INCIDENCE AND RISK-FACTORS OF ACUTE DELTA-HEPATITIS IN ITALY - RESULTS FROM A NATIONAL SURVEILLANCE SYSTEM

The incidence of hepatitis Delta virus in the general Italian populati on was estimated by a specific surveillance system for acute viral hep atitis over the period 1987-1992. The hepatitis Delta virus incidence rate declined from 3.1/1 000 000 inhabitants in 1987 to 1.2/1 000 000 in 1992. Males predominated (83.8% of cases); the sex ratio was 5.2. O nly 2.5% of cases occurred in subjects younger than 15 years. There we re 119 (49.4%) coinfections of Delta and B hepatitis and 122 (50.6%) D elta superinfections in chronic HBsAg carriers. Jaundice was present i n 83.6% of cases. The hospitalization rate was 97.5%; median stay in h ospital was 25 days (range 1-98 days). The results of multivariate ana lysis showed that a history of intravenous drug abuse (odds ratio 34.9 ; confidence interval 95%=16.8-72.5), household contact with an HBsAg( +) carrier (odds ratio 10.7; confidence interval 95%=4.36-23.30) and a history of two or more sexual partners within the previous 6 months ( odds ratio 2.44; confidence interval 95%-1.34-4.43) were independent r isk factors associated with Delta hepatitis. No association was found with the other risk factors considered, such as blood transfusion surg ical intervention, hospitalization, other percutaneous exposures, dent al therapy, contact with an icteric case, and household contact with a n i.v. drug abuser. These findings indicate that, in Italy, Delta hepa titis currently has a minor impact. In addition to intravenous drug ab use and household contact with an HBsAg(+) carrier, heterosexual activ ity appears to be an efficient route of HDV transmission. (C) Journal of Hepatology.