HCV reinfection rates among people who use drugs

Key take-home messages

• HCV affects people differently. Some are able to spontaneously clear the virus on their own; others develop chronic HCV infection that affects their health and requires treatment.
• There appears to be no major difference in reinfection rates among people who have been treated successfully — that is, achieved a sustained viral response (SVR) (i.e. undetectable HCV RNA for at least 24 weeks after treatment is complete) — and those who clear HCV spontaneously.
• Studies report contradictory results about HCV reinfection rates among people who use drugs. The only available pooled estimate of HCV reinfection risk among people who use drugs seems to be low: 2.4 (95% CI 0.9–6.1) per 100 person-years (6). However, in communities with higher HCV prevalence, people who inject drugs and who have been treated for HCV appear to be at higher risk for reinfection (7). HCV reinfection incidence may be higher in young (<30 years) people who inject drugs.
• In general, people who use drugs who have been treated for HCV have only been followed for 2–5 years. Further studies on the risk of reinfection are needed to assess the long-term effectiveness of HCV treatment in this population.
• HCV reinfection does not always lead to persistent infection. Spontaneous clearance of HCV has been frequently recorded and data suggest that some individuals can clear HCV after one exposure more efficiently than others. Overall, clearance of the reinfection strain is relatively common, with some individuals able to spontaneously clear HCV with different genotypes from that of the initial infection.
• None of the identified studies investigated HCV reinfection attributed to non-drug-using behaviours.

• Population(s)
  • People who use drugs
• Co-infections
  • Hepatitis B, C