Introduction

Hepatitis A is a viral infection which can be silent. Worldwide, but most common where sanitary conditions are poor and the safety of drinking water is not well controlled. Areas of high risk are Central and South America, Africa and Southern Asia out to Indonesia.

Causative agent: Hepatitis A virus, a member of the Picornavirus family

Transmission: The virus is acquired directly from infected persons by the faecal-oral route or by close contact, or by consumption of contaminated food or drinking water.

Common source outbreaks have been related to contaminated water, food contaminated by infected food handlers, including foods not cooked or handled after cooking, raw or undercooked mollusks harvested from contaminated waters and contaminated produce such as lettuce and strawberries.

Incubation period: Average 28-30days (range 15-50days)

Sign & Symptoms

Abrupt onset of fever, malaise, nausea and abdominal discomfort, followed by the development of jaundice a few days later.

More severe in adults with illness lasting several weeks and recovery taking several months.

Infection in very young children is usually mild or asymptomatic, older children are at risk of symptomatic disease.

Complication

In general, severity increases with age, but complete recovery without sequelae or recurrences is the rule.

Reported case fatality is normally low 0.1 – 0.3% for adults over 50yearrs old.

Treatment

Specific treatment – None

Symptomatic treatment: Advise rest, drink plenty of fluids and take antipyretic (e.g. Paracetamol) to relieve symptom of fever.

Prevention & Precautions

Travellers who are non-immune to Hepatitis A (i.e Have never had the disease and have not been vaccinated) should take particular care to avoid potentially contaminated food and water.

Type of vaccine: Inactivated, given i.m

Number of doses: Two (2)

Schedule: Second dose 6 – 24 months after the first

Booster: May not be necessary, Propose after 10 years.

Contraindications: Hypersensitivity to previous dose

Adverse reactions: Mild local reaction of short duration, mild systemic reaction

Before departure: Protection 4 weeks after first dose, some protection immediately after first dose

Recommended for: All non-immune travelers to moderate to highly endemic areas

Special precautions: None

References organisation/ support

International Travel & Health, WHO 2006

Control of Communicable Diseases Manual, 18th Edition by David L. Heymann, MD, Editor, 2004

http://travelhealth.co.uk/