[Nosocomial risk factors of hepatitis C infection. A multicenter study in a hospital-based population]

Drug abuse and blood transfusion are well known risk factors for hepatitis C virus (HCV) infection. However, the route of transmission remains undetermined for 30% of HCV infections. The potential for nosocomial transmission of HCV in health care settings has been suggested but remains poorly estimated. The aim of the study was to assess the prevalence and to identify risk factors for hepatitis C virus (HCV) infection in hospitalized patients frequently exposed to invasive procedures.

A multi-center sero-prevalence study was conducted in hospitalized patients who underwent invasive procedures in interventional radiology wards in 6 University hospitals in Paris between 1998 and 1999. Each patient presenting in the ward was consecutively interviewed by a medical investigator. Data were collected on a standardized questionnaire including items on socio-demographic characteristics, past exposure to intravenous drug use, blood transfusions, underlying diseases and type and number of previous invasive procedures. Before procedure, HCV antibody testing (ELISA) was performed in all patients after informed consent. In all HCV-positive patients, HCV viremia was detected using polymerase chain reaction.

Overall, 91 of 944 (9.7%) patients were HCV-positive, of whom 90% had positive viremia and 10 were identified HCV positive by the screening. HCV prevalence decreased with age and ranged from 4.5% to 22% according to center. Logistic regression analysis showed that intravenous drug use, history of blood transfusions and endoscopy were found as independent risk factors for HCV infection (odds ratio [CI95%]: 77.3 [23.3-256.3], 4.7 [2.7-8.2] et 1.20 [1.01-1.44]). No other risk factor for nosocomial or iatrogenic transmission was identified.

The results suggest that, except for blood transfusions, other healthcare-related procedures may partly explain HCV transmission. This emphasizes the need to reinforce compliance with standard precautions of hygiene.