Seafood Poisoning
W.A.Dulanjali M. Wijethilake
Aquatic science (Sp.) – Part II
Seafood Poisoning
EPITOME 1. • Introduction
2. • Global distribution of toxins
3. • Finfish poisoning
4. • Shellfish poisoning
5.• Other factors associate with
seafood poisoning6. • New and emerging toxins
7. • Detection methods of seafood
poisoning8. • Symptoms of seafood poisoning
9.• Hygienic errors for seafood
poisoning10. • Prevention, control and monitoring
11.• Long term consequences of
seafood poisoning12. • Future perspectives
13.• Sri Lankan situation of seafood
poisoning14. • Discussion
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Seafood Poisoning W.A.Dulanjali M. Wijethilake
A group of acute illnesses due to ingestion of contaminated finfish, bivalve mollusks and snails may result allergy, toxemia from foods, those inherently poisonous or those contaminated by poisons. Seafood containing poisons formed by bacteria or food borne infections. ( Source - medical-dictionary)
Introduction
What is seafood poisoning?
Seafood products are important both nutritionally and economically
About 16% of all animal protein
Seafood Vs. other food
Toxic microscopic algae
Indigenous factors
Accumulate through food chain
Seafood Poisoning W.A.Dulanjali M. Wijethilake
The toxins can produce various
Consumers are exposed to seafood poisoning while travelling abroad
Mainly fish and shellfish
Main issue is poisonous seafood shows no visible signs of contamination
Diagnosis may be complicated due to ..
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Neurological and gastrointestinal illness
Toxins normally accumulate in the
a. Digestive gland
b. Roe
c. Viscera
d. Flesh/muscles
e. Skin
Adductor muscle in bivalve mollusks
Human activities also trigger the seafood poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Finfish poisoning
1 Scombroid fish poisoning
2 Ciguatera fish poisoning
3 Puffer fish poisoning4 Sardine poisoning
5 Hallucinogenic fish poisoning
6 Palytoxic fish poisoning
Shellfish poisoning1 Paralytic shellfish
poisoning.2 Neurotoxic
shellfish poisoning3 Diarrhetic
shellfish poisoning4 Amnestic
shellfish poisoning.
5 Azapiracid poisoning
Other factors1 Parasites2 Bacteria3 Viruses
4 Heavy metals5 Red whelk
poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Categories of Seafood poisoning
Syndrome Affected Areas
Amnesic shellfish poisoning (ASP)
U.S. west coast including Alaska Atlantic Canada Georges Bank Chile Australia New Zealand United Kingdom
Azaspiracid shellfish poisoning (AZP)
England Scotland Ireland France Spain Morocco Norway
Ciguatera fish poisoning (CFP)
Hawaii Gulf of Mexico Puerto Rico Caribbean Australia Many Pacific islands
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Global distribution of toxins
Diarrhetic shellfish poisoning (DSP)
Europe Japan Atlantic Canada South Africa Chile Thailand New Zealand Australia
Neurotoxic shellfish poisoning (NSP)
U.S. Gulf coast New Zealand
Paralytic shellfish poisoning (PSP)
U.S. west coast including Alaska New England coastal states Canada Chile Brazil Europe South Africa Asia Australia New Zealand
Swimmer's itch Dermatitis
Australia Florida worldwide throughout the tropics and subtropics
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 1 : Global distribution of PSP,NSP,DSP and ASP
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 2 : Global distribution of CFP and AZP
1. Scombroid fish poisoning (SFP)
Most common cause Histamine poisoning or pseudo allergic reaction Scombroid fish species – Tuna, Bonito and
mackerel Non scombroid fish
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Finfish poisoning
Figure 3 : formation of histamine
Histidine decarboxylase enzyme producing bacteria
a. E.coli
b. Klebsiella pneumonias
c. Hafnia alvei
d. Morganella morganii
Biogenic amines also play major role
Recommended Histamin levelsI. 5mg/100g = safe
II. 10-20/100g = maximum level
III. >50mg/100g = unsafe
Seafood Poisoning W.A.Dulanjali M. Wijethilake
2. Ciguatera fish poisoning (CFP)
Coral reef and inshore habitat fish species
Eg – Barracuda, Amberjack, King mackerel, Groupers, Snappers
Toxin – Ciguatoxin (CTX) and Maitotoxin (MTX) Agent – Gambierdiscus toxicus and benthic dinoflagellates
Mechanism
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 4 : Structure of Ciguatoxin
CFP does not affect the appearance, odour and taste
What is harmful effect of disturbance of sea bottom ?
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 5 : Food chain accumulation of dinoflagellates
3. Puffer fish poisoning
Fishes include blowfish, globe fish, blue ringed octopus, gobies, starfish, horseshoe crab eggs
Toxin – Tetrodotoxin
Mechanism
Toxin concentrated in various parts
Seafood Poisoning W.A.Dulanjali M. Wijethilake
4. Sardine poisoning
Rare and very poorly reported one
Fish species include sardines, herrings and anchovies
Toxin - unknown
But …
Seafood Poisoning W.A.Dulanjali M. Wijethilake
5. Hallucinogenic fish poisoning
Ichthyoallyeinotoxism
Rare
Fish species include Siganus spinus
Exact toxin - unknown
Similarities with CFP
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 5 : Siganus spinus
6. Palytoxic fish poisoning
Grazing animals on Palythoa sp.
Toxin – Palytoxin
Neurotoxic
Similarities with CFP
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 6 : Palythoa sp.
1. Paralytic shellfish poisoning (PSP)
Most common and widespread shellfish poisoning
Toxin – Saxitoxin (STX) Agent –Alexandrium sp., Gymnodinium catenatum
and Pyrodinium spp.
Mechanism
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Shellfish poisoning
Figure 7 : Structure of saxitoxin
2. Neurotoxic shellfish poisoning (NSP)
Known since centuries
Toxin – Brevetoxins Agent – Gymnodinium breve, Karenia brevis ,
Karenia brevisulcatum
Mechanism
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 8 : Structure of brevetoxin
3. Diarrhetic shellfish poisoning (DSP)
Mild poisoning
Toxin – Okadaic acid and derivative Agent – Dinophysis sp., Prorocentrum sp.
Filter feeding bivalves
Mechanism
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 9 : Structure of Okadaic acid
4. Amnestic shellfish poisoning
One of the potentially serious poisoning
Toxin – Domoic acid Agent - Pseudonitzchia sp.
Mechanism
20µg DA/g – Safety limit
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 10 : Structure of Domoic acid
5. Azaspiracid poisoning
More recently discovered poisoning
Toxin – Azaspiraicd 1 Agent - Protoperidinium crassipes
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 11 : Structure of Azaspiracid 1
1. Parasites in seafooda. Anisakis simplex
b. Diphyllobothrium sp.
c. Paragonimus sp.
d. Opisthocris sp.
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Other factors associate with seafood poisoning
Figure 12 : Anisakis simplex (Leff) and Diphyllobothrium sp. (Right)
Protozoansa. Cryptosporidium parvum
b. Entamoeba histolytica
c. Giardia lamblia
d. Cyclospora sp.
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 13 : protozoans in fish species
2. Bacteria in seafooda. E.coli
b. Staphylococcus aureus
c. Salmonella sp.
d. Vibrio cholerae
e. Vibrio parahaemolyticus
f. Listeria monocytogenes
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 14 : Bacteria in fish species
3. Viruses in seafood
a. Hepatitis A virus
b. Norovirus
4. Heavy metals in sea food
5. Red whelk poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
The occurrence of seafood toxins seems to be increasing and new potential food poisoning hazard
1. Azaspiracid
2. Cyanobacteria toxins
3. Pfiesteria toxin
4. Other compounds – Gymnodinine and procentrolide
Seafood Poisoning W.A.Dulanjali M. Wijethilake
New and emerging toxins
Mouse bioassays for
Limitations of specificity and accuracy
Due to ethical reasons
Alternatives
a. Cell culture assays
b. ELISA s
c. HPLC – ASP detection , Tetradotoxin
d. CE-MS
e. LC-MSSeafood Poisoning W.A.Dulanjali M. Wijethilake
Detection methods of seafood poisoning
f. Ion exchange chromatography – Histamin
g. Capillary zone electrophoresis – Histamin
h. High voltage electrophoresis - Tetramine
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 15 : Ion exchange chromatography machine
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Symptoms of seafood poisoningSyndrome Symptoms
Scombroid poisoning Breathing problems (in severe cases)Extremely red skin on face and bodyFlushingHives and itchingNauseaVomiting
Ciguatera fish poisoning Abdominal crampsDiarrhea (severe and watery)NauseaVomiting
Tetradotoxin fish poisoning Paresthesia of the lips and tongue HypersalivationSweatingHeadacheWeaknesslethargy
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Paralytic shellfish poisoning Numbness or tingling in mouth. This sensation may spread down to arms and legs. become very dizzy, have a headachein some cases, arms and legs may become temporarily paralyzed
Neurotoxic shellfish poisoning The symptoms are very similar to Ciguatera poisoning
Amnestic shellfish poisoning With nausea, vomiting, and diarrhea, followed by short-term memory loss, as well as other less frequent neurologic symptoms.
Fish hygiene relates to “All conditions and measures necessary to ensure the safety and suitability at all stages of the fish handling".
These hygienic measures aim at preventing or reducing fish
contamination and microbial growth.
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Hygienic errors of seafood poisoning
Aspects related to the hygienic design of facilities during
• On-board, • Transportation• Processing and distribution• Personnel hygiene• Cleaning and sanitation
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Faults doing by fishermenSituation Errors
Fish in hold Fish kept in melted waterLoosening ice with harbour waterNo sorting by species or catching date
Unloading Unload straight on to pier by handPier is highly contaminated due to..Pier is used for auctioning and packing
Washing Use contaminated harbour waterWashing water not change frequently
Reloading Inappropriate vehicles Icing not done correctlyCross contamination
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Transportation Many different types of transportation•Refrigerated truks•Unrefrigerated trucks•Three wheelers•Motorbikes•bicycles
Cutting Wooden cutting boards and it wash by harbor waterNo waste bins
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 16 : Bad hygienic practices in Negombo fish landing centre
Prevention , control and monitoring
No seafood should be collected or consumed during or for several days after a bloom (red or green tide)
No seafood should ever be eaten uncooked and only freshly caught fish should be purchased
Keep seafood on ice or refrigerated at less than 4°C to prevent spoilage
Keep fresh tuna, mackerel, grouper, and mahi mahi refrigerated to prevent formation of histamine
In the case of shrimp removing head immediately
When catch big fishes degut first and the keep in iceSeafood Poisoning W.A.Dulanjali M. Wijethilake
Freezing, drying, salting, canning and chilling may reduced the spoilage
Do not use bulbs when selling fish
care should be taken when eating shellfish, and special caution exercised with very large predatory tropical fish
the seafood has been cooked should be discarded, and the viscera of any fish should not be consumed
Proper hygienic practices
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Figure 17 : Posters exhibited in NARA – IPHT devisionFigure 17 : Posters exhibited in NARA – IPHT devision
Long term consequences of seafood poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
• Toxins can influence ecosystems from both the top-down (i.e., affecting predators and influencing grazing) and
• from the bottom-up (i.e., affecting plankton and benthic communities).
• Long-term effects of biotoxins on the health of aquatic animals include increased susceptibility to disease, immunosuppression, abnormal development, and the induction of tumors.
Ecosystem
Long term consequences of seafood poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
• Fish kills, bird kills, manatees and whales
• Sea lion mortalities - linked to the ASP toxin passed through the food web.
• Humpback whales - associated with domoic acid poisoning.
Wildlife
Long term consequences of seafood poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
• Public health impacts account for the largest economic impacts, followed by commercial fisheries and tourism.
Socioeconomic
Occurrence of toxins which threaten valuable seafood resources seem to be increasing in frequency, intensity and geographic distribution
Overall, there are needs to develop and validate diagnostic methods for illness, remedial treatments, and antidotes where appropriate.
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Future perspectives
Urgent need to undertake appropriate risk assessments for marine toxins which take into account all relevant factors
More research is required to gain a better understanding of the factors that determine seafood toxicity, and to develop processes by which intoxicated seafood can be detoxified
Seafood Poisoning W.A.Dulanjali M. Wijethilake
New legislation will have important economic implications for national and international trade
Improved detection methods are also urgently required to replace mouse bioassays
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Discussion There are global distribution of seafood
poisoning cases.
There are life threatening finfish and shellfish poisoning in world
Not only microalgae but also other factors are cause for seafood poisoning
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Occurrence of toxins which threaten valuable seafood resources seem to be increasing in frequency, intensity and geographic distribution
Most seafood poisoning types are neurotoxic and affect to CNS or Peripheral NS.
Behind the seafood poisoning main issue is improper hygienic practices of fishermen
Thus long term consequences occur to ecosystem, wild life and socioeconomic.
Seafood Poisoning W.A.Dulanjali M. Wijethilake
References Harmful algae from
http://www.whoi.edu/redtide/page.do?pid=15315
Jorge, R. R. (2007). Ciguatera1. 3-4.
Mclauchlin, J., Little, C. (2007). Hobb’s Food poisoning and food hyegiene, 7th edition. 219-222.
Roberts, D., Greenwood, M. (2003). Practical food Microbiology, 3rd edition. 228-229.
Science for environmental policy. Low toxic heavy metal risk for the average Spanish consumer of sea food.
Whittle, K., Gallacher, S. (2000). Marine toxins. Journal of British medical bulletin, 236-253.
Seafood Poisoning W.A.Dulanjali M. Wijethilake
Seafood Poisoning W.A.Dulanjali M. Wijethilake
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