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10 SEAFOOD SAFETY 



During the same period, scombroid poisoning reportedly caused a similar 

 number of outbreaks as ciguatera but was much more widespread in occurrence. 

 Tuna, mahimahi, and biuefish were implicated as the major cause of scombroid 

 poisoning in the United States. The disease is generally mild and self-resolving, and 

 symptoms can be ameliorated by antihistamine drugs. Because the histamine that 

 causes scombroid poisoning is produced after the fish have been caught, as a 

 consequence of improper temperature control, the disease can be prevented by rapidly 

 cooling fish after capture to 10°C or lower (e.g., 0°C if kept for an extended period) 

 and holding them at or below this temperature at all times before cooking and eating. 

 A HACCP-based system would control this poisoning for commercially handled fish, 

 but the education of subsistence and recreational fishers is also necessary. 



Paralytic shellfish poisoning was a minor cause of seafood-borne illness in 1978- 

 1987, with only two deaths reported. This is a remarkable record in view of the annual 

 occurrence of toxic situations among shellfish on both the East and the West coasts of 

 the United States, which indicates that current control measures applied by coastal 

 states are highly effective. However, the increasing occurrence of toxic dinoflagellate 

 blooms and changing eating practices (e.g., eating whole scallops) among some sectors 

 of the consuming public require increased surveillance and the development of more 

 rapid and simple tests for toxic shellfish. 



Although none of the other natural seafood intoxications, except for a single 

 outbreak of NSP, have been reported recently by U.S. consumers, the potential for 

 their occurrence either from domestically produced seafoods or from imports is real. 

 Increased vigilance concerning imported products based on a requirement for certified 

 nontoxicity is recommended. Moreover, both state and federal laboratories should be 

 prepared to test for these "other" toxins, and procedures to deal with outbreaks should 

 be in place. 



Principal Conclusions 



• Natural toxin risks are highly regional or species associated. 



• Natural toxins are present in the environment and are not affected by 

 procedures during or after harvest. The one exception is scombroid shellfish poisoning, 

 which is due to postharvest mishandling. 



• Reliable, rapid tests for the natural toxins are either unavailable or not fully 

 developed. 



• Although PSP is well controlled by state inspection systems and industry 

 controls are in place for scombroid poisoning, there are no regulations for the control 

 of ciguatera. 



• Recreational and subsistence fish eaters are at particular risk from natural 

 toxins, and there is a lack of understanding by consumers of this risk. 



Principal Recommendations 



• Control for natural toxins in the food chain should be at, or prior to, harvest, 

 either by closures or by testing at the point of harvest. 



