Objectives To gauge the seroprevalence of antibodies to hepatitis A disease

Objectives To gauge the seroprevalence of antibodies to hepatitis A disease (anti-HAV) inside a health strategy human population of travelers and to determine whether prevaccination testing for anti-HAV can reduce unnecessary vaccination and thus promote the most effective, economic use of hepatitis A vaccine. and country of origin. This strategy could lead to a more economic use of the vaccine and medical center resources. Intro Travelers to nonindustrialized countries or to areas endemic for hepatitis A disease (HAV) are at risk for contracting hepatitis A, primarily through contact with contaminated food or water. For frequent or long-term travelers, the new hepatitis A vaccine provides longer-lasting safety than immune serum globulin (ISG),1 which was previously the only prophylactic medication available to travelers to areas of endemic hepatitis A. The vaccine provides much higher antibody titers and much longer-lasting safety than that provided by ISG. The symptoms of HAV SRT3190 infection are slight or unnoticed often. Therefore, the real prevalence of HAV an infection is tough to determine.2 Previous analysis has identified particular groups of individuals who are much more likely to have antibodies to HAV (anti-HAV). In non-industrialized countries, HAV an infection occurs in kids and is normally mild or asymptomatic frequently. 2 Virtually all kids in regions of endemic HAV possess anti-HAV before age group a decade SRT3190 highly.3,4 Thus, people given birth to in non-industrialized countries possess an increased prevalence of anti-HAV compared to the general US human population.4,5 Moreover, because sanitation in america and in CKS1B other industrialized nations has improved in the past half century, the prevalence of anti-HAV is higher in the elderly and reduced those born before 30 to 40 years.6 In industrialized nations, individuals aged 51 years or older possess historically had the highest seroprevalence rates of anti-HAV: 50% to 60% of the population aged 51 years or older test positive for anti-HAV in serum specimens.4 In a 3-month pilot study conducted at Kaiser Permanente Medical Center in Denver, Colorado, during 1996, travelers were screened for anti-HAV.7 Of the 49 seropositive patients found, 22 (45%) were born outside the United States, and 26 (96%) of the SRT3190 27 remaining seropositive patients were aged 55 years or older.7 Travelers to areas of endemic hepatitis A, particularly those who deviate from normal tourist routes, can also be presumed to have a higher incidence of anti-HAV.1 We undertook this study to ascertain the seroprevalence of anti-HAV in our health maintenance organization (HMO) population by examining factors other than age alone. After groups with the highest incidence of anti-HAV are identified, methods to implement selective prevaccination screening could be developed to reduce unnecessary vaccination. METHODS Kaiser Permanente Medical Center in Sacramento, California, is a staff-model HMO facility that provides care to more than 500,000 Kaiser Foundation Health Plan members who live in the surrounding area. All members of this health plan who travel outside the country receive information and immunizations at an adult injection clinic supervised by 2 registered nurses in consultation with a physician specializing in infectious disease. With the use of a prospective questionnaire administered in the injection clinic from June 1995 through April 1996, travel medicine needs were evaluated for 527 members from ages 18 through 82 years who were traveling to nonindustrialized countries. This pilot work was used to devise a strategy for the most economic use of hepatitis A vaccine. On the basis of questionnaire responses, travelers were categorized by age, country of origin, vaccination history, and previous travel experience. Only travelers who denied having previous vaccination with hepatitis A vaccine, known infection with HAV, or injection with ISG within the previous 6 months were included in the study. Before vaccination, travelers were screened.