Travellers

Travel Health Information Sheets

Hepatitis A

Introduction

Hepatitis A is a small, unenveloped, symmetrical RNA virus within the genus Hepatovirus, a member of the Picornavirus family.

Epidemiology

Data from the Travel Health Surveillance section of the Health Protection Agency Communicable Disease Surveillance Centre. (Data source: Laboratory reports to Health Protection Agency, Communicable Diseases Surveillance Centre collated by the Travel Health Surveillance Section)

Link to Global Epidemiology

Link to Hepatitis A Risk in UK Travellers

 

Risk for Travellers

The risk of hepatitis A in resource rich countries is low. The risk in resource poor regions depends on several factors including living conditions, length of stay and standards of food and water hygiene. The risk is highest in those intending to visit rural areas where there may be poor sanitation, however cases have occurred in tourists staying in standard hotel accommodation

Hepatitis A is the most common of the vaccine preventable diseases, although there is a lack of recent data. A review paper in 1994 estimated the monthly incidence rate to be 3 cases per 1000 travellers. Amongst those travellers who do not adhere to food and water hygiene precautions, the risk increases to 20 cases per 1000 travellers [1].

Transmission

Hepatitis A in travellers is generally acquired through food or water contaminated by human faeces. Foods that grow close to the ground such as strawberries and lettuce are particular risks. Bottom feeding crustaceans such as oysters and clams are also a risk. Food handlers excreting hepatitis A virus may contaminate foods if they do not observe proper hygiene.

It is also possible to contract the disease directly through close personal contact, in conditions of poor faecal hygiene. This mode of transmission may occur between children, and during certain sexual practices.

Virus shedding occurs in the faeces during the incubation period, and continues for a few days after the onset of jaundice. It is at this stage that patients are most infectious. Virus shedding can be greatly prolonged in immunocompromised persons.

Signs & Symptoms

Hepatitis A is usually a sub clinical illness in young children, with less than 10% of those under the age of 6 years developing jaundice. However, the disease becomes much more serious with advancing age, with approximately 2% mortality rate in those over 50 years of age [2].
After a relatively long incubation period of on average 28 days, with a range of 15-50 days, patients can experience a prodrome of malaise, anorexia, nausea and fever before developing jaundice [3]. Recovery takes on average a month in young people, but some patients are ill for many weeks. Complications are more likely in those with pre-existing liver disease, and include fulminant hepatitis.

Following infection with hepatitis A, patients acquire life long immunity.

Treatment

There is no specific anti viral treatment for hepatitis A, but rather supportive intervention.

Prevention

Hepatitis A is transmitted via the faecal-oral route, therefore the most common mode of infection for travellers is through eating contaminated food, or drinking contaminated water. The risk of acquiring hepatitis A can be reduced by following simple guidelines on food and water hygiene and by ensuring good personal hygiene.

Several highly effective and well-tolerated hepatitis A vaccines are available for those travellers intending to visit endemic areas. However, the vaccine should not be an alternative to food and water hygiene precautions.

References

1. Hawker J, Begg N, Blair I, Reintjes R, Weinberg J. Communicable Disease Control Handbook. 2001. 103-5. Oxford Blackwell Science Ltd

2. Steffen R, Kane MA, Shapiro CN et al. Epidemiology and prevention of hepatitis A in travellers. JAMA 1994;272:885-889

3. WHO. Hepatitis A vaccines WHO position paper. Weekly Epidemiological Record 2000; 75:38-44

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