[Society and hepatitis C--knowledge, perceptions, and public action].

Despite its significantly higher prevalence, hepatitis C, now a serious public health problem, has long been overshadowed by HIV infection in France. The aim of this paper is to examine the factors that limit or prevent the conversion of scientific knowledge into public programs to tackle this transmissible viral infection. After an assessment of the knowledge currently available-quantitative data, routes of transmission, risk factors for hepatitis C and means of detection of HCV-we will analyse the interactions between the general public's representations and public decisions concerning detection, health care and prevention. Uncertainty concerning the sexual transmission of HCV makes a comparable mobilization to that observed in the case of the HIV infection improbable. It is necessary to target public measures at the different groups, both those at risk of contamination and those at risk of transmitting HCV, but it presupposes that answers can be found to the following questions: who can consider himself or herself at risk? What behaviours shape risk? Who is actively responsible for the risk when the HCV infection is transmitted? Better knowledge of the attitudes and perceptions of these specific groups and of risk-inducing situations will make public decisions more accurate in their contents and in their targets.