Serious illness which is a consequence of consumption of toxic bivalve shellfish (mollusks) such as mussels, oysters and clams that have ingested, by filter feeding, large quantities of micro-algae containing saxitoxin or its derivatives.

Note: Initially there is tingling, numbness and burning of the tongue and lips, which spreads to the face, neck, arms, fingertips, legs and toes and this is followed by weakness of the upper and lower limbs, loss of motor coordination and, in severe cases, paralysis.