Amnesic shellfish poisoning 5040533 201134505 2008-03-26T20:06:21Z Gomm 2067872 no evidence of passing up the food chain '''Amnesic shellfish poisoning''' (ASP) is caused by consumption of shellfish that contain the marine toxin, [[domoic acid]]. Many shellfish contain marine toxins, which are naturally occurring chemicals that can [[bioaccumulate]] in [[filter feeding]] [[Bivalvia|bivalve mollusks]] such as [[mussel]]s, [[clam]]s, [[oyster]]s and [[scallop]]s. The toxins are produced by microscopic [[alga]]e in the form of [[dinoflagellate]]s and [[diatom]]s. ASP is a rare syndrome caused by a toxin made by a microscopic, red-brown, salt-water plant, or diatom called [[Pseudo-nitzschia]]. The toxin produced by these diatoms, domoic acid, is concentrated in shellfish and causes disease when the contaminated shellfish are eaten. The chemical can [[bioaccumulation|bioaccumulate]] in [[ocean|marine]] organisms that eat [[phytoplankton]], such as [[shellfish]], [[anchovy|anchovies]], and [[sardine]]s. 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. == Symptoms and treatment == In the brain, domoic acid especially damages the [[hippocampus]] 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 there are neurological symptoms that 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, [[hiccough]]s, 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 quickly go to the hospital. Cooking or freezing affected fish or shellfish tissue does not lessen the toxicity. == Discovery== ASP was first discovered late in 1987, when a serious outbreak of food poisoning occurred in eastern [[Canada]]. 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.<ref>M. A. Quilliam, J. L. C. Wright, Anal. Chem., 61 (1989) 1053A</ref> 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 poison and other known toxins. On December 12, 1987, a team of scientists was assembled at the [[National Research Council of Canada]] laboratory in [[City of Halifax|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. == Possible animal effects == On [[June 22]], [[2006]], a [[Brown Pelican|California brown pelican]], possibly under the influence of domoic acid, flew through the windshield of a car on the [[Pacific Coast Highway (US)|Pacific Coast Highway]]. The acid is found in the local seas. Domoic acid poisoning may also have caused a 1961 invasion of thousands of frantic seabirds in [[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 (film)|The Birds]]'' (1963). 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. ==Notes== {{Reflist}} == External links == *[http://www.whoi.edu/redtide/illness/asp.html Amnesic Shellfish Poisoning] at [[Woods Hole Oceanographic Institution]] *[http://www.inchem.org/documents/pims/chemical/pim670.htm Domoic acid] at [[International Programme on Chemical Safety]] *[http://wdfw.wa.gov/fish/shelfish/razorclm/domacid.htm DOMOIC ACID - A MAJOR CONCERN TO WASHINGTON STATE’S SHELLFISH LOVERS] at [[Washington Department of Fish and Wildlife]] *[http://www.glf.dfo-mpo.gc.ca/pls/inter/dapr_view_intro?langE=en Domoic acid and ''Pseudo-nitzschia'' references] at [[Fisheries and Oceans Canada]] *[http://www.ibrrc.org/pr_04_25_2007.html Crisis off our coast] - [[International Bird Rescue Research Center]] http://www.healthebay.org/news/2007/04_30_domoicacid/default.asp http://www.cdc.gov/ncidod/dbmd/diseaseinfo/marinetoxins_g.htm http://www.whoi.edu/redtide/illness/asp.html {{Poisoning and toxicity}} [[Category:Seafood]] [[Category:Medical emergencies]] [[Category:Foodborne illnesses]] [[gl:ASP]] [[pl:Zatrucie toksynami morskimi mięczaków]]