Possible estuary-associated syndrome: Symptoms, vision, and treatment

The human illness designated as possible estuarine-associated syndrome (PEA S) by the Centers for Disease Control and Prevention (CDC) has been associa ted with exposure to estuaries inhabited by toxin-forming dinoflagellates, including members of the fish-killing toxic Pfiesteria complex (TPC), Pfies teria piscicida and Pfiesteria shumwayae. Humans may be exposed through dir ect contact with estuarine water or by inhalation of aerosolized or volatil ized toxin(s). The five cases reported here demonstrate the full spectrum o f symptoms experienced during acute and chronic stages of this suspected ne urotoxin-mediated illness. The nonspecific symptoms most commonly reported are cough, secretory diarrhea, headache, fatigue, memory impairment, rash, difficulty in concentrating, light sensitivity, burning skin upon water con tact, muscle ache, and abdominal pain. Less frequently encountered symptoms are upper airway obstruction, shortness of breath, confusion, red or teari ng eyes, weakness, and vertigo. Some patients experience as few as four of these symptoms. The discovery that an indicator of visual pattern-detection ability, visual contrast sensitivity (VCS), is sharply reduced in affected individuals has provided an objective indicator that is useful in diagnosi ng and monitoring PEAS. VCS deficits are present in both acute and chronic PEAS, and VCS recovers during cholestyramine treatment coincident with symp tom abatement, Although PEAS cannot yet be definitively associated with TPC exposure, resolution with cholestyramine treatment suggests a neurotoxin-m ediated illness.