| Protozoa: | Resistance to chlorine |
| Balantidium coli | High |
| Blastocystis hominis | High |
| Isospora belli | High |
| Microsporidia | Moderate |
| Toxoplasma gondii | High |
| Helminthes: | |
| Fasciola spp. | High |
| Free-living nematodes (other than Dracunculus medinensis) | High |
| Schistosoma spp. | Moderate |