Marine Toxins & Intoxications

Transcription

1 Marine Toxins & Intoxications Brian J Ward JD MacLean Centre for Tropical Diseases Colloque Blue 2012

2 Overview of talk Toxins fish (eg: ciguatera scromboid) shellfish (eg: domoic acid) phyto/zooplankton Stings/envenomations vertebrates (eg: rays, lionfish) invertebrates (eg: jellys, cones,corals) phyto/zooplankton

3 You Never Really Know Who You ll be Sharing the Water With... travel.webshots.com/photo

4 Toxins & Intoxications Fish ciguatera scromboid puffer fish Shellfish PSP, DSP, ASP, etc Phyto/zooplankton Pfisteria spp

5 Human Illnesses Associated with Marine & Estuarine Plankton Amnesic Shellfish Poisoning (ASP) Paralytic Shellfish Poisoning (PSP) Neurotoxic Shellfish Poisoning (PSP) Ciguatera Fish Poisoning (CFP) Diarrhetic Shellfish Poisoning (DSP) Pfiesteria Intoxication

6 Ciguatera Intoxication Ingestion of bioaccumulated dinoflagellate toxins in tropical reef fish (snapper, barracuda.) Dinoflagellate species (various) Gambierdiscus toxicus, Prorocentrum spp., Amphidinium.spp. Major Toxins Ciguatoxin --opens voltage dependent Na channels Maitotoxin --Calcium channel activator

7 Ciguatera Plankton - Dinoflagellates Reef Fish - Snapper

8 Ciguatera Incidence/Prevalence Reported Incidence and Prevalence of CFP Geographic Region Incidence/10,000/year Data time period Reference Reunion Island Quod 1996 [25] Queensland, Australia Gillespie 1986 [4] Hawaii Anderson 1983 [96] US Virgin Islands Morris 1982 [97] Guadeloupe Czernichow 1984 [98] South Pacific Region Lewis 1986 [99] Marshall Islands 2, Lewis 1986 [99] French Polynesia 5, Lewis 1986 [99] Dade County, FL Lawrence 1980 Culebra, Puerto Rico Luber, In prep [100] Geographic Region Prevalence (%) Time range Citation US Virgin Islands 4.4 Annual (1980) McMillan 1980 [101] Puerto Rico 7 Lifetime Holt 1984 [102] Tahiti 8.45 Annual (1966) Bagnis 1979 [16] Hao (Tuamotos) 43 Annual (1978) Lewis 1986 [99] Polynesian Islands 70 Lifetime Lewis 1986 [99] Mar Drugs September; 6(3):

9 Ciguarera - Clinical Presentation Constellation of neurologic, GI, and cardiovascular symptoms nausea, vomiting, diarrhea paresthesias, headache, numbness, weakness (paralysis and coma may ensue) arrhythmias, hypotension, brady/tachycardia Neurologic Sx: median duration 2-3 weeks, but chronic or relapsing syndromes can occur for years

10 Reef Russian Roulette Eat me you lose

11 Treatment IV mannitol (0.5-1 g/kg over minutes) Little convincing evidence of benefit Little risk Very little evidence of effect >72 hours Avoidance of certain foods (idiosyncratic) including fish, alcohol, nuts, caffeine, pork Supportive Mar Drugs September; 6(3): Mattei C et al. Brevenal inhibits pacific ciguatoxin-1b-induced neurosecretion from bovine chromaffin cells. PLoS One. 2008;3(10):e3448. Epub 2008 Oct 20.

12 Canadian Shellfish Sanitation Program (CSSP) Department of Fisheries and Oceans, the Canadian Food Inspection Agency and Environment Canada Telephone survey 1400 (390 coastal): 37% of non-coastal visited coast(s) 27% had eaten shellfish harvested by themselves: 9% in last 12 months 10% had bought shellfish from the back of a truck and 10% from fisherman 70% thought all shellfish sold in Canada is safe 16% thought shellfish caught by themselves or friends might be unsafe Most thought that pollution was the main risk (23% said mercury) 54% didn t think that eating any shellfish was a serious risk for healthy adults 70% believe shellfish are safe after cooking Executive Summary Consumer Awareness and Perceptions of Shellfish Consumption and Recreational Harvesting: Findings from the Baseline Survey Prepared for Canadian Food Inspection Agency December 15, 2006

13 Paralytic Shellfish Poisoning Ingestion of bioaccumulated dinoflagellate toxins in shellfish (mussels, clams, oysters.) Dinoflagellate species Alexandrium spp Gonyaulax spp Major Toxins: Saxitoxins: Voltage dependent Na channel blockade (extremely potent toxins)

14 PSP - clinical presentation Predominantly neurologic syndrome: tingling, burning, numbness, drowsiness, dysarthria, and paralysis: can be life-threatening. Signs & symptoms usually appear within ~one hour of eating contaminated shellfish Residual sequelae uncommon Prevention through shellfish monitoring

15 Red Tide pathtosustainable.wordpress.com

16 Eutrophication an increase in chemical nutrients in an ecosystem to an extent that increases the primary productivity of the ecosystem.

17 Neurotoxic Shellfish Poisoning Ingestion of bioaccumulated dinoflagellate toxins in shellfish (bivalves). Rarely, aerosol exposure to toxins Dinoflagellate: Karenia breve (Gymnodinium) Toxin: brevetoxins: linear polycyclic ethers (similar structure to ciguatoxins) Voltage dependent Na channel activation

18 NSP - Clinical presentation Clinical symptoms include both neurologic and gastrointestinal effects: circumoral paresthesias, dizziness, ataxia nausea, abdominal pain, vomiting, diarrhea respiratory symptoms with aerosol exposure Clinical onset within minutes to hours; recovery usually complete. Prevention: monitoring G. breve counts Errera RM et al. Variation in brevetoxin and brevenal content among clonal cultures of Karenia brevis may influence bloom toxicity. Toxicon Feb-Mar;55(2-3):

19 Bivalves - Natures Filters Filter-concentration of up to 40 GALLONS of water per day Plankton toxins Hepatitis A Polio (?) Other viruses (?) Cholera Cryptosporidium

20 Diarrhetic Shellfish Poisoning Ingestion of bioaccumulated dinoflagellate toxin in shellfish (mussels, scallops, clams.) (Japan, Europe. Not reported in U.S.) Dinophysis fortii, D. acuminata Toxin: okadaic acid polycyclic ether compound protein phosphatase 1 & 2A inhibitor

21 DSP - Clinical presentation DSP produces gastrointestinal symptoms, usually within 30 minutes of consumption of contaminated shellfish. Diarrhea (may be incapacitating), nausea, vomiting, abdominal cramps, chills. Recovery within 2-3 days, with or without treatment. No sequelae identified

22 Amnestic Shellfish Poisoning Ingestion of bioaccumulated diatom toxins in shellfish (mussels, clams, oysters..) Nitzschia pungens & Pseudo-nitzchia sp Recognized outbreaks: Maritime Canada, U.S. northern Atlantic & Pacific coasts Toxin: domoic acid (water soluble) structurally related to the excitatory amino acid neurotransmitter glutamic acid

23 ASP - Clinical presentation Life-threatening disorder with both gastrointestinal and neurologic symptoms GI: nausea, vomiting, diarrhea, cramps Neurological: dizziness, headache, seizures, diorientation, short-term memory loss, coma information encoding, generally intact delayed recall significantly impaired hippocampal & amygdaloid nucleus necosis

24 ASP - Clinical presentation II Disease most severe in the elderly and those with renal impairment. Among survivors, sequelae may include significant memory deficits and motor neuropathy Prevention through water and shellfish monitoring (diatom counts, toxin assays)

25 Pfiesteria piscicida cause of fish deaths in aquaria at North Carolina University Veterinary School cause of natural habitat fish kills in the estuarine system of North Carolina. Since then, repeatedly identified as a cause of fish kills in North Carolina ( fish)

26 Ambush or Predator Dinoflagellates Dinoflagellate species which are induced, upon chemical detection of prey, to: undergo stage transformations swarm or multiply (for Pfiesteria)... produce toxin (s) exploit nutritional source then, re-encyst, or disperse

27 Trophic controls of Pfiesteria Heterotrophic with cleptochloroplasts Benthic forms (amoebae, cysts) predominant Factors influencing Pfiesteria toxin production (and stage transformation) not fully known, but include: presence of live fish abundance of algal prey species water nutrient levels (phospates, nitrates)

28 Pfiesteria Toxins Several toxins have been isolated, and partially characterized Lipid soluble toxins (fractions) one kills fish rapidly; is difficult to isolate one peels skin off fish (takes time) Water soluble toxin appears to be unique (i.e. not one of the above) icthyotoxic, cytotoxic in cell culture

29 Pfiesteria - Clinical presentation Cardinal Signs & Symptoms Memory Loss, OR Confusion, OR Skin burning on contact with water, OR Secondary Signs & Symptoms 3 or more of the following: headache skin rash eye irritation upper respiratory irritation muscle cramps gastrointestinal complaints /images/_20403_human.jpg

30 Why is this happening?

31 Why is this happening - II? geology.com/news/2006/01/global-warming-graph

32 Scromboid Commonest poisoning worldwide Dark-fleshed, fatty fish Common - tuna, bonito, mackerel, barracuda Rare - sardines, anchovies, salmon, herring Histamine poisoning (?? unclear) Biogenic amines (histamine, putrescine, cadaverine, and tyramine)? bacterial metabolism of histidine? histamine-spiked fish - minimal toxicity

33 Scromboid - Clinical presentation Non-specific symptoms Tingling of lips/mouth/tongue Flushing, sweating, bright red rash Swelling of face/tongue swelling, wheezing GI distress: nausea, vomiting, diarrhea Tachycardia --> cardiovascular collapse

34 Other Toxins Puffer fish (tetrodotoxin) 50 deaths/year in Japan? Bacterial (Vibrio spp) toxin concentrated in fish Red Whelk (tetramine) Curare-like effects Cyanobacteria (microcystins, nodularin, anatoxins) Mussels (azaspiracid)

35 Other agents Jellyfish of all sizes & shapes Corals (eg: fire coral) Sea urchin spines Fish spines (eg: lion fish, sting ray, catfish) Conidiae Sea snakes thestashbox.wordpress.com

36 Jellyfish Stings firstaid.about.com life-sea.blogspot.com

37 Treatment? Urine Acidification Diabetes Diarrhea Dehydration Acidosis Starvation Meat eater lifestyle.ca.msn.com diveinstead.com

38 Other agents - Corals Various Corals Fire Coral

39 Other agents - Corals Fire Coral Stings

40 Other agents - Sea Urchin (& Other) Spines bcrc.bio.umass.edu Black Sea Urchin spressivo.com/isa/coralreef/animals.htm Crown-of-Thorns Starfish

41 Other agents - Stonefish aquaviews.net Masters of... Disguise jaysdaysaway.blogspot.com

42 Other agents - Fish Spines Lionfish/Zebrafish Ray - Tail barb Triggerfish

43 Other agents - Cones home.comcast.net/ www-tc.pbs.org

44 Other agents - Seasnakes >80% of bites envenomed potent myotoxins & (less) neurotoxins divehappy.com Green Seasnake Yellow Seasnake fieldherpforum.com

45 Other agents Octopus exxxplorer.files.wordpress.com Seaworms greennature.com

46 The marine environment isn t always safe but there are benefits too.

47 It s Not Just Us Right Whale poop for exposure to paralytic shellfish toxins (PSTs) domoic acid (DA) 140 Fecal Samples studied 70-80% + PSTs 25-30% + domoic acid Doucette GJ, etal. Endangered North Atlantic right whales (Eubalaena glacialis) experience repeated, concurrent exposure to multiple environmental neurotoxins produced by marine algae. Environ Res Jan;112:67-76.