The hepatitis C care cascade in California state prisons: Screening and treatment scale-up and progress toward elimination, 2016–2023

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INTRODUCTION

California Correctional Health Care Services (CCHCS) is the state agency that provides medical care to adult residents of California Department of Corrections and Rehabilitation (CDCR) state prisons. As of September 2023, 25% (23,904) of nearly 95,000 residents in 33 prisons had a history of HCV (Ab-positive), of whom 17% (3924; 4% of all residents) with viremia (RNA detected indicating current infection) were at risk of developing liver disease, HCC, and transmission to others.

In 2016, CCHCS integrated universal opt-out HCV screening into the intake health assessment for new arrivals at all 6 prison reception centers. In 2018, CCHCS conducted outreach to unscreened residents in 35 prisons statewide to increase the proportion aware of their HCV status and provide linkage to care. This effort coincided with additional state funding in fiscal year (FY) July 2018 to June 2019 to rapidly expand HCV treatment with direct-acting antivirals.

To facilitate HCV treatment scale-up during the first year, CCHCS transitioned from a central team model to a hub and spoke model where prison-based primary care teams coordinated screening, pretreatment workup, and treatment monitoring for most patients (Figure 1). HCV medications [ledipasvir-sofosbuvir (Harvoni), elbasvir-grazoprevir (Zepatier), sofosbuvir-velpatasvir (Epclusa), glecaprevir-pibrentasvir (Mavyret), sofosbuvir-velpatasvir-voxilaprevir (Vosevi)] were administered with directly observed therapy. Patients were routinely scheduled for primary care monitoring visits at 4, 6, and 12 weeks after treatment initiation. HCV RNA testing was provided at 4 weeks into treatment and 12 weeks post-treatment to determine sustained virologic response (SVR). The central team continued to provide clinical consultation and manage complex patients including those with compensated and decompensated cirrhosis, HIV and HBV co-infection, prior HCV treatment failures, and reinfections.

FIGURE 1.

Timeline of HCV screening, care, and treatment models, California Correctional Health Care Services, 2016–2023. ^*Fiscal year (July 2018 to June 2019) initiated funding to support rapid scale-up of HCV treatment. ^†High-risk patients annually offered HCV-Ab screening or RNA retesting: history of HCV infection (successfully treated or naturally cleared), substance or alcohol use disorder, and drug overdose. ^‡Complex care HCV patients include those with compensated and decompensated cirrhosis, HCC, liver transplantation, serious extrahepatic manifestations of HCV, HIV, and hepatitis B co-infection; prior HCV treatment failures; and reinfections. ^§Direct-acting antiviral HCV medications administered by directly observed therapy. ^¶HCV treatment inclusion criteria: Advanced fibrosis or advanced liver disease eligible for treatment: FIB4 1.45–3.25: Fibrosis Stage 2 and FibroScan >7 and <9.5 (if done) and HIV-positive; Fibrosis Stage 2-3 and FibroScan ≥9.5 (if done); FIB4 ≥3.25: Fibrosis stage 4 and FibroScan ≥12 (if done) with compensated cirrhosis; decompensated cirrhosis in consultation with hepatologist. Defer treatment and assess annually: FIB4 <1.45: Fibrosis stage 0 to 1 and FibroScan ≤7 (if done); Fibrosis Stage 2 and FibroScan 7–9.5 (if done) and HIV-negative). HCV treatment exclusion criteria: expected to be released from prison before the pretreatment workup and course of treatment can be completed (5 months for noncirrhotic patients, 8 months for decompensated cirrhosis); life expectancy <12 months that cannot be remediated by HCV treatment, liver transplantation, or by other directed therapy. Abbreviations: FIB4, Fibrosis-4 index for liver fibrosis; PCP, primary care physician; RC, reception center.

There are limited data from carceral settings describing HCV treatment scale-up and outcomes in the direct-acting antiviral era.^1–7 This report examines HCV screening and the care cascade among California state prison residents who initiated treatment in the first year of program scale-up, including treatment completion, SVR, reinfection, and progress toward HCV microelimination.

EVALUATING THE HCV CARE CASCADE

CCHCS HCV laboratory and treatment data available in the electronic health record for CDCR residents were analyzed to meet 4 program evaluation objectives.

First, to assess HCV screening and test positivity rates at entry, individuals who entered a prison reception center during FY 2018-2019 were matched with HCV-Ab and reflexed RNA tests (ie, automatically performed on residual Ab-positive specimens) collected within 2 weeks of entry.

Second, to assess the impact of HCV screening of the general prison population, 2 analyses were conducted. The proportions of unscreened residents were compared before (October 2018) and after (June 2019) the intervention. HCV screening rates and prevalence of any HCV history (Ab-positive) and viremia (RNA detected) were calculated for a cohort of previously unscreened residents on October 1, 2018, who were followed for 1 year while incarcerated.

Third, to assess the HCV care cascade, a retrospective cohort study was conducted including prison residents who were eligible for treatment (positive RNA with ≥5 months of incarceration remaining) on July 1, 2018, and initiated treatment within 1 year. Rates of HCV treatment completion, timely RNA testing (77–98 days post-treatment) for SVR, and reinfection among individuals incarcerated for ≥14 weeks post-treatment were estimated. HCV reinfections (RNA detected after SVR) per 100 person-years (PY) follow-up while incarcerated were calculated. Follow-up end points were reinfection, release from CDCR, or study end (October 17, 2020).

Fourth, to assess the impact of HCV treatment scale-up toward microelimination, we compared the proportions of residents with viremia before and after FY 2018-2019.

HCV screening

During FY 2018-2019, 32,365 (93.6%) of 35,594 individuals who entered a reception center in 6 prisons were screened for HCV within 2 weeks of entry; 5705 (17.6%) were HCV-Ab positive, of whom 4127 (72.3%) had viremia. Among individuals screened within 2 weeks of entry, 12.8% (4127/32,365) with HCV viremia were all eligible for treatment.

From October 2018 through June 2019, HCV screening offered to previously unscreened residents in all 35 prisons decreased the proportion with unknown status from 10.5% (12,889/122,549) to 3.3% (4,043/121,508). Among 11,638 previously unscreened residents identified at the start of the intervention who remained incarcerated for ≥1 year, 8612 (74.0%) were screened for HCV; 735 (8.5%; 6.3% of previously unscreened) screened Ab-positive, of whom 540 (73.5%) were newly diagnosed with viremia.

HCV care cascade

Of 15,320 prison residents with HCV viremia eligible for treatment on July 1, 2018, 6147 (40.0%) initiated treatment within 1 year. Of 5731 residents who remained incarcerated for ≥14 weeks post-treatment, 5501 (96.0%) completed treatment, 3937 (71.6% of 5,501) had an SVR RNA collected, 3736 (94.9% of 3,937) achieved SVR (Figure 2). Among 3736 residents with SVR, 1909 (51.1%) were subsequently retested during the same incarceration; 378 (10.1% overall; 19.8% among those retested) had reinfection. HCV reinfections per 100 PY follow-up ranged from 6.7 (378/5608 PY) among all who achieved SVR to 24.2 (378/1565 PY) among retested individuals.

FIGURE 2.

HCV care cascade among California state prison residents who were eligible for treatment on July 1, 2018, initiated treatment within 1 year and were followed while incarcerated for at least 14 weeks post-treatment. Abbreviation: SVR, sustained virologic response.

Overall, during the first year of HCV treatment scale-up (FY 2018-2019), 7622 residents initiated treatment. The prevalence of HCV viremia among all residents (including unscreened) at mid-year decreased from 14.0% (17,089/122,334) in 2018 to 11.5% (13,952/121,575) in 2019, 1 year after treatment scale-up (Figure 3).

FIGURE 3.

Number and proportion of California state prison residents with a history of HCV infection (HCV-antibody positive) and current HCV infection (HCV RNA detected), mid-year, 2018–2023.

DISCUSSION

CCHCS achieved high rates of HCV screening, treatment, and SVR during the first year (July 1, 2018, to June 30, 2019) of treatment scale-up in California state prisons. Screening upon prison entry combined with targeted screening for existing residents resulted in nearly all residents becoming aware of their HCV status, allowing earlier linkage to care. Rapid HCV treatment scale-up led to 40% of residents with viremia starting treatment and reduced the prevalence of HCV viremia across prisons statewide by 18% (14.0%–11.5%) within the first year. However, an estimated 10%–20% of those with documented post-treatment SVR were reinfected, similar to limited published data in carceral settings.^5–8

This cohort study has several limitations. The SVR rate may be under or overestimated given nearly one-third of treated residents did not have timely HCV RNA testing. HCV reinfection rates are not directly comparable due to a lack of systematic RNA testing after SVR, follow-up time variability, and differences in the underlying prevalence of viremia and risk factors across carceral systems. Given HCV RNA retesting was not routinely done earlier in CCHCS’ program expansion, individuals at higher risk may have sought or had provider-recommended retesting, leading to overestimation of the reinfection rate or conversely avoided retesting, leading to underestimation. Finally, the reinfection rate may be inflated due to the shorter follow-up, given that people who continue risk behavior are likely to be reinfected earlier.

In 2020, to address the underlying cause of new HCV infections and reinfections, CCHCS began rapid scale-up of substance use disorder (SUD) screening and treatment for state prison residents, including medication for opioid use disorder and cognitive behavioral interventions. As of September 2023, among approximately 96,000 residents, over 94,000 had been screened for SUD, 37,000 were assessed for treatment needs, and 16,000 were receiving medication for opioid use disorder.

Also, in 2020, CCHCS further decentralized HCV treatment by integrating care delivery between primary care teams and nurses who coordinate pretreatment workup, treatment monitoring, SVR RNA testing, and provide risk-reduction counseling during each visit (Figure 1). Since 2020, CCHCS has primarily treated HCV with sofosbuvir-velpatasvir (Epclusa) with directly observed therapy (other medications available when clinically indicated). Primary care monitoring visits are scheduled at 4 weeks into treatment for treatment-naive patients with and at 2, 4 (with RNA testing), 8, and 12 weeks for treatment-experienced patients (with or without cirrhosis). CCHCS continuously improves HCV care services by maintaining up-to-date clinical guidance for providers consistent with the American Association for the Study of Liver Diseases guidelines.⁹ Beginning in 2019 through 2022, CCHCS developed or significantly updated decision support tools for program managers and care teams, including a HCV patient registry and internal and public HCV dashboards to measure progress toward goals for timely treatment (within 180 days of diagnosis), timely SVR RNA testing (12-week post-treatment), annual RNA retesting for individuals with cleared/cured infections, annual screening for individuals at higher risk for infection, and linkages between the HCV and SUD treatment programs.¹⁰

Since the start of HCV treatment scale-up (July 1, 2018), 28,275 residents have initiated treatment, steadily reducing the prevalence of viremia by 71% (14.0%–4.1%). About 84% of residents with any HCV history (25% of the total population) either naturally cleared their infection or were treated with SVR, demonstrating program sustainability and progress toward the World Health Organization goal of treating 80% of currently infected individuals by 2030.¹¹

Providers serving high-risk patients, including people who are incarcerated or who inject drugs, should expect to see higher rates of HCV reinfection, at least initially, as screening and treatment programs are expanded. This is due to the increased numbers treated with documented SVR and the higher baseline prevalence of HCV viremia and ongoing risk, especially in carceral settings with limited access to harm reduction strategies such as addiction services and syringe services programs. Declining infection and reinfection rates are anticipated as HCV prevalence is reduced in California state prisons with increased access to HCV and SUD screening and treatment. However, the impact of these programs could be improved with access to harm reduction strategies aimed at primary prevention for people who use or inject drugs.

CONFLICTS OF INTEREST

The authors have no conflicts to report.