Seafood poisoning by Dulanjali M. Wijethilake

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


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


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 ..


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


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


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


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



Figure 1 : Global distribution of PSP,NSP,DSP and ASP


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


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


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

CFP does not affect the appearance, odour and taste

What is harmful effect of disturbance of sea bottom ?


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


4. Sardine poisoning

Rare and very poorly reported one

Fish species include sardines, herrings and anchovies

Toxin - unknown

But …


5. Hallucinogenic fish poisoning

Ichthyoallyeinotoxism

Rare

Fish species include Siganus spinus

Exact toxin - unknown

Similarities with CFP


Figure 5 : Siganus spinus

6. Palytoxic fish poisoning

Grazing animals on Palythoa sp.

Toxin – Palytoxin

Neurotoxic

Similarities with CFP


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


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


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


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


Figure 10 : Structure of Domoic acid

5. Azaspiracid poisoning

More recently discovered poisoning

Toxin – Azaspiraicd 1 Agent - Protoperidinium crassipes


Figure 11 : Structure of Azaspiracid 1

1. Parasites in seafooda. Anisakis simplex

b. Diphyllobothrium sp.

c. Paragonimus sp.

d. Opisthocris sp.


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.


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


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


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


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


Figure 15 : Ion exchange chromatography machine


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


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.


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


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


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


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



Figure 17 : Posters exhibited in NARA – IPHT devisionFigure 17 : Posters exhibited in NARA – IPHT devision

Long term consequences of seafood poisoning


• 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



• 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



• 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.


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


New legislation will have important economic implications for national and international trade

Improved detection methods are also urgently required to replace mouse bioassays


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


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.


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.


http://www.whoi.edu/redtide/page.do?pid=15315


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Seafood poisoning by Dulanjali M. Wijethilake

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