Hepatitis E was once classified as a member of the Calciviridae family but has since been reclassified into its own family called simply 'HEV-like viruses'. It has some structural similarities to the rubella virus as well as major concern for infection during pregnancy.

It is especially severe for pregnant women where it can cause fulminant hepatitis and lead to death of the foetus in up to a fifth of the women infected. It has been also been known to cause fulminant hepatitis in a few other cases.

Transmission

Like hepatitis A it is transmitted via the faecal-oral route. This means that the faeces of someone with HAV is infectious and if this matter is swallowed by another person they contract the disease. Commonly this happens in countries where untreated sewage is discharged straight into rivers that also supply drinking water or eating uncooked foods that have been washed in contaminated water.

HAV-infected persons are infectious for only a relatively brief period of time.

However, many sexual practices facilitate faecal-oral transmission of HEV, and inapparent faecal contamination is not unusual during anal sex. Rimming is an obvious risk for HEV.

Tests

Hepatitis E can be diagnosed by an antibody test and a PCR test which shows presence of the virus is also available.

Treatment

It is similar to Hepatitis A and usually resolves itself within a few weeks or months. Bed rest and drinking plenty of fluids is the usual recommendation for someone with HEV.

Is there a vaccine?

Not yet. One is being trialled by the US army in Nepal but is not yet commercially available. The hope is that if it proves effective it will be available in 2007.

Epidemiology

Although cases have been identified all over the world it is found more frequently in Asia, North Africa and Mexico and is the commonest form of hepatitis in India. In the western world it is generally seen as a disease which affects travellers to developing countries.