Possible Estuary-Associated Syndrome: Symptoms, Vision, and Treatment
Shoemaker, Ritchie C., Hudnell, H. Kenneth, Environmental Health Perspectives
The human illness designated as possible estuarine-associated syndrome (PEAS) by the Centers for Disease Control and Prevention (CDC) has been associated with exposure to estuaries inhabited by toxin-forming dinoflagellates, including members of the fish-killing toxic Pfiesteria complex (TPC), Pfiesteria piscicida and Pfiesteria shumwayae. Humans may be exposed through direct contact with estuarine water or by inhalation of aerosolized or volatilized toxin(s). The five cases reported here demonstrate the full spectrum of symptoms experienced during acute and chronic stages of this suspected neurotoxin-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 contact, muscle ache, and abdominal pain. Less frequently encountered symptoms are upper airway obstruction, shortness of breath, confusion, red or tearing 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 diagnosing and monitoring PEAS. VCS deficits are present in both acute and chronic PEAS, and VCS recovers during cholestyramine treatment coincident with symptom abatement. Although PEAS cannot yet be definitively associated with TPC exposure, resolution with cholestyramine treatment suggests a neurotoxin-mediated illness. Key words. cholestyramine, chronic neurotoxic illness, harmful algal blooms, Pfiesteria, possible estuary-associated syndrome, visual contrast sensitivity. [Online 14 May 2001]
A 32-year-old male commercial fisherman worked on the Pocomoke River, a tributary of the Chesapeake Bay on the Eastern Shore of Maryland, since age 16 without any significant illness until October 1996. In association with harvesting multiple species of fish with deep, penetrating ulcers, the patient had initial onset of memory impairment, headache, hypersensitivity to bright light, fatigue, cough, muscle ache, skin rash, diarrhea, and anorexia. Subsequently, the patient was treated by several local physicians with antibiotics for recurrent pneumonia (seven episodes in 6 months). The diagnoses of pneumonia were based on clinical parameters alone, without additional confirmatory tests. The patient lost 40 pounds, became weak and lethargic, and continued to suffer from the symptoms listed above. He continued to work in the estuaries.
Table 1. Estuarine exposure and illness. PEAS Illness condition date Case 1 Chronic(a) Oct 1996-Sep 1997 Acute Jun 1998 Case 2 Acute Jul 1999 Acute Oct 1999 Acute Dec 1999 Case 3 Acute Dec 1998 Acute Feb 1999 Cases 4 and 5 Chronic Sep 1998-Mar 1999 Acute Jul 1999 Estuarine contact < 2 weeks Dead or lesioned before illness onset fish contact Case 1 Pocomoke River, MD Y Pocomoke River, MD Y Case 2 Pocomoke River, MD Y and Bulbeggar Creek, VA Indian River, DE N Rehoboth Bay and tributaries, DE Y Case 3 Chicamacomico River, MD Y Chicamacomico River, MD Y Cases 4 and 5 Back Creek, Manokin River, MD Y Back Creek, Manokin River, MD N Ever tested positive for TPC References Case 1 Y (1) Y (1) Case 2 Y (1,2) Y (3) Y (3) Case 3 Y (4) Y (4) Cases 4 and 5 Y (4,5) Y (4,5) (a) Chronic PEAS is defined as PEAS symptoms present > 1 month. …