WATER AND VIRAL-HEPATITIS

The main agents responsible for acute viral hepatitis throughout the w orld are the hepatitis A virus (HAV) and the hepatitis E virus (HEV). Both are transmitted by fecal-oral route and can provoke large epidemi cs, HAV in developed countries and HEV in developing countries. Water is a major vehicle of spread. However, two different epidemiological p atterns have to be distinguished: level of HAV excretion is short but high. Because of its resistance to physical and chemical agents, HAV r emains infectious for a long time under environmental conditions. Prog ress in hygiene have nearly stopped the circulation of HAV in industri alized countries, making populations more susceptible to the infection and increasing the epidemic risk. Conventional measures sometimes fai l to prevent HAV infections. Vaccine is currently the best way for hep atitis A prophylaxis; HEV is excreted briefly and at low concentration s. Viral particles are fragile in vitro and their viability in environ ment is not yet understood. Epidemics mainly occur in countries with p oor sanitary conditions, resulting from heavy water pollutions. High c ase-fatality rates are observed, especially among pregnant women. The control of enterically transmitted viral hepatitis remains a major pub lic health challenge. Virological surveillance of waste water could im prove strategies based on hygiene, sanitation and supply of drinking w ater.