Changes in the epidemiology of hepatitis B virus infection following the implementation of immunisation programmes in northeastern Greece.

The objective of this study was to investigate changes in the epidemiology of hepatitis B virus infection in the general population and selected groups of immigrants in the region of northeastern Greece over the last decade in relation to the introduction of hepatitis B vaccination programmes. Two population-based seroprevalence surveys were carried out during the years 1992-1994 and 1998-2006. In total, 25,105 individuals were tested for the presence of hepatitis B virus markers: HBsAg, anti-HBs and anti-HBc. Childhood/adolescence immunisation programmes began early in 1994 in selected groups of immigrants and were complemented by the national vaccination programme in 1998. Between 1992-1994 and 1998-2006, the HBsAg carrier rate declined from 5.4% [95% CI: 4.5-5.9] in adults (20-60 years old) and 1.9% [95% CI: 1.6-2.4] in children/adolescents (5-19 years old) of indigenous residents to 3.4% [95% CI: 2.9-3.8] and 0.6% [95% CI: 0.2-1.4] respectively (p<0.05). In spite of a decrease compared with 1992-1994, the percentage of HBsAg carriers was still relatively high in 1998-2006 among the Muslim religious minority group (8.2% [95% CI: 8.0-8.7] in adults and 2% [95% CI: 1.7-2.4] in children/adolescents) and in immigrants from the former Soviet Union (4.3% [95% CI: 3.6-4.7] in adults and 1.1% [95% CI: 0.8-2.4] in children/adolescents) (p<0.05 for both selected groups versus general population). The decline of the prevalence of HBsAg in the general population and selected groups of immigrants in northeastern Greece over the last decade supports the effectiveness of the ongoing immunisation programme although the information on the actual number of cases of acute HBV infection is not available.

Natural history of chronic HBV infection: a cohort study with up to 12 years follow-up in North Greece (part of the Interreg I-II/EC-project).

The aim of the study was to assess the long-term outcome of chronic hepatitis B surface antigen (HBsAg) carriers in the general population in North Greece (Thrace), an area with an intermediate endemicity. This was a part of the Interreg I-II EC project. Two hundred sixty three chronic HBsAg+ carriers, median age 34 years (20-65), were evaluated prospectively for a median follow-up of 5 years (2-12). Hepatitis B virus (HBV) markers and ALT were examined every 6 months and serum HBV-DNA every 12 months. Liver biopsy was undertaken at presentation and every 2-4 years. Fourteen of 263 (5.3%) subjects were HBeAg+ and 249/263 (94.7%) HBeAg(-)/anti-HBe+ of whom 48 (19.3%) had elevated ALT, and HBV-DNA levels ranging from 1.4 x 10(5)-4 x 10(7) copies/ml. Inactive carriers (98/195 (50.3%)) had detectable HBV-DNA (median 2.6 x 10(3) range 0.042 x 10(4)-1.9 x 10(4) copies/ml); 4/195 (2%) exhibited HBV reactivation during the observation period (all had HBV-DNA >10(4) copies/ml at presentation). Patients (7/14 (50%) HBeAg+) developed anti-HBe+, annual rate 10%. Subjects (16/195 (8%)) lost HBsAg, all were inactive carriers; 10 developed anti-HBs (annual rate 1%). Liver biopsy was normal or with minimal changes in 92/95 (97%) inactive carriers and remained so at 4 years follow-up. In contrast, 4/48 (8.3%) HBeAg(-)/anti-HBe+ patients with active disease had deterioration of liver histology. In this cohort study: (a) the annual seroconversion rate was 1% for the HBsAg and 10% for the HBeAg, (b) 23.6% of the HBsAg+ carriers had active liver disease and 39% moderate fibrosis at presentation of whom a small proportion deteriorated over the observation period, (c) HBsAg carriers with HBV-DNA level <10(4) copies/ml had persistently normal ALT and unchanged liver histology over the follow-up period of up to 12 years.