In general, the key findings describe the impact of the closure and subsequent relocation of WAHS primary NSP to a mobile service on IDUs living in or near St Marys. Given the high population density of Penrith LGA compared to the other LGAs within WAHS, and the reported historical concentration of IDUs around St Marys, the emphasis on the needs of IDUs within this area is not unwarranted. Moreover, it is vital to call attention to the link between area of greatest need and IOU concentration, lack of access to primary NSP services and re-use and sharing of injecting equipment. The interconnection of these factors has implications for the transmission and spread of blood-borne viruses such as HIV and HCV and other harms related to the re-use of used injecting equipment, such as septicemia, thrombosis and vein damage. Significantly, participants reported sharing and re-using injecting equipment with greater frequency since the advent of the mobile service.