For many infectious diseases, contact patterns that lead to spread of the disease are far from random. They are defined by complex social interactions which can be difficult to measure. Particularly for blood borne viruses such as Hepatitis C, contracted predominantly through injecting drug use, contacts capable of transmitting disease are well defined. It is well known that the nature of the contact network can potentially play a role in the rapidity of spread of infectious diseases and position in the network can also determine how likely an individual is to become infected.This work focuses on a well-documented injecting network, both parameterising the features of the network itself and exploring ways in which the network influences the spread of hepatitis C and can potentially impact on any interventions to reduce infection. The work has shown that focussing on an injecting clique of individuals is an efficient way of reducing hepatitis C transmission using a treatment strategy –the “treat your friends” approach.