Pathogen and transmission
Hepatitis E is an inflammation of the liver that is caused by infection with the hepatitis E virus (HEV). The virus is transmitted in different ways depending on its genotype. In Europe and North America it is spread to humans by animals (such as domestic pigs and wild boar) via the food chain. Products containing raw pork liver pose a particular risk here. In parts of Asia, Africa and Mexico the transmission of HEV is faecal-oral, i.e. through the direct or indirect ingestion of infected faeces, generally by drinking contaminated water.
Pathology
Hepatitis E is an acute disease that produces fever, joint and stomach pains, a loss of appetite and nausea. In rarer cases, jaundice may also develop. The disease has an incubation period of two to six weeks. Estimates suggest, however, that over 90 per cent of hepatitis E infections pass without symptoms. Most symptomatic cases heal without treatment. Persons with a pre-existing liver condition are more susceptible to developing a more severe case of the disease. With immunosuppressed persons and those who have received a liver transplant, the infection may become chronic and, if left untreated, can lead to cirrhosis of the liver (scarring of the liver tissue). Cases of this kind can be treated with antiviral drugs. In rarer cases involving hepatitis E, neurological complications have also been reported, such as muscle degeneration or neuralgic amyotrophy (pain and paralysis in the shoulder area).
Distribution and frequency of occurrence
The hepatitis E virus is found all over the world, with different genotypes in different regions producing different disease pathologies. Europe and North America are home to HEV Genotypes 3 and 4, which are transmitted through food; and in parts of Asia, Africa and Mexico it is HEV Genotypes 1 and 2, which are transmitted via contaminated water, that regularly cause hepatitis E epidemics, sometimes producing several hundred thousand cases, especially among young adults and pregnant women.
Prevention
Immunosuppressed persons and those with liver disease, older persons, pregnant women and children should avoid eating raw pork or wild boar products. To prevent possible transmission of HEV via meat products, all such products should be fully cooked through before consumption. There is no hepatitis E vaccine available in Switzerland.
For further information on the global distribution of hepatitis E and ways and means to avoid HEV infection, consult your GP or a doctor specialising in travel medicine.