标题：Hepatitis A Virus Immunity and Seroconversion Among Contacts of Acute Hepatitis A Patients in Amsterdam, 1996–2000: An Evaluation of Current Prevention Policy
摘要：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. Hepatitis A is an acute liver disease caused by the hepatitis A virus (HAV) and transmitted from the feces of an infected person via contaminated food, water, hands, or contaminated items (fomites). Although the disease is rarely symptomatic among children aged younger than 5 years, morbidity and mortality can be high among adults. The prevalence of hepatitis A is strongly associated with economic conditions: in less-developed countries, the disease occurs widely among children; as a result, most adults are immune. In more developed countries, the number of adult symptomatic infections increases. In the Netherlands, as in most Western countries, the seroprevalence of anti-HAV antibodies declined sharply among people born after World War II, 1 making a majority of the population susceptible. In Amsterdam, the Netherlands, the incidence of hepatitis A follows a largely seasonal pattern, peaking in August and September, when children of migrant-worker families (mainly from Turkey and Morocco) return from summer holidays in the country of parental origin. 2 Hepatitis A also causes year-round microepidemics among homosexual men, 3, 4 but sequencing of the viruses suggests that different subgenotypes circulate among different at-risk groups. 5 In the Netherlands, a diagnosis of hepatitis A must be reported to the Municipal Health Service (MHS). To prevent secondary cases, persons (“household contacts”) who are cohabitants of each primary patient are identified and are given advice on hygienic precautions and passive immunization with immune globulin if they are found to be susceptible. We evaluated the serological results of testing household contacts for acute hepatitis A (1996–2000) to determine the percentage who were immune at presentation and the predictors for such immunity. We also analyzed the follow-up of susceptible contacts to determine the incidence of symptomatic and asymptomatic HAV infection.
