EPIDEMIOLOGY AND PREVENTION OF HEPATITIS-A IN TRAVELERS

Objective.-To assess the risk of hepatitis A in international traveler s and to recommend preventive measures. Data Sources.-Index Medicus, 1 974 through 1983; MEDLINE, 1984 through 1993; and unpublished data of the Centers for Disease Control and Prevention. Study Selection.-Revie w of all retrospective and cohort studies on hepatitis A and other vac cine-preventable diseases in travelers, of seroepidemiologic surveys o f hepatitis A virus (HAV) antibodies in travelers, of data on the vari ous hepatitis A vaccines, of economic analyses, and of recommendations of recognized organizations. Data Extraction.-Independent analysis by multiple observers. Data Synthesis.-The incidence rate for unprotecte d travelers, including those staying in luxury hotels, is estimated to be three per 1000 travelers per month of stay in a developing country . Persons eating and drinking under poor hygienic conditions have a ra te of 20/1000 per month. This makes hepatitis A the most frequent infe ction in travelers that may be prevented by immunization. In many indu strialized countries persons born after 1945 have an HAV antibody sero prevalence (immunity) of less than 20%. New inactivated HAV vaccines i nduce protective antibodies in more than 95% of recipients and offer p rotection estimated to last for 10 years or more, whereas protection b y immune globulin lasts only 3 to 5 months. Conclusions.-Hepatitis A v accine, or immune globulin where HAV vaccine is not available, is reco mmended for all nonimmune travelers visiting developing countries. Pre screening for antibodies to HAV in travelers living in countries with low prevalence is usually not necessary in persons born after 1945.