Reinfection in a large cohort of prison inmates with sustained virological response after treatment of chronic hepatitis C in Catalonia (Spain), 2002–2016

Abstract

Background

Prisoners and other high-risk patients who show a sustained virological response (SVR) after treatment for hepatitis C virus (HCV) can become reinfected. We aimed to calculate the rate of HCV reinfection in a large cohort of inmates with SVR and to determine factors that predict reinfection.

Methods

We included all inmates treated for hepatitis C in Catalonia (Spain) from January 2002 to December 2016 who achieved SVR and in whom viral load was subsequently determined. The incidence rate was calculated per 100 person-years (100 py) of follow up. Risk factors associated with reinfection were evaluated by bivariate log-rank test and multivariate Cox regression. Hazard ratio (HR) and their 95% confidence intervals (CI) were calculated.

Results

602 patients were included, with a mean age of 37.9 years: 95% were men, 74.1% had a history of intravenous drug use (IDU) and 28.7% were HIV-infected. Patients were followed for a total of 2154.9 years (average 3.58 ± 3.1 years). 63 (10.5%) had HCV reinfection. 41 (65.1%) presented different genotype/subgenotype, 8 the initial genotype/subgenotype, and in 14 (22.2%) the genotype could not be determined. Of the 21 reinfected patients who were interviewed, 20 (95.2%) reported IDU after antiviral treatment, and 7 (33.3%) during treatment. The overall incidence of reinfection was 2.9 cases per 100 py. All reinfections occurred in patients with IDU history. At multivariate level, HIV infection was associated with reinfection (HR = 3.03; CI:1.82-5.04).

Conclusion

In HIV-infected inmates with IDU history, the rate of reinfection of HCV post-SVR is very high. Prisons play a key role in the detection and treatment of infection and reinfection by HCV and in the post-treatment monitoring in these patients, which should be combined with counseling and the optimization of the harm reduction programs. Effective control of these vulnerable groups favours the elimination of the HCV infection.

Introduction

In recent years, the emergence and development of direct-acting antivirals (DAA), which act at various steps of the viral replication cycle, has revolutionized the treatment of chronic hepatitis C. Currently, the probability of achieving cure with the available DAA combinations is 95–100% in most scenarios. These drugs are characterized by their high efficacy, their good safety profile and their short period of administration, and are therefore enormously attractive for clinicians and patients. If their economic cost continues to fall, the use of DAA may spread to countries with more limited economic resources, and the challenge of eliminating HCV infection in the short or medium term may no longer seem unattainable. However, this goal may be difficult to achieve in certain patients with high risk of reinfection such as people who inject drugs (PWID), patients coinfected with HIV, men who have sex with men, and prison inmates.

In general, the studies which have tried to establish the true incidence of HCV reinfection have been limited by the sample size, the short follow-up time, and by the low number of cases of reinfection detected. An exception is the study of Islam et al. (2017), from the British Columbia Center for Disease Control Public Health Laboratory, which included more than 5000 patients with an incidence rate of 1.27 per 100 person/years. However, studies of prison inmates are few and far between (Bate, Colman, Frost, Shaw, & Harley, 2010; Marco et al., 2013), probably due to the difficulty of accessing treatment in some countries (Beckman et al., 2016; Webster, 2015) and also due to the loss of follow-up caused by transfers between prisons, release from prison, and so on.

Catalonia (an autonomous community in Spain) has 11 prisons with a total of 13,868 inmates/year. Prison policy, including the provision of health resources, is the responsibility of the autonomous government. Among prison inmates in Catalonia the prevalence of HCV infection is 8.2% (Direcció General de Serveis Penitenciaris, 2018) and most infected patients have a history of intravenous drug use (IDU) and/or HIV infection. In a study carried out by the Centre for Epidemiological Studies on HIV/AIDS and STIs in Catalonia, some 70% of PWID had been in prison at some point, and 35.3% of Spanish PWID and 16.5% of foreign PWID reported injecting drugs in prison (Folch et al., 2016). Besides, the persistence of high-risk behaviors among PWID during leave from prison or after release is well known, and favours HCV infection and transmission both inside the prison and in the community. All inmates have the same access to treatment as the general population, and the same efficacy is obtained (Marco et al., 2018). The majority of inmates are still in prison after sustained virological response (SVR) or have re-entered prison: for example, in 2017, 54.8% of inmates were serving at least their second term. In Catalonia, universal screening for HCV infection is performed upon prison admission. All these circumstances argue in favour of periodically determining HCV-RNA in inmates at risk of reinfection such as patients with a history of IDU, and also when they re-enter prison. The objective of our study is to determine the incidence rate and predictive factors of HCV reinfection in a large cohort of inmates with SVR after antiviral treatment.