HCV Re-infection Is Common, Mainly Due to Injection Drug Use, among Canadian Prisoners Treated for Hepatitis C

By Liz Highleyman

Hepatitis C is common among current and former prison inmates, largely because sharing equipment for injection drug use is an efficient means of transmitting the virus and people are often imprisoned for drug-related offenses. It is estimated that somewhere between 24% and 80% of inmates in Canadian federal correctional institutions are infected with HCV.

Researchers in British Columbia conducted a retrospective chart review of long-term outcomes among hepatitis C patients treated through their clinic in Vancouver. The investigators previously reported that hepatitis C patients can be successfully treated in correctional institutions, but longer-term data are scarce.

The present analysis included 479 individuals (96% men) who started treatment with conventional or pegylated interferon alfa (Pegasys or PegIntron) plus ribavirin between August 1999 and March 2009.

The participants' mean age was 38 years, 70% were white, 24% were Canadian natives or aboriginals, and 6% were of other racial/ethnic groups. 142 were considered likely to have initially acquired HCV through injection drug use. Patients were followed on average every 6 months, either in prison if they remained incarcerated or in the community if they were released. Follow-up continued for up to 4 years.

Results

One-quarter of the participants were lost to follow-up after starting treatment.

Others discontinued therapy due to non-response (13%) or adverse events (3%).

Of the 479 who started treatment, 187 (40%) achieved sustained virological response (SVR; undetectable HCV viral load 6 months after completion of therapy).

Among 110 sustained responders, 24 people (22%) became re-infected with HCV (most had a different HCV genotype than befoe, indicating likely re-infection rather than late relapse).

The major risk factors for re-infection were:

	Injection drug use (76%);
	Other known risk factors including tattooing, piercing, sexual activity, or direct contact with blood, for example during a fight (15%);
	Unidentified risk (9%).

A majority of re-infections occurred within the first year after achieving SVR (mean 47 weeks), but some occurred as long as 2 years later.

The researchers concluded that, "Re-infection is an emerging important consideration for treatment of HCV in [injection drug users]." They added that the 24 cases seen in this study is probably an underestimate, because many participants did not return for follow-up visits, and individuals who resumed active drug use may be more likely to fall into this group.

"Addressing addiction issues must be an integral part of any successful program for treating HCV in [injection drug users]," the investigators recommended. "Harm reduction strategies should also be continually reinforced pre, during and post-treatment. Otherwise, re-infection may decrease the overall effectiveness of the HCV treatment program."

Dr John Farley Inc., Vancouver, Canada.

9/18/09

References
JD Farley, L. Chinybayeva, and W Shum. Treatment of HCV Infection in Intravenous Drug Users in Inmates of Correctional Institutions, Canada: Four Year Follow Up - Significant Likelihood of Reinfection. 49th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2009). San Francisco. September 12-15, 2009. Abstract H-219.