Besides observing good personal hygiene, and avoidance of eating raw seafood and water contaminated with sewage, a more specific measure would be immunization. Such general measures would apply especially if one is travelling or living in areas where Hepatitis A is endemic like Southeast Asia ( including Singapore ), Mexico, Caribbean, South & Central America, Africa and Eastern Europe.
There are 2 methods of immunisation for Hepatitis A:
Passive Immunisation by immune globulin which is a preparation of antibodies collected from blood of persons who have been exposed to the Hepatitis A. This method of immunization is getting obsolete because of the short supply of immune globulin and the potential risk of transmission of other infection through blood products.
Active immunisation with hepatitis A vaccine. Hepatitis A vaccine consists of the virus in an inactivated form. It is given in 2 doses, with the second dose being given 6 - 12 months later. Immunity after hepatitis A lasts for 10 - 20 years. Protection against hepatitis A begins 4 weeks after vaccination. We are however, not sure if the Hepatitis A vaccine is completely safe in pregnancy and lactation because of the theoretical risk to the developing foetus. It can however be used in immunocompromised patients eg persons on hemodialysis or persons with AIDS.
Hepatitis A vaccination could be useful also for:
Travellers from low risk regions visiting endemic areas should observe scrupulous personal and food hygiene.
For protection, travellers can be immunised using Hepatitis A vaccines. Vaccines may be administered 2 weeks prior to departure, followed by a booster 6 - 12 months later. Frequent or long-term travellers should consider this option as such immunity lasts for 10 - 20 years.