Quite possibly the most common of all of the shellfish poisoning is Diarrheal Shellfish Poisoning, or DSP. The other three syndromes are Paralytic (PSP), Amnesic (ASP) and Neurologic (NSP). As the name suggests, a person will suffer from diarrhea after eating contaminated shellfish. Okadaic acid is the poison that causes this type of shellfish poisoning.
Diarrheal Shellfish Poisoning and Neurologic Shellfish Poisoning toxins are often found in filter feeders such as clams, scallops, mussels and oysters. Marine animals and other fish that survive off of eating shellfish can also get DSP from the contaminated shellfish.
What Is Okadaic Acid?
Okadaic acid is a toxin that affects humans when they consume shellfish that has consumed algae and plankton that contain the dinoflagellates genus Dinophysis. Dinoflagellates are the bacteria that create okadiac acid. They grow most commonly in warmer climates and are also the cause of red tides. This toxin is fat soluble, which makes it harder or the body to get rid of.
Symptoms And Treatment Of DSP
Diarrheal Shellfish Poisoning has few symptoms. Symptoms usually begin within 30 minutes to twelve hours after eating the contaminated shellfish. Diarrhea is the most common symptom, but other symptoms that have been reported to public health officials are:
There have never been any reported deaths associated with DSP. It is treated the same as any one with a stomach flu and is often mistaken for the flu. Dehydration is needed from loss of fluids and electrolytes and patients usually recover in one to two days. Diarrheal Shellfish Poisoning is most commonly found in the shellfish in Europe and Japan but any shellfish anywhere that there is a red tide can be infected.
It is safest to avoid eating shellfish during the warmer summer months in order to avoid getting a food borne illness due to contaminated shellfish. State health departments are very good at checking the water for contaminations and posting bulletins when it is unsafe to harvest shellfish. The toxins are completely odorless and tasteless. Cooking the shellfish does not kill the bacteria that causes DSP, PSP, ASP or NSP.
Sources: Northwest Fisheries Science Center “Harmful Algae Blooms” (author and date unknown)
Center For Disease Control “Marine Toxins” (author and date unknown)