TABLE 1.

Viability of C. parvum oocysts exposed at room temperature to Ox-Virin or Ox-Agua based on in vitro excystation and dye permeability assays^a

Disinfectant and concn	Excysted oocysts (%)			Viable oocysts (%)
	30 min	60 min	120 min	30 min	60 min	120 min
2% Ox-Virin	25.3*	14.2*	7.6*	43.4	33.8	23.1*
5% Ox-Virin	7.4*	2.9*	0.4*	30*	7.1*	2*
10% Ox-Virin	7.8*	0.8*	0*	9.6*	2.3*	1*
Control	64.6	65.2	62.7	46.7	47.4	47.2
1% Ox-Agua	35.2*	22*	12*	40.4	30.8*	16.4*
3% Ox-Agua	15.1*	11.8*	4.4*	34	16*	11.1*
5% Ox-Agua	17.9*	9*	0*	24*	16*	0*
Control	62.3	59.8	60.8	47.3	47.3	47.2

^aPercentages of excysted oocysts and viable oocysts were determined by the in vitro excystation and dye permeability assays, respectively. Each number represents the mean of three replicates of at least 100 oocysts observed per replicate. *, statistically significant differences between disinfectant-exposed and control oocysts.