HCV reinfection rates in HIV-positive gay men

Several research groups that highlighted the increased rates of sexual HCV transmission in HIV-positive gay men have also included reports of reinfection with HCV after achieving successful HCV treatment.

In a cohort of 62 HIV-positive men from the Netherlands, Thomas and colleagues compared HCV genetic samples obtained during initial acute HCV infection to the last available sample (median time 2.1 years; IQR 0.53.8). Of the 58 patient with successful samples expanded in the NS5B gene, HCV genotype switches were found in 10 people: genotype 1a to 4d (n=4), 4d to 1a (n=3), 1a to 3a (n=1), 3a to 1a (n=1) and 4a to 4d (n=1). [1]

HVR1 sequences (which allow for clade comparison within genotypes) were successfully expanded in 37/48 people without a genotype switch and showed that reinfection with the same genotype occurred in two people (one with genotype-1a and one genotype-4d).

The researchers concluded that reinfection occurred frequently in this group of patients: in 12 of 58 (21%) a different virus was detected at the end of follow-up than the initial virus. The study also suggested that partial immunity against re-infection with the same genotype might exist in HIV-positive people.

In a second poster from the same group, Femke Lambers and colleagues looked at rate of HCV reinfection in HIV-positive men in Amsterdam who had achieved sustained virological responses (SVR) to HCV treatment. Of 26 people who became PCR-negative, maintained for two months, six were reinfected. One person was excluded from the analysis because his genotype was unknown. Total follow-up time in these 25 people was 35.5 years; median follow-up 1.1 years (IQR 0.4 to 1.9). The median time between test intervals was 2.9 months (IQR 1.6 to 4.1).

This led to an incidence of HCV reinfection in this group of 16.9 /100 person-years (95%CI 6.9 to 35.2), which is approximately 10-fold higher that HCV infection rates in HIV-positive men who have not previously been infected with HCV.