Waterborne diseases

The waterborne diseases below are those most commonly encountered by traveller to underdeveloped countries where water treatment is either substandard or non-existent.

Disease	Causes	Symptoms
Leptospirosis (Weil's disease)	Contracted through swallowing water contaminated with the Leptospira bacterium, which is transmitted through rat, mouse, dog, pig and cattle urine and faeces	Flu-like symptoms (headaches, shivers, aching muscles and fever). Can lead to kidney failure, haemorrhaging, meningitis, jaundice and heart failure
Schistosomiasis (Bilharzia)	Contracted by bathing or swallowing contaminated water. The minute worm burrows its way through the body to set up home in a favoured organ, often the intestine.	Itching, coughing and wheezing, blood in the urine
Shigella (Bacillary dysentery)	Very powerful pathogen that is contracted through swallowing infected water	Severe and bloody diarrhoea
Amoebic dysentery	Contracted through drinking water contaminated with infected faeces	Bloody diarrhoea and/or with pus, infection of the colon, other possible complications include perforation of the bowel, hepatitis and liver problems.
Hookworms	Parasitic larvae that enters the body through the skin (by paddling or walking barefoot through damp grass) or by drinking infected water	Adult worm attaches to the stomach and, in large numbers, can cause blood leaking from the gut and eventually anaemia.
Giardiasis	Microscopic heart-shaped parasite caught by drinking water contaminated with infected faeces or urine	Diarrhoea, a lot of bad smelling belches and farts, bad smelling and floating stools
Cyclospora	Caused by pathogens, which resemble blue-green algae. Resistant to iodine and chlorine treatment. Most common during the monsoon period in Central Asia	Diarrhoea, which lasts for 6-12 weeks

The only effective way to prevent the waterborne diseases listed above is to avoid contacted with contaminated water and to buy bottled mineral/purified water or purify all drinking water yourself.