Sexual Exposure to Blood and Behavioural Risks Among STI Clinic Patients in Cape Town, South Africa

Although it is well known that the vast majority of HIV infections in South Africa are the result of heterosexually transmitted HIV, the rapid growth of South Africa's HIV epidemic and the behavioural risk factors that facilitate HIV transmission in South Africa have not been fully explained. As one potentially important co-factor, bleeding during sexual intercourse significantly increases the risk for HIV transmission during anal intercourse and vaginal intercourse," the authors explained. Even after controlling for rates of sexual behavior and other potential confounds, patients who report sexual contact involving blood have higher rates of sexually transmitted infections (STIs).

The researchers investigated sexual exposure to blood among 415 men and 127 women receiving STI treatment services from a Cape Town public health clinic who completed anonymous sexual health behavior surveys.

More than 30 percent of both men and women in the sample reported engaging in sexual intercourse involving genital bleeding in the previous three months. Having engaged in sexual intercourse involving bleeding was associated with a having a greater number of sex partners in the past three months (OR=1.6, 95 percent, CI=1.1-2.3), higher rates of unprotected vaginal intercourse (OR=1.2, 95 percent, CI=1.1-1.2), history of exchanging sex for money or materials (OR=3.1, 95 percent, CI=1.7-5.5), and having experienced condom breaks (OR=1.7, 95 percent, CI=1.2-2.4). Sexual intercourse involving bleeding was not associated with STI diagnoses or symptoms, but participants who reported sex involving blood were considerably less likely to have been tested for HIV.

"Genital bleeding during vaginal sex increases the per-contact HIV transmission risks to those that approximate unprotected anal intercourse," the authors wrote. "For men, the most likely sources of bleeding are penile ulcers, a common blood-related HIV transmission risk factor in southern Africa. However, more men reported engaging in sexual contact that involved blood than there were men who had genital ulcers, suggesting that other potential sources of penile bleeding cannot be ruled out, including incomplete circumcision healing and penile trauma caused by various sex practices (e.g., dry sex, rough sex). For women, possible sources of bleeding during sex included genital ulcers, menses, and trauma to vaginal tissues."

"These findings suggest that exposure to blood during vaginal intercourse is prevalent among STI clinic patients in Cape Town and may be an important contributing factor to the rapid spread of HIV in South Africa," the researchers concluded.

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