Research and analysis

Unlinked Anonymous Monitoring (UAM) survey of HIV and viral hepatitis among people who inject drugs (PWID): 2023 report

Updated 19 January 2024

Main findings

Main messages from the Unlinked Anonymous Monitoring (UAM) survey of people who inject drugs (PWID) in England, Wales, and Northern Ireland (EWNI) for the period 2013 to 2022 are listed below.

Recruitment to the UAM survey in 2022 has recovered to pre-pandemic levels.

From 2013 to 2022, the median age of UAM participants increased from 36 to 43 years, indicating an ageing group of PWID. Concurrently, the proportion of young injectors (under 25 years) decreased from 6% in 2013 to 1.5% in 2022. While this is reflective of the changing demographics of the wider injecting population, further work needs to be done to compare the UAM survey participants to other behavioural and risk factor data from the wider injecting population.

HIV prevalence among UAM survey participants has remained low and stable over the past decade ranging from 0.8% to 1.5%. However, prevalence varies by nation and region of England.

Overall, chronic hepatitis C (hepatitis C ribonucleic acid (RNA) and antibody positive) prevalence continues to decline from 49% in 2017 to 23% in 2022. This decline is noted alongside the scale-up of direct-acting antiviral (DAA) treatment for hepatitis C virus (HCV) in this population. However, decreases in chronic HCV prevalence are not similar across all nations and regions of England.

There is no evidence to suggest a decline in chronic HCV prevalence among people who have recently started injecting drugs (up to 3 years prior to survey participation), which implies prevention of new and re-infections remains a challenge.

Overall, the proportion of UAM survey participants with HCV antibodies (a marker of ever HCV infection) has increased significantly over the past decade (from 49% in 2013 to 54% in 2022) and is higher in the older cohort. This suggests continued exposure to HCV and a treatment effect, with increased uptake of HCV treatment resulting in those recruited to the UAM who are ever-infected living longer.

Among UAM survey participants recruited in Northern Ireland, HIV and HCV antibody prevalence has increased during 2020 to 2022, to 3.8% and 48% respectively in 2022, which is reflective of an ongoing outbreak in the country.

The proportion of participants testing positive for HCV antibodies who were aware of their infection, had seen a specialist nurse or doctor (hepatologist) for their HCV and reported having been offered and accepted treatment, increased from 30% in 2017 to 70% in 2022. Among those who were aware of their infection and had been treated, 14% reported having been infected with HCV more than once.

Over the past decade, the percentage of participants reporting a recent (current or past year) HCV diagnostic test rose from 35% in 2013 to 48% in 2022. However, awareness of infection among those who remain infected remains low.

The prevalence of antibodies to hepatitis B virus (HBV) core antigen (anti-HBc) (a marker of ever infection) declined significantly from 16% in 2013 to 7.8% in 2022, indicating fewer people have ever been infected with HBV. However, self-reported HBV vaccination uptake has declined over the past decade from 72% in 2013 to 61% in 2022, suggesting that PWID remain at risk of HBV infection. In 2022, HBV vaccine uptake was particularly low among those aged under 25 years (27%) and people who have recently started injecting drugs (39%).

Significant increases in injecting risk behaviours were noted in 2022 when compared to a decade ago. Direct sharing of injecting equipment has increased from 16% in 2013 to 19% in 2022. Although 82% of all PWID in the UAM survey reported that they had accessed a needle exchange in 2022, this is a notable decline from the 90% reported pre COVID-19 pandemic.

In 2022, nearly a quarter of those who had injected drugs in the past year reported experiencing a non-fatal overdose during that year, an increase from 16% in 2013. The increase in non-fatal overdose was noted particularly in people aged 25 and over and was similar among participants regardless of whether they had been in drug treatment previously.

The percentage of participants carrying naloxone in the past year rose significantly, from 54% in 2017 to 68% in 2022. Moreover, 59% of those who reported overdosing in the previous year had naloxone administered, an increase from 46% in 2013.

In 2022, heroin was the most commonly injected drug, at 92% among people who had injected in the preceding 4 weeks, followed by crack cocaine at 55%, a figure that is similar to the 2018 peak at 60% and an increase from 37% in 2013.

The injection of other forms of cocaine significantly increased from 6.9% in 2013 to 29% in 2022 among people who had injected in the preceding 4 weeks. In Northern Ireland, reported recent injection of powdered cocaine surged from 5.9% in 2018 to a remarkable 84% in 2022.

Introduction

The UAM survey of PWID aims to monitor the prevalence of HIV, HBV and HCV infections, as well as associated risk and protective behaviours among PWID. People who have ever injected psychoactive drugs, such as heroin, crack cocaine and amphetamines, are recruited through specialist drug and alcohol agencies across England, Wales, and Northern Ireland (EWNI) (see the Methods section for more details).

This report presents an update on the latest UAM survey, focusing on the discussion and interpretation of trend data found in the annual data tables. Within these tables, UAM survey data for 2013 to 2022 are presented for EWNI combined, as well as by each country and the regions of England separately. UAM survey data for 2020 and 2021 have been combined for some sub-groups (for example, people who have recently started injecting) and most geographies (except for England), where participant numbers during these years were too small for them to be presented separately. Where data is compared between years for significant changes in trend, age, gender, and region are controlled for in the statistical analyses (see Appendix 3).

Methods

The UAM survey is an annual, cross-sectional, bio-behavioural survey that recruits PWID through specialist agencies within EWNI. These agencies provide a range of services to people who inject psychoactive drugs, from medical treatment to needle and syringe programmes and outreach work. People using these services, who are either currently injecting drugs or who have done so previously, are asked to take part in the survey by service staff. Those who consent to take part in the survey provide a dried blood spot (DBS) sample that is tested for HIV, HBV, and HCV infection or exposure.

Additionally, a brief anonymous self-completed questionnaire is administered to gather limited demographic and behavioural information. The questionnaire covers topics such as diagnostic testing uptake for HIV and HCV, HBV vaccination, and injecting risk behaviours. Participants retain the option to decline answering any questions. While the questions asked have varied over time, core questions have remained comparable. The characteristics of people who take part in the survey can vary between years and may be different to the wider population of PWID.

Survey participants receive a high street voucher in acknowledgement for their time, and as part of ongoing efforts to enhance participation, the voucher amount increased from £4 to £8 outside of London and £5 to £10 in London in September 2022.

The UAM survey does not collect personal identifiers. Questionnaire data is linked to a corresponding DBS sample but unlinked from any client identifying information. This ensures that the questionnaire and specimen testing procedures are conducted anonymously. The co-ordination of the UAM Survey is overseen by the UK Health Security Agency (UKHSA), with support from Public Health Wales and the Public Health Agency for Northern Ireland.

Results 

During 2020 and 2021, recruitment to the UAM survey was impacted by the COVID-19 pandemic. Fewer drug and alcohol services were able to take part, and the overall number of participants recruited was lower when compared to previous years. Recruitment to the survey has since recovered to pre-pandemic levels. In 2022, 117 drug and alcohol services participated in the UAM survey compared to 77 centres in 2021 and 64 in 2020. The number of participants in the UAM survey was 3,165 compared to 955 in 2020 and 1,525 in 2021. The number of services taking part and the number of participants is comparable to 2019 (115 sites and 3,258 participants). (Appendix 1, Figure 1).

The geographical distribution of participating services, as well as the numbers of participants from regions in 2022 differed from pre-pandemic levels. Compared to 2019, there were fewer centres participating in the East of England and the South East and an increase in participating centres in the East Midlands. There was also a decrease in the number of participants recruited in the East of England, London and Wales and an increase in the North West and East Midlands when compared to 2019 (Appendix 1, Figure 1).

Figure 1. Map of drug and alcohol services participating in the UAM Survey of PWID, EWNI, 2022 (see also Appendix 2)

Demographics

The proportion of male participants in the 2022 UAM surveys was 73% (95% confidence interval (CI): 71% to 75%) (Data Table 1; Statistical note a).

Over the period 2013 to 2022, the median age of participants increased from 36 years in 2013 (age range 13 to 73 years; interquartile range (IQR): 31 to 42 years) to 43 years (age range 15 to 72 years; IQR: 37 to 49 years) in 2022. Age at first injection has remained stable over the same period (age range 21 to 22 years), which suggests that the increase in median age is a result of an ageing cohort of PWID, as opposed to new PWID who have started injecting at an older age. This ageing cohort is also evident in other data sources nationally and internationally, reflecting the demographics of the wider injecting population in England. Further work is needed to compare the UAM survey to data from the wider injecting population.

The proportion of participants aged 25 years and under has also decreased significantly over the same period from 6.0% (95% CI: 5.2% to 6.9%) in 2013 to 1.5% (95% CI: 1.1% to 2.0%) in 2022 (Data Table 1; Statistical note a), although this should be interpreted with caution due to the smaller number of people in the aged 25 years and under age group in 2022.

The proportion of UAM survey participants who reported injecting drugs in the past year continues to decline from 72% (95% CI: 71% to 74%) in 2013 to 55% (95% CI: 53% to 57%) in 2022 (Data Table 1; Statistical note a).

Similarly, the proportion of UAM survey participants who first injected drugs within the preceding 3 years continues to decline, from 10% (95% CI: 9% to 11%) in 2013 to 6% (95% CI: 5% to 7%) in 2022. This is consistent with other data suggesting a decline in people starting injecting drug use both nationally and internationally.

Environmental risk factors

Homelessness and imprisonment have been associated with increased risk of HCV and bacterial infections and recent release from prison has been associated with an increased risk of non-fatal overdose. Compared with the general population, PWID experience severe health inequities across a wide range of health conditions and service access, including stigmatising attitudes among staff, which are even greater for PWID experiencing homelessness and or imprisonment.

Approximately two-thirds (65%, 95% CI: 63% to 66%) of UAM survey participants in 2022 reported ever being in prison, which is a decrease from 72% (95% CI: 70% to 73%) in 2013 (Data Table 1; Statistical note b).

The proportion of participants reporting homelessness in the past year or current homelessness increased from 35% (95% CI: 33% to 37%) in 2013 to 41% (95% CI: 39% to 43%) in 2022. The proportion was similar to 2019 (42%, 95% CI: 41% to 44%) and 2021 (42%, 95% CI: 39% to 45%) (Data Table 1; Statistical note b).

Bloodborne viruses

Figure 2 shows HIV, hepatitis B and hepatitis C prevalence among PWID who took part in the UAM survey across EWNI between 2013 and 2022.

Figures 3 to 5 show bloodborne virus prevalence for people who first injected during the preceding 3 years.

Figure 6 shows the prevalence of chronic hepatitis C infection (HCV RNA positive) among people with antibodies to hepatitis C virus in the UAM survey of PWID over the period 2013 to 2022.

Figure 2. Prevalence of antibodies to HIV, HBV core antigen and HCV among participants in the UAM survey of PWID: EWNI, 2013 to 2022 (shaded areas show the 95% CI)

Notes for figure 2 :

‘Ever had hepatitis B’ denotes the proportion of participants who tested positive for antibodies to HBV core antigen, expressed as a percentage.

‘Ever had hepatitis C’ denotes the proportion of participants who tested positive for the presence of HCV antibodies, expressed as a percentage.‘Living with HIV’ denotes the proportion of participants who tested positive for antibodies to the HIV, expressed as a percentage.

HIV prevalence

Overall , the prevalence of HIV among participants in the UAM survey across EWNI has remained low over the past decade. In 2022, it was 1.2% (95% CI: 0.8% to 1.6%), showing no significant difference from 2013 (Figure 2; Data Table 2; Statistical note c).

When stratified by nation, HIV prevalence was slightly higher in Northern Ireland at 3.8% (95% CI: 0.8% to 10.7%) which may be reflective of a recent outbreak of HIV and HCV in the country. However, CIs are wide and there is no evidence for a significant increase in HIV antibody prevalence, but this should be interpreted cautiously due to the small number of PWID testing positive.

When examining different geographical regions in England, HIV prevalence was notably higher in London (5.0%, 95% CI: 2.8% to 8.1%) compared to the rest of England 0.6% (95% CI: 0.4% to 1.0%) (Data Table 13 and 23, Statistical note c) and this is consistent with patterns observed in previous years.

The prevalence of HIV among people who first injected during the preceding 3 years is an indicator of recent transmission. The prevalence of HIV among people who recently started injecting drugs in the survey has remained relatively stable over the last decade and was 0.8% (95% CI: 0.0% to 4.1%) in 2022 (Figure 3; Data Table 24; Statistical note c).

Figure 3. Prevalence of HIV among participants in the UAM survey of PWID by time since first injecting: EWNI, 2013 to 2022 (shaded area shows 95% CI)

Hepatitis B prevalence

PWID are at higher risk of HBV infection by sharing needles and drug use paraphernalia.

The prevalence of antibodies to the HBV core antigen (anti-HBc), a marker of ever being infected with HBV has declined to 7.8% (95% CI: 6.9% to 8.8%) in 2022 from 16% (95% CI: 15% to 17%) in 2013 (Figure 2; Data Table 3; Statistical note d). In Northern Ireland, anti-HBc prevalence in 2022 was 1.3% (95% CI: 0.0% to 6.9%; Data Table 23) and was 5.2% (95% CI: 1.7% to 11.7%; Data Table 22; Statistical note i) in Wales. In England, the prevalence of anti-HBc in 2022 was 8.1% (95% CI: 7.1% to 9.1%; Data Table 12).

The prevalence of anti-HBc among people who have recently started injecting drugs across EWNI was 0.0% (95% CI: 0.0 % to 3.0%) in 2022, a decline from 5.6% (95% CI: 3.3% to 8.8%) in 2013 (Figure 4; Data Table 24).

Figure 4. Prevalence of hepatitis B infection among participants in the UAM survey of PWID by time since first injecting: EWN I, 2013 to 2022 (shaded area shows 95% CI)

DBS samples that test positive for anti-HBc are also tested for HBV surface antigen (HBsAg), a marker of current HBV infection. In 2022, the proportion of people with antibodies to HBc who were HBsAg positive was 5.1% (95% CI: 2.6% to 8.7%), a non-significant increase from 3.8% (95% CI: 2.3% to 6.0%) in 2013 (Data Table 3; Statistical note d).

Hepatitis C prevalence

The most important risk factor for HCV infection in the UK continues to be injecting drug use.

The proportion of UAM survey participants across EWNI with HCV antibodies (anti-HCV) (indicating someone has ever been exposed to the HCV virus) was 54% (95% CI: 52% to 55%) in 2022 which was higher than in 2013 (50% (95% CI: 52% to 55%)) (Figure 2; Data Table 4; Statistical note e). However, after adjusting for gender, age and nation, anti-HCV prevalence was significantly lower in 2022 than in 2013 and 2017 when DAAs became widely available. The higher prevalence overall is reflective of ongoing new infections, which are associated with long-term injecting use and an ageing population with people with HCV antibody living longer as they are treated for chronic HCV.

Across all survey years from 2013 to 2022, HCV antibody prevalence was higher among older compared to younger participants. In 2022, the proportions were 10% (95% CI: 3% to 23%), 43% (95% CI: 54% to 48%), and 56% (95% CI: 54% to 58%) for the age groups aged 25 years and under, aged 25 to 34, and aged 35 years and over, respectively. However, these proportions should be interpreted with caution due to the smaller number of participants in the aged 25 years and under age group.

When stratified by nation, anti-HCV prevalence has increased significantly in Northern Ireland over the past 10 years. In Northern Ireland, 48% (95% CI: 37% to 60%) of participants had evidence of current or previous infection with HCV in 2022 compared to 32% (95% CI: 25% to 39%) in 2013. The sharp increase in anti-HCV prevalence in Northern Ireland in 2020 to 2021 to 57% (95% CI: 48% to 66%) is reflective of an ongoing outbreak of HIV and HCV in the country (Data Table 23; Statistical note e). HCV antibody prevalence has non-significantly increased over the last decade among participants recruited in Wales; increasing to 64% (95% CI: 54% to 74%) in 2022 from 47% (95% CI: 40% to 54%) in 2013 (Data Table 22; Statistical note i).

As most new HCV infections are acquired via injecting drug use, the detection of anti-HCV in a person who has recently initiated injecting drug use is indicative of recent transmission. The prevalence of antibodies to HCV among people who have recently started injecting drugs has remained relatively stable over recent years and was 23% (95% CI: 16% to 31%) in 2022 (Figure 5; Data Table 24; Statistical note e), suggesting that new infections continue to occur.

Similarly, as younger adults who inject drugs are at risk of newly acquiring HCV infection, the prevalence of infection among PWID aged 25 years and under can be used as an indicator of recent transmission. The percentage of PWID in the UAM survey aged 25 years and under who have ever had HCV has shown a steady decline from 28% (95% CI: 22% to 35%) in 2013 to 10% (95% CI: 2.7% to 22.6%) in 2022 (Data Table 4). However, interpreting the trend is challenging due to the small and declining number of participants aged 25 years and under in the survey.

Figure 5. Prevalence of hepatitis C among participants in the UAM survey of PWID by time since first injecting: EWNI, 2013 to 2022 (shaded area shows 95% CI)

Chronic HCV prevalence

Chronic HCV infection is indicated by a positive test for HCV ribonucleic acid (RNA) in addition to HCV antibodies. Over the last decade, the prevalence of HCV RNA among people who were anti-HCV positive (combination of undiagnosed and diagnosed but not treated or currently in treatment) declined significantly from 49% (95% CI: 46% to 52%) in 2017 to 23% (95% CI: 21% to 25%) in 2022 (Figure 6, Data Table 4; Statistical note f). This decrease remained significant after adjusting for injecting in the past year, ever being homeless and ever being in prison, gender, age, and region (Statistical note f). The decline in chronic HCV infection from 2017 onwards corresponds with the scale-up of DAA treatment for HCV among PWID.

Evidence suggests that people who have injected in the past year are more likely to test positive for HCV RNA. In 2022, 26% (95% CI: 23% to 29%) of those injecting drugs in the past year had a chronic HCV infection, a significant decrease from 50% (95% CI: 47% to 54%) in 2017 (Data Table 26). Correspondingly, the prevalence of cleared HCV infection among those injecting drugs in the past year has increased in recent years, from 2017 where it was 52% (95% CI: 49% to 56%) to 74% (95% CI: 71% to 77%) in 2022. The decreasing proportion of chronic HCV infection when coupled with the increasing proportion of cleared HCV infection provides further evidence of a fall in HCV chronic prevalence and that DAA drugs are having an impact.

When stratified by nation, a sharp increase in chronic HCV prevalence was observed in Northern Ireland in 2020 and 2021 combined, and this trend continues in 2022 (Data Tables 12 to 23). Chronic HCV prevalence in Northern Ireland increased from 28% (95% CI: 13% to 47%) in 2019 to 57% (95% CI: 39% to 73%) in 2022 (Data Table 23; Statistical note f). This increase is reflective of a recent HCV outbreak in the country which started in 2020. UKHSA has worked alongside the Public Health Agency Northern Ireland to support case finding and outbreak monitoring using whole genome sequencing.

Figure 6. Prevalence of chronic Hepatitis C (RNA-positive) among people with antibodies to HCV in the UAM survey of PWID: EWNI, 2013 to 2022

Note for figure 6:

Retrospective analysis of HCV RNA (2011 to 2016) was performed as part of the Evaluating the population impact of hepatitis C direct acting antiviral treatment as prevention for PWID (EPIToPE ) study, funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme (Grant Reference Number RP-PG-0616- 20008). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Injection site infections

Injection site infections are common among PWID and can be a significant cause of morbidity and mortality. In 2022, 40% (95% CI: 38% to 43%) of survey participants who reported injecting drugs during the preceding year reported that they had experienced an abscess, sore or open wound at an injection site over that year. This is a significant decrease from 50% (95% CI: 47% to 52%) in 2017 (Data Table 10; Statistical note g). However, there remains an unmet need for easy-to-access wound management services to improve skin and soft tissue infection diagnosis and treatment before they become severe.

Among PWID who reported injecting drugs in the past year and who had symptoms of an injection site infection during that period, less than half, 42% (95% CI: 38% to 45%), reported that they had treatment for their symptoms at a service.

Uptake of interventions and services

Hepatitis B vaccination

PWID face a heightened risk of acquiring HBV, making vaccination advisable for those who currently inject drugs and for those who are likely to start injecting and their close contacts.

The UAM survey collects information on self-reported uptake of HBV vaccine (Figure 7; Data Table 7; Statistical note h). Self-reported uptake of at least one dose of HBV vaccine among survey participants has declined significantly over the last decade from 72% (95% CI: 70% to 73%) in 2013 to 61% (95% CI: 59% to 62%) in 2022. The decline was observed across all age groups, but HBV vaccine uptake was particularly low in people under 25 years and people who first injected within the preceding 3 years. However, the number of people in the 25 years and under age group (Data Table 7) as well as people who recently started injecting (Data Table 24) participating in the UAM survey are small (and declining) and should be interpreted cautiously.

Figure 7. Uptake of hepatitis B vaccination, and of hepatitis C and HIV testing in the current or previous year, among participants in the UAM survey of PWID: EWNI, 2013 to 2022

HBV vaccine uptake has also declined among individuals reporting current homelessness or homelessness in the past year, with 62% (752 out of 1,214, 95% CI: 59% to 65%; not included in data tables) reporting vaccine uptake in 2022 compared with 70% (740 out of 1,057, 95% CI: 67% to 73%) in 2013.

HIV testing

Self-reported uptake of diagnostic testing for HIV among UAM survey participants has remained relatively stable over the last decade, with a slight increase in 2022. In 2022, 81% (95% CI: 80% to 82%) of PWID reported ever being tested for HIV, and 39% (95% CI: 37% to 41%) reported being tested in the current or previous year. In 2013, the figures were 76% (95% CI: 75% to 78%) and 31% (95% CI: 29% to 32%), respectively (Figure 7, Data Table 8; Statistical note i).

When stratified by nation, the proportion reporting recent HIV testing shows a significant increase in England and Northern Ireland. In Northern Ireland and England, the proportion reporting a recent test increased from 26% (95% CI: 19% to 33%) in 2013 to 57% (95% CI: 45% to 68%) in 2022 (Data Table 23; Statistical note i). Recent HIV testing has remained stable in England in the past decade with a slight increase reported in 2022. In Wales, testing has been mostly stable but there was a temporary decline during the COVID-19 pandemic. In 2020 and 2021 the proportion was 15% (95% CI: 8.1% to 24%) but it has since recovered to pre-pandemic levels at 38% (95% CI: 28% to 48%) (Data Table 22; Statistical note i).

Missed opportunities for HIV testing and prompt diagnosis remain. Guidance recommends regular BBV testing for those at ongoing risk of infection. In 2022, 17% (95% CI: 16% to 19%) of PWID who injected drugs in the last year reported never being tested for HIV, and an additional 40% (95% CI: 38% to 42%) reported not being tested in the last 2 years, despite having accessed various health services in the previous year.

The proportion of participants across EWNI with antibodies to HIV who were aware they were living with HIV was 88% (95% CI: 72% to 97%) in 2022 (Data Table 8; Statistical note i). This proportion was not statistically different from that of 2013 (96%, 95% CI: 82% to 100%) and 2021 (81%, 95% CI: 54% to 96%).

HCV testing

The proportion of UAM survey participants reporting ever being tested for HCV has remained stable over the last decade with 87% (95% CI: 86% to 88%) reporting ever being tested for HCV in 2022, similar to 83% (95% CI: 82% to 84%) in 2013 (Figure 7, Data Table 9; Statistical note j).

While the proportion of participants reporting ever being tested for HCV has remained steady in England and Northern Ireland over the past decade, there was a temporary decline during the COVID-19 pandemic among participants recruited in Wales. In 2020 and 2021, the proportion was 69% (95% CI: 59% to 79%), but it has since recovered to pre-pandemic levels, reaching 86% (95% CI: 78% to 93%) in 2022 (Data Table 22; ). This reflects the disruption in service provision and BBV testing during the pandemic (‘Harm Reduction Database Wales: prevention and detection of infectious disease amongst people accessing substance misuse services. Annual Report 2020 to 2021’).

The proportion who reported being tested for HCV in the current or previous year increased from 35% (95% CI: 33% to 36%) in 2013 to 48% (95% CI: 46% to 50%) in 2022 (Data Table 9; Statistical note i). Since 2013, recent uptake of HCV testing in England has risen from 34% (95% CI: 32% to 36%) in 2013 to 48% (95% CI: 46% to 50%) in 2022. In Northern Ireland, this increase has been even more notable, increasing from 29% (95% CI: 22% to 36%) in 2013 to 59% (95% CI: 47% to 70%) in 2022 (Data Table 12 and 23; Statistical note i). Recent HCV test uptake in Wales declined during the pandemic to 18% (95% CI: 11% to 28%) in 2020 and 2021. In 2022, the proportion reporting a recent HCV test increased to 43% (95% CI: 33% to 53%) (Data Table 22; Statistical note i).

Among individuals who injected drugs in the last year, the percentage of those who self-reported having ever been tested for HCV has seen a notable increase in EWNI over the past decade. As of 2022, 90% (95% CI: 88% to 91%) reported that they had ever been tested, with 53% (95% CI: 50% to 55%) indicating testing within the current or preceding year. This reflects a slight rise in overall testing but a significant increase in recent HCV testing compared to the figures from 2013, which were 84% (95% CI: 83% to 86%) and 37% (95% CI: 35% to 39%) respectively (Data Table 25).

Among people who started injecting within the preceding 3 years in 2022, 70% (95% CI: 62% to 78%) reported ever uptake of an HCV test which is similar to 67% (95% CI: 61% to 72%) seen in 2013. However, there was an increase in the percentage who reported recent uptake of a HCV test from 37% (95% CI: 32% to 43%) in 2013 to 53% (95% CI: 44% to 61%) in 2022, respectively (Data Table 24; Statistical note i).

Awareness of HCV infection

Awareness of HCV infection is an important indicator of unmet testing and treatment needs. As treatment with DAAs is more widely available, people aware of their status are more likely to have been treated, and those who remain un- or under-tested are less likely to be aware of their primary or re-infection and as a result have unmet testing and treatment needs. UAM survey data can be used to assess the proportion of PWID who are unaware of their HCV status. These data can be used to identify at need populations and can help target testing initiatives. With increased testing, access to, and engagement with treatment, the proportion of participants with chronic HCV infection who are aware of their infection status is expected to decline over time.

In 2022, 31% (95% CI: 25% to 37%) of UAM survey participants in EWNI with chronic HCV infection reported that they were aware of their infection status, a significant decline in reported awareness since 2017 (51%, 95% CI: 47% to 56%) (Data Table 9; Statistical note i). Diagnostic BBV testing is frequently offered by participating drug and alcohol services alongside the UAM survey, with respondents likely to receive their results shortly after completion of the survey. Therefore, the proportion aware of their chronic infection is likely an underestimate. Among UAM survey participants with chronic HCV who were unaware of their infection in 2022, 39% (95% CI: 31% to 46%) reported receiving an HCV diagnostic test at the time of completing the survey.

HCV care and treatment

Among UAM survey participants testing positive for HCV antibodies who were aware of their infection in 2022, 70% (381 out of 545, 95% CI: 66 to 74%; not included in data tables) had seen a specialist nurse or doctor (hepatologist) for their HCV and had been offered and accepted treatment. This is a significant increase from 30% (152 out of 508, 95% CI: 26% to 34%) in 2017 (Statistical note k). Among this group, 12% (44 out of 381, 95% CI: 8.5% to 15%) had a chronic HCV infection. This increase in HCV treatment uptake seen from 2017 onwards corresponds with the scale-up of DAA treatment for HCV among PWID.

In 2022, among participants who had ever had a HCV infection, were aware of their status and had ever seen a hepatitis nurse or doctor, 14% (52 out of 360, 95% CI: 11% to 19%) reported having been infected with HCV more than once. The majority (81%, 95% CI 67% to 90%) of those who reported having been infected with HCV more than once also reported that they injected drugs in the past year.

In 2022, 87% of participants (311 out of 359, 95% CI: 83% to 90%) who were offered treatment and took it reported that they completed their most recent round of HCV treatment, and of these 82% (238 out of 292, 95% CI: 77% to 86%) reported a successful outcome (that they cleared HCV). Among those who reported that they cleared their HCV, 7% (17 out of 238, 95% CI: 77% to 86%) showed evidence of chronic HCV. This could be re-infections or people who have not successfully cleared their infection.

Needle exchange use

The majority of PWID who took part in the UAM survey in 2022 had ever accessed a needle exchange (82%, 95% CI: 81% to 83%). Although this proportion remains high, this is a significant decrease from 90% (95% CI: 89% to 91%) who reported needle exchange use before the COVID-19 pandemic in 2019 (Data Table 1; Statistical note l). During 2022, the proportion who reported ever accessing a needle exchange in Wales and Northern Ireland was significantly higher than in England (Statistical note l).

Drug treatment

Engagement with drug treatment services was high, with over three quarters (77%, 95% CI: 75% to 78%) of survey participants reporting current engagement with treatment for their drug use (prescription of a detox or maintenance medicine) in 2022, a proportion that is higher than that seen in 2013 (70%, 95% CI: 69% to 72%) (Data Table 1; Statistical note m).

Injecting risk behaviour

Injecting equipment sharing

Sharing of injecting equipment is an important contributor to BBV transmission. During the COVID-19 pandemic, many harm reduction services, including Needle and Syringe Programmes (NSPs), were reduced, or suspended to redeploy staff or to facilitate social and physical distancing measures.

Across EWNI, sharing and re-use of injecting equipment remained common in 2022. The level of needle and syringe (direct) sharing reported by survey participants who had injected during the preceding month (4 weeks) was 19% (95% CI: 17% to 22%) in 2022, a significant increase from 16% (95% CI: 15% to 18%) in 2013 (Data Table 5; Statistical note n). The increase in direct sharing remained significant after adjusting for homelessness, ever being in prison, gender, age, and region (Statistical note n). On the other hand, sharing of needle, syringe and other injecting paraphernalia like filters and spoons (direct and indirect sharing) remained consistent at 39% (95% CI: 36% to 42%) among individuals who had injected in the past month in 2022, similar to the 2013 figure of 39% (95% CI: 37% to 42%) (Data Table 6; Statistical note o).

Between 2013 and 2022, direct sharing was consistently higher among female participants compared to male participants (Data Table 5). There has also been a notable increase in direct sharing within the age group of 35 years and over (Figure 8; Data Table 5).

Direct sharing has also increased among individuals reporting homelessness in the past or current year, with 22% (125 out of 577; 95% CI: 18% to 25%) in 2022 reporting sharing needles and syringes compared with 19% (131 out of 688; 95% CI: 16% to 22%) in 2013 (not in data tables; Statistical note n).

The risk of infections increases when individuals reuse their own injecting equipment, especially from bacterial contamination during handling. Shared storage of equipment can also increase the potential for accidental sharing and therefore BBV transmission. In EWNI, 65% (95% CI: 62% to 68%) of people who recently injected reported equipment reuse in the last month, a comparable proportion to the 2020 figure of 64% (95% CI: 59% to 69%) when data on reuse was initially collected (not in Data Table).

Adequate provision of new, sterile injecting equipment is vital to reduce sharing and reuse, as well as easily accessible information on the associated risks. Needle and syringe provision is considered ‘adequate’ when the reported number of needles and syringes received met or exceeded the number of times the individual injected. In 2022, 68% (378 out of 552; 95% CI: 64% to 72%) of people who reported injecting drugs during the preceding month in EWNI had adequate needle and syringe provision; this is comparable to previous years.

Number of ‘missed hits’

Having to insert a needle multiple times before accessing a vein (achieving a ‘hit’) can increase the risk of developing injection site infections. In 2022, approximately two-thirds of participants who injected in the past year (63%, 1,066 out of 1,697, 95% CI: 60% to 65%; not included in data tables) reported that they needed to insert the needle more than once before getting a ‘hit’, and one out of four (424 out of 1,697, 95% CI: 23% to 27%) reported that it took 4 or more attempts before achieving a ‘hit’. The proportion of PWID reporting that they needed to insert the needle more than once before getting a ‘hit’ has not changed since 2017 (Statistical note p).

Figure 8. Levels of needle and syringe sharing by age group among participants in the UAM survey of PWID who had injected during the preceding 4 weeks: EWNI, 2013 to 2022

Injection into the groin

Injecting into the groin has been associated with several complications, including damage to the femoral vein and artery, injecting site infections and vascular problems. The proportion of people who reported injecting into their groin in the past month was 39% (95% CI: 36% to 42%) in 2022, similar to that seen in 2013 (Data Table 1; Statistical note q).

Sexual risk behaviour

PWID are also at risk of acquiring and transmitting bloodborne viruses and other infections through sexual transmission. In 2022, 54% (95% CI: 52% to 56%) of UAM survey participants reported having anal or vaginal sex during the preceding year, which is a decrease from 70% (95% CI: 69% to 72%) in 2013 (Data Table 11; Statistical note r).

Of those who reported sex in the preceding year, 39% (95% CI: 37% to 41%) reported having had 2 or more sexual partners during that time and, of these, only 18% (95% CI: 15% to 21%) reported always using condoms for anal or vaginal sex (Data Table 11).

Drug trends

Heroin remained the most commonly injected drug, reported by 92% (1,050 out of 1,142, 95% CI: 90% to 93%; not included in data tables) of those who had injected in the preceding month in 2022, with crack cocaine following at 55% (95% CI: 52% to 58%). This is much higher than the proportion reporting crack injection in 2013 at 37% (95% CI: 35% to 39%), but not statistically different to 2018 when crack injection was at its highest at 60% (95% CI: 57% to 62%) (Data Table 1; Figure 9; Statistical note s). Crack cocaine injection is associated with behaviours known to increase the risk of BBVs and skin and soft tissue infections, including the sharing of injecting equipment, groin injection and higher injection frequency.

There was also a significant increase in the injection of other forms of cocaine among those who had injected in the preceding month; 29% (95% CI: 27% to 32%) in 2022 versus 6.9% (95% CI: 5.7% to 8.2%) in 2013 (Data Table 1; Figure 9; Statistical note s). This increase was particularly marked in Northern Ireland, where reported injection of other forms of cocaine in the past month has increased significantly from 5.9% (1 out of 17, 95% CI: 0.15% to 29%) in 2018 to 84% (36 out of 43, 95% CI: 69% to 93%) in 2022 (not in data tables; Statistical note s).

The injection of amphetamine and amphetamine-type drugs among those who injected drugs in the last month continued to decline from a high of 23% (95% CI: 21% to 25%) in 2013 to 8.5% (95% CI: 6.9% to 10%) in 2022 in EWNI (Data Table 1; Figure 9; Statistical note s).

Figure 9. Levels of crack, amphetamines and cocaine use among the participants in the UAM survey of PWID who had injected during the preceding 4 weeks: EWNI, 2013 to 2022

Non-fatal overdose and naloxone use

In 2021, there were 4,859 deaths related to drug poisoning registered in England and Wales (84.4 deaths per million) reported by the Office for National Statistics, a new record high and a 6.5% increase from 2020 (4,561); 3,060 were related to substance misuse (53.2 deaths per million). The upward trend in drug-related deaths in the UK is primarily driven by deaths involving the use of opioids, but the number of deaths involving other substances like cocaine is also increasing.

Among UAM survey participants who reported injecting during the preceding year, 24% (95% CI: 22% to 26%) reported having overdosed to the point of losing consciousness in the preceding year in 2022, an increase from 16% (95% CI: 15% to 18%) in 2013 when data for non-fatal overdose was first collected (Data Table 26; Statistical note t). This increase was significant for age groups 25 to 34 years and 35 years and older (Data Table 26; Statistical note t).

In 2022, the proportion who self-reported non-fatal overdose in the past year was similar among PWID who had never been in drug treatment (29%, 95% CI: 23% to 37%) and PWID who had previously been in drug treatment (30%, 95% CI: 24% to 37%) (Data Table 26; Statistical note t).

Naloxone is an opioid antagonist which can temporarily reverse the effects of an opioid overdose and is distributed to individuals who use drugs, as well as their friends, family members, and various healthcare and other professionals who may encounter overdose situations. The proportion of participants who had injected in the last year and who reported carrying naloxone has increased significantly from 54% (95% CI: 52% to 56%) in 2017 to 68% (95% CI: 66% to 71%) in 2022 (Data Table 25; Statistical note t). Over half at 59% (95% CI: 53% to 64%) of those who reported overdosing in the preceding year reported having had naloxone administered, an increase from 46% (95% CI: 39% to 52%) in 2013 (Data Table 25; Statistical note t).

Conclusions

Recruitment to the UAM survey in 2022 has recovered to pre-pandemic levels, but changes in the geographic and demographic distribution of those recruited may affect the generalisability of the findings. Nonetheless, the UAM survey remains vital to providing essential information on infections and other injection-related harms across EWNI.

HIV prevalence in EWNI has consistently remained at a low and stable level over the past decade. In 2022, there was an increase in participants self-reporting ever and recent uptake of HIV testing and being aware of their HIV status. The increase may be attributed to the relaxation of COVID-19 restrictions and ongoing efforts to promote service utilisation.

In 2020 and 2021, there was a substantial increase in HIV prevalence among UAM survey participants in Northern Ireland, associated with a stimulant injection-driven outbreak. Similar outbreaks have been observed in Scotland and other European countries, including Greece and Romania, Luxembourg and Dublin. To address this and prevent ongoing transmission, the importance of harm reduction services including increase in needle exchange and HIV testing were emphasised; partners of people living with HIV were offered pre-exposure prophylaxis and linkage to services to reduce the risk of subsequent reinfection was enhanced.

The proportion of participants who have ever been exposed to anti-HBc has declined over the past decade and the proportion with a current HBsAg has remained low. The explanation for the decline in anti-HBc is unclear but could reflect a decline in exposure to, and transmission of, HBV over time, as a result of vaccination. Anti-HBc titres could also be waning with time after resolution of HBV.

Of concern, HBV vaccine uptake among UAM survey participants continues to decline and is at its lowest level in a decade, declining across all age groups. UAM survey data shows that these individuals report recent contact with services, such as general practice, prison health services and drug treatment, highlighting missed opportunities for HBV vaccination. Urgent action is needed to improve vaccination uptake, especially among PWID of younger age and those who have recently started injecting, for whom reported uptake is lower.

Further work is needed to explore the facilitators and barriers to offer and uptake of HBV vaccination to inform policy and practice. The findings can be used to support the delivery of evidence-based interventions that aim to improve vaccine coverage.

In 2022, HCV remained the most common infection among PWID across EWNI. The proportion with evidence of ever being infected with HCV has increased over the past decade and is higher in the older cohort suggesting that an ageing cohort who have ever been infected with HCV is living for longer.

The proportion of UAM survey participants with chronic HCV infection (anti-HCV positive and HCV RNA positive) declined significantly in recent years since 2017. When considered together with the increase in HCV antibody prevalence, the fall in chronic prevalence among PWID in the EWNI overall is likely to be due to better uptake of HCV treatment rather than improved prevention of new infections through harm reduction initiatives.

The indirect effect of treatment as prevention, which would result in a decline in HCV antibody positive results, is unlikely to be apparent until greater reductions in chronic prevalence have been achieved over time.

An increasing proportion of UAM survey participants report having been offered and accepting treatment for HCV infection. The reasons for these increases are multifactorial, including recovery from the impact of the COVID-19 pandemic on service provision, which resulted in the increased uptake of services. In 2021, 6.5% of PWID surveyed in EWNI who started HCV treatment before the COVID-19 pandemic reported some form of HCV treatment disruption. The increase in treatment uptake among those aware of their diagnosis has been observed from 2017 onwards and corresponds with the scale-up of DAA treatment for HCV among PWID.

There was also an increase in the proportion of participants reporting a recent HCV diagnostic test in 2022. Expanded community outreach testing and linkage to care through peer support can help reach underserved groups and those not in contact with services. Such models of service delivery are relevant to achieving and sustaining HCV elimination, particularly in the wake of the pandemic. To achieve and sustain elimination, community scale-up of HCV testing and treatment needs to be combined with improvements in harm reduction coverage and retention, accompanied by strategies such as education, counselling, and linkage to services to reduce the risk of subsequent reinfection.

Despite this, awareness of infection among those who remain infected (either through un-or under-diagnosis) remains low even when considering that some of those who were unaware of their diagnosis had a diagnostic test on the day of completing the survey. More work needs to be done to understand who remains unaware of their HCV infection, and their needs so that holistic testing interventions can be targeted in a timely manner.

Sharing and re-use of injecting equipment among PWID remains common. The provision of needles and syringes is often insufficient due to individuals requiring multiple attempts to insert a needle before successfully accessing a vein.

In 2022, two-thirds of PWID reported inadequate access to needles and syringes. To address this issue, a range of easily accessible harm reduction services for all PWID, including NSP and opioid agonist therapy (OAT), need to be provided. A better understanding of the range and scope of NSP provision in non-drug service settings is needed.

Clients should be supported to use low dead space equipment, including detachable needles and syringes that have lower dead space, to further reduce the risk of BBV transmission. PWID experiencing additional social exclusion such as homelessness and those not currently in contact with drug and alcohol services, should receive additional targeted support to enable them to access harm reduction services, regular BBV testing andcare.

The changing patterns of psychoactive drug injection in the UK remain a concern, as changes in psychoactive drug preferences can lead to riskier injecting practices. The proportion of PWID reporting injection of crack cocaine has remained high in EWNI and there has been an increase in reported injection of powder cocaine across the UK in recent years. The latter has been linked with ongoing BBV outbreaks in Scotland and Northern Ireland. There is a need for local treatment and harm reduction systems that can respond to both the increasing numbers and the specific needs of people who use crack and powder cocaine.

Reports of both fatal and non-fatal overdose have increased in the UK, with overdose most common among people using and or injecting opioids. This is in the context of improved availability of naloxone, an emergency antidote for opioid overdose, and increased self-reported carriage of take-home naloxone among PWID. Local areas should ensure that they commission readily accessible OAT, NSP and take-home naloxone services to meet service user needs and preferences. In addition, services working with PWID should provide materials to increase awareness of, and information about, overdose risks and provide training for peers and family members in overdose prevention, recognition, and response.

Chronic prevalence of HCV remains high in younger age groups and among people who have recently started injecting, suggesting ongoing new infections. This combined with increased sharing of injecting equipment and low reported NSP provision suggests that there needs to be renewed investment and focus on harm reduction if we are to achieve HCV and HIV elimination goals. Strategies should be developed to better engage these groups in testing and treatment services including targeted information on HCV, more accessible harm reduction, as well as improvements in diagnostic testing (including re-testing) and linkage to care among these groups will be important to prevent new and re-infections.

Together, these findings indicate that individuals continue to be at risk through their injecting practices and that there is a need to maintain and strengthen public health interventions that aim to reduce injection-related risk behaviours and take a holistic approach to addressing the needs of PWID.

Appendix 1. Changes to recruitment and representativeness in 2020 to 2022

Table 1a. Geographic distribution of UAM survey participants in 2022 compared to 2019, 2020 and 2021

Region	2019 number (n)	2019 (%)	2020 (n)	2020 (%)	2021 (n)	2021 (%)	2022 (n)	2022 (%)
East of England	256	7.9	96	10	71	4.7	143	4.5
London	456	14	191	20	181	12	311	9.8
South East	418	13	78	8.2	209	14	404	12.8
South West	264	8.1	111	12	214	14	326	10.3
West Midlands	312	9.6	46	4.8	39	2.6	298	9.4
North West	393	12	59	6.2	99	6.5	569	18.0
Yorkshire and Humber	355	11	84	8.8	97	6.4	314	9.9
East Midlands	320	9.8	94	9.8	332	22	418	13.2
North East	146	4.5	168	18	77	5.1	202	6.4
Wales	219	6.7	2	0.21	95	6.2	100	3.2
Northern Ireland	119	3.7	26	2.7	111	7.3	80	2.5
Total	3,258	100	955	100	1,525	100	3,165	100

Note. The geographic distribution was significantly different in all years when compared to 2022 (Pearson’s chi-squared text (Χ²)) p<0.001).

Table 1b. Geographic distribution of participating centres in 2022 compared to 2019, 2020 and 2021

Region	2019 (n)	2019 (%)	2020 (n)	2020 (%)	2021 (n)	2021 (%)	2022 (n)	2022 (%)
East of England	13	11	6	9.4	7	9.1	8	6.8
London	16	14	8	13	11	14	14	12.0
South East	17	15	9	14	10	13	14	12.0
South West	8	7.0	3	4.7	6	7.8	11	9.4
West Midlands	11	9.6	6	9.4	5	6.5	11	9.4
North West	16	14	7	11	8	10	18	15.4
Yorkshire and Humber	10	8.7	8	13	5	6.5	10	8.5
East Midlands	8	7.0	8	13	11	14	16	13.7
North East	7	6.1	5	7.8	6	7.8	7	6.0
Wales	5	4.3	1	1.6	2	2.6	3	2.6
Northern Ireland	4	3.5	3	4.7	6	7.8	5	4.3
Total	115	100	64	100	77	100	117	100

Note: The geographic distribution was significantly different in all years when compared to 2022 (Pearson’s Χ² test p<0.001).

Appendix 2. Participating centres in 2022

North East

• Change Grow Live, Gateshead Needle Exchange
• Durham Lifeline, Old Elvet
• Durham Lifeline, Peterlee
• HepC Trust, North East
• North Tyneside Recovery Partnership, North Tyneside
• South Tyneside Adult Recovery Service, South Tyneside
• We Are With You, Redcar

North West

• Achieve, Bolton
• Achieve, Salford Recovery Service, Salford
• Achieve, Trafford
• Achieve , Bury
• Calico, Blackburn
• Change Grow Live, Bootle
• Change Grow Live, Bradnor
• Change Grow Live, Carnarvon Street
• Change Grow Live, East Lancashire
• Change Grow Live, Inspire, Pendle
• Change Grow Live, - Inspire, Preston
• Change Grow Live, Knowsley
• Change Grow Live, Manchester Outreach Team
• Change Grow Live, Southport
• Change Grow Live, Saint Helens Drug and Alcohol Integrated Service
• Change Grow Live, Tameside
• HepC Trust, Cumbria
• NHS Unity, Carlisle

Yorkshire and Humber

• Barnsley Recovery Steps, Barnsley
• Calderdale Recovery Steps, Calderdale
• Change Grow Live, Rotherham
• East Riding Partnership, Bridlington
• East Riding Partnership, Goole
• East Riding Partnership, Hull
• Forward, Leeds
• HepC Trust, Yorkshire
• We Are With You, Grimsby
• We Are With You, Scunthorpe

London

• Better Lives, Islington
• Camden and Islington NHS Trust, Margarete Centre
• Change Grow Live, Bromley
• Change Grow Live, Camden
• Change Grow Live, New Direction, Lewisham
• Change Grow Live, Newham
• Drug and Alcohol Wellbeing Service, Kensington and Chelsea
• Kingston Wellbeing Service, Kingston
• Lambeth Drug and Alcohol Service, Lambeth
• Richmond Community Drug and Alcohol Service, Twickehham
• Turning Point, Harrow Road
• Turning Point, Wardour Street
• VIA, Greenwich
• Wandsworth Community Drug and Alcohol Team, Battersea

East Midlands

• Change Grow Live, Nottinghamshire, County South (Hucknall)
• Change Grow Live, Nottinghamshire, Mansfield
• Change Grow Live, Nottinghamshire, Newark on Trent
• Change Grow Live, Nottinghamshire, Worksop
• Change Grow Live, Substance to Solution, Corby
• Change Grow Live, Substance to Solution, Kettering
• Derby Drug and Alcohol Recovery Service, Derby
• Derbyshire NHS, Chesterfield
• Derbyshire NHS, Ilkeston
• Derbyshire NHS, Ripley
• Derbyshire NHS, Swadlincote
• Health Shop, Nottingham
• HepC Trust, Leicester
• We Are With You, Boston
• We Are With You, Grantham
• We Are With You, Lincoln

West Midlands

• Alcohol and Drug Services, Stoke-on-Trent
• Change Grow Live, Birmingham, Blucher Street
• Change Grow Live, Birmingham, Church Lane
• Change Grow Live, Birmingham, Griffins Brook Lane
• Change Grow Live, Birmingham, Hospital Street
• Change Grow Live, Coventry
• Change Grow Live, Leamington Spa
• Change Grow Live, Nuneaton
• Change Grow Live, Rugby
• Recovery Near You, Wolverhampton
• Swanswell Worcestershire, Worcester

East of England

• Change Grow Live, Spectrum, Hatfield
• Change Grow Live, - Spectrum, Stevenage
• Change Grow Live, Watford
• Essex Specialist Treatment and Recovery Service, Basildon
• Essex Specialist Treatment and Recovery Service, Chelmsford
• Essex Specialist Treatment and Recovery Service, Colchester
• Essex Specialist Treatment and Recovery Service, Harlow
• Inclusion Visions, Thurrock

South East

• Change Grow Live, Southampton
• Change Grow Live, STAR, Eastbourne
• Change Grow Live, STAR, Hastings
• HepC Trust, East Kent
• HepC Trust, West Kent
• Inclusion, Aldershot
• Inclusion, Aylesbury
• Inclusion, Hampshire
• Inclusion, Isle of Wight
• Inclusion, Wycombe
• Portsmouth Recovery Service, Portsmouth
• Turning Point, Banbury
• Turning Point, Didcot
• Turning Point, Roads to Recovery, - Oxford

South West

• Addaction, Bournemouth Engagement and Assessment Team, - Bournemouth
• Avon Drug Problem Team, Bristol
• Bath and North East Somerset Drug and Alcohol Treatment Service, Bath City Centre
• Bath and North East Somerset Drug and Alcohol Treatment Service, Bath Homeless Service (Manvers Street Hostel)
• Bath and North East Somerset Drug and Alcohol Treatment Service, Midsummer Norton
• Reach Drug and Alcohol Services, Christchurch and East Dorset
• Reach Drug and Alcohol Services, North Dorset
• Reach Drug and Alcohol Services, Weymouth and West Dorset
• Somerset Drug and Alcohol Service, Yeovil
• Turning Point Impact, Salisbury
• West Somerset Drug and Alcohol Service, Taunton

Northern Ireland

• Belfast Health and Social Care Trust, Belfast
• Community Addiction Team, Downshire and Lisburn
• Lough House Addiction Service, Newtownards
• Railway Community Addiction Service, Ballymena
• St Lukes Hospital Community Addiction Unit, Armagh

Wales

• Cardiff On Site Dispensing Service, DaTT, Cardiff
• Betsi Cadwaladr University Health Board, North Wales
• Barod, Swansea

Appendix 3. Statistical notes

Introductory note

All trend analyses were adjusted for age, gender, and region of recruitment (English regions, Wales, Northern Ireland) in a multi-variable analysis, unless otherwise specified. For analyses on HIV prevalence, region of recruitment was specified as London versus elsewhere to account for the small number of positive samples. Non-aggregated regional data was used in all other analyses. Results shown are for EWNI combined, unless specified otherwise.

a) Demographics

The adjusted odds ratio for being male in 2022 versus 2013 was 0.73 (95% CI: 0.65 to 0.82), indicating a significant decrease in the proportion of male participants between these 2 years, despite the proportions appearing to be equivalent. When comparing the proportion of participants under 25 years of age in 2022 versus 2013, the adjusted odds ratio was 0.25 (95% CI: 0.18 to 0.34), indicating a significant decrease in the proportion aged under 25 years between these 2 years. The decline in the proportion reporting injecting drugs in the past year between 2022 and 2013 was significant, with an adjusted odds ratio of 0.61 (95% CI: 0.54 to 0.68).

b) Environmental risk factors 

The adjusted odds ratio for past imprisonment in 2022 versus 2013 was 0.63 (95% CI: 0.56 to 0.71), indicating a significant decrease in the proportion of participants reporting ever being in prison or young offender’s institution between 2022 and 2013.

The proportion reporting homelessness in the past year increased significantly when comparing 2022 versus 2013, with an adjusted odds ratio of 1.68 (95% CI: 1.51 to 1.88).

c) HIV prevalence

The adjusted odds ratio of being a person living with HIV in 2022 versus 2013 was 1.34 (95% CI: 0.82 to 2.20), indicating no evidence for a change in the HIV prevalence among PWID between these 2 years. In 2022, HIV prevalence was higher among those recruited in London when compared with those recruited outside of London, with the adjusted odds ratio for those recruited in London being 9.81 (95% CI: 4.70 to 20.49); this difference was statistically significant.

When comparing HIV prevalence among people who had recently started injecting in 2022 versus 2013 the adjusted odds ratio was 0.66 (95% CI: 0.07 to 6.54), indicating no evidence for a change in prevalence between these 2 periods.

d) Hepatitis B prevalence

The adjusted odds ratio for ever being infected with HBV in 2022 versus 2013 was 0.19 (95% CI: 0.16 to 0.23), indicating a significant decrease in ever HBV infection (anti-HBc) among PWID during this period. While there was a change in the prevalence of current HBsAg between 2022 versus 2013, with an adjusted odds ratio of 1.98 (95% CI: 0.88 to 4.50), this change was not statistically significant and provides no evidence for a change in prevalence.

e) Hepatitis C antibody prevalence

The adjusted odds ratio of HCV antibody prevalence in 2022 versus 2013 was 0.87 (95% CI: 0.78 to 0.97), indicating a statistically significant decrease in HCV antibody prevalence among PWID in EWNI between these 2 years.

Among those who injected in the last year, the adjusted odds ratio of HCV antibody prevalence in 2022 versus 2013 was 1.14 (95% CI: 0.99 to 1.30), indicating no evidence of change in the HCV antibody prevalence in this group between these years.

When stratifying by nation, in England the adjusted odds ratio of HCV antibody prevalence when comparing 2022 versus 2013 was 0.83 (95% CI: 0.74 to 0.92), in Wales it was 1.63 (95% CI: 0.97 to 2.74) and in Northern Ireland it was 2.10 (95% CI: 1.20 to 3.67). This indicates a significant increase in HCV antibody prevalence in Northern Ireland between these 2 periods, however a statistically significant decrease in HCV antibody prevalence among PWID in England.

Among people who had started injecting within the preceding 3 years, the adjusted odds ratio of HCV antibody prevalence in 2022 versus 2013 was 0.81 (95% CI: 0.49 to 1.33), indicating no evidence of change in the HCV antibody prevalence in this group between these years.

f) Chronic hepatitis C prevalence (anti-HCV positive, RNA-positive)

The adjusted odds ratio for chronic HCV prevalence (HCV RNA positive among anti-HCV positive) in 2022 versus 2013 was 0.25 (95% CI: 0.21 to 0.30), indicating a significant decrease in chronic HCV prevalence among PWID between these years. No significant decrease was observed for years 2013 to 2016. Chronic HCV prevalence was significantly lower than in 2013 from 2017 onwards. After adjusting for injecting in the past year, ever being homeless, and ever being in prison, in addition to gender, age and region, the decline in chronic HCV prevalence remained significant (adjusted odds ratio for 2022 versus 2013: 0.25 (95% CI: 0.21 to 0.30).

When comparing chronic HCV prevalence among PWID in Northern Ireland for 2022 to that seen in 2013 and 2019, the adjusted odds ratios were 1.85 (95% CI: 0.76 to 4.49) and 3.06 (95% CI: 1.01 to 8.89) respectively, indicating no evidence of change in HCV RNA prevalence in Northern Ireland between 2013 and 2022 and no evidence of a change (increase) between 2019 and 2022.

Among people who had started injecting within the preceding 3 years, the adjusted odds ratio of chronic HCV prevalence for 2022 versus 2013 was 0.91 (95% CI: 0.34 to 2.43), indicating no evidence of change in HCV RNA prevalence among people who have recently started injecting.

Among those who injected in the last year, the adjusted odds ratio of chronic HCV prevalence for 2022 versus 2013 was 0.26 (95% CI: 0.21 to 0.32), indicating a significant reduction change in HCV RNA prevalence between these years.

g) Symptoms of an infection at an injecting site

The adjusted odds ratio for infection at an injecting site for 2022 versus 2017 was 0.69 (95% CI: 0.60 to 0.80), indicating a significant decrease in the proportion of PWID reporting symptoms of infection at an injecting site between these years.

h) Hepatitis B vaccine uptake

The adjusted odds ratio for HBV vaccine uptake for 2022 versus 2013 was 0.59 (95% CI: 0.52 to 0.66), indicating a significant decline in vaccination between these years.

The adjusted odds ratios for HBV vaccine uptake in 2022 versus 2013 among the 25 years and under age group and people who recently started injecting were 0.16 (95% CI: 0.07 to 0.34) and 0.37 (95% CI: 0.24 to 0.56) respectively, indicating significant decreases in reported vaccine uptake between the 2 years in these groups. Among PWID aged 25 to 34 years and those aged 35 years or over, the adjusted odds ratios for 2022 versus 2013 were 0.35 (95% CI: 0.27 to 0.44) and 0.69 (95% CI: 0.60 to 0.79) respectively, indicating a significant decrease in reported vaccine uptake in both age groups between these 2 years.

When comparing HBV vaccine uptake in 2022 versus 2013 among those reporting current homelessness or homelessness in the past year the adjusted odds ratio was 0.63 (95% CI: 0.53 to 0.76), indicating a significant decrease in HBV vaccine uptake between these years.

i) Testing for HIV

The adjusted odds ratio for reported uptake of ever HIV testing among PWID in 2022 versus 2013 was 1.22 (95% CI: 1.07 to 1.40), indicating a significant increase in reported testing uptake when comparing 2022 to 2013. When comparing ever uptake of testing for HIV by nation, the adjusted odds ratios were as follows:

• 1.16 (95% CI: 1.02 to 1.33) in England in 2022 versus 2013
• 1.48 (95% CI: 0.78 to 2.79) in Wales in 2022 versus 2013
• 0.83 (95% CI: 0.34 to 2.01) in Northern Ireland in 2022 versus 2013

This indicates an increase in ever uptake of a HIV test between 2013 to 2022 for England, but no evidence for a change between 2013 and 2022 for both Northern Ireland and Wales.

A notable increase in reported uptake of a recent HIV test (current or previous year) among PWID can be seen for 2022 versus 2013, with the adjusted odds ratio of 1.75 (95% CI: 1.57 to 1.96). When comparing recent HIV testing uptake by nation, the adjusted odds ratios were as follows:

• 1.60 (95% CI: 1.43 to 1.80) in England in 2022 versus 2013
• 1.22 (95% CI: 0.72 to 2.08) in Wales for 2022 versus 2013
• 4.44 (95% CI: 2.44 to 8.07) in Northern Ireland in 2022 versus 2013

This indicates an increase in recent HIV testing between 2013 and 2022 for EWNI. However, the increase was only statistically significant for England and Northern Ireland. A decline in recent HIV testing for Wales has been observed between 2019 and 2020 and 2021 combined. Uptake increased in 2022 but was not statistically significant.

Among individuals reporting homelessness in the past year or current homelessness, the adjusted odds ratio for ever and recent uptake of a HIV test for 2022 versus 2013 was 1.44 (95% CI: 1.16 to 1.79) and 1.71 (95% CI: 1.43 to 2.04) respectively, indicating a significant increase in ever or recent uptake of a HIV test between these 2 years.

The adjusted odds ratio for awareness of HIV among people living with HIV in 2022 compared to 2013 was 0.33 (95% CI: 0.03 to 5.03), showing no evidence of a change in HIV awareness between these 2 years. Similarly, when comparing 2022 to 2021, an odds ratio of 1.52 (95% CI: 0.27 to 8.57) indicated no evidence of change.

j) Testing for hepatitis C

The adjusted odds ratio for ever uptake of HCV testing among PWID in 2022 versus 2013 was 1.13 (95% CI: 0.97 to 1.31), indicating no significant change when comparing these years. When stratifying ever uptake of a HCV test by nation, the adjusted odds ratios were as follows:

• 1.16 (95% CI: 0.99 to 1.35) for England for 2022 versus 2013
• 0.95 (95% CI: 0.47 to 1.94) for Wales in 2022 versus 2013
• 0.76 (95% CI: 0.31 to 1.85) for Northern Ireland in 2022 versus 2013

This indicates no evidence for a change in ever testing for HCV between 2013 to 2022 in EWNI.

The adjusted odds ratio for reported uptake of a recent HCV test (current or previous year) in 2022 versus 2013 was 1.93 (95% CI: 1.74 to 2.16), indicating a significant increase in the reported uptake of a recent HCV test between these 2 years. When stratifying recent uptake of a HCV test by nation, the adjusted odds ratios were as follows:

• 1.90 (95% CI: 1.70 to 2.13) for England for 2022 versus 2013
• 1.05 (95% CI: 0.63 to 1.76) for Wales in 2022 versus 2013
• 3.88 (95% CI: 2.17 to 6.96) for Northern Ireland in 2022 versus 2013

This indicates a significant increase in uptake of a recent HCV test between 2013 to 2022 in England and Northern Ireland and no evidence in uptake of a recent HCV test in Wales between 2013 and 2022.

Among people who started injecting within the preceding 3 years, the adjusted odds ratio for ever uptake of a HCV test showed no evidence of significant change between 2013 and 2022 at 1.11 (95% CI: 0.70 to 1.75). However, among this group a significant increase in recent uptake of a HCV test over the same period was observed at 1.81 (95% CI: 1.18 to 2.76).

Among individuals reporting homelessness in the past year or current homelessness, the adjusted odds ratio for ever and recent uptake of a HCV test was 1.28 (95% CI: 1.00 to 1.62) and 1.84 (95% CI: 1.55 to 2.18) respectively, indicating no evidence for a change in ever uptake of a HCV test but a significant increase in uptake of a recent HCV test between 2013 and 2022.

The adjusted odds ratio for awareness of chronic HCV infection in 2022 versus 2017 was 0.42 (95% CI: 0.30 to 0.59), indicating a significant decrease in awareness when comparing both years.

k) Uptake of hepatitis C treatment

The adjusted odds ratio for reporting having seen a specialist nurse or doctor (hepatologist) for their HCV and been offered and accepted treatment (among those anti-HCV positive and aware of their infection) in 2022 versus 2013 was 7.71 (95% CI: 5.84 to 10.18), indicating a significant increase in the proportion of PWID reporting uptake of hepatitis C treatment in 2022.

l) Needle exchange use

The adjusted odds ratio for reporting ever using a needle exchange in 2022 versus 2013 was 0.39 (95% CI: 0.33 to 0.46), indicating a significant decrease in the proportion of PWID reporting needle exchange use between these 2 years. During 2022, when comparing the proportion ever using a needle exchange across nations with England as baseline, the adjusted odds ratios were 3.42 (95% CI: 1.49 to 7.87) for Wales and 2.80 (95% CI: 1.20 to 6.50) for Northern Ireland. This indicates significantly higher proportion of PWID ever accessing a needle exchange in Wales and Northern Ireland than in England during 2022.

m) Drug treatment uptake

The adjusted odds ratio for reporting current treatment for drug use in 2022 versus 2013 was 1.23 (95% CI: 1.09 to 1.39), indicating an increase in the proportion of participants currently being treated for drug use between these 2 years.

n) Direct sharing (sharing of needles and syringes)

The adjusted odds ratio for reported direct sharing of needles and syringes in 2022 versus 2013 was 1.38 (95% CI: 1.12 to 1.70), indicating an increase in direct sharing in 2022 compared to 2013. After adjusting for injecting in the past year, homelessness, and ever being in prison, in addition to gender, age and region, the increase in sharing of needles and syringes remained significant (adjusted odds ratio for 2022 versus 2013: 1.35 (95% CI: 1.09 to 1.67).

In 2022, the adjusted odds ratio for direct sharing was significantly lower among males compared to females, with an odds ratio of 0.57 (95% CI: 0.40 to 0.80).

Among those under 25 years and those aged 25 to 34, the adjusted odds ratio of direct sharing for the period 2022 versus 2013 was 0.97 (95% CI: 0.38 to 2.50) and 1.19 (95% CI: 0.79 to 1.79) respectively, indicating no evidence for a change in sharing among these age groups between these 2 years. Among those 35 years of age or older, the adjusted odds ratio of direct sharing was 1.37 (95% CI: 1.04 to 1.79) indicating that direct sharing among this age group was significantly higher in 2022 than in 2013.

Among those reporting current homelessness or homelessness in the past year, the adjusted odds ratio of direct sharing for 2013 versus 2022 was 1.36 (95% CI: 1.01 to 1.82), indicating an increase in direct sharing between these years in this group.

o) Direct and indirect sharing (sharing of needles, syringes, and other injecting equipment)

The adjusted odds ratio for direct and indirect sharing (sharing of needles, syringes, and other injecting equipment) in 2022 versus 2013 was 1.07 (95% CI: 0.91 to 1.26), indicating no evidence for a change in reported direct and indirect sharing in 2022 compared to 2013. After adjusting for injecting in the last year, homelessness, ever being in prison, gender, age, and region, sharing of needles, syringes and other injecting equipment showed no evidence of change in those years (adjusted odds ratio for 2022 versus 2013: 1.02 (95% CI: 0.86 to 1.20).

p) Missed hits

The adjusted odds ratio for missed hits in 2022 versus 2017 was 1.11 (95% CI: 0.99 to 1.24), indicating that there was no evidence for a change in the proportion of participants injecting in the last year reporting needing to insert the needle more than once before getting a ‘hit’.

q) Injecting into the groin

The adjusted odds ratio for reporting injecting into the groin in the past month in 2022 versus 2013 was 1.00 (95% CI: 0.85 to 1.18), indicating that there was no evidence for a change in the proportion of participants reporting injecting into their groin in the past month between these years.

r) Sex

The adjusted odds ratio for reporting sex in the past year in 2022 versus 2013 was 0.72 (95% CI: 0.64 to 0.80), indicating that reported sex in the past year among PWID was significantly lower in 2022 than in 2013.

s) Stimulant drugs injected during preceding month

The adjusted odds ratio for crack injection for 2022 versus 2013 was 2.19 (95% CI: 1.85 to 2.59), indicating that the proportion reporting crack injection in the preceding month was significantly higher in 2022 than in 2013. The adjusted odds ratio for reporting crack injection in 2022 versus 2018, when crack injection was at its highest, was 0.89 (95% CI: 0.74 to 1.05), indicating no evidence that the proportion reporting crack injection in the preceding month has changed between 2018 and 2022.

The adjusted odds ratio for cocaine injection for 2022 versus 2013 was 7.16 (95% CI: 5.61 to 9.14), indicating a significant increase in cocaine injection in the preceding month between these 2 years. In Northern Ireland, the adjusted odds ratio for cocaine injection for 2022 versus 2018 was 110 (95% CI: 12 to 1018), indicating a large and significant increase in cocaine injection in the country between these years.

The adjusted odds ratio for amphetamine injection in the preceding month for 2022 versus 2013 was 0.33 (95% CI: 0.25 to 0.42), indicating a significant decrease between these 2 years.

t) Overdose and naloxone among those who injected during the preceding year

The adjusted odds ratio for reported non-fatal overdose in the preceding year in 2022 versus 2013 was 1.87 (95% CI: 1.57 to 2.22), indicating that the proportion of PWID who injected in the past year reporting a non-fatal overdose was higher in 2022 than in 2013.

In the 25 years and under age group, the adjusted odds ratio for reporting a non-fatal overdose for 2022 versus 2013 was 2.10 (95% CI: 0.87 to 5.06) indicating no evidence of change in reporting a non-fatal overdose in the preceding year. The adjusted odds ratio for reporting a non-fatal overdose in 2022 versus 2013 amongst the 25 to 34 years age group and 35 years and older age groups were 1.95 (95% CI: 1.40 to 2.71) and 1.66 (95% CI: 1.34 to 2.06) respectively. This indicates a significant increase in reporting a non-fatal overdose in the preceding year for these age groups between these years.

In 2022, the adjusted odds ratio for reporting a non-fatal overdose in the past year was 1.41 (95% CI: 1.01 to 1.97) and 1.33 (95% CI: 0.90 to 1.95) for those previously prescribed drug treatment and never prescribed drug treatment respectively versus those currently prescribed drug treatment. This indicates that the proportion reporting non-fatal overdose in the past year was higher in those previously prescribed treatment than those currently prescribed drug treatment, but there was no evidence for any difference in reported overdose between those currently prescribed drug treatment versus those who have never been prescribed drug treatment.

The adjusted odds ratio for naloxone administration in 2022 versus 2013 was 1.72 (95% CI: 1.23 to 2.41), indicating that reported administration of naloxone after overdosing in the previous year was higher in 2022 than in 2013.

The adjusted odds ratio for naloxone carriage in 2022 versus 2017 was 1.77 (95% CI: 1.52 to 2.06), indicating that reported carriage of naloxone was higher in 2022 than in 2017.

Acknowledgements     

We would like to thank all the staff of collaborating drug services, Hepatitis C Trust Peer teams, and participants in the UAM survey of PWID.

Prepared by: Bennet Dugbazah, Holly Mitchell, Eleanor Clarke, Helen Dwyer, Jennifer Gunther, Lababa Hasan, Ross Harris, Samreen Ijaz, Debbie Mou, Sarah Murdoch, Jacquelyn Njoroge, John Poh, Rachel Roche, Justin Shute, Monica Desai

Suggested citation

UKHSA. UAM survey of HIV and viral hepatitis among PWID, data to end of 2022. London: UKHSA, January 2024.