1Department of Tropical and Infectious Diseases, Policlinico Umberto I, Roma.
2Department of Gastroenterology, Ospedale Molinette, Torino.
3Department of Gastroenterology, Ospedale Niguarda, Milano.
4Gastroenterology Unit, Fondazione Casa Sollievo della Sofferenza IRCCS, San Giovanni Rotondo.
5Hepatology Unit, Ospedale Garibaldi, Catania.
6Internal Medicine Unit, Policlinico S. Pietro, Bergamo.
7Department of Clinical Medicine and Surgery. Gastroenterology and Hepatology Unit, University of Naples Federico II.
8Infectious Diseases Unit, Caserta hospital.
9Clinic of Infectious Diseases, University of Naples.
10Clinic of Infectious Diseases, University of Sassari.
11National Health Institute, National Center for Global Health. Rome
In Italy, HDV-infection-endemicity has greatly decreased overtime. Migratory flow may change this scenario as migrants often come from high HDV-endemicity areas. Here we studied characteristics of HDV-infection in Italy, particularly addressed to the birth-area of subjects. Chronic HBsAg-carriers consecutively referring to 9 units in Italy prospectively enrolled for a six months period in 2019 were tested for anti-HDV by ELISA. Multiple logistic regression analysis was performed to identify anti-HDV positivity independent predictors.A total of 894 HBsAg-positive subjects were enrolled. Of them, 786 (87.9%) were tested for anti-HDV. Anti-HDV overall prevalence was 9.9% (6.4% in Italian-natives and 26.4% in non-natives; p<0.001). HDV-RNA was checked in 63 (80.8%) of the 78 anti-HDV+ subjects, 49 (77.8%) tested positive. Compared to non-natives, Italians were more likely males (male/female 1.6 vs. 0.6; p<0.05) and older (median-age 57y vs 46y; p<0.05). Multivariate analysis showed that non-natives (O.R.=6.02; C.I.95%=3.06-11.84) and cirrhosis (O.R.9.6; C.I.95%=5.39-17.30) were independently associated with anti-HDV positivity. A remarkable changing pattern in some characteristics of anti-HDV positive subjects was observed over 1987-2019: a decreasing male/female ratio, an increasing mean-age and proportion of cirrhotic subjects. Anti-HDV prevalence decreased from 7.4% to 6.4% among Italians, increasing from 12.2% to 26.4% among non-natives during 2001-2019. Hence HDV-infection in Italians is further decreasing and mostly affects old people and subjects with advanced disease reflecting a survival effect. Conversely, non-natives are six-fold more likely anti-HDV positive with an increasing trend. Migratory flow may be a new challenge for HDV-infection at the beginning of the third millennium.