Hepatitis A (Human)

Primary reference(s)

WHO, 2020. Hepatitis A. World Health Organization (WHO). Accessed 8 November 2020.

Additional scientific description

The hepatitis A virus (HAV) is primarily spread when an uninfected and unvaccinated person ingests food or water that is contaminated with the faeces of an infected person. It is one of the most frequent causes of foodborne infection. There are also outbreaks among men who have sex with men and persons who inject drugs (ECDC, 2017).

The symptoms of hepatitis A can include fever, malaise, loss of appetite, diarrhoea, nausea, abdominal discomfort, darkcoloured urine and jaundice (a yellowing of the skin and whites of the eyes). Not everyone who is infected will have all of the symptoms. Hepatitis A does not cause chronic liver disease and is rarely fatal, but it can cause debilitating symptoms. In very rare instances it can cause acute liver failure, which is often fatal (WHO, 2020a).

Specific diagnosis is made by the detection of HAV-specific immunoglobulin M (IgM) antibodies in the blood. Additional tests include reverse transcriptase polymerase chain reaction (RT-PCR) to detect the hepatitis A virus RNA and may require specialised laboratory facilities (WHO, 2020b).

Epidemics related to contaminated food or water can erupt explosively, such as the epidemic in Shanghai in 1988 that affected about 300,000 people. Epidemics can also be prolonged, affecting communities for months through person-to-person transmission. Hepatitis A viruses persist in the environment and can withstand food-production processes routinely used to inactivate and/or control bacterial pathogens (WHO, 2020b).

Hepatitis A can lead to significant economic and social consequences in communities. It can take weeks or months for people recovering from the illness to return to work, school, or daily life. The impact on food establishments identified with the virus, and local productivity in general, can be substantial (WHO, 2020b).

The World Health Organization (WHO) has published guidance on case classification and surveillance standards (WHO, 2018).

Metrics and numeric limits

Hepatitis A occurs sporadically and in epidemics worldwide, with a tendency for cyclic recurrences. Epidemics related to contaminated food or water can erupt explosively (WHO, 2019).

In 2016, 7134 persons were estimated to have died from hepatitis A worldwide (accounting for 0.5% of the mortality due to viral hepatitis) (WHO, 2019).

Examples of drivers, outcomes and risk management

Hepatitis A is closely associated with unsafe water or food, inadequate sanitation, poor personal hygiene and oral-anal sex (WHO, 2020b).

The disease is most common in low- and middle-income countries with poor sanitary conditions and hygienic practices. In high-income countries with good sanitary and hygienic conditions, infection rates are low (WHO, 2020b).

Epidemics can be prolonged and cause substantial economic loss (WHO, 2020b).

A safe and effective vaccine is available to prevent hepatitis A (WHO, 2020b).

Safe water supply, food safety, improved sanitation, hand washing, and the hepatitis A vaccine are the most effective ways to combat the disease (WHO, 2020b).