IAS 2015Among people with HIV, chlamydia and gonorrhea infections in the rectum do not influence the likelihood of transmitting the virus to others, Healio reports. Researchers presented their findings at the 8th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Vancouver, British Columbia.

Among men, chlamydia and gonorrhea infections can occur in the urethra, rectum or throat. Having an infection in one of those three areas does not necessarily mean that an individual will be infected in another site. Past research has suggested that sexually transmitted infections (STIs) may raise the likelihood that an HIV-positive person will transmit HIV.

Researchers looked at 42 HIV-positive MSM. Half of the study group was on treatment for HIV, and seven of them were rectally infected with gonorrhea and chlamydia. Researchers took rectal swabs from the participants and analyzed them for HIV viral load, the presence of STIs and the expression of cytokines, which are pro-inflammatory agents of the immune system. They sampled those who were infected with gonorrhea and chlamydia two weeks or more after they received treatment for the STIs.

The presence of STIs made no difference in the rectal viral load or cytokine levels, in both those on and off HIV treatment. There were also no significant shifts in HIV viral load or plasma viral load after men were treated for the two STIs.

These findings do not suggest that STIs don’t influence the likelihood of HIV transmission through semen, however—urethral STIs may influence the likelihood of HIV-positive men transmitting the virus through insertive anal (being the top) or vaginal sex.