142 Marine Food-Borne Poisoning, Envenomation, and Traumatic Injuries
Key Points• Scombroid is thought to be caused by breakdown of histidine into histamine in dark-meat marine fish and can be managed with antihistamines.
• Ciguatera poisoning results from the consumption of large tropical predatory reef fish that have bioaccumulated ciguatoxin; it causes gastrointestinal distress and neurologic symptoms.
• Tetrodotoxin blocks sodium channels and can lead to ascending paralysis and respiratory failure.
• box jellyfish (Cubozoa). Portuguese man-of-war (Hydrozoa), and other stinging marine invertebrates envenomate humans via nematocysts that contain a stinging barb and venom.
• The box jellyfish (Chironex fleckeri) and related species cause the most morbidity and mortality of all marine envenomations.
• Acetic acid immersion is recommended for the treatment of box jellyfish envenomation but may worsen man-o-war envenomation.
• Hot water immersion appears to be an effective treatment of almost all marine envenomations.
• Sea snake venom is neurotoxic and myotoxic. Treatment with antivenom is effective.
• Evaluation for a retained foreign body should be considered with stingray and spiny fish envenomation.
• Wound infection is a common complication of spiny fish and stingray envenomation, and prophylactic antibiotics effective against common pathogens such as Vibrio species should be considered.
• Direct marine injuries are usually abrasions and contusions, but fatal attacks by sharks and large predatory fish do occur.
Marine Food-Borne Poisonings
Pathophysiology
The toxins responsible for the signs and symptoms of marine food-borne illnesses are primarily produced in microorganisms such as dinoflagellates, diatoms, and marine bacteria and are bioaccumulated by shellfish or fish, which are then ingested by humans and result in toxicity. Most of these toxins modulate neuronal and muscle sodium channels. Scombroid is not caused by a preformed toxin but rather by breakdown of histidine into histamine in inadequately stored dark-meat fish. Table 142.1 lists the common marine food-borne poisonings, causative toxins, and typical sources of such poisonings.8
Presenting Signs and Symptoms
Table 142.1 lists the typical onset and common symptoms associated with marine food-borne poisonings. Typically, a history of seafood ingestion can be obtained. In most cases the symptoms are manifested within minutes to hours and include a mixture of gastroenteritis (nausea, vomiting, and diarrhea) and often dramatic neurologic findings.
