Results of a modeling study showed that in dense urban settings with high prevalence of hepatitis C among people who inject drugs, HCV treatment-as-prevention strategies will have little impact over 10 years unless coverage is greatly expanded.
“With the availability of more tolerable and eective direct-acting antivirals, HCV treatment-as-prevention strategies could substantially curtail HCV transmission and reduce the burden of HCV,” Alexei Zelenev, PhD, from the Yale School of Medicine in Connecticut, and colleagues wrote. “Completely eliminating HCV ... will require a strategic combination of prevention (eg, harm reduction) and treatment-as-prevention strategies, including the expansion of HCV treatment into dierent clinical care settings.”
The study design included a network model that evolved from an empirically-based risk network of PWIDs and a transmission model that captured the process of HCV and HIV transmission among individuals who shared injection equipment.
The model showed that at the highest HCV prevalence among PWIDs (85%), expanded treatment coverage will not substantially reduce HCV prevalence over 10 years or 20 years for any of the following treatment-as-prevention strategies: random patient selection regardless of available primary contacts, chain treatment from random patient to referrals, or targeting highest number of injection partners regardless of available primary contacts.
However, if baseline HCV prevalence among PWIDs reached 60%, strategies that treat more than 120 individuals per 1,000 PWIDs per year would likely eliminate HCV within 10 years. Additionally, if HCV prevalence was 30%, HCV could be eliminated with a lower coverage of 60 individuals per 1,000 PWIDs.
If HCV treatment coverage was expanded, Zelenev and colleagues found that strategies in which treatment is assigned to a randomly chosen PWID and their primary contacts performed better than strategies that target individuals with the highest number of injection partners.
“Treating highest degree first (ie, those with whom an individual directly injects with) might appear useful, because it could reduce HCV prevalence; however, the high rates of HCV re-infection render this strategy ineective, unless treatment coverage is near universal,” the researchers wrote. “Strategies that include random allocation across individuals and incorporate treatment of members of the injection network perform better than do strategies that focus solely on the individual.” – by Talitha Bennett
Disclosure: Zelenev reports no relevant financial disclosures. Please see the full study for the other authors’ relevant financial disclosures.