Hepatitis E

What is Hepatitis E?

Hepatitis E is an acute inflammatory disease of the liver. Every year 20 million cases of hepatitis E virus infection are registered. In most of the patients, the infection is acute and resolves in 4-6 weeks. However, it can become fulminant hepatitis, especially in pregnant women in the third trimester of pregnancy, causing acute liver failure and death.

Cases of chronic hepatitis E and reactivation of the disease have been described in people with low defenses. Although hepatitis E affects all areas of the world, in eastern and southern Asia there are more cases (more than 60% of infections), as well as in countries with limited access and resources for drinking water supply, sanitation and hygiene.

Causes of Hepatitis E

It is caused by infection with hepatitis E virus (VEH), which is a positive, single-stranded RNA virus with no cover of the Hepeviridae family. There are several genotypes (from 1 to 4) with different geographical distribution and modes of transmission.

Thus, genotype 1 is generally detected in developing countries and causes epidemic outbreaks, while genotype 3 is found in developed countries and does not usually lead to epidemic outbreaks. It is considered a potentially zoonotic disease (that is, it is transmitted from animals to humans), in particular by genotypes 3 and 4 of VEH identified in pigs and wild boars. VEH strains have also been detected in birds, rabbits, rats, bats, etc.

Each year there are 20 million cases of infection with the hepatitis E virus.
Dr. Vicente Carreño

Pathways of Hepatitis E infection

Hepatitis E is transmitted mainly by fecal-oral route, by ingesting water contaminated with feces, products derived from infected animals (for example, pork) and contaminated foods such as vegetables, seafood, etc. It can also be transmitted by transfusion of infected blood products and from a pregnant woman to the fetus (vertical transmission).

Diagnosis

It can be diagnosed by analyzing liver enzymes (transaminases) and detecting antibodies to virus E (anti-VEH) of IgM and IgG type or RNA in faeces, blood or liver. Symptomatic infection occurs mostly in young people and adults aged 15 to 40 years. In children, the infection by VEH is usually asymptomatic.

Prevention

There is no specific vaccine against the VEH. Vaccines have been developed in experimental animals but are not available for use in humans (except in China). Prevention is the most effective measure against the disease. The risk of infection can be reduced by avoiding drinking non-potable water and adopting hygienic practices.

Treatment of Hepatitis E

In the case of hepatitis E it has been shown that ribavirin can be very effective. Hospitalization is usually not required, except in cases of fulminating hepatitis (in infected pregnant women).

There is no specific Hepatitis E vaccine, although some are being investigated in animals.

References

Quiroga JA, et al. Hepatitis E virus seroprevalence in acute viral hepatitis in a developed country confirmed by a supplemental assay. J Med Virol 1996;50:16-9.
Carreño V, Castillo I (eds.). Hepatitis víricas: Biología, clínica y tratamiento. 1ª ed. Barcelona: Springer Verlag Ibérica. Parte VI: Virus C de la hepatitis. 2001; p 449.
Johne R, et al. Hepeviridae: an expanding family of vertebrate viruses. Infect Genet Evol 2014;27:212-29.
Mirazo S, et al. Transmission, diagnosis, and management of hepatitis E: an update. Hepat Med 2014;6:45-59.