Prevalence of antibodies against hepatitis C virus the elderly: a seroepidemiological study in a nursing home and in an open population. T collaborative Group.

BACKGROUND: The prevalence of antibodies against hepatitis C virus (anti-HCV) increases in the general population with advancing age. Several discrepancies exist in the epidemiology of HCV, however, when selected elderly population groups are tested. OBJECTIVE: To evaluate the HCV prevalence in two groups of elderly people living in the same geopgraphical area of northeast Italy, i.e., one including residents of a nursing home, the other including subjects living at home. METHODS: The overall sample included 496 subjects (mean age 79.31 +/- 8.9 years); 288 were in a nursing home, and 208 were living at home. Enrollment in the latter group was based on all subjects over 65 years old listed under the public health service in the same district. The overall rate of adhesion to the study was 90%. Each subject was administered an anonymous questionnaire testing sociodemographic data and risk factors for HCV infection. Serological tests included: anti-HCV and hepatitis B virus serum markers. Multiple logistic regression analysis was performed to evaluate risk factors for anti-HCV positivity. RESULTS: Anti-HCV positivity was found in 34 of 288 (11.8%) elderly in the nursing home and in 23 of 208 (11.1%) in the open population. When the total population was considered, females exhibited a significantly a higher prevalence of anti-HCV than males (13.4 vs. 7.5%, p < 0.05). In both males and females, the highers rate of anti-HCV prevalence was found among the 75- to 79-year-old subjects. A decline in anti-HCV prevalence was observed in the very old subjects (over 80 years of age). None of the anti-HCV-positive subjects was found to be coinfected with hepatitis B surface antigen. However, multiple logistic regression analysis identified the age group between 70 and 79 years, female gender, and positivity for antihepatitis B surface antigen and/or antihepatitis B core antigen as independent variables significantly associated with HCV prevalence. CONCLUSIONS: The prevalence of anti-HCV proved identical among elderly people living in the nursing home or at home, suggesting that nursing homes do not represent a risk factor for HCV infections; the significant association between HCV prevalence and antihepatitis B surface antigen and/or antihepatitis B core antigen positivity supports a common route of transmission of the two viruses; these findings would suggest that there was an epidemic of HCV infection during the Second World War and in the years immediately afterwards.