Hepatitis E is a viral infection of the liver that causes inflammation of the organ. The Hepatitis E virus is a positive-sense single-stranded RNA virus with an icosahedral structure comprising a genome of 7.5 kilobases. It was initially classified as belonging to the Caliciviridae family but has since been classified as a member of the Hepeviridae family.
Four “genotypes” of the hepatitis E virus exist. Of these, genotype 1 is found in Asia and Africa; gentoytpe 2 in Mexico, Chad and Nigeria; genotype 3 has been found to exist almost worldwide and genotype 4 is found in Asia.
Transmission of the virus
Like the hepatitis A virus, hepatitis E is spread via the fecal-oral route. This means the infection is acquired when a person consumes water or food that has been contaminated with feces containing hepatitis E.
Hepatitis E can therefore transmitted if a person eats food prepared by an infected person who has not washed their hands after using the bathroom, for example. Outbreaks of the virus usually occur after monsoons and heavy downpours that disrupt water supplies.
Examples of hepatitis E symptoms include nausea, jaundice and fatigue. In most cases, symptoms take three to eight weeks to develop and then last for days or weeks to follow. However, in some immunocompromised individuals, hepatitis E can become a chronic infection that can lead to liver fibrosis and cirrhosis.
The virus is particularly dangerous in pregnant women, in whom an acute form of the infection can lead to death in 20% of cases.
Diagnosis and treatment
Hepatitis E is diagnosed using a blood test that can detect antibodies the body has produced against the virus. A polymerase chain reaction (PCR) test can also be performed on a blood sample and the most effective diagnostic approach is to use these two tests together.
There is no specific treatment for hepatitis E infection, although off-label treatment with ribavarin has been shown to help clear the virus in chronic cases.
Reviewed by Sally Robertson, BSc