The study consists to Identify viral variants involved in the transmission of hepatitis C and characterize the antigenic and functional properties of their envelope glycoproteins at very early stage of infection (before seroconversion).

Inclusion Criteria:

• age > 18 years
• agree to participate in this study (signing the consent form or information form signed and letter of no objection for subjects contaminated by blood exposure).

These criteria are specific to contaminated subjects:

• primary infection before development of HCV antibody (seroconversion): nucleic acid testing positive in the absence of HCV antibodies.

These criteria are specific to individual sources :

• HCV antibody positive.

Exclusion Criteria:

• refusal to participate
• private about freedom
• under guardianship
• under justice
• minor or major person unable to consent