Seroepidemiology of hepatitis A antibodies among children's hospital staff.

BACKGROUND: With improved socioeconomic conditions, adults are more frequently seronegative for hepatitis A virus (HAV) and therefore susceptible to infection. A safe and efficacious active HAV vaccine has been developed and licensed. The general recommendation is to vaccinate populations at increased occupational exposure to HAV. AIM: To determine the seroprevalence of HAV antibodies among children's hospital employees and to correlate seropositivity with demographic and occupational variables as a basis for formulating vaccine recommendations. METHODS: The staff of a tertiary pediatric medical center participated by answering a structured questionnaire on demographic and occupational data and by donating venous blood for determining HAV antibodies by an enzyme immunoassay. Univariate and multivariate analyses were conducted to identify variables associated with HAV seropositivity. RESULTS: HAV antibodies were found in 48.3% of the 499 employees studied, being lowest in pediatricians (38.7%), and increased with years of work at the hospital, job percentage and contact with pediatric patients. However, multivariate analysis showed that only the sociodemographic variables (age and crowding during childhood) were independently and significantly associated with seropositivity. CONCLUSIONS: HAV seropositivity was associated mainly with sociodemographic variables. Most children's hospital employees, especially pediatricians and other young (<40 years) employees, are seronegative and therefore susceptible to HAV. Vaccination of the high risk groups should be considered.

Cost-utility analysis of hepatitis A prevention among health-care workers in Israel.

This study was conducted to evaluate the efficiency of different strategies of preventing hepatitis A (HA) among physicians, nurses, and paramedical staff by means of cost-effectiveness analysis. The strategies compared were passive immunization during a hepatitis A outbreak, systematic mass vaccination of all workers, and screening for antibodies to HA virus followed by vaccination of nonimmune employees. To predict the prevented number of HA cases, an epidemiological model was incorporated based on our previous nationwide study on clinical HA cases, seroepidemiological survey, and other scientific medical literature. Under the model assumptions, the lowest cost per prevented HA case ($6240) was achieved by screening prior vaccination among 18- to 39-year-old physicians and paramedical workers, and highest ($61,858) by mass vaccination of nurses over age 39 years. Because the price per prevented case may show that mass vaccination is highly cost-effective, especially among 18- to 39-year-old physicians and paramedical workers ($6399 and $8196, respectively), the cost per gained quality-adjusted life-year seems less attractive ($56,532 and $61,350, respectively). This cost per saved quality-adjusted life-year is similar to many other medical interventions but is markedly higher than other primary prevention vaccines, which are mostly associated with a negative ratio. In view of the conducted study, and taking $60,000 as a limit cost per saved quality-adjusted life-year, we propose selective vaccination for physicians and for paramedical workers. Mass vaccination should be offered to all health care workers, aside from nurses 40+ years of age, once the active HA vaccine price is reduced to $23.

Risk of exposure to hepatitis A virus among day-care workers in Israel: implications for preventive measures.

Hepatitis A is an important infectious disease in Israel. The high incidence of hepatitis A, the declining prevalence of antibodies against hepatitis A virus throughout the past decade, and the availability of an active immunization for hepatitis A have engendered the identification of occupations in which workers are at increased risk of acquiring the disease. A prevalence study for hepatitis A antibodies was conducted during the first half of 1998 in a random sample of 37 day-care centers in different parts of Israel. A short interview was conducted, and serum samples were then collected from each worker. The control group comprised a sample of factory workers, blood donors, and women in maternity wards. Ninety percent (402 of 446) of the day-care workers had antibodies to hepatitis A. In a logistic-regression analysis, seropositivity was associated with increased age, minimal education, and lack of military service. When the authors compared a subsample of workers aged 18-40 yr with the control group, seropositivity was associated with the following: birth in Israel, duration of residence in Israel, very minimal education, military service, and employment in a day-care center. These results, together with earlier reports, indicate that day-care workers are at high risk of occupational exposure to hepatitis A. These results may imply that seronegative workers have a 2-fold chance of acquiring hepatitis A. Appropriate preventive measures should be considered, and active immunization of susceptible workers should be undertaken.