RISK-FACTORS IN COMMUNITY-ACQUIRED CHRONIC HEPATITIS-C VIRUS-INFECTION - A CASE-CONTROL STUDY IN ITALY

Aims/Methods: A case-control study was carried out in Italy to assess the risk factors associated with chronic hepatitis C virus infection. Five hundred consecutive chronic anti-hepatitis C virus positive cases and 500 sex and exactly age-matched anti-hepatitis C virus negative/H BsAg negative controls entered the study. Information was collected th rough an interviewer-administered questionnaire. The adjusted Odds Rat ios linking hepatitis C virus infection and risk factors were estimate d by conditional multiple logistic regression. Demographic and socio-e conomic characteristics were similar in cases and controls. Seventy-fi ve percent of patients were aged over 40: males were prominent in the group less than or equal to 40, while the number of females increased with age. Results: As expected, drug addiction and blood transfusion e merged as independent risk factors: blood transfusion in all ages and in both sexes, drug addiction only in subjects under 41 years and most ly in males. Other risk factors independently associated with hepatiti s C virus infection were: previous use of non-disposable needles, prev ious tuberculosis, and prolonged hospitalization before 1970. A histor y of sexually-transmitted diseases was not associated. Conclusions: Th is study shows that the great spread of hepatitis C virus in Italy may have occurred several years ago through parenteral routes which are n ot now operating. Modern hygienic and sanitation measures have signifi cantly controlled exposure to the infection, which in the younger gene rations is confined to high-risk groups such as drug addicts.