High incidence of hepatitis C virus reinfection within a cohort of injecting drug users

Abstract

A retrospective cohort study was established of injecting drug users (IDUs) to assess evidence for hepatitis C virus (HCV) protective immunity through a comparison of incidence of initial HCV infection and HCV reinfection. Incidence of initial HCV infection was determined among HCV seronegative IDUs, and HCV reinfection determined among IDUs with newly acquired HCV infection, HCV viraemia and subsequent HCV RNA clearance. Serum was available for HCV RNA analysis from stored samples taken at the time of prior blood-borne virus screening. Potential HCV reinfection was defined as a positive HCV RNA following at least one negative HCV RNA. Incidence of initial HCV infection was 17/100 person-years (95% CI, 14-20/100 person-years). The incidence of potential HCV reinfection was 42/100 person-years (95% CI, 25-61/100 person-years), and after excluding cases without a change in HCV genotype and less than three consecutive HCV RNA negative assessment, incidence of reinfection was 31/100 person-years (95% CI, 17-62/100 person-years). Following adjustment for HCV risk behaviour variables the incidence rate ratio of HCV reinfection to initial infection was 1.11 (P = 0.8). Several cases of HCV reinfection appear to have developed persistent infection.

HCV‐specific T‐cell responses in injecting drug users: evidence for previous exposure to HCV and a role for CD4+ T cells focussing on nonstructural proteins in viral clearance

“…However, a more recent study did not confirm this and calculated the reinfection rate to be 41/100 PY [45]. Therefore, the observed T-cell responses before onset of infection may be merely a reflection of exposure to the virus, as has been reported in homosexual men who seroconverted for HIV despite detectable HIV-specific cytotoxic T-cell responses well before HIV-seroconversion [48].…”

“…On the other hand, we may have overestimated the time required for viral clearance on account of some wide HCV-RNA testing intervals. Late viral clearance (>24 months) has been reported before [45]. A possible caveat in our study might be the use of HCVpeptide pools based on the genotype 1a consensus sequence, as six out of 13 patients were infected with genotype 3a strains, which may result in underestimation of T-cell responses in these patients.…”

Lifestyle-Related Diseases of the Digestive System: A New In Vitro Model of Hepatitis C Virion Production: Application of Basic Research on Hepatitis C Virus to Clinical Medicine

“…There is a fair possibility of success in the development of an HCV vaccine, although several problems still need to be resolved. For instance, one group showed that there was a high incidence of HCV reinfection within injectable drug users (54). This report suggests that protective HCV vaccines should be based on epitopes from multiple genotypes.…”

A quasi-markov model for transmission and disease elimination: Hepatitis C among people who inject drugs

“…And, P11=P44, P12=P42, P13=P43, P17=P27=P37=P47= P57=P67=μ and for k=1,…, (27, Some research has found that following spontaneous clearance of an acute infection a proportion of individuals may have protective immunity to re-infection; however, findings regarding a conferring of a protective immunity are equivocal [40][41][42][43]. In order to capture the possibility of some level of a protective immunity, a corresponding state (z) was included in the natural history model with a low transition probability (0.25) [19].…”

“…Third, given the equivocal nature of protective immunity, the model was evaluated removing this state in the natural history. Lastly, the model was run assuming the proportion of individuals who spontaneously clear the infection (probability of transitioning from susceptible (x, x 1 ) to acutely infected (h 2 )) was larger based upon results presented in the literature (0.26 compared to 0.23) [42].…”