What is the impact of a Hepatitis C ‘test, trace and treat’ pilot using peer workers?

Chronic Hepatitis C virus (HCV) infection is a major cause of morbidity and deaths worldwide. HCV treating teams are working toward the goal of eliminating HCV by 2030. People who inject drugs (PWIDs) are at high risk of HCV but contact tracing is not routine practice. Here, we present the outcomes of a HCV ‘test, trace and treat’ pilot using peer workers to test contacts of individuals with HCV. PWIDs with HCV were invited to participate when they presented for treatment. For those agreeing to participate, a peer approached them to invite potential contacts for HCV testing. Data were collected on uptake, HCV test results, treatment rates and reasons for declining. Overall, 295 individuals (162 recent HCV [<1 year], 69 reinfections, 64 known chronic HCV) were invited to participate, of whom 147 (50%) agreed and 30 (20% of those agreeing) brought forward 120 contacts for testing. Of these, 44 (37%) were HCV RNA positive, including 23 who were not known to services. 34 (77%) started antiviral treatment. HCV RNA positivity was highest in contacts of reinfections (45%) compared with recent HCV (33%) and known chronic HCV (25%). The most common reason for index individuals declining participation was that they reported no longer being in contact with individuals from their injecting network (65%). In conclusion, half of PWIDs with HCV agreed to participate in the pilot, but only 20% of these brought contacts forward. The frequency of active HCV was high in the contacts and the majority started antiviral treatment.

participate when they presented for treatment.For those agreeing to participate, a peer approached them to invite potential contacts for HCV testing.Data were collected on uptake, HCV test results, treatment rates and reasons for declining.Overall, 295 individuals (162 recent HCV [<1 year], 69 reinfections, 64 known chronic HCV) were invited to participate, of whom 147 (50%) agreed and 30 (20% of those agreeing) brought forward 120 contacts for testing.Of these, 44 (37%) were HCV RNA positive, including 23 who were not known to services.34 (77%) started antiviral treatment.HCV RNA positivity was highest in contacts of reinfections (45%) compared with recent HCV (33%) and known chronic HCV (25%).The most common reason for index individuals declining participation was that they reported no longer being in contact with individuals from their injecting network (65%).In conclusion, half of PWIDs with HCV agreed to participate in the pilot, but only 20% of these brought contacts forward.The frequency of active HCV was high in the contacts and the majority started antiviral treatment.

K E Y W O R D S
contact tracing, direct acting antiviral treatment, harm minimisation, injecting drug use, people who inject drugs, reinfection Abbreviations: HCV, Hepatitis C virus infection; PWIDs, People who inject drugs; DAA, direct acting antiviral drugs; WHO, World Health Organization; Ab, antibody; RNA, Ribonucleic acid; HBsAg, hepatitis B surface antigen; HIV, Human immunodeficiency virus; NHS, National Health Service.
90% of prevalent cases and treatment of more than 80% of identified infections. 1 In England, more than 70,000 individuals with HCV have had antiviral treatment since 2015 and its prevalence is falling. 3spite this progress, reinfection with HCV is common among people who inject drugs (PWIDs).In North-East England, we have observed an overall HCV reinfection rate of 10.5 per 100 person years among individuals treated 2016-2021. 4Reducing HCV reinfection is vital to achieve elimination.
Contact tracing, a tool successfully used to identify and treat cases in other infectious diseases, is not routine practice in HCV, but this approach has been suggested as an important intervention in the attempt to achieve elimination. 5A previous small study showed that it was feasible to use a peer-based intervention to recruit PWIDs into HCV testing and treatment from social networks. 6reover, modelling studies show that use of a 'bring a friend' model with contact tracing in social networks, coupled with antiviral treatment, would be an efficient testing strategy to reduce HCV prevalence and maintain micro-elimination in PWIDs. 7,8r aim was therefore to evaluate outcomes of a 'real world' peer-based HCV 'test, trace and treat' pilot among PWIDs with HCV in North-East England.Specific aims were (1) to assess the proportion of index individuals who engaged with the programme and brought forward contacts for testing, (2) to determine HCV antibody (Ab) and HCV ribonucleic acid (RNA) positivity rate among contacts and (3) to assess the rate of antiviral treatment initiation for those contacts with active HCV.

| ME THODS
PWIDs with HCV were identified from our regional multidisciplinary meeting where all cases of HCV from North-East England are discussed.Eligible individuals (currently injecting or injected within the last 6 months) were invited to participate when they presented to our service for treatment.The programme was discussed with the index individual during their appointment with a specialist nurse.For those index individuals who agreed to participate, consent was obtained for them to be contacted by a Hepatitis C Trust peer worker who asked them to invite potential contacts for HCV testing, which was subsequently conducted in the community using dry blood spot testing for HCV Ab, HCV RNA, HBsAg and HIV.Incentives (vouchers for a food outlet) were given to index individuals and contacts upon HCV testing to compensate them for their time.
Data were collected on engagement of index individuals and the number of contacts tested, HCV test results, treatment rates and outcomes, and reasons for declining participation by the index individuals.Our regional HCV Database, HepCare, was interrogated to determine if HCV RNA positive contacts were known to services or were not previously known to have HCV.'Recent infection' was defined as HCV suspected of being acquired within the last year.
'Reinfection' was defined as having previous antiviral treatment with sustained virological response and subsequent viraemia, and 'known chronic' were infections of greater than 1 year duration.

| RE SULTS
Between April 2022 and April 2023 (13 months), 295 individuals were invited to participate, including 162 (55%) with suspected recent HCV, 69 (23%) with reinfection and 64 (22%) with known chronic HCV.The overall outcomes of the pilot are summarised in Figure 1.One hundred and forty-seven individuals (50%) agreed to being approached by a peer worker and 55 (19%) were successfully contacted.In total, 30 (10% of all, 20% of those agreeing) index individuals brought forward 120 contacts (range 1 to 25 contacts per index case) for testing.Details of the number of contacts tested and their HCV blood results for each index case is shown in Table S1.
To date, 34 (77%) have started antiviral treatment.Of those not treated, three spontaneously cleared the infection, one was deceased, one declined treatment, two are still in workup for treatment and three persistently missed appointments.
The most common reason for index individuals declining participation was that they reported no longer being in contact with individuals from their injecting network (65%; Figure 1).

| DISCUSS ION
In North-East England, we have observed a high rate of HCV reinfection following DAA treatment. 4This has been seen despite an active regional HCV testing and treatment programme in all the addiction services, prisons and other community sites such as pharmacies and homeless hostels.This suggests there is a significant burden of untreated infection in the community among individuals who may not be in contact with services-the 'hidden' HCV infections.To try and address this, we implemented a pilot of a 'test, trace and treat' programme using peer workers to offer testing to contacts of individuals with HCV.Overall, 50% of individuals agreed to take part in the programme and 19% (37% of those agreeing) were successfully contacted by a peer worker who asked them to bring forward potential contacts from their injecting network for HCV testing.In total, 30 (10% overall, 20% of those agreeing) index individuals brought 120 contacts forward for testing and of these 37% had active HCV.About half of those with HCV viraemia were 'new', indicating that the programme was successful in accessing individuals not known to services.Probably not surprisingly, rates of HCV viraemia were higher among contacts of index cases with reinfection than those with recent infection or known chronic infection.This emphasises the importance of targeting those with HCV reinfection for contact tracing, as well as ensuring they are provided with good harm minimisation advice to reduce risk of onward transmission.
As part of this work, we explored reasons for index individuals not wanting to participate, and approximately two-thirds reported that they were no longer in contact with their injecting network.
Fears of personal safety and stigma, which have previously been identified as potential barriers to a contact tracing approach, 5 were uncommon (11% and 6%, respectively).Work is ongoing to refine the pathway to increase uptake.
A previous study from the USA using a similar peer-based model found a higher rate of initial engagement than we achieved with 17 of 36 (47%) primary index cases recruiting at least one network member for testing. 6Our approach appeared less targeted in that all PWIDs attending our service were invited to participate, which may be an explanation for the lower engagement seen.However, the proportion HCV RNA individuals starting DAA treatment was higher in our pilot than their study (77% vs. 20%).The strong support provided by the peers and nurses through the treatment pathway in our pilot may be one explanation for the high rate of treatment initiation.
Differences in engagement with the programme and treatment initiation rates may also reflect differences in the healthcare systems.
Efficient use of HCV testing will be critical as services get closer to elimination to maximise identification of viraemic individuals.A recent modelling study using data from a well-characterised injecting network in Southampton, UK, showed that a network 'bring a friend' testing approach with contact tracing would be more efficient than traditional approaches in maintaining HCV elimination. 7Therefore, expansion of the peer-based 'test, trace and treat' model is likely to be an effective approach if used more widely, particularly since we observed such a high rate of HCV viraemia among the contacts.
In conclusion, a peer-based HCV 'test, treat and trace' approach for contacts of PWIDs yielded a high frequency of previously undiagnosed HCV infection and the majority of those with active HCV were initiated on DAA treatment.However, overall engagement by index individuals was relatively low, with the major reason for nonparticipation cited as no longer being in contact with their injecting network, and further work is needed to refine this approach.The Individuals with active HCV were offered treatment with DAAs as per National Health Service (NHS) England recommendations.The peer workers supported individuals with active HCV through their assessment and treatment.Detailed harm minimisation advice was given to all index cases and contacts.This service improvement project was funded by NHS England and registered with the Newcastle upon Tyne Hospitals NHS Foundation Trust Clinical Governance Department(Ref No. 14589).
peer-based 'test, treat and trace' model may become an important addition to the portfolio of interventions to achieve and maintain HCV elimination.F I G U R E 1 Overall outcomes of the peer-based HCV 'Test, Trace and Treat' programme.