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United States Department of Agriculture

Agricultural Research Service

Title: Recovery of Infectious Cryptosporidium Parvum Oocysts from Artificial Seawater and Experimentally Infected Oysters

item Trout,l, James - USDA, ARS, BELTSVILLE, MD
item Lewis, Earl - NAT MARINE FISH SERV. MD
item Graczyk, Thaddeus - JOHNS' HOPKINS UNIV. MD

Submitted to: International Congress of Protozoologists
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 1997
Publication Date: N/A

Technical Abstract: Oocysts of Cryptosporidium parvum (Cp) have been found in surface waters worldwide, and outbreaks of cryptosporidiosis have been associated with contaminated drinking water from surface water sources. Many surface waters flow into brackish and marine water environments. Runoff containing animal feces from adjacent agricultural land, leakage from septic tanks, effluent from waste water treatment plants, storm sewer effluent containin animal feces, and dumping of raw human sewage may increase the number of Cp oocysts in these environments. Oysters, which can remove small particulate matter while routinely filtering 10 liters of water or more per hour, and other filter feeders could potentially remove Cp oocysts from the water and retain them on or within their tissues. Evidence indicates that other enteric pathogens such as Vibrio have been associated with eating raw oysters. Data will be presented that demonstrates how long Cp oocysts remain infectious in artificial seawater at salt concentrations of 10, 20 and 30 ppt and at temperatures of 10 and 20 degrees C. Additional data will demonstrate that oysters held in aquaria containing artificial seawater will filter out Cp oocysts placed in that water and will describe where oocysts are found within these oysters and how long oocysts remain infectious in such oysters.

Last Modified: 4/22/2015
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