Submitted to: United States Environmental Protection Agency Chesapeake Bay Program Report
Publication Type: Abstract Only
Publication Acceptance Date: September 26, 1999
Publication Date: September 26, 1999
Technical Abstract: Cryptosporidium parvum is a protozoan parasite found in over 100 species of mammals, including humans, worldwide. In humans and young livestock, ingestion of the organism in contaminated food or water results in moderate to severe diarrhea lasting days to weeks. Immune compromised persons or animals develop severe and often fatal illness because there is no effective treatment or vaccine. The source of this parasite is fecal contamination. Utilizing oysters as biological indicators for the presence of this organism, Cryptosporidium was found at 11 sites in the Chesapeake Bay and its tributaries. Oyster bars near cattle farms, near sewage outfalls from three cities, and at commercial harvesting sites were all contaminated. Attempts are also underway to determine if season and rainfall affect the levels of contamination. Increases in Pfiesteria populations have been implicated in fish kills in the Chesapeake Bay watershed. However, it is possible that other agents not yet identified may be involved as well. Ongoing research is examining fish behavior and health problems related to fungal, algal, bacterial and chemical toxins. Unique methods to culture fish brain cells have been developed and are being employed to determine the types of brain cell injury that results from exposure to toxins from both infectious and noninfectious agents. Fish lesions associated Pfiesteria events are being histopathologically examinedd for the presence of infectious and noninfectious agents. Multiple agents have been observed in these lesions without detection of harmful algal cells. A primary goal is to identify specific agents and toxins and their influence on fish health.