Hepatitis A

Hepatitis A is an active liver disease that occurs following infection with a virus commonly referred to as the Hepatitis A virus (HAV) Hepatitis A is common in the developing world where infections are acquired during early childhood and are usually asymptomatic or mild.

The incubation period for Hepatitis A virus is 15 – 50 days (average 28 days).  Individuals are infectious two weeks before the onset of jaundice and the infectivity begins to fall.  Most individuals will remain infectious for 1 -2 weeks following the onset of jaundice.  However prolonged excretion of the virus in stools has been documented, resulting in longer periods of infectivity.

HOW IS THE DISEASE TRANSMITTED?

Person-to-person spread is the most common method of transmission via the faecal-oral route.  Transmission via blood products has also been described but is infrequent.

Other ways in which the virus can spread include.

      Exposure to contaminated water, ice or shellfish harvested from sewage-contaminated water.

      From fruits, vegetables or other foods eaten uncooked that were contaminated during harvesting or subsequent handling.

The hepatitis A virus can live outside the body for months even under high levels of environmental stress but is inactivated by boiling at 85 degrees Centigrade for 1 minute or exposure to household bleach (1.100 dilutions with water).

SIGNS AND SYMPTOMS

      HAV infection may be asymptomatic or its clinical manifestation may range from a mild illness lasting 1 – 2 weeks, to a severely disabling disease lasting several months.  When symptoms are present, they usually occur abruptly and can include the following:

      Fever                            

      Abdominal pain

      Fatigue

        Loss of appetite

        Nausea

        Vomiting

        Dark urine

         Clay coloured bowel movements

         Joint pain

          Jaundice

In children <6 years, 70% of infections are asymptomatic.  If illness does occur, it is typically not accompanied by jaundice.  Among older children and adults, infection is typically symptomatic with jaundice occurring in >70% of patients.

INDIVIDUALS AT HIGHER RISK OF HEPATITIS A INFECTION

      Persons living in areas considered endemic for Hepatitis A (i.e. most of South Africa)

      Household contact of infected individuals – the secondary attack rate for symptomatic disease in these individual is 20 – 50%.

      Healthcare workers.

      Travellers from non-endemic to endemic areas.

      Preschool children attending day-care centres, their parents and siblings

      Refugees residing in temporary camps following catastrophes or displacement.

      Employees of day-care centres.

      Residents and staff of closed communities particularly where personal hygiene may be compromised for example where residents are incontinent or wear nappies.

Individuals with chronic liver disease are not at higher risk for infection but are at risk for severe disease.

 HIGH RISK AREAS

Hepatitis A occurs worldwide but major geographic differences exist in endemicity.  The degree of endemicity is closely related to hygienic and sanitary conditions and other indicators of the level of development.  Areas of high emdemicity are usually found in some parts of Eastern Europe and South America have transitional or intermediate endemcity and North America and Western Europe have low or very low endemcity.

Your travel health consultant can provide you with more information on the level of endemicity for your destination.

ABOUT PREVENTING HEPATITIS A

There are two basic actions that can be taken to prevent Hepatitis A.

 1.     Avoiding risky foods and beverages

·         Boiling or cooking food and beverages for at least 1 minute to 85 degrees Centigrade inactivates the Hepatitis A virus, foods and beverages heated to this temperature and for this length of time cannot serve as vehicles for HAV infection unless the become contaminated after heating

·         Avoid drinking beverages (with or without ice) if unknown purity.

·         Avoid eating uncooked shellfish, and uncooked fruits or vegetables that are not peeled or prepared by yourself.

2.     Getting vaccinated

Any person travelling for any purpose, frequency or duration to countries that have high risk or intermediate endemicity of HAV infections should be vaccinated.  Vaccination may also be considered for persons travelling to any destination as Hepatitis A occurs worldwide.