This study determined the prevalence and clinical features of occult hepatitis B infection (OBI) in a population of recent immigrants to Italy. Two hundred-five immigrants were tested for HBV-infection and were classified as seropositive-OBI or false-OBI. Biochemical/virological activities and imaging diagnostics were determined in anti-HBc-positive subjects. Among the tested subjects, 39.0% were anti-HBc-positive/HBsAg-negative; 11.2% had persistently normal ALT levels with mild detectable HBV-DNA, seropositive-OBI; 6.2% had slightly elevated ALT and positive serum HBV-DNA with a mean level of viral load: 3275 copies/mL-false-OBI. The total prevalence of OBI was 6.8%; 4.4% were seropositive-OBI and 2.4% were false-OBI. Diagnosis by echo-tomography was achieved in 35.7% OBI subjects with alterations of the hepatic echo-texture. We found a moderate prevalence of occult hepatitis B-infection in immigrants. Frequently, these subjects present false-OBI.
Keywords: HBV infection; Italy; OBI; Recent immigrants.