Amnesic shellfish poisoning
Encyclopedia
Amnesic shellfish poisoning (ASP) is a human illness caused by consumption of the marine biotoxin called domoic acid
. This toxin is produced naturally by marine diatom
s belonging to the genus Pseudo-nitzschia
and the species Nitzschia navis-varingica. When accumulated in high concentrations by shellfish during filter feeding, domoic acid can then be passed on to humans via consumption of the contaminated shellfish. Although human illness due to domoic acid has only been associated with shellfish, the toxin can bioaccumulate
in many marine
organisms that consume phytoplankton
, such as anchovies
, and sardine
s. Intoxication by domoic acid in non-human organisms is frequently referred to as "domoic acid poisoning" or "DAP". In mammal
s, including human
s, domoic acid acts as a neurotoxin
, causing permanent short-term memory
loss, brain
damage, and death
in severe cases.
and amygdaloid nucleus. It damages the neuron
s by activating AMPA
and kainate receptors, causing an influx of calcium
. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate.
Gastrointestinal symptoms can appear 24 hours after ingestion of affected molluscs. They may include vomiting
, nausea
, diarrhea
, abdominal cramp
s and haemorrhagic gastritis
. In more severe cases, neurological symptoms can take several hours or up to three days to develop. These include headache
, dizziness
, disorientation, vision disturbances, loss of short-term memory
, motor weakness, seizure
s, profuse respiratory secretions, hiccoughs, unstable blood pressure
, cardiac arrhythmia and coma
.
People poisoned with very high doses of the toxin or displaying risk factors such as old age and renal failure
can die. Death has occurred in 4 of 107 confirmed cases. In a few cases, permanent sequela
e included short-term memory loss and peripheral polyneuropathy
.
There is no known antidote available for domoic acid, so if symptoms fit the description, it is advised to go quickly to the hospital. Cooking or freezing affected fish or shellfish tissue does not lessen the toxicity.
. Three elderly patients died and other victims suffered long-term neurological problems. Because the victims suffered from memory loss, the term "amnesic" shellfish poisoning is used. The story made front-page newspaper headlines.
Epidemiologists from Health Canada
quickly linked the illnesses to restaurant meals of cultured mussels harvested from one area in Prince Edward Island
, a place never before affected by toxic algae. Mouse bioassays on aqueous extracts of the suspect mussels caused death with some unusual neurotoxic symptoms very different from those of paralytic shellfish poisoning
toxins and other known toxins. On December 12, 1987, a team of scientists was assembled at the National Research Council of Canada
laboratory in Halifax
, Nova Scotia
. Integrating bioassay-directed fractionation with chemical analysis, the team identified the toxin on the afternoon of December 16, just 4 days after the start of the concerted investigation .
, possibly under the influence of domoic acid , flew through the windshield of a car on the Pacific Coast Highway. The phycotoxin is found in the local coastal waters.
Since March 2007, marine mammal and seabird strandings and deaths off the Southern California coast have increased markedly. These incidents have been linked to the recent and dramatic increase of a naturally occurring toxin produced by algae. Most of the animals found dead tested positive for domoic acid.
According to the Channel Islands Marine and Wildlife Institute (CIMWI) , "It is generally accepted that the incidence of problems associated with toxic algae is increasing. Possible reasons to explain this increase include natural mechanisms of species dispersal (currents and tides) to a host of human-related phenomena such as nutrient enrichment (agricultural run-off), climate shifts or transport of algae species via ship ballast water."
(original air-date: February 2, 1992), Sharon and Gus get amnesia after eating bad shellfish, and Chris seizes the opportunity to convince them that they are his best friends.
Domoic acid poisoning may have caused an August 18, 1961 invasion of thousands of frantic seabirds in Capitola
and Santa Cruz, California
. Director Alfred Hitchcock
heard about this invasion while working on his adaptation of Daphne du Maurier
novella "The Birds" for his feature film The Birds
(1963), and asked the Santa Cruz Sentinel
newspaper for any further news copy as "research for his new thriller".
Domoic acid
Domoic acid , the neurotoxin that causes amnesic shellfish poisoning , also known as zombie acid, is a kainic acid analog, heterocyclic amino acid associated with certain harmful algal blooms.-Occurrence:...
. This toxin is produced naturally by marine diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s belonging to the genus Pseudo-nitzschia
Pseudo-nitzschia
The genus Pseudo-nitzschia includes several species of diatoms known to produce the neurotoxin known as domoic acid, a toxin which is responsible for the human illness called amnesic shellfish poisoning...
and the species Nitzschia navis-varingica. When accumulated in high concentrations by shellfish during filter feeding, domoic acid can then be passed on to humans via consumption of the contaminated shellfish. Although human illness due to domoic acid has only been associated with shellfish, the toxin can bioaccumulate
Bioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
in many marine
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
organisms that consume phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
, such as anchovies
Anchovy
Anchovies are a family of small, common salt-water forage fish. There are 144 species in 17 genera, found in the Atlantic, Indian, and Pacific Oceans. Anchovies are usually classified as an oily fish.-Description:...
, and sardine
Sardine
Sardines, or pilchards, are several types of small, oily fish related to herrings, family Clupeidae. Sardines are named after the Mediterranean island of Sardinia, around which they were once abundant....
s. Intoxication by domoic acid in non-human organisms is frequently referred to as "domoic acid poisoning" or "DAP". In mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, including human
Human
Humans are the only living species in the Homo genus...
s, domoic acid acts as a neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
, causing permanent short-term memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
loss, brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
damage, and death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
in severe cases.
Symptoms and treatment
In the brain, domoic acid especially damages the hippocampusHippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
and amygdaloid nucleus. It damages the neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s by activating AMPA
AMPA
AMPA is a compound that is a specific agonist for the AMPA receptor, where it mimics the effects of the neurotransmitter glutamate....
and kainate receptors, causing an influx of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate.
Gastrointestinal symptoms can appear 24 hours after ingestion of affected molluscs. They may include vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
, abdominal cramp
Cramp
Cramps are unpleasant, often painful sensations caused by muscle contraction or over shortening. Common causes of skeletal muscle cramps include muscle fatigue, low sodium, and low potassium...
s and haemorrhagic gastritis
Gastritis
Gastritis is an inflammation of the lining of the stomach, and has many possible causes. The main acute causes are excessive alcohol consumption or prolonged use of nonsteroidal anti-inflammatory drugs such as aspirin or ibuprofen. Sometimes gastritis develops after major surgery, traumatic...
. In more severe cases, neurological symptoms can take several hours or up to three days to develop. These include headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, dizziness
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, disorientation, vision disturbances, loss of short-term memory
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...
, motor weakness, seizure
Seizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
s, profuse respiratory secretions, hiccoughs, unstable blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, cardiac arrhythmia and coma
Coma
In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
.
People poisoned with very high doses of the toxin or displaying risk factors such as old age and renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
can die. Death has occurred in 4 of 107 confirmed cases. In a few cases, permanent sequela
Sequela
A sequela) is a pathological condition resulting from a disease, injury, or other trauma.Chronic kidney disease, for example, is sometimes a sequela of diabetes, and neck pain is a common sequela of whiplash or other trauma to the cervical vertebrae. Post-traumatic stress disorder may be a...
e included short-term memory loss and peripheral polyneuropathy
Polyneuropathy
Polyneuropathy is a neurological disorder that occurs when many peripheral nerves throughout the body malfunction simultaneously. It may be acute and appear without warning, or chronic and develop gradually over a longer period of time. Many polyneuropathies have both motor and sensory...
.
There is no known antidote available for domoic acid, so if symptoms fit the description, it is advised to go quickly to the hospital. Cooking or freezing affected fish or shellfish tissue does not lessen the toxicity.
Discovery
ASP was first discovered in humans late in 1987, when a serious outbreak of food poisoning occurred in eastern CanadaCanada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. Three elderly patients died and other victims suffered long-term neurological problems. Because the victims suffered from memory loss, the term "amnesic" shellfish poisoning is used. The story made front-page newspaper headlines.
Epidemiologists from Health Canada
Health Canada
Health Canada is the department of the government of Canada with responsibility for national public health.The current Minister of Health is Leona Aglukkaq, a Conservative Member of Parliament appointed to the position by Prime Minister Stephen Harper.-Branches, regions and agencies:Health Canada...
quickly linked the illnesses to restaurant meals of cultured mussels harvested from one area in Prince Edward Island
Prince Edward Island
Prince Edward Island is a Canadian province consisting of an island of the same name, as well as other islands. The maritime province is the smallest in the nation in both land area and population...
, a place never before affected by toxic algae. Mouse bioassays on aqueous extracts of the suspect mussels caused death with some unusual neurotoxic symptoms very different from those of paralytic shellfish poisoning
Paralytic shellfish poisoning
Paralytic shellfish poisoning is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks . These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as...
toxins and other known toxins. On December 12, 1987, a team of scientists was assembled at the National Research Council of Canada
National Research Council of Canada
The National Research Council is an agency of the Government of Canada which conducts scientific research and development.- History :...
laboratory in Halifax
City of Halifax
Halifax is a city in Canada, which was the capital of the province of Nova Scotia and shire town of Halifax County. It was the largest city in Atlantic Canada until it was amalgamated into Halifax Regional Municipality in 1996...
, Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
. Integrating bioassay-directed fractionation with chemical analysis, the team identified the toxin on the afternoon of December 16, just 4 days after the start of the concerted investigation .
Possible animal effects
On June 22, 2006, a California brown pelicanBrown Pelican
The Brown Pelican is the smallest of the eight species of pelican, although it is a large bird in nearly every other regard. It is in length, weighs from and has a wingspan from .-Range and habits:...
, possibly under the influence of domoic acid , flew through the windshield of a car on the Pacific Coast Highway. The phycotoxin is found in the local coastal waters.
Since March 2007, marine mammal and seabird strandings and deaths off the Southern California coast have increased markedly. These incidents have been linked to the recent and dramatic increase of a naturally occurring toxin produced by algae. Most of the animals found dead tested positive for domoic acid.
According to the Channel Islands Marine and Wildlife Institute (CIMWI) , "It is generally accepted that the incidence of problems associated with toxic algae is increasing. Possible reasons to explain this increase include natural mechanisms of species dispersal (currents and tides) to a host of human-related phenomena such as nutrient enrichment (agricultural run-off), climate shifts or transport of algae species via ship ballast water."
In popular culture
In the "Bad Fish" episode of Get a LifeGet a Life (TV series)
Get a Life is a television sitcom that was broadcast in the United States on the Fox Network from September 23, 1990, to March 8, 1992. The show starred Chris Elliott as a 30-year-old paperboy named Chris Peterson. Peterson lived in an apartment above his parents' garage...
(original air-date: February 2, 1992), Sharon and Gus get amnesia after eating bad shellfish, and Chris seizes the opportunity to convince them that they are his best friends.
Domoic acid poisoning may have caused an August 18, 1961 invasion of thousands of frantic seabirds in Capitola
Capitola, California
Capitola is a city in Santa Cruz County, California, United States, on the coast of Monterey Bay. The population was 9,918 at the 2010 census.-History:...
and Santa Cruz, California
Santa Cruz, California
Santa Cruz is the county seat and largest city of Santa Cruz County, California in the US. As of the 2010 U.S. Census, Santa Cruz had a total population of 59,946...
. Director Alfred Hitchcock
Alfred Hitchcock
Sir Alfred Joseph Hitchcock, KBE was a British film director and producer. He pioneered many techniques in the suspense and psychological thriller genres. After a successful career in British cinema in both silent films and early talkies, Hitchcock moved to Hollywood...
heard about this invasion while working on his adaptation of Daphne du Maurier
Daphne du Maurier
Dame Daphne du Maurier, Lady Browning DBE was a British author and playwright.Many of her works have been adapted into films, including the novels Rebecca and Jamaica Inn and the short stories "The Birds" and "Don't Look Now". The first three were directed by Alfred Hitchcock.Her elder sister was...
novella "The Birds" for his feature film The Birds
The Birds (film)
The Birds is a 1963 horror film directed by Alfred Hitchcock based on the 1952 short story "The Birds" by Daphne du Maurier. It depicts Bodega Bay, California which is, suddenly and for unexplained reasons, the subject of a series of widespread and violent bird attacks over the course of a few...
(1963), and asked the Santa Cruz Sentinel
Santa Cruz Sentinel
The Santa Cruz Sentinel is a daily newspaper published in Santa Cruz, California, covering Santa Cruz County, California, and owned by MediaNews Group Inc....
newspaper for any further news copy as "research for his new thriller".
See also
- Diarrheal shellfish poisoningDiarrheal shellfish poisoningDiarrhetic shellfish poisoning is one of the four recognized symptom types of shellfish poisoning, the others being paralytic shellfish poisoning, neurotoxic shellfish poisoning and amnesic shellfish poisoning....
- Neurotoxic shellfish poisoningNeurotoxic shellfish poisoningNeurotoxic Shellfish Poisoning is caused by the consumption of shellfish contaminated by breve-toxins or brevetoxin analogs.Symptoms in humans include vomiting and nausea and a variety of neurological symptoms such as slurred speech...
- Paralytic shellfish poisoningParalytic shellfish poisoningParalytic shellfish poisoning is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks . These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as...
External links
- Amnesic Shellfish Poisoning at Woods Hole Oceanographic InstitutionWoods Hole Oceanographic InstitutionThe Woods Hole Oceanographic Institution is a private, nonprofit research and higher education facility dedicated to the study of all aspects of marine science and engineering and to the education of marine researchers. Established in 1930, it is the largest independent oceanographic research...
- Domoic acid and Pseudo-nitzschia references at Fisheries and Oceans CanadaFisheries and Oceans CanadaFisheries and Oceans Canada, frequently referred to as DFO , is the department within the government of Canada that is responsible for developing and implementing policies and programs in support of Canada's economic, ecological and scientific interests in oceans and inland waters...
- Amnesic Shellfish Poisoning, Domoic Acid, and Pseudo-nitzschia links at the ISSHA website
- Domoic acid at International Programme on Chemical SafetyInternational Programme on Chemical SafetyThe International Programme on Chemical Safety was formed in 1980 and is a collaboration between three United Nations bodies—the World Health Organization, the International Labour Organization and the United Nations Environment Programme to establish the scientific basis for safe use of...
- DOMOIC ACID — A MAJOR CONCERN TO WASHINGTON STATE’S SHELLFISH LOVERS at Washington Department of Fish and Wildlife
- Crisis off our coast at the International Bird Rescue Research Center
- Domoic Acid Poisoning Linked to Recent Marine Strandings and Deaths at Heal the Bay
- Domoic Acid Information and History at the Channel Islands Marine and Wildlife Institute