Condomless receptive intercourse, ulcerative sexually transmitted infections (STIs), fisting and sharing sex toys are all associated with sexual acquisition of hepatitis C virus (HCV) among HIV-positive men who have sex with men (MSM), Project Inform reports. Sharing straws when snorting drugs is a risk factor for hep C acquisition among this population as well. Researchers from the MOSAIC study identified acute cases of hep C among HIV-positive MSM from 2009 onward in five hospitals in the Netherlands. The researchers compared the risk factors of 82 of these men with those of 131 HCV-uninfected HIV-positive MSM controls. They presented their findings at the 2015 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.

The researchers found that the following factors were associated with the following magnitudes of likeliness of contracting hep C: Those who had an ulcerative STI were 5.26 times as likely to contract hep C; receptive condomless anal intercourse, 5.05 times as likely; sharing sex toys, 3.98 times as likely; sharing straws when snorting drugs, 3.46 times as likely; having a lower CD4 count at last read before testing positive for hep C was also linked to a raised risk of hep C.

Just 12 men reported injection drug use, a behavior which was not found to be significantly associated with hep C risk among this population—nor were anorectal douching, rectal bleeding, the number of sex partners, the location of the sex, or group sex participation.

This is considered to be the largest-ever case-control study of hep C transmission among HIV-positive MSM. The researchers concluded that the study confirms that sexual transmission and non-injection drug use are risk factors for hep C acquisition among this population. They believe future studies are needed to determine if lower CD4 cell counts facilitate hep C acquisition, are a result of acute hep C infection, or both.

To read the Project Inform report, click here.

To read the conference abstract, click here.