Table 9.4.

Typical Biological Contaminants of Water

Sr. No.	Biological Contaminant	Types (Examples)	Diseases Produced or Health Hazards
1	Bacterial pathogens	Salmonella, Shigella, Campylobacter and various pathogenic strains of Escherichia coli	Cholera, salmonellosis, shigellosis, leptospirosis
2	Viral pathogens	Norwalk virus, hepatitis virus, and other human enteric viruses	Hepatitis A, dengue fever, SARS CoV, legionellosis
3	Protozoan parasites	Entamoeba histolytica, Giardia lambia, Cryptosporidium parvum, Cyclospora, Plasmodium	Diarrhea, malaria
4	Helminthes	Schistosomes, Tinia solium, Liver fluke. Clonorchis sinensis	Schistosomiasis, clonorchiasis
5	Fungal species	Molds, yeast, and others	Toxins
6	Algae	Spirogyra and others	Toxins

List is illustrative only and not exclusive/exhaustive.