Injection drug users represent the largest cohort of patients with established hepatitis C virus infection.
The group is also at highest risk for new infections.
Most published studies have focused on the clinical consequences of established hepatitis C infection and have not examined the consequences of new infection.
Dr Dove and colleagues measured the virological consequences of hepatitis C in patients with ongoing injection drug use.
The researchers assessed whether the virological consequences might pose a risk for new and/or for superinfection with additional strains of hepatitis C.
The research team examined 3 groups.
|None of 6 patients with resolved infection had detectable hepatitis C RNA at 1 year |
|Journal of Viral Hepatitis|
Group 1 included those with resolved hepatitis C infection with ongoing injection drug use and Group 2 were those with chronic infection who continued to inject.
The team included those with chronic infection who no longer injected in Group 3.
The researchers' study demonstrated a spectrum of responses.
The team found that the majority of patients appeared to be 'protected' from new infection.
None of 6 patients with resolved infection had detectable hepatitis C RNA by quantitative or qualitative polymerase chain reaction when followed for 1 year.
Similarly, the researchers noted that despite ongoing injection drug use, no patient with persistent infection had a 'switch' in hepatitis C genotype.
There was no indication of possible superinfection.
Virological analysis of hepatitis C quasispecies was undertaken to detect possible infection with new variants of hepatitis C in patients with 'stable' infection.
The research team showed that these analyses indicated divergence of virus over time, divergence that was unrelated to injection drug behaviour.
Dr Dove's team commented, “Patients with ongoing or prior hepatitis C infection appear to develop immunity that protects against further infection with hepatitis C despite repeated exposure.”