HCV antiviral therapy in injection drug users: difficult to treat or easy to cure?

Telemedicine Improves HCV Elimination among Italian People Who Use Drugs: An Innovative Therapeutic Model to Increase the Adherence to Treatment into Addiction Care Centers Evaluated before and during the COVID-19 Pandemic

People who use drugs (PWUDs) are generally considered "hard-to-treat" patients, due to adherence to HCV antiviral therapy or re-infection concerns. Linkage-to-care still remains a significant gap for HCV elimination, worsened by the COVID-19 pandemic. To reduce time-to-treat and improve treatment adherence, we have developed a patient-tailored model-of-care, decentralized within the addiction center and supervised remotely by hepatologists. From January 2017 to December 2020, patients were enrolled in one addiction care center in Southern Italy, where a complete hepatologic assessment, including blood chemistry, ultrasound, and transient elastography examination, was provided. DAAs treatment has been adapted on clinical features, also performing a daily administration during an outpatient visit, and monitored remotely by specialists via telemedicine interactions. Adherence was evaluated on the accomplishment of therapy or on the percentage of attended visits. From a total of 690 PWUDs, 135 had an active HCV infection and were enrolled in the study. All patients started the treatment within 3 weeks after HCV diagnosis. Six drop-outs were recorded, obtaining a sustained virological response at week 12 (SVR12) in 98.5% of PWUDs. There were only two cases of treatment failure, one of which is re-infection. No differences were found between the SVR12 rates before and during the COVID-19 pandemic. We obtained a high SVR12 rate, providing a comprehensive assessment within the addiction care center, tailoring the drug administration with a hepatologic remote stewardship. Our therapeutic model should improve the time-to-treat and treatment adherence in PWUDs.

Evolutionary characteristics and immune mutation of hepatitis C virus genotype 1b among intravenous drug users in mainland, China

China is one of the countries with the heaviest burden of hepatitis C virus (HCV) worldwide, especially subtype 1b. To better control hepatitis C, insights into the characteristics of dynamic spread and genomic mutations are urgently needed. We retrieved sequences of HCV-1b NS5B among intravenous drug users (IDUs) and general people (Non-IDUs) in China from 2000 to 2011 in NCBI. Bayesian phylogenetic and phylogeographic analyses were used to evaluate the transmission dynamics of HCV-1b. Non-synonymous substitutions were detected to illustrate immune adaptation. Evolutionary history demonstrated that HCV-1b effective population size experienced a sharp increase in 1990. HCV-1b sequences among IDUs had a higher estimated evolutionary rate (5.7185 × 10^-3  substitutions/site/year) than overall (7.7332 × 10^-4 ). 105/136 (77.2%) of HCV-1b sequences clustered into 38 networks. The average non-synonymous HCV-1b immune epitopes among IDUs were 0.211, higher than non-IDUs, especially in the HLA-A*02 molecular recognition region. All of these posed significant challenges for the prevention and treatment of HCV. Heterogeneity and genetic linkages of HCV-1b suggest that evolutionary surveillance of HCV in cities in east-central China and among IDUs could not be neglected.

HCV prevalence and risk behaviours among injectors of new psychoactive substances in a risk environment in Hungary-An expanding public health burden

BACKGROUND

In Hungary a large increase in injecting new psychoactive substances (NPS) coincided with decreasing harm reduction efforts and rising HCV infection. We describe these, and assess changes in HCV prevalence and risk behaviours, 2011-2014, among NPS injectors, using 2011-2015 syringe exchange programme (SEP) data as a key contextual ('risk environment') variable.

METHODS

We conducted repeated national sero-behavioural surveys in people who inject drugs (PWID) injecting in the last month and attending SEPs or drug treatment centres (n=399, 2011; 384, 2014), using face-to-face interviews and dried blood-spot samples. Prevalence of injected drugs and SEP coverage (2011-2015) were assessed through our national SEP monitoring system and using population size estimates.

RESULTS

NPS injecting tripled among PWID attending SEPs in Hungary (2011: 26%; 2015: 80%). Among NPS injectors, HCV prevalence, sharing syringes and sharing any injecting equipment (last month), doubled (2011-2014: 37%-74%, 20%-48%, 42%-71%, respectively), significantly exceeding prevalence in other PWID groups. Among young NPS injectors (aged<25), HCV prevalence increased 7-fold (12%-76%), among new injectors (injecting<2years) 4-fold (13%-42%), coupled with high levels of equipment sharing (79% and 72% respectively). Not using a condom at last intercourse (79%), ever-imprisonment (65%) and last-year homelessness (57%) were highly prevalent among NPS injectors (2014). The number of syringes distributed per estimated PWID nationally fell from 114 to 81 (2011-2014) and dropped to 28 in 2015.

CONCLUSION

NPS injectors in Hungary are at severe risk of blood-borne infections due to high levels of injecting and sexual risk behaviours within a high-risk environment, including continuously low SEP provision, imprisonment and homelessness. An HIV outbreak cannot be excluded. Stronger investment in evidence-based prevention measures, with special focus on young and new injectors, and expansion of hepatitis C treatment are urgently needed.