The aim of the Needle Exchange Surveillance Initiative is to measure and monitor the prevalence of blood-borne viruses – hepatitis C virus and HIV – and injecting risk behaviours among people who inject drugs (PWID) in Scotland. NESI provides information to evaluate and better target interventions aimed at reducing the spread of infection amongst PWID. This latest report presents the results:

• Scotland level across seven surveys – from 2008 to 2009 through to 2019 to 2020
• NHS board level for the 2019 to 2020 survey – for eight of the 11 mainland Scottish NHS boards

The initiative was initially funded by the Scottish Government as part of the Hepatitis C Action Plan, which stated that efforts to prevent hepatitis C virus (HCV) in Scotland must focus on preventing transmission of the virus among PWID. More recently, however, the initiative has been funded under the Scottish Government’s Sexual Health and Blood Borne Virus Framework. The most recent survey conducted in 2019 to 2020 was supported by the National Institute for Health Research (NIHR) Programme Grants for Applied Research Programme. It was part of the ‘Evaluating the Population Impact of Hepatitis C Direct Acting Antiviral Treatment as Prevention for People Who Inject Drugs’ (EPIToPe) study. [Data files are available on the Public Health Scotland website]

Key findings
• The average age of NESI participants has increased with each survey from 33 years old in 2008–09 to 41 years old in 2019–20, reflecting an ageing cohort of people who inject drugs (PWID) in Scotland.
• While heroin continues to be the most prevalent drug injected, cocaine injecting has increased in recent years, with 37% of those who had injected in the past six months reporting using it in 2019–20.
• Uptake of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) testing has steadily increased over time with some of the highest rates reported in 2019–20, with 60% and 52% tested within the previous 12 months respectively.
• The proportion of participants who reported vaccination for the hepatitis B virus (HBV) is on a decreasing trend, with 68% reporting receipt of at least one dose in 2019–20 from a high of 77% in 2015–16.
• Whilst the majority of participants (63%) in 2019–20 had been prescribed a take-home naloxone kit in the past year, a minority (21%) were carrying naloxone at the time of interview.
• The prevalence of chronic HCV (i.e. active infection) has reduced markedly from 37% in 2015–16 to 19% in 2019–20, contemporaneous with the scale-up of HCV treatment among PWID in community settings. More than half (53%) of participants who would have been eligible for therapy (i.e. with evidence of either current or past chronic infection) reported having been treated for their HCV infection. 
• Despite the reduction in chronic HCV prevalence, the incidence of infection remains high at 12 new HCV cases per 100 person-years in 2019–20.
• Seventy-three cases of HIV were detected in 2019–20, equating to a national prevalence of 3.1%. Most of these cases were interviewed at sites in NHS Greater Glasgow and Clyde (GGC) (n=49) and neighbouring NHS Lanarkshire (n=16). In NHS GGC (the setting of an HIV outbreak since 2015), the prevalence of HIV has stabilised at 4.8% in both the 2017–18 and 2019–20 surveys.
• More than half of participants in 2019–20 who were found to have chronic HCV or HIV (based on their anonymous dried blood spot test) reported that they were unaware of their infection.