Incidence of and risk factors for hepatitis A in Italy: Public health indications from a 10-year surveillance

Background/Aims: This study aimed to evaluate the incidence of and risk factors for acute viral hepatitis A (HAV) in Italy. Methods: Data were from a surveillance system for type-specific acute viral hepatitis (SEIEVA), To estimate the association of hepatitis A cases with the potential risk factors (Odds Ratios) and the proportion of all hepatitis A cases attributable to a given risk factor (population attributable risk), hepatitis B cases were used as controls, Independent predictors of HAV were estimated by conditional multiple logistic regression, Results: During the period 1985-1994, 25553 viral hepatitis cases were reported, Of these, 6408 (25%) were due to hepatitis A (HAV), HAV incidence declined from 10/100 000 in 1985 to 2/100 000 in 1987. Since 1991, however, an increase in HAV has been observed. The majority of cases were 15-24 years old; the incidence was higher in males and in subjects residing in southern Italy, Only one death (0.02%) was observed, Shellfish consumption was the most frequently reported risk factor (62%), The proportion of cases reporting personal contact with an icteric case, travel to a high-medium endemic areas, and family contact with a child attending a day-care centre (household of day-care child) was 17%, 19% and 15%, respectively. The results of multivariate analysis showed that shellfish consumption (OR=2.6; 95% CI=2.4-2.9), travel to endemic areas for people residing in northern and central Italy (OR=5.4; 95% CI=4.6-6.2) and household of day-care child (OR=1.2; 95% CI=1.03-1.4), were all types of exposure independently associated with HAV The estimates of population-attributable risk show that shellfish consumption explained as many as 42.2%, travel to high-medium endemic areas for people residing in northern and central Italy 24.2%, and household of day-care child only 1.4% of all acute hepatitis A cases in Italy. Conclusions: These findings indicate that HAV in Italy is mainly a food-borne disease, Vaccination against hepatitis A is strongly recommended for travellers to endemic areas.