Men may acquire hepatitis C virus (HCV) sexually from the rectums of HIV/HCV-coinfected men even when there is no blood present, HIVandHepatitis.com reports. Researchers took rectal fluid samples from 45 coinfected men who have sex with men (MSM), 12 of whom were acutely infected. They presented their findings at the Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) in San Francisco.

The 21st century has seen an emerging epidemic of sexually transmitted hep C among MSM, particularly those living with HIV, in Europe, North America and Australia.

The investigators of this new study also measured the participants’ hep C viral loads, and tested them for rectal sexually transmitted infections (STIs) and syphilis.

Twenty of the 45 samples (47 percent) had detectable hep C. (Two samples could not be processed.) There was a strong correlation between the viral load in the rectal fluid and in the blood; those participants who had a high blood viral load were much more likely to have detectable virus in their rectal fluid.

The researchers found no correlation between the detectability of hep C in the rectal fluid and whether the men were acutely or chronically infected, or whether they had rectal STIs or syphilis.

The researchers concluded that the levels of hep C found in the rectal fluid would be sufficient for transmission of the virus during anal sex. Other sexual activities that may facilitate hep C transmission without blood include group sex, the use of sex toys, fisting, or through the use of anorectal douching equipment.

Another study presented at the meeting analyzed stool samples from 98 men and women monoinfected with hep C. The investigators found that 68 samples (69 percent) had detectable hep C, with blood only present in five of those samples. Eighty-three percent of the samples from the men had detectable virus, compared with 52 percent of the samples of the women.

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