You are here:
Criteria For Evaluation of Proposed Protozoan Detection Methods
Citation:
DUFOUR, A. P., M. Fiege, H. LINDQUIST, M. MESSNER, S. REGLI, C. RODGERS, F. W. SCHAEFER, S. SCHAUB, J. L. SINCLAIR, AND L. J. WYMER. Criteria For Evaluation of Proposed Protozoan Detection Methods. U.S. Environmental Protection Agency, Washington, DC, 1999.
Impact/Purpose:
see description
Description:
Currently, the only EPA approved method for detection and quantitation of protozoan cysts and oöcysts in source and drinking water, is the “ICR Protozoan Method for Detecting Giardia Cysts and Cryptosporidium Oöcysts in Water by a Fluorescent Antibody Procedure (ICR Microbial Laboratory Manual, Section VII, EPA/600/R-95/178, April 1996). Experience with the ICR protozoan method has shown that it usually underestimates the levels and occurrence of Giardia sp. and Cryptosporidium sp., the two protozoan parasites that it was designed to detect. False positives and false negatives have been found during testing in a number of laboratories. The ICR method has also been criticized for being complex and difficult to perform, yielding highly variable results, demonstrating differential response in a variety of water matrices, and being costly (Clancy, et al. 1997, Schaefer, 1997). To address these issues, alternate methods have been proposed and preliminarily tested. Not all of the alternatives are complete methods. Some are method components meant to substitute for the sampling, processing, staining or detection steps used in the ICR method.