This document discusses seafood poisoning from toxins produced by algae and bacteria. It covers the major types of finfish and shellfish poisoning including ciguatera, paralytic shellfish, diarrhetic shellfish, and amnestic shellfish poisoning. Toxins are often concentrated up the food chain and can cause neurological and gastrointestinal symptoms in humans. Prevention focuses on proper handling and cooking of seafood to reduce risks. Monitoring programs aim to detect algal blooms and toxin levels to protect consumers and coastal communities that rely on seafood.

3. EPITOME
1.
• Introduction
2.
• Global distribution of toxins
3.
• Finfish poisoning
4.
• Shellfish poisoning
5.
• Other factors associate with seafood poisoning
6.
• New and emerging toxins
7.
• Detection methods of seafood poisoning
8.
• Symptoms of seafood poisoning
9.
• Hygienic errors for seafood poisoning
10.
• Prevention, control and monitoring
11.
• Long term consequences of seafood poisoning
12.
• Future perspectives
13.
• Sri Lankan situation of seafood poisoning
14.
• Discussion
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

4. 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 - medicaldictionary)
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

5.  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

6.  The toxins can produce various
Neurological and gastrointestinal illness
 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

7.  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

8. Categories of Seafood poisoning
Finfish
poisoning
Shellfish
poisoning
1 Scombroid fish
poisoning
2 Ciguatera fish
poisoning
3 Puffer fish
poisoning
4 Sardine poisoning
5 Hallucinogenic
fish poisoning
6 Palytoxic fish
poisoning
1 Paralytic shellfish
Seafood Poisoning
poisoning.
2 Neurotoxic
shellfish poisoning
3 Diarrhetic
shellfish poisoning
4 Amnestic shellfish
poisoning.
5 Azapiracid
poisoning
Other factors
1 Parasites
2 Bacteria
3 Viruses
4 Heavy metals
5 Red whelk
poisoning
W.A.Dulanjali M. Wijethilake

9. Syndrome
Amnesic shellfish poisoning
(ASP)
Azaspiracid shellfish poisoning
(AZP)
Ciguatera fish poisoning
(CFP)
Seafood Poisoning
Affected Areas
U.S. west coast including Alaska
Atlantic Canada
Georges Bank
Chile
Australia
New Zealand
United Kingdom
England
Scotland
Ireland
France
Spain
Morocco
Norway
Hawaii
Gulf of Mexico
Puerto Rico
Caribbean
Australia
Many Pacific islands
W.A.Dulanjali M. Wijethilake

10. Diarrhetic shellfish poisoning
(DSP)
Neurotoxic shellfish poisoning
(NSP)
Paralytic shellfish poisoning
(PSP)
Swimmer's itch
Dermatitis
Seafood Poisoning
Europe
Japan
Atlantic Canada
South Africa
Chile
Thailand
New Zealand
Australia
U.S. Gulf coast
New Zealand
U.S. west coast including Alaska
New England coastal states
Canada
Chile
Brazil
Europe
South Africa
Asia
Australia
New Zealand
Australia
Florida
worldwide throughout the tropics and
subtropics
W.A.Dulanjali M. Wijethilake

11. Figure 1 : Global distribution of PSP,NSP,DSP and ASP
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

12. Figure 2 : Global distribution of CFP and AZP
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

13. 1. Scombroid fish poisoning (SFP)
 Most common cause
 Histamine poisoning or pseudo allergic reaction
 Scombroid fish species – Tuna, Bonito and
mackerel
 Non scombroid fish
Figure 3 : formation of histamine
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

14.  Histidine decarboxylase enzyme producing
bacteria
a.
b.
c.
d.
E.coli
Klebsiella pneumonias
Hafnia alvei
Morganella morganii
 Biogenic amines also play major role
 Recommended Histamin levels
I. 5mg/100g = safe
II. 10-20/100g = maximum level
III. >50mg/100g = unsafe
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

15. 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
Figure 4 : Structure of Ciguatoxin
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

16. Figure 5 : Food chain accumulation of dinoflagellates
 CFP does not affect the appearance, odour and taste
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

17. 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

18. 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

19. 5. Hallucinogenic fish poisoning
 Ichthyoallyeinotoxism
 Rare
 Fish species include Siganus spinus
 Exact toxin - unknown
 Similarities with CFP
Figure 5 : Siganus spinus
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

20. 6. Palytoxic fish poisoning
 Grazing animals on Palythoa sp.
 Toxin – Palytoxin
 Neurotoxic
 Similarities with CFP
Seafood Poisoning
Figure 6 : Palythoa sp.
W.A.Dulanjali M. Wijethilake

21. 1. Paralytic shellfish poisoning (PSP)
 Most common and widespread shellfish poisoning
 Toxin – Saxitoxin (STX)
 Agent –Alexandrium sp., Gymnodinium catenatum
and Pyrodinium spp.
 Mechanism
Figure 7 : Structure of saxitoxin
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

22. 2. Neurotoxic shellfish poisoning (NSP)
 Known since centuries
 Toxin – Brevetoxins
 Agent – Gymnodinium breve, Karenia brevis ,
Karenia brevisulcatum
 Mechanism
Figure 8 : Structure of brevetoxin
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

23. 3. Diarrhetic shellfish poisoning (DSP)
 Mild poisoning
 Toxin – Okadaic acid and derivative
 Agent – Dinophysis sp., Prorocentrum sp.
 Filter feeding bivalves
 Mechanism
Figure 9 : Structure of Okadaic acid
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

24. 4. Amnestic shellfish poisoning
 One of the potentially serious poisoning
 Toxin – Domoic acid
 Agent - Pseudonitzchia sp.
 Mechanism
 20µg DA/g – Safety limit
Figure 10 : Structure of Domoic acid
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

25. 5. Azaspiracid poisoning
 More recently discovered poisoning
 Toxin – Azaspiraicd 1
 Agent - Protoperidinium crassipes
Figure 11 : Structure of Azaspiracid 1
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

26. 1. Parasites in seafood
a.
b.
c.
d.
Anisakis simplex
Diphyllobothrium sp.
Paragonimus sp.
Opisthocris sp.
Figure 12 : Anisakis simplex (Leff) and Diphyllobothrium sp. (Right)
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

27.  Protozoans
a.
b.
c.
d.
Cryptosporidium parvum
Entamoeba histolytica
Giardia lamblia
Cyclospora sp.
Figure 13 : protozoans in fish species
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

28. 2. Bacteria in seafood
a.
b.
c.
d.
e.
f.
E.coli
Staphylococcus aureus
Salmonella sp.
Vibrio cholerae
Vibrio parahaemolyticus
Listeria monocytogenes
Figure 14 : Bacteria in fish species
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

29. 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

30.  The occurrence of seafood toxins seems to be
increasing and new potential food poisoning
hazard
1.
2.
3.
4.
Azaspiracid
Cyanobacteria toxins
Pfiesteria toxin
Other compounds – Gymnodinine and procentrolide
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

31.  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-MS
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

32. f. Ion exchange chromatography – Histamin
g. Capillary zone electrophoresis – Histamin
h. High voltage electrophoresis - Tetramine
Figure 15 : Ion exchange chromatography machine
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

33. Syndrome
Symptoms
Scombroid poisoning
Breathing problems (in severe cases)
Extremely red skin on face and body
Flushing
Hives and itching
Nausea
Vomiting
Ciguatera fish poisoning
Abdominal cramps
Diarrhea (severe and watery)
Nausea
Vomiting
Tetradotoxin fish poisoning
Paresthesia of the lips and tongue
Hypersalivation
Sweating
Headache
Weakness
lethargy
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

34. Paralytic shellfish poisoning
Numbness or tingling in mouth.
This sensation may spread down to
arms and legs.
become very dizzy, have a
headache
in 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.
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

35. 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
contamination and microbial growth.
Seafood Poisoning
fish
W.A.Dulanjali M. Wijethilake

36.  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

37. Faults doing by fishermen
Situation
Errors
Fish in hold
Fish kept in melted water
Loosening ice with harbour water
No sorting by species or catching
date
Unloading
Unload straight on to pier by hand
Pier is highly contaminated due to..
Pier is used for auctioning and
packing
Washing
Use contaminated harbour water
Washing water not change
frequently
Reloading
Inappropriate vehicles
Icing not done correctly
Cross contamination
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

38. Transportation
Many different types of
transportation
•Refrigerated truks
•Unrefrigerated trucks
•Three wheelers
•Motorbikes
•bicycles
Cutting
Wooden cutting boards and it
wash by harbor water
No waste bins
Figure 16 : Bad hygienic practices in Negombo fish landing centre
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

39.  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 ice
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

40.  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

41. Figure 17 : Posters exhibited in NARA – IPHT devision
Seafood Poisoning
W.A.Dulanjali M. Wijethilake

42. • Toxins can influence ecosystems from
both the top-down (i.e., affecting
predators and influencing grazing) and
Ecosystem
Seafood Poisoning
• 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.
W.A.Dulanjali M. Wijethilake

43. Wildlife
Seafood Poisoning
• 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.
W.A.Dulanjali M. Wijethilake

44. Socioeconomic
Seafood Poisoning
• Public health impacts account for the
largest economic impacts, followed by
commercial fisheries and tourism.
W.A.Dulanjali M. Wijethilake

45.  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

46.  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

47.  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

48.  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

49.  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

50.  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

51. Seafood Poisoning
W.A.Dulanjali M. Wijethilake