Who is at risk from hepatitis A?
Unlike hepatitis B and C, hepatitis A infection does not cause chronic liver disease and it does not cause long-term liver damage. 1Although hepatitis A itself is rarely fatal, it can cause debilitating symptoms and fulminant hepatitis (acute liver failure), which is associated with high mortality or need for emergency liver transplantation (in up to 50% of cases). 12
The disease 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. 1
Does the risk of infection increase with age?
Anyone who has not been vaccinated or previously infected can get hepatitis A. 1
In areas where the virus is widespread (high endemicity), most hepatitis A infections occur during early childhood. The severity and presentation of symptoms increases with age. 1
- People travelling to or from countries with a high prevalence of the disease (without being immunised)
- People with chronic liver disease
- Men who have sex with men
- People receiving clotting factors
- Injection drug users
- People who work with non-human primates
Risk factors for becoming infected with hepatitis A include: 1
- Poor sanitation
- Lack of safe water
- Injecting drugs
- Living in a household with an infected person
- Being a sexual partner of someone with acute hepatitis A infection
- Travelling to areas of high endemicity
Other groups are not at increased risk of infection but might have a critical source of HAV transmission in common: 4
- Food service workers
- Sewage workers
- Healthcare workers
Is hepatitis A a worldwide problem?
Hepatitis A occurs sporadically and in epidemics worldwide, with a tendency for cyclic recurrences. The estimated 1.4 million cases of hepatitis A worldwide per year is subject to an under-reporting rate of at least 80%. 15
The hepatitis A virus is one of the most frequent causes of food-borne infection. Epidemics related to contaminated food or water can erupt explosively, such as the epidemic in Shanghai in 1988 that affected about 300,000 people. 1
- WHO. Hepatitis A Fact Sheet 328. 2014. Available at: http://www.who.int/mediacentre/factsheets/fs328/en/. Last accessed June 2015.
- Taylor RM, Davern T, Munoz S, et al. Fulminant hepatitis A virus infection in the United States: Incidence, prognosis, and outcomes. Hepatology 2006;44:1589-1597.
- CDC. Hepatitis A FAQs for Health Professionals. Available at: http://www.cdc.gov/hepatitis/HAV/HAVfaq.htm. Last accessed June 2015.
- André F, Van Damme P, Safary A, Banatvala J. Inactivated hepatitis A vaccine: immunogenicity, efficacy, safety and review of official recommendations for use. Expert Rev Vaccines 2002;1:9–23.
- WHO. The immunological basis for immunization series: module 18: Hepatitis A. Available at: http://whqlibdoc.who.int/publications/2011/9789241501422_eng.pdf. Last accessed June 2015.