Cholera, typhoid fever and hepatitis A are water-related diseases often associated with developing countries. These diseases are making a comeback in some European countries and central Asia. Others, which are even more widespread, are hitting countries otherwise known for their high level of sanitation.
Most public water supplies are routinely monitored, but private supplies may not be subject to the same quality standards. In the Russian Federation, half the population uses water that fails to meet quality standards. In Latvia, 55% of water samples from shallow wells fail to meet microbiological standards. Yet half the rural population relies on these wells as a source of drinking-water. Some 50% of Armenian supplies also fail to meet quality standards. Even in countries where most residents are connected to a water supply network, there may be frequent interruptions in supply. In southern Russia, water may be available for only a few hours a day. In Romania, some supply systems do not function for more than 12 hours a day. Around 30% of Italy's islanders also suffer interruptions in their water supply. Apart from contamination with microbes and viruses, water may also be polluted with lead, arsenic, fluorides or nitrates. Agriculture also affects water quality through run-off containing pesticides and fertilizers.
In Albania, 25 people died of cholera in 1994 after drinking contaminated water. In Latvia, several hundred cases of hepatitis A and bacterial dysentery are attributed to contaminated drinking-water each year. In Tajikistan, some 4000 cases of typhoid fever were reported in 1996 following heavy rainfall. In the past decade there have been some 190 outbreaks of bacterial dysentery, 70 outbreaks of hepatitis A and 45 outbreaks of typhoid fever associated with drinking-water and recreational water in Europe and central Asia.
In Sweden in the past decade, there have been six outbreaks of waterborne campylobacteriosis, which causes gastroenteritis. In fact, a total of 27 000 people suffered from waterborne disease in Sweden in those ten years. During the same period, the United Kingdom reported 13 outbreaks of cryptosporidiosis, which also causes gastroenteritis and can usually be traced back to agricultural pollution.
Most swimming-related diarrhoea is caused by infective agents of the genus Cryptosporidium. Unlike bacteria, the parasites are extremely resistant to chlorine and may remain infective for several days in swimming pool water containing recommended chlorine concentrations. A single infected faecal discharge in a swimming pool is potent enough that a few mouthfuls water can result in infection.