SUMMARY BackgroundIn developed countries, hepatitis E is a porcine zoonosis caused by hepatitis E virus (HEV) genotype 3. In developing countries, hepatitis E is mainly caused by genotype 1, and causes increased mortality in patients with preexisting chronic liver disease (CLD).

Patients with HEV-NA are usually anicteric and have a distinct clinical phenotype, with predominately bilateral asymmetrical involvement of, and more extensive damage to, the brachial plexus. Involvement outside the brachial plexus is more common in HEV-NA. The relationship between HEV and NA is likely to be causal, but is easily overlooked. Patients presenting with NA should be tested for HEV, irrespective of liver function test results. Prospective treatment/outcome studies of HEV-NA are warranted.

Hepatitis E virus (HEV) infection is a worldwide disease. It is the first cause of acute viral hepatitis in the world with an estimated 20 million cases every year and 56 000 deaths. In developing countries, hepatitis E is a waterborne infection. In these countries, HEV genotypes 1 and 2 cause large outbreaks and affect young subjects with a significant mortality rate in pregnant women and patients with cirrhosis. In the developed countries, HEV genotypes 3 and 4 are responsible for autochthonous, sporadic hepatitis and transmission is zoonotic. HEV can cause neurological disorders and in immunocompromised patients, chronic infections. The progression of acute hepatitis E is most often mild and resolves spontaneously. Diagnostic tools include anti-HEV IgM antibodies in serum and/or viral RNA in the blood or stools by PCR. Ribavirin is used to treat chronic infection. A vaccine has been developed in China. Keywords acute viral hepatitis -chronic hepatitis -hepatitis E virus -neurological symptoms -ribavirin -zoonosisHepatitis E virus (HEV) was discovered by immune electron microscopy in 1983 by Dr. Balayan, who was investigating an outbreak of unexplained hepatitis in Russian soldiers stationed in Afghanistan (1). The hepatitis E genome was sequenced in 1991. The same year, a test was developed for detecting anti-HEV antibodies (2). The purpose of this paper is to review the virology, epidemiology, clinical aspects and treatment of hepatitis E. Background and virology