[realmswalker (OP)]

What are the most commonly found disease causing virus' and bacteria in water?

[chris]

There are many of them, and it depends to a certain extent on where you are geographically. Most of them are picked up by ingesting contaminated food and water.

Common bacterial culprits include the family of enterobacteriacea, including E. coli (ETEC), which causes traveller's diarrhoea, and salmonellae (such as S. typhi and paratyphi), which are linked to typhoid and enteric fever. In central America, Vibrio cholerae is the problem bug that causes cholera.

Common viral infections include hepatitis A, which passes out in faeces and can be concentrated by filter-feeding shellfish, and hepatitis E, which classically causes outbreaks around the times of monsoons and floods because drains overflow and contaminate drinking wells. Other faecal-oral viruses include the Norwalk-like agents (which cause dramatic outbreaks especially on cruise ships), Rotaviruses, which often attack young children, and Adenoviruses, which can occasionally trigger stomach upsets.

Chris

[RenRen]

Of course, you also have to worry about parasites and chemical contaminants that can also make water unsafe to drink. One parasite, cryptosporidium, caused a severe outbreak of diarrhea in Milwalkee, Wisconsin, USA, when the water treatment plant failed. Interestingly enough, the beer was about the only safe thing to drink in the town for a few days! Most people recovered, but those with HIV/AIDS suffered the effect long-term.