Viral hepatitis of enteric origin.

Hepatitis viruses of oral-fecal origin are responsible for a high morbidity and mortality throughout the world, even ii they never result in chronic h epatitis. Two viruses, he virus of hepatitis A (VHA) and of hepatitis E (VH E) are at present the cause of severe viral hepatitis of enteric origin. Water is the principle vector in the spread of these viruses. However the e pidemiological aspects vary according to the pathogenic agent. VHA is excre ted in a highly concentrated form in the feces for a relatively short perio d of time. Since it resists in an exterior environment the virus remains in fectious for a long time. VHE is excreted for a short period of time and in low concentrations. The v iral particles are fragile in vitro and their variability in the environmen t is little known. The possible reservoir role of certain animals has been envisaged. Epidemics arise especially in countries suffering from poor hygi ene and massive water pollution. Hepatitis A should no longer be considered a benign disease of childhood. T he progress made in hygiene and economic development in industrialized coun tries have made contacts with this virus scarce, rendering the populations more receptive to it and epidemics more widespread. When the sickness occur s later in life, infection is more often symptomatic and can be serious, re sulting sometimes long term indisposition. Hepatitis E has a vast distribution throughout the world and manifests itse lf either in epidemic or endemic-sporadic form in many poor countries. In d eveloped countries, it comes about mostly as a result of imported pathology even ii there exists a much less than substratum much greater than of infe ction in these areas. The main clinical aspects, such as we were able to st udy them in 39 cases of military men from Tchad, Guyana and Somalia, are co mparable to those of hepatitis A. The reasons for the particular gravity of symptoms in pregnant women are unknown. These affections have no specific treatment. in the field of prevention, va ccination is at present the best means for hepatitis A prophylaxis. Until a vaccine against hepatitis E is found, prevention depends on hygiene, sanit ation measures et distribution of drinking water.