Table 1.
Summary of die-off rates (the first-order K values) of Giardia cysts and Cryptosporidium oocysts on a variety of surfaces incubated in different environmental conditions.
| Parasite | Test material | Test conditions | |||||
|---|---|---|---|---|---|---|---|
| 12°C 50% RH | 25°C 50% RH | 37°C 70% RH | |||||
| NS | S | NS | S | NS | S | ||
| Giardia | Fabric | −0.24609 | −0.3409 | −0.45487 | −0.39509 | −0.54514 | −0.5132 |
| Ceramic | −0.2572 | −0.29622 | −0.35363 | −0.28729 | −0.36001 | −0.47733 | |
| Formica | −0.2572 | −0.29622 | −0.33656 | −0.28729 | −0.36001 | −0.48086 | |
| Skin | −0.14704 | −0.11569 | −0.25754 | −0.20598 | −0.74951 | −0.6331 | |
| Stainless steel | −0.34612 | −0.35842 | −0.7764 | −1.04699 | −0.89851 | −1.07793 | |
| Average K | −0.25073 | −0.28149 | −0.4358 | −0.44453 | −0.58264 | −0.63648 | |
|
| |||||||
| Cryptosporidium | Fabric | −0.16294 | −0.09118 | −0.58958 | −0.5037 | −1.08403 | −0.85624 |
| Ceramic | −0.46996 | −0.40785 | −0.58958 | −0.5037 | −1.08403 | −0.85624 | |
| Formica | −0.0663 | −0.04954 | −0.58958 | −0.5037 | −0.81303 | −0.64218 | |
| Skin | −0.04837 | −0.04609 | −0.09552 | −0.08723 | −0.16308 | −0.13251 | |
| Stainless steel | −0.46996 | −0.40785 | −0.58958 | −0.5037 | −1.08403 | −0.85624 | |
| Average K | −0.24351 | −0.2005 | −0.49077 | −0.42041 | −0.84564 | −0.66868 | |
S: surface soiled with 5% organic matter; NS: surface not soiled (clean).