SUMMARY: More than 25% of HIV positive men treated for acute hepatitis C in Amsterdam became re-infected within about 1 year, indicating the need for better prevention efforts, researchers reported at CROI 2011.

By Liz Highleyman

Starting around 2000 clinicians began reporting cases of apparently sexually transmitted acute hepatitis C virus (HCV) infection among HIV positive gay and bisexual men. These reports first came from the U.K., followed by major cities in Europe, Australia, and the U.S.

On average, HIV/HCV coinfected people experience more rapid liver disease progression and do not respond as well to interferon-based hepatitis C treatment. But whether HIV positive or negative, treatment is more effective if started during acute infection. Unlike some other diseases, however, HCV infection does not confer immunity, and people can become infected multiple times.

As reported at the 18th Conference on Retroviruses and Opportunistic Infection (CROI 2011) last month in Boston, Femke Lambers from the Amsterdam Public Health Service and colleagues looked at HCV re-infection among HIV positive gay/bisexual men diagnosed and treated for sexually transmitted acute hepatitis C at a city HIV outpatient clinic.

Some data suggest HCV infection within this population has leveled off -- stabilizing at around 15% -- but the rate of re-infection after successful treatment is unknown.

The researchers looked at outcomes among patients who had undetectable HCV RNA viral load at the end of treatment with interferon-based therapy started during acute infection. Since most relapses occur within 2 months after completion of treatment, they defined HCV re-infection as having a positive HCV RNA test after having had a negative test at least 2 months after completing therapy.

To further rule out relapses, the researchers decided to only count cases in which patients had a different new HCV genotype, clade, or strain. The median follow-up period was about 1 year and the median interval between tests was 2.7 months.

Results

	During treatment for the first case of acute HCV, 28 men became HCV RNA negative and remained so until at least 2 months after the end of therapy.
	Within 2 months after treatment completion, 2 of the 28 men presumably relapsed and were omitted from the analysis.
	According to the researchers' definition, 7 of the 26 men who were followed beyond 2 months after treatment experienced HCV re-infection.
	All re-infections occurred within 2 years.
	The resulting incidence rate of HCV re-infection in this group was 19.6 per 100 person-years.
	This rate is about 10 times higher than the initial HCV infection rate among HIV positive gay/bisexual men in Amsterdam.
	Most men switched from HCV genotype 1 to 4 or vice versa (genotype 4 is uncommon in Europe outside the HIV/HCV coinfection clusters among gay men).

"Despite high clearance rates and a possible decrease in incidence of primary HCV infection among HIV+ [men who have sex with men] in Amsterdam, an alarmingly high incidence of HCV re-infection was found in this group," the investigators concluded.

This high re-infection rate "indicates that prevention measures should not only be discussed early after diagnosis, but also during and after treatment," they advised. Furthermore, they added, "regular HCV RNA testing should be continued early after successful treatment."

Investigator affiliations: Public Health Service, Amsterdam, Netherlands; Academic Medical Center, Amsterdam, Netherlands.

4/8/11

Reference
F Lambers, M Prins, X Thomas, et al. High Incidence Rate of HCV Reinfection after Treatment of Acute HCV Infection in HIV+ MSM: Amsterdam. 18th Conference on Retroviruses and Opportunistic Infections (CROI 2011). Boston. February 27-March 2, 2011. Abstract 958.