Rationale:

• Susceptible travelers to high or intermediate endemic areas are at substantial risk for HAV infection.

Evidence:

• A meta-analysis of retrospective, cohort, and seroepidemiologic studies identified from Index Medicus (1974-1983) and Medline (1984-1993), as well as unpublished data from the CDC, suggests that hepatitis A is the most frequent infection in travelers that may be prevented by immunization (30).
• A case-control study of travelers to developing countries compared with travelers to the Greek or Canary Islands determined that hepatitis A is the most frequent vaccine-preventable disease in travelers to developing countries (31).
• A literature review of hepatitis A vaccine use in travelers to developing countries suggests that hepatitis A vaccine is a safe and effective method for travelers to HAV-endemic areas to protect themselves against hepatitis A (32).
• A literature review of numerous studies conducted over the past four decades indicates that immunoglobulin is safe and effective for short-term preexposure prevention against hepatitis A (33).

Comments:

• Travel to endemic areas of the world is the most commonly reported risk factor for hepatitis A among reported cases in which a risk factor is identified (34).
• The risk of travel-associated hepatitis A may be decreasing; however, the risk to nonimmune patients, including immigrants returning to visit friends and relatives, remains considerable (35; 36).
• Hepatitis A vaccination is preferred for children aged 1 year or older, adolescents, and adults who plan frequent travel to or who reside for long periods in high-risk areas.
• Immunoglobulin does not provide long-term protection and must be administered every 2 to 6 months, depending on the dose administered.
• Hepatitis A vaccine and immunoglobulin may be administered simultaneously.
• Manufacturers of hepatitis A vaccine (GlaxoSmithKline [HAVRIX®] and Merck & Co. [VAQTA®]) recommend that primary immunization be completed at least 2 weeks before expected exposure.
• Although hepatitis A vaccine is recommended to be given 2 to 4 weeks before travel, vaccine may be beneficial in the last-minute traveler (37).