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  52nd ICAAC Interscience Conference on
Antimicrobial Agents and Chemotherapy
September 9-12, 2012, San Francisco
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HIV in Semen of More than 1 in 10 Gay Men With Sub-50 Plasma Load
  52nd ICAAC, September 9-12, 2012, San Francisco

Mark Mascolini

Confirming results of earlier studies, a longitudinal analysis by Paris researchers found that 13% of gay men with an undetectable viral load in plasma had intermittently detectable HIV RNA in semen [1]. No men had signs of sexually transmitted infections (STIs) when they entered the study, but 20% had asymptomatic STIs diagnosed upon testing.

Prior research in 304 heterosexual men in France determined that 6.6% with undetectable plasma HIV RNA had detectable virus in semen [2]. This proportion did not change much from year to year in the 2002-2011 study. To pursue this line of research, a team at Bicetre Hospital in Paris conducted this study in HIV-positive men who identified themselves as men who have sex with men (MSM).

All study participants were taking a stable antiretroviral regimen and had a plasma viral load below 50 copies for at least 6 months. No one had clinical symptoms of STIs, and all agreed to abstain from sex for 2 days before sample collection. The investigators collected paired semen and blood samples at a baseline visit and 4 weeks later. Everyone got tested for common STIs.

The 157 men enrolled had a median age of 44 years (range 27 to 67), a median 10.4 years since HIV diagnosis (range 0.8 to 26.3), a median 6.6 years on antiretroviral therapy (range 0.7 to 21.8), and a median 3.3 years with a plasma viral load under 50 copies (range 0.5 to 13.7). Median current CD4 count stood at 637 (range 152 to 1721), and 26 men (17%) had a history of AIDS. Of the 99 men (63%) with a stable partner, 62 (63%) had casual sexual encounters in the last 3 months. The median number of casual partners was 10 and ranged from 1 to 160.

HIV RNA could be detected in 23 of 304 semen samples (7.6%) at a median load of 146 copies/mL (range 50 to 1475). Twenty-one men (13% of 157) had detectable virus in semen. Virus could be detected in the first seminal samples given by 5 men, in the second samples of 14 men, and in both samples of 2 men.

Thirty-two men (20%) had an asymptomatic STI, and 2 men had 2 STIs. Eighteen men had Ureaplasma urealyticum, 6 had syphilis, 4 had Gardnerella vaginalis, 2 had gonorrhea, and 1 has Mycoplasma infection.

Logistic regression analysis identified two factors associated with detectable HIV RNA in semen. A CD4 count of 544 to 735 (versus under 554) lowered the odds 70% (OR 0.3, 95% confidence interval [CI] 0.1 to 0.9, P = 0.027). An HIV DNA level in peripheral blood mononuclear cells above 2.5 log10 copies per million cells tripled the risk of detectable HIV RNA in semen (OR 3.1, 95% CI 1.2 to 7.7, P = 0.015). Factors that did not affect chances of detectable seminal virus included having an STI at the baseline visit, CDC HIV disease stage, current or nadir CD4 count, duration of undetectable plasma load, adherence to antiretroviral therapy, and number of sex partners.

Whether the low HIV seminal levels detected in this study are infectious remains to be determined, the researchers cautioned. They observed that although a higher cellular HIV DNA level predicted seminal HIV shedding, men with lower HIV DNA load also intermittently shed HIV RNA in semen.


1. Ghosn J, Delobelle A, Leruez-Ville M, et al. Prevalence of HIV-1 seminal shedding in HIV-1 infected men who have sex with men and association with the size of intracellular HIV-1 reservoir (ANRS EP49). 52nd Interscience Conference on Antimicrobials and Chemotherapy (ICAAC). September 9-12, 2012. San Francisco. Abstract H-1570f.

2. Lambert-Niclot S, Tubiana R, Beaudoux C, et al. Detection of HIV-1 RNA in seminal plasma samples from treated patients with undetectable HIV-1 RNA in blood plasma on a 2002-2011 survey. AIDS. 2012;26:971-975.