Enteroviruses in water environment--a potential threat to public health.

Enteroviruses belong to the Picornaviridae family and are the smallest, nonenveloped viruses known to infect both humans and animals. The spread of enteroviral infections is mainly by the faecal-oral and oral-oral route, but also through direct contact with secretions from ophthalmic and dermal lesions. Water, food and soil contaminated by infected faeces are an exogenous infection source which creates many opportunities for the transfer of the infection, and cause an epidemic outbreak in a short period of time. Enteroviruses are being isolated from all types of water: ground, sea, sewage and fresh water environments but also--and what is the most important from the epidemiological point of view--drinking water. They are resilient organisms, able to withstand high concentrations of sodium chloride (NaCl) and large changes in temperature. These abilities allow the viruses to flourish in a water environment, their natural reservoir. The number of infections in temperate climate regions peak in summer months and early autumn. Detection of enteroviruses in the water environment is performed by virus isolation in cell cultures and the use of molecular techniques. Many researches conducted in different countries with the use of methods mentioned above, reveal widespread environmental contamination by enteroviruses.