What is Hepatitis A?
Hepatitis is an inflammation of the liver and hepatitis A (HAV) is a viral disease transmitted via the faecal-oral route that affects the liver. Infection with hepatitis A provides life-long immunity and it is rarely fatal and does not cause chronic disease, unlike hepatitis B and C.
Typically, infection is passed on through the eating or drinking of food and/or water contaminated by the faeces of an infected person, (commonly associated with the eating of seafood, such as oysters or inadequately cooked shellfish). HAV can also be transmitted by eating raw vegetables grown in soil fertilised with infected faeces, drinking untreated water, illicit IV drug use and through some sexual activities (particularly oral-anal). Some large-scale outbreaks have been caused by contaminated food (such as frozen berries, seafood, and fresh fruit and vegetables). The virus is relatively hardy and survives in the environment for months; it is resistant to freezing but heat of 85°C for at least one minute will render it inactive.
What are the symptoms?
The period between exposure and onset of symptoms for hepatitis A virus is generally around 28 days (ranging from 15 to 50 days) with common symptoms including: fever, loss of appetite, nausea and pain in the right upper abdomen, followed within several days by jaundice, a condition that results in yellowing of the skin and whites of eyes. Symptoms may range from mild to severe, with some individuals displaying none. Children under 6 years of age are often asymptomatic (meaning they do not display any symptoms) but they are capable of transmitting the infection to others.
The infection can persist for anywhere from 1 to 2 weeks and the severity varies from a mild illness to a severely disabling disease lasting several months. Approximately 10%-15% of infected people have prolonged or relapsing symptoms over a 6- to 9-month period. Severe complications including fulminant hepatitis and liver failure are rare but more likely to occur in older adults and people with underlying liver disease.
Where is it found?
HAV is common in areas with poor sanitation and restricted access to clean water. In countries with high HAV endemicity, as in some African and Asian countries, many adults are immune to HAV as a result of infection during childhood, and epidemics of hepatitis A are uncommon. In areas such as Central and South America, Eastern Europe and parts of Asia with intermediate HAV endemicity, childhood transmission is less common and so more adolescents and adults are vulnerable to infection; outbreaks then become more likely. In countries such as Australia, the United States and Western Europe where there is low HAV endemicity, infection is less common in the general community, but disease occurs among people in high-risk groups (e.g. Aboriginal and Torres Strait Islanders) as communitywide outbreaks.
Risk to travellers
All individuals travelling for any purpose, frequency, or duration to countries with high or intermediate HAV endemicity should be vaccinated before departure.
Large outbreaks of hepatitis A have been reported in developed countries among people who have been exposed to imported food contaminated with HAV, men having sex with men, drug users, and the homeless. Taking into consideration the difficulty of interpreting hepatitis A risk maps and the potential risk of foodborne hepatitis A in countries with low endemicity, some travel health providers advise individuals travelling outside of Australia to consider hepatitis A vaccination regardless of destination.
To avoid acquiring hepatitis A, it is important to ensure food and water precautions and maintain high standards of hygiene and sanitation.
How is Hepatitis A treated?
Currently there is no cure for HAV and the only recommendation is bed rest. The illness itself is not pleasant – especially if you are travelling in a foreign country - making prevention the best possible option.
To avoid the transmission of hepatitis A, it is important to ensure proper hygiene, avoid sharing food or crockery and always drink bottled or filtered water. While this is best practice for many diseases and should always be employed when in a developing country, the best way to ensure you do not contract HAV on your next trip is through vaccination.
What is Hepatitis A Vaccination?
Inactivated Hepatitis A vaccine is a safe and highly effective option.
- Inactivated virus vaccine (Havrix / Avaxim / Vaqta)
- Inactivated combination vaccine* with hepatitis B (Twinrix)
- Inactivated combination vaccine with typhoid (Vivaxim)
Contraindications: Hepatitis A–containing vaccines should not be administered to travellers with a history of hypersensitivity to any vaccine component, including neomycin. Twinrix should not be administered to people with a history of hypersensitivity to yeast.
The tip caps of prefilled syringes of Havrix and Twinrix and the vial stopper, syringe plunger stopper, and tip caps of Vaqta may contain dry natural rubber, which may cause allergic reactions in latex-sensitive people.
- Inactivated monovalent vaccine (Vaqta, Havrix, Avaxim): Single dose, followed by a booster at 6 to 12 months
- Hepatitis A and B combined vaccine (Twinrix)*: Three doses at 0, 1 and 6 months
- Hepatitis A and Typhoid combined vaccine: Single dose, followed by Hepatitis A booster at 6-36 months - licensed for people aged ≥16 years.
*Accelerated schedules for Twinrix are available for adults.
Level of protection
Randomised controlled trials show that the vaccines have protective efficacy of nearly 100%. The duration of immunity after vaccination is uncertain, however vaccine-induced antibodies against HAV probably persist for many years. Booster doses are not required.
Possible Side Effects
The most commonly reported adverse events after receiving a hepatitis A vaccine include mild injection site reactions of short duration, such as redness, swelling, a hard lump or bruising around the injection site (56%–67%) and headache (14%–16%).
As with all vaccines, there is a small risk of allergic reaction.
Where can I get a Hepatitis A vaccination from?
If you require vaccination against hepatitis A, head to a Travelvax clinic near you. Staffed by trained professionals who have access to state-of-the-art equipment, we can help keep you safe on your next trip.
Australian Immunisation Handbook https://immunisationhandbook.health.gov.au/vaccine-preventable-diseases/hepatitis-a
US Centers for Disease Control & Prevention https://www.cdc.gov/hepatitis/hav/pdfs/HepAGeneralFactSheet.pdf