Risk of parenterally transmitted hepatitis following exposure to surgery or other invasive procedures: results from the hepatitis surveillance system in Italy

Background/Aims: To evaluate the strength of association between parenterally transmitted viral hepatitis and specific types of invasive procedures. Methods: Data from the surveillance system for type-specific acute viral hepatitis (SEIEVA) during the period 1994–1999 were used. The association of acute hepatitis B virus (HBV) and hepatitis C virus (HCV) infection with the potential risk factors (odds ratios (OR)) was estimated comparing 3120 hepatitis B and 1023 hepatitis C cases with 7158 hepatitis A cases, used as controls, by multiple logistic regression analysis. Results: Most procedures resulted in being associated with the risk of acquiring acute HBV or HCV. The strongest associations were: for HBV infection, abdominal surgery (adjusted OR=3.9; 95% confidence intervals (CI)=2.0–7.5), oral surgery (OR=2.7; 95% CI=1.6–4.5) and gynaecological surgery (OR=2.6; 95% CI=1.2–5.5); for HCV infection, obstetric/gynaecological interventions (OR=12.1; 95% CI=5.6–26.3), abdominal surgery (OR=7.0; 95% CI=3.2–14.9) and ophthalmological surgery (OR=5.2; 95% CI=1.1–23.2). Biopsy and/or endoscopy were associated with HCV, but not with HBV infection. Conclusions: Invasive procedures represent an important mode of HBV and HCV transmission. Since a large proportion of the adult general population is exposed to these procedures and an effective HCV vaccine is not yet available, non-immunological means of controlling iatrogenic modes of transmission are extremely important.