Pathogens and transmission
Hepatitis A is an infectious liver inflammation that is triggered by the hepatitis A virus. The virus is eliminated through the intestine. Transmission is faecal-oral, i.e. via pathogens absorbed into the body through direct or indirect contact with faecal matter. This occurs most frequently through contaminated food products or water as well as frequently used items or in the context of close personal contact (e.g. in kindergarten or a common household), through sexual contact (mainly in men who have sex with men) or through foods, drinking water or articles of daily use that are contaminated with faeces. Transmission through blood or blood products (including the use of shared injection equipment among drug users) is possible but extremely rare.
Hepatitis A is an acute disease characterised by fever, discomfort, jaundice, loss of appetite and nausea. The incubation period is 15-50 days (generally 25-30 days). Only 30% of infected children under six years of age show any symptoms. Symptoms do appear in most infected older children and adults, which in 70% of cases include jaundice. The illness usually lasts several weeks (up to six months), and in most cases there is a spontaneous recovery. The infection is never chronic and leads to lifelong immunity.
Frequency and distribution
The virus exists worldwide but is prevalent in regions with poor hygienic conditions. Up to 60 cases of hepatitis A are recorded in Switzerland every year, most of which appear after trips into a high-risk region. Young and old alike are equally affected, as are both genders.
Vaccination can prevent an infection. It is recommended, among others, for travellers before a trip to a high-risk region (a region with medium to high prevalence of hepatitis A in the population) and for men who have sex with men. Beyond vaccination, the most important measures for preventing transmission of hepatitis A include the observation of the basic rules of hygiene such as hand washing, especially after using the lavatory, before preparing food and before eating. In high-risk regions, it also includes avoiding unboiled water, heating only sufficiently heated dishes and mussels, and peeling one's own fruit.