Background: While Directly Acting Antivirals (DAA) can clear HCV in nearly all HIV/HCV co-infected individuals, high rates of reinfection may hamper efforts to eliminate HCV in this population. This analysis aimed to examine reinfection after achieving sustained virologic response (SVR) in HIV/HCV co-infected individuals in Europe.
Methods: Individuals from EuroSIDA that achieved SVR 12 or 24, with ≥24 months follow-up and ≥1 HCV-RNA test after SVR were included. Factors associated with the odds of reinfection were assessed using multivariable logistic regression.
Results: Overall, 675 individuals were included. The median age was 45.9 (IQR 39.8-51.5 years), 78.4% were male, 48.7% were IDUs, 30.2% were MSM, and the majority received an interferon-based regimen (610, 90.4%). Overall, 89 (13.2%, 95% confidence interval (CI) 10.6%-15.7%) individuals were re-infected by 24 months. Central-East Europe had the highest proportion of reinfections (20.0%), while Southern Europe had the lowest (8.0%; p=0.0097). Reinfections in MSM were 14.2%, similar to IDUs (13.5%; p=0.67). After adjustment, Central-West and Central-East Europe had higher odds of reinfection (compared to Southern Europe; Figure 1), as did those with CD4 count >500 cells/mm3. Those who achieved SVR ≥2014 had lower odds of reinfection There was no statistically significant association between age, gender, prior use of treatment, use of DAAs and reinfection, although all had wide confidence intervals.
Conclusions: The proportion of reinfections among HIV/HCV co-infected individuals within 24 months of achieving SVR was 13%, with evidence suggesting this is decreasing over time. We cannot rule out that some late relapses could have been misclassified as reinfection, though this is unlikely, and that clinics have targeted testing to those at highest risk or with signs of reinfection. Active surveillance to detect early HCV reinfection with an offer of early treatment is essential as is harm reduction in those treated to reduce rates of reinfection.

Figure 1
[Figure 1]