Hepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus, a small, non-enveloped hepatotropic virus classified in the genus Hepatovirus within the family Picornaviridae.
The disease is highly transmissible through faecal-oral route. Hepatitis A is often asymptomatic or mild, particularly in children below five years of age, but the severity increases with age. Up to 90% of hepatitis A infections in children present no symptoms. In adults, the onset of illness is usually abrupt with fever, loss of appetite, nausea and vomiting. Jaundice is the predominant symptom. Symptoms may last between 1 to 2 weeks, or up to months. About 15% of patients have prolonged or relapsing symptoms over a 6–9-month period.
Transmission and prevention
Hepatitis A is highly transmissible and has an average incubation period of 28 to 30 days (range 15–50 days). The maximum infectivity is during the second half of the incubation period (i.e. while asymptomatic) and most cases are considered non-infectious after the first week of jaundice.
Hepatitis A is excreted in faeces by infected patients and transmitted further either through person-to-person contact or through consumption of contaminated food or water. The incubation period of symptomatic cases ranges between two and seven weeks. Patients are infectious from two weeks before the onset of symptoms and may continue to be infectious for one week or more after.
A safe and effective vaccine is available, but if you have been naturally infected once, you will have a lifelong immunity. The main public health control measures for hepatitis A are assuring adequate sanitation and housing, education about sound personal hygiene practices, particularly hand hygiene, and pre-exposure immunisation of individuals in populations at increased risk.
Epidemiology and burden in EU/EEA
In 2011, Hepatitis A was the fourth most commonly reported gastrointestinal infection in the EU/EEA area, and rates were particularly high in Romania, Estonia, and Slovakia. There were 12659 confirmed reported cases in 29 EU/EEA countries and the overall rate of confirmed cases was 2.51 per 100.000 population.