HBsAg carriers among blood donors in Italy--a multicentre study in 107 blood banks.

We investigated the incidence of HBsAg carriers among blood donors from 107 Italian blood banks during 1986. The overall prevalence of HBsAg carriers was 1.98%. This percentage was higher in Southern (2.69%) than in Northern (1.78%) or Central Italy (0.83%). Notable differences were found in the various regions and in single centres belonging to the same region. In some small areas a prevalence of carriers as high as 10% was recorded. Most carriers had normal aminotransferase values, HBeAg was detected in 8.8% of the carriers and anti-delta in 2.9% of them. The figures from this study still suggest a persistence of an intermediate endemicity level of HBV infection in Italy, with some hyperendemic niches.