P.10 Hepatitis B is a potentially life-threatening infection that presents in both acute and chronic forms. The risk of developing chronic disease, which may result in cirrhosis, liver failure or cancer, depends on the age of acquisition. The WHO estimates that infection acquired in adulthood results in chronic disease in less than 5% of people, while those acquired in infancy and early childhood leads to chronic hepatitis in 95% of cases1. In the UK, 95% of newly diagnosed chronic hepatitis B cases are amongst people originating from high prevalence countries. These individuals may have acquired the infection in their country of origin either at birth or in early childhood, and a small proportion acquired through behavioural risk. HBV transmission is by parenteral exposure to infected blood or body fluids, through: • unprotected vaginal or anal intercourse • through blood to blood contact (percutaneous exposure e.g. sharing of injecting equipment, unsafe surgical or dental practices, needlestick injuries) • perinatal transmission from mother to child The dominant route of transmission may vary by the country of exposure. For high prevalence countries, transmission is mostly perinatal/vertical, while infection related to travel/transmission within high prevalence countries, unprotected sex and sharing of injecting equipment are likely routes for lower prevalence countries such as UK.

Hepatitis C can present in both acute and chronic infection, which can range from mild to a serious illness such as liver failure and cancer. Few acute cases are diagnosed as many new HCV infections are asymptomatic. About 30% of newly infected individuals with HCV usually clear the infections naturally within 6 months. The remainder (~70%) develop chronic HCV infection, and some might remain undetected until later stages when symptoms of serious illness become visible. Most HCV infections in the UK occur through exposure to blood from sharing of needles or other injecting equipment in people who inject drugs. Other transmission routes include historic transfusion of infected blood or blood products (prior to 1991), re-use or inadequate sterilization of medical equipment, needlestick injuries, exposure to infected blood e.g. through sharing personal items (such as razors or toothbrushes), tattooing and body piercing.

P.13 Needle and syringe programmes (NSPs) Injecting drug use, whether current or previous, remains the primary mode of transmission of hepatitis C in the UK. Needle and Syringe Programmes (NSPs) provide sterile injecting equipment and other paraphernalia in line with best practice guidance8,9.  In Wales, the Harm Reduction Database Wales (HRD) is the system used to collect all NSP activity data.  In recent years, data on NSP activity have indicated substantial reduction in engagement with NSPs by people who inject drugs, changes in drug use and related risk behaviours and HRD data quality and completeness issues by staff. Work is currently ongoing to understand the nature of these changes and their impact on NSPs...