Hepatitis A virus immunity and seroconversion among contacts of acute hepatitis A patients in Amsterdam, 1996-2000: An evaluation of current prevention policy

Objectives. We evaluated the hepatitis A virus (HAV) control policy (hygienic precautions and passive immunization with immune globulin) for "household contacts" (defined as all people who lived in the same house and who shared the same toilet with the patient, people who took care of an HAV-infected child, and sexual partners of the patient) of acute hepatitis A patients between 1996 and 2000. Methods. We examined the characteristics and the serological outcomes of household contacts. All susceptible contacts were invited for retesting 6 weeks after they received immune globulin. Results. Of 1242 contacts of 569 HAV patients, more than 50% (n=672) were found to be HAV immune. Among the remaining contacts, 161 (28.2%) had a concurrent infection, and 86 of these individuals were symptomatic. The remaining 409 susceptible contacts received immune globulin, with 186 (45%) returning for retesting 6 weeks later (64 [34%] were infected, but only 12 had symptoms). Conclusions. Immune globulin does not protect all household contacts from HAV infection; however, it attenuates symptoms and effectively reduces further HAV transmission