[Hepatitis C: risk factors].
Risk factors associated to at least 50% of hepatitis C cases are blood transfusion and injection-drug use. Less important factors are high-risk sexual behavior, job appointment in a healthcare setting and hemodialysis. Intra-familial and perinatal transmission are minor contributors to the overall prevalence of infection. The role of tattooing, acupuncture and piercing in hepatitis C transmission is controversial. There is still an important number of cases in whom no risk factor can be identified.