Hepatitis C is transmitted almost exclusively through blood-to-blood contact. If infected blood enters the bloodstream of another person, this can cause a hepatitis C infection.

Hepatitis C can be transmitted by:

• Blood and blood products

Blood and blood products have been screened for hepatitis C since a test became available in 1991. Before 1991, HCV was often transmitted via contaminated blood transfusions and other products made from blood or blood plasma, such as coagulants (e.g. for people with haemophilia) or immunoglobulins (e.g. anti-D immunoprophylaxis for rhesus-negative pregnant women). Today, blood transfusions and blood products in Europe are considered to be safe.

• Sharing needles and other equipment used to inject or snort drugs

HCV is frequently transmitted between people who inject drugs by the shared use of needles, syringes and other equipment used to prepare a drug for injection. Sharing a straw or rolled-up banknote to snort drugs through the nose can lead to infection with hepatitis C if traces of blood are present.

• Contact with infected blood (e.g. needlestick injuries)

Healthcare workers who come into contact with blood are at risk of becoming infected with HCV. Accidental injuries with contaminated needles and cannulae are among the most frequent routes of transmission in healthcare settings.

• Medical or dental procedures

Hepatitis C can be transmitted during medical or dental procedures if instruments or equipment have not been sterilised. Inadequate sterilisation of equipment used in kidney dialysis or internal investigations such as bronchoscopy may also result in transmission. The risk of transmission during medical or dental procedures is estimated to be low in Europe today, but remains high in many regions of the world.¹ Re-use of needles or syringes is still a common practice in medical settings in poorer regions of the world and is also a route of transmission.

• Use of unsterilised instruments in tattooing, piercing, acupuncture

HCV can be transmitted by using unsterilised instruments in tattooing or by dyes which are used more than once, when carrying out piercings or even reusing contaminated acupuncture needles.

See also Less common routes of transmission.