBacteria, e.g. E coliViruses, e.g. norovirus

Fish which can be eaten raw such as oysters or mussels are always a risky choice as well as being a likely candidate for food poisoning. So, if you enjoy the taste of oysters, especially a raw one then be aware that the odds of getting food poisoning are quite high.*JOSHparasitesFood poisoning caused by parasites is rare, especially in countries such as the UK. It occurs as a result of eating raw fish which has been contaminated with any of the following parasites:Clonorchis sinensisAnisakisDiphyllobothriumThese are all names for different types of fish tapeworms which enter the gastrointestinal tract during consumption. Once there they cause a range of problems which includes abdominal pain, nausea, vomiting and diarrhoea.

*JOSHtoxinsThere is a wide range of toxins present in seawater which are produced by any number of agents such as marine plankton and algae. These are capable of a range of health problems such asciguatera poisoningalthough this is uncommon.Shellfish toxin (Shellfish poisoning)

*JOSH6BacteriaA well known example of this isE coli. This bacterium is present in nearly all types of shellfish as a result of contact with water contaminated by raw sewage.

*JOSHvirusThe virus in this case is the norovirus which is spread via contaminated food and water, and personal contact with someone who is already infected.There are two types of foods which often cause an outbreak of the norovirus: salads and shellfish. In the latter case it usually occurs due to insufficient heating of shellfish before consumption.

*JOSHSYMPTOMS OF NOROVIRUSLow-grade feverChillsHeadacheMuscle achesFatigue*JOSHnorovirusMost of these symptoms aren't serious, but diarrhea and vomiting can deplete your body of the fluid it needs and you can become dehydrated

DIAGNOSIS: Stool test.small percentage of people who are infected with norovirus never have any symptoms, which suggests they might have some natural protection from the virus.*JOSHTreatment for norovirusNoroviruses, like other viruses, don't respond to antibiotics, which are designed to kill bacteria. No antiviral drug can treat noroviruses, but in healthy people the illness should go away on its own within a couple of days. Most people don't have any long-term problems from the virus.To prevent dehydration, make sure to drink plenty of liquids, especially water and juices. Give children an oral rehydration solution (such as Pedialyte) to replace lost fluids and electrolytes. Avoid sugary drinks, which can make diarrhea worse, as well as alcohol and caffeinated beverages, which can dehydrate you further.Symptoms of dehydration include dizziness when standing, dry mouth, and a decrease in urination. If severe dehydration develops, contact your doctor. Severe dehydration is sometimes treated with intravenous (IV) fluids.*JOSHTypes of FISH poisoningCommon types of fish poisoning includes:Ciguatera poisoningScombroid poisoningPufferfish poisoning or Fugu poisoningShellfish poisoning*SAMCiguatera poisoningThis is a type of fish food poisoning which occurs when someone eats fish which have become infected by toxins that are produced by seaweed, algae or coral. These are usually found in tropical seawaters.

*SAMCauses of ciguatera poisoningCiguatera is the name given to food poisoning caused by the ciguatoxin a type of toxin found in some species of tropical fish. Other types of toxins include maitotoxin and palytoxin.This is produced by organisms called dinoflagellates which live in both sea and fresh water environments. They attach themselves to seaweed or algae where they are consumed by fish, living in these waters.Note: algae are a type of organism that has a similar appearance to seaweed.There are around 5 types of ciguatoxin.What happens is that small, plant eating fish consume these algae only to be themselves consumed by larger, meat eating fish. This enables these toxins to move higher up the food chain where they build up in strength over time.So, if you eat fish which has consumed algae which is infected with these toxins then you will develop ciguatera food poisoning. Examples of infected fish include: sea bass, red snapper, eel and Spanish mackerel.*SAMSymptoms of ciguatera poisoningCiguetera poisoning affects the digestive, neurological and cardiovascular systems. The symptoms appear quickly, often within 12 hours of consuming infected fish.They include:NauseaStomach painVomitingDiarrhoeaThese are the first set of symptoms to appear and last for a couple of days. These affect the digestive system.

*SAMSymptoms of ciguatera poisoningThe second set of symptoms affects the neurological system. They include:Poor co-ordination/lack of balanceMental confusionPain in the teeth (may feel loose)DizzinessMuscle painsJoint painHeadachesHallucinationsThese symptoms can appear in as little as a few hours or after several days following consumption. They can persist for up to several months.*SAMSymptoms of ciguatera toxinThe third set of symptoms affect the cardiovascular system. They include a very slow heart rate and high blood pressure which can cause dizziness and physical weakness.other symptoms of ciguatera poisoning:SweatingChills Stiff neckComplications: include long term fatigue, persistent headaches and difficulty with balance and co-ordination.*SAMTreatment for ciguatera poisoningCiguatera poisoning cannot be cured. The disease is managed and supported instead with the aim of helping someone to recover rather than an outright cure.Most people recover but it takes a long time to do so.Some people suffer a relapse, often following contact with certain allergens which may cause long term damage.Medication such as calcium channel blockers, e.g. Verapamil may help to treat some of the symptoms which occur after the initial digestive stage.Vitamin supplements and steroids can support recover rather than reducing the effect of the toxin.

*SAMPreventing ciguatera toxinOne way is to avoid eating large amounts of shellfish especially those which live in tropical waters. This is because the ciguatera toxins tend to live in tropical (and sub-tropical) seas such as the Pacific Ocean

*SAMScombroid poisoningScombrotoxin, also called scombroid poisoning or histamine poisoning, occur if fish is not properly refrigerated after it has been caught or poor hygiene on the part of the handler. What can happen is that the fish becomes warm after capture which causes it to release histamine as part of a toxic reaction.This histamine then causes a reaction within the person who has eaten the fish.

*SAMCauses OF scombroid poisoningif fish which has been caught is not stored at the correct temperature within a refrigerator then it releases a toxin called histidine. Histidine naturally occurs in most species of fish and converts to histamine if the fish is exposed to a warm environment.This is why it is so important to keep fish at cold temperatures.If the fish is allowed to become too warm it then produces very high levels of histamine which is part of the decaying process. This process also produces other substances which form part of the toxic side effects.Examples of fish which contain this toxin include tuna, mackerel, sardines and anchovies.This type of food poisoning is not caused by a virus or bacteria.

*SAMSymptoms of scombroid poisoningThe symptoms of this particular type of food poisoning appear very quickly. In some cases, they occur within a few minutes of eating the infected fish.They include:NauseaDizzinessFlushed faceSweatingBurning taste in the mouthHeadacheTachycardia (rapid heartbeat)Stomach pain These symptoms can be mistaken for an allergic reaction so make sure that you mention that you have recently eaten fish.

*SAMSymptoms of scombroid poisoningThese then develop into the following:HivesOedema (swelling)Stomach crampsDiarrhoeaAny diarrhoea is likely to be short term only.In severe cases you may experience a swollen tongue, blurred vision and difficulty in breathing.These symptoms tend to last for 24 hours at most although they can return if you eat fish which has not been stored at the correct temperature, or on a bed of ice.*SAMTreatment of scombroid poisoningThis usually involves fluids to treat dehydration caused by vomiting or diarrhoea and oxygen in cases of respiratory distress.A type of medication called an antihistamine may also be given. This nullifies the affects of histamine.In other words, it blocks the effect of histamine on the body.

*SAMantihistaminesloratadine (Claritin), is now available over the counter. It does NOT tend to cause drowsiness or affect learning in children. Longer-acting antihistamines cause less drowsiness, can be equally effective, and usually do not interfere with learning. These medications, which require a prescription, include fexofenadine (Allegra), and cetirizine (Zyrtec). Other nonprescription antihistamines include diphenhydramine (Benadryl), chlorpheniramine maleate (Chlor-Trimeton, Coricidin) and clemastine (Tavist). New to the market, and available by prescription only, is an antihistamine nasal spray called azelastine (Astelin)*SAMPreventing scombroid poisoningBe careful when eating canned fish such as sardines or tuna. Try to ensure that any fish you eat has been stored at the right temperature via a fridge or within ice.

If you have bought any fish which you think may have spoiled or gone offthen do not eat this under any circumstances but throw it away instead

*SAMPuffer fish poisoning(FUGU POISONING)Tetrodotoxin, also called pufferfish poisoning or fugu poisoning, is a much rarer form of fish poisoning, but it is potentially very serious. This is almost exclusively associated with the consumption of the pufferfish.The different bacteria living in pufferfish liver, gonads, intestines and skin, are known to synthesize a very potent heat stable neurotoxin called tetrodotoxin.FUGU is a traditional delicacy, prepared and sold in special restaurants where trained and licensed chefs carefully remove the viscera to reduce the danger of poisoning.*KAYECauses of puffer fish poisoningThe poison found in organs and skin of the pufferfish, blowfish, balloon fish, toads, sunfish, porcupine fish, toadfish, globefish, and swellfish is a tetrodotoxin.Tetrodotoxin is one of the most toxic poisons found in nature which is more toxic than cyanide to humans .*KAYESymptoms of puffer fish poisoningSymptoms generally occur 10-45 minutes after eating the pufferfish poison, victims experience numbness around the mouth, trouble coordinating movement, difficulty swallowing within minutes of ingesting the toxin, excess salivation, twitching, and loss of ability to talk.Symptoms progress rapidly to convulsions, tingling in the extremities and paralysis that spreads upward the body.The victim goes into respiratory failure generally leading to death.*KAYETetrodotoxin intoxication is divided into four stages based on neurologic signs:Grade 1 Rapidly after ingestion (10 min to 2 hours) numbness and/or paresthesia of the lips and tongue and often of fingers occur.

Grade 2 Sensory symptoms progress markedly.

Grade 3 Muscular paralysis of extremities occur. Motor incoordination progresses and paralysis develops, but consciousness is maintained. Voice production is difficult because of bulbar muscle paralysis.

Grade 4 Consciousness may progressively deteriorate and respiratory paralysis can cause death.*KAYETreatment of puffer fish poisoningTreatment for pufferfish poisoning consists of:limiting the body's absorption of the toxinIngest activated charcoal to bind the toxin. This will prevent the toxin from being further absorbed by your body and will lessen the severity of the situation.Induce vomiting if you are conscious and you have ingested the fish within 3 hours. Since absorption of the toxin is unwanted, vomiting the toxin or tetrodotoxin is the best remedy. Rapidly turn the person onto his or her side if vomiting occurs.relieving symptoms, andtreating life-threatening complications.There is no known antidote for tetrodotoxin.The person may become paralyzed. Artificial respirations may keep the person alive until medical attention in a hospital's emergency department is possible.*KAYEPreventing puffer fish poisoningSome puffer fish are eaten, but most consumers are not able to distinguish the dangerous versus safe species. For this reason, the safest recommendation is to DO NOT eat puffer fish.*KAYEShellfish POISONINGShellfish poisoning (shellfish toxin) is a general term used to indicate poisoning that occurs when shellfish (mainly oysters, clams, scallops or mussels) are eaten by humans. Shellfish are usually associated with saltwater habitats, but some species inhabit freshwater. Both freshwater and saltwater shellfish may cause poisoning.*KAYEclinical studies have separated the group of shellfish poisonings into four groups:Amnesic shellfish poisoning (ASP)Diarrheal shellfish poisoning (DSP)Neurotoxic shellfish poisoning (NSP)Paralytic shellfish poisoning (PSP)

*KAYEAmnesic shellfish poisoning (ASP)This is a very rare form of poisoning which occurs as a result of eating infected shellfish. These shellfish will have consumed this when feeding upon a type of algae called diatoms or brown algae which produces the toxin domoic acid.This toxin is found in sardines and anchovies as well as shellfish.This neurotoxin causes a range of gastrointestinal symptoms which include: vomiting, abdominal pain, and diarrhea which appear within 24 hours of eating infected shellfish.These are then followed by neurological symptoms which include: headache, mental confusion, dizziness/disorientation, memory loss, visual disturbances, and seizuresIn severe cases, paralysis and even death may occur.There is no known antidote so anyone with these symptoms requires hospital treatment as soon as possible.*KAYEDiarrheal shellfish poisoning (DSP)Diarrhea is the main symptom - hence the name but it also includes other symptoms such as nausea, vomiting, chills and abdominal pains.This type of poisoning is caused by a variety of toxins which includes okadaic acid and yessotoxin. Okadaic acid is the toxin which is directly responsible for causing persistent diarrhoea.These symptoms develop very quickly, usually within an hour after eating contaminated shellfish. They last for a day or so and tend to resolve themselves without the need for treatment.The one exception to this is if someone experiences severe diarrhoea which leads to dehydration. In this case they will require fluid replacement therapy via an intravenous drip.Depletion of fluids caused by diarrhoea and/or vomiting can be dealt with at home if it is not severe. This means drinking plenty of fluids such as water and adding electrolytes to them to replace those lost through this illness.These electrolytes are essential minerals such as sodium (salt) and potassium which come in powder form and can be added to a glass of water. They can be purchased over the counter at a local pharmacy.*KAYENeurotoxic shellfish poisoning (NSP)Another type of poisoning which occurs following consumption of infected shellfish. In this case, the shellfish contain a type of toxin called brevetoxins which cause symptoms very similar to those of paralytic poisoning or ciguatera poisoning.Symptoms of neurotoxic poisoning include:Numbness/tingling in the mouth, arms and legsDry mouthPoor co-ordinationSlurring of the speechDrowsinessNauseaVomitingDiarrhoeaThis also causes both neurological and gastrointestinal symptoms.Recovery takes 2 to 3 days from neurotoxic poisoning.*KAYEParalytic shellfish poisoning (PSP)This is the most common type of shellfish poisoning. It is caused by the consumption of shellfish which contain a number of chemicals that are derived from saxitoxin.Saxitoxin is a neurotoxin which when consumed, attacks the nervous system within humans as well as causing gastrointestinal illness.Symptoms of paralytic poisoning include:TinglingBurningDrowsinessLack of co-ordination/clumsinessSlurred speechDry mouthChoking feeling in throatThis also includes the usual symptoms of food poisoning, for example nausea, vomiting and diarrhea.These symptoms appear 30 minutes to an hour after consumption and can cause serious damage such as muscle paralysis and respiratory failure which can be fatal. This poisoning is particularly serious in children.*KAYEShellfish poisoningShellfish poisoning typeSymptomsCausesamnesicpermanent short term memory loss, brain damage, deathdomoic aciddiarrhealdiarrhea, nausea, vomitingokadaic acid, azaspiracidneurotoxicslurred speech, nausea, vomitingbrevetoxinsparalyticparesthesia, coordination loss, speech defects, nausea, vomiting, deathsaxitoxin, neosaxiton and gonyautoxins I to IV*KAYETreatment of shellfish poisoningThis often depends upon the species of shellfish and the type of toxin (or toxins). But it is important to remember that there are no specific treatments for these toxins.As all of these forms of poisoning cause vomiting and diarrhea then fluids will need to be replaced which have become depleted as a result of these. This involves drinking fluids which contain electrolytes to restore essential vitamins and minerals.Some cases will require hospital treatment especially those which involve children or people with a medical condition or a weakened immune system. This treatment will be supportive and involve fluid replacement and medication.Drugs such as antihistamines*KAYEPreventing shellfish poisoningIf shellfish is cooked thoroughly and at the correct temperature then it should not result in food poisoning. Many species of shellfish contain bacteria such as E.coli and viruses which include norovirus but these are destroyed during cooking.One exception to this is oysters which many people enjoy eating raw. If this applies to you then be aware that there will always be a risk with this and any other type of raw fish.This unfortunately, doesnt apply to toxins such as those found in algae and marine organisms. This also includes ciguatera poisoning as these toxins are impervious to cooking, freezing, salting and pickling.

*KAYEAntibiotics used in fish poisoning depends when:If the fish poisoning is contaminated with the causative agent E.coli

TreatmentThird-generation cephalosporins (eg, ceftriaxone).*JOSHSymptoms of fish poisoningThese are similar to symptoms for other types of food poisoning and include:NauseaVomitingDiarrhoeaUpset stomachStomach painsMuscle/joint painsHeadacheThese symptoms develop within 48 hours of eating contaminated fish.The severity of these symptoms will vary between individuals. Some people will have a much worse experience than others which may depend upon how much contaminated fish they have eaten.There are groups of people who for a variety of reasons, are at a greater risk of getting this type of food poisoning. These include people with a poorly functioning immune system, are currently suffering from a medical condition or work in an environment where they handle raw fish.If any of this applies to you then take a few extra precautions to reduce the risk of this happening.

*JOSHTreatment for fish poisoningThis depends upon the extent of your illness. If your food poisoning is relatively mild then you can treat it at home. This means bed rest and plenty of liquids.If you are worried about the risk of dehydration then replace any essential vitamins and minerals lost as a result of your food poisoning. Drink plenty of fluids, e.g. water but add a sachet of re-hydration salts to it which will replace these as well as ensuring that you are properly hydrated.Dehydration is a major risk of food poisoning and is something to avoid if possible. But if you do become dehydrated then you will require hospital treatment.This means re-hydration via an intravenous drip

*JOSHPreventing fish poisoningCan you prevent yourself from getting food poisoning from fish?You can reduce the likelihood of this happening by applying a few common sense measures. These include:Ensuring fish has been properly cooked or if eaten raw (e.g. sushi) has been frozen beforehand.Do not store fish especially shellfish in waterSeparate raw fish from cooked fishWash your hands before and after handling fish. Also wipe down any chopping boards, utensils and kitchen worktops afterwards.Store fish in the fridge as soon as possible after purchase

*JOSHReptilesReptiles cold-bloodedegg-layingvertebrates that has anoutercoveringofhorny scalesorplatesIncludes snakes,lizards,crocodiles,andturtles

Snakes - any limbless scaled reptiles with a long tapering body and with salivary glands often modified to produce venom which is injected through grooved or tubular fangs Lizards are reptiles that typically has a long body and tail, four legs, movable eyelids, and a rough, scaly, or spiny skin.Crocodiles - large carnivorous thick-skinned long-bodied semi-aquatic reptiles Turtles - a slow-moving reptile, enclosed in a scaly or leathery domed shell into which it can retract its head and thick legs.

Venom - a poisonous substance secreted by animals

Envenomationthe process by whichvenomis injected into some animal by the bite (or sting) of a venomous animalLizardsLizardsFamily: Helodermatidae Genus : Heloderma Beaded Lizard (H. horridum)Gila monster (H. suspectum)

Are the only lizards known to have evolved an overt venom delivery system Helodermameans "studded skin" (Ancient Greek: hlosthe head of a nail or stud anddrma meaning skin.)Horrdum, is theLatinword meaning rough or rudeType of Poison(1.) Neurotoxina substance which inhibits the functions of neuronsAction: damage neurons so that they cannot function. attack the signaling capability of neurons blocks the release of various chemicalsinterfering with the methods of reception/transmissions/sending of false signalsEffect : Neuromuscular paralysis dizziness drooping eyelid (ptosis) paralysis of one or moreextraocular muscles (opthalmoplegia) flaccid facial muscle paralysis inability to swallow paralysis of larger muscle groups paralysis of respiratory muscle asphyxiation coma deathType of Poison(2.) Hemotoxinare toxins that destroy red blood cells ,disrupt blood clotting, and/or cause organ degeneration and generalized tissue damageEffect : swelling necrosis (tissues/organs) cardiovascular damage loss of blood pressure deathType of PoisonConstituents of Lizard VenomHyaluronidase spreading factor Hydrolase enzyme that degrades hyaluronic acid Result: increase tissue permeability facilitates venom diffusion into tissue Hyaluronic acid mucopolysaccharide that is an important component of connective tissueType of PoisonSerotoninNeurotransmitterMediates inflammation, vasodilation ,smooth muscle activity and cause platelet aggregationNeurons Serotonin signal smooth muscle activity

Type of Poison Monoamine OxidaseBreak-down excess neurotransmitter (e.g. serotonin)Normal:Abnormal: neurotransmitter neurotransmitter synaptic gapsynaptic gap

Normal levels of MAO enzymes levels of MAO = activityexcess neurotransmitter levels of neurotransmitter flushed out /deactivatedflushed out / deactivatedType of PoisonPhospholipase A2- disrupts the release of neurotransmitter in nerve synapses blocks acetylcholine release parasympatholytic effectIncrease heart rateMydriasis/cycloplegia/decreased lacrimationReduce secretionrelaxation- indirect degranulating effect on mast cells histamine inflammationincrease permeability of capillariesType of PoisonGila Toxin - lethal factor- 3-5% of venom volume- action : release bradykinin from kininogen- effects :bradykinin inflammation vasodilation fall of blood pressure bronchoconstriction dry cough natriuresis fall of blood pressure contraction of uterus smooth muscleType of PoisonHelotherime- hypothermic toxin- Action: inhibits Ca+ influx from sarcoplasmic reticulum- Result : muscle relaxation- Effect : lethargy , partial paralysis of rear limbs, intestinal distention, lowering of body temperatureType of Poison Helodermatine - hypotensive enzyme- kinin-like activity induce vasodilation and contraction of smooth muscle- effects: dose-dependent decrease of the arterial blood pressure.Mechanism of PoisoningVenom Glands capillary action release of venoms through (Venom storage) the ducts in large teeths(Lower Jaw) (Lower Jaw)

Gilas/beaded lizards latch onto their victims & chew to allow neurotoxins to move through grooves in their teeth and into the open wound

Mechanism of Poisoning Venom Open wound release LOCAL EFFECTS Hyaluronidase Phospholipase A2 Other Proteolytic enzymes

increased tissue permeability inhibits cellular respirationlocal tissue damagedeeper penetration cell membrane destructionspread of other venomTissue necrosis inhibits platelet aggregationcomponents inflammatory response (release of histamine)

SYSTEMIC EFFECTS Gila ToxinHelotherimeHelodermatine Pain, hypotension hypothermia, lethargy, hypotensionClinical ManifestationsPainEdema ( caused by Histamine & Bradykinin)HypotensionNauseaVomitingWeakness/ muscle paralysisDiaphoresis (excessive sweating)-caused by serotoninTarget OrganNeurotoxinsNervous System (neurons,neurotransmitters)Muscles (skeletal,smooth)Hemotoxins Circulatory systemBlood vessels,blood,tissues

Type of ExposureAccidental Dermal BiteAntidote/TreatmentNo antivenin is commercially available. Treatment is supportive.First Aid :Disengage the lizard that is still attached to the victimIrrigate the bite site w/ 2% LidocaineProbed the wound w/ 25-gauge needle to detect any embedded toothDiazepam useful in sedating agitated or painful patient AnalgesicBroad Spectrum antibiotic*co-amoxiclav / doxycycline*prevents infection of wound Assessment & Monitoring- development of hypotension/shockAntidote/TreatmentSuction or compression may impede venom movement, they are unproved.Cryotherapy, tourniquet, and excision are dangerous and should not be used.