Source The Kirby Institute for infection and immunity in society, The University of New South Wales, Sydney, Australia. jgrebely@kirby.unsw.edu.au.

BACKGROUND AND AIMS: To evaluate reinfection and superinfection during treatment for recent HCV.

METHODS: ATAHC was a prospective study of the natural history and treatment of recent HCV. Reinfection and superinfection were defined by detection of infection with an HCV strain distinct from the primary strain (using RT-PCR and subtype-specific nested RT-PCR assays) in the setting of spontaneous or treatment-induced viral suppression (one HCV RNA <10 IU/ml) or persistence (HCV RNA >10 IU/mL from enrolment to week 12).

RESULTS: Among 163, 111 were treated, 79% (88 of 111) had treatment-induced viral suppression and 60% (67 of 111) achieved SVR. Following treatment-induced viral suppression, recurrence was observed in 19% (17 of 88), including 12 with relapse and five with reinfection [4.7 cases per 100 person-years (py), 95% CI; 1.9, 11.2]. Among 52 untreated, 58% (30 of 52) had spontaneous viral suppression and recurrence was observed in 10% (3 of 30), including two with reinfection. Following reinfection, ALT levels >1.5x the upper limit of normal were observed in 71% (5 of 7). Among 37 with persistence, superinfection was observed in 16% (3 of 19) of those treated and 17% (3 of 18) of those untreated. In adjusted analysis, reinfection/superinfection occurred more often in participants with poorer social functioning at enrolment and more often in those with ongoing injecting drug use (IDU).

CONCLUSIONS: Reinfection and superinfection can occur during treatment of recent HCV and are associated with poor social functioning and ongoing IDU. ALT levels may be a useful clinical marker of re-exposure.