Toxic Pfiesteria and human health

Toxic activity of a Pfiesteria-like organism occurred for much of 1997 in the waters of the lower Pocomoke River on Maryland's Eastern Shore. Maryland's experience with these toxic blooms of dinoflagellates, current knowledge of their potential human health effects, and the actions taken by state government agencies in response to a potential public health threat are reviewed. A medical diagnostic team commissioned by the Department of Health and Mental Hygiene evaluated a group of persons with intense exposures to lesioned fish or the waters from which they came and/or prominent symptoms following exposure to affected waters or lesioned fish. The principal findings of the team included consistent complaints of memory problems, acute burning of the skin following direct contact with water, and respiratory irritation. Findings on examination were limited to neurocognitive deficits in short-term memory and learning difficulties. Physicians and citizens are asked to continue to report, through their local health departments, illnesses thought to be related to exposure to lesioned fish or the waters from which they are taken. Persons with questions or wishing to report finding lesioned fish should call the state Pfiesteria hotline at 1-888-584-3110.