In this study quantitative sequence detection (QSD) primers and fluorogenic probes were evaluated using recombinant plasmid DNA containing the C. parvum hsp70 target and C. parvum oocysts DNA. CC-QSD was then used as a quantitative cell culture infectivity assay to evaluate the effects of water sample matrices on the potassium permanganate (KMnO4) and chlorine dioxide (ClO2) inactivation of C. parvum. Methods used include: oocysts and microscopy; oocyst treatments; in vitro cell culture of C. parvum; sample preparation for QSD and CC-QSD; and, QSD and CC-QSD. Includes 9 references, table, figures.