Herpes simplex virus 2 serostatus and viral loads of HIV-1 in blood and semen as risk factors for HIV transmission among men who have sex with men

Abstract

Objective Human immunodeficiency virus type 1 blood plasma viral load is correlated with the sexual transmission of HIV, although transmission from men involves virus from semen instead of blood. We quantified HIV-1 RNA in the blood and semen of men who did or did not transmit HIV to their sex partners. We compared the relationships of HIV-1 transmission risk with blood plasma viral load, seminal plasma viral load, herpes simplex virus 2 serostatus and other factors. Design A case–control study. Methods Participants were men evaluated for primary HIV infection and their recent male sex partners. They were interviewed, and clinical specimens were collected. Epidemiologic and phylogenetic linkages were determined by history and molecular techniques. Couples were grouped on the basis of transmission after exposure. Fisher’s exact test and Wilcoxon tests were used for comparisons between groups. Multivariable logistic regressions were fit to identify independent predictors of transmission. Results HIV-transmitting partners (n=15) had a higher median seminal plasma viral load (P<0.015) and median blood plasma viral load (P<0.001) than nontransmitting partners (n=32). Herpes simplex virus 2 serostatus was associated with transmission only when the HIV-infected source partner was herpes simplex virus 2 seropositive and the HIV-exposed partner was not (odds ratio 16, P<0.03). Adjusting for other factors, HIV transmission was significantly associated with blood plasma viral load (odds ratio 13.4, P<0.02) but not seminal plasma viral load (odds ratio 0.69, P=not significant). Conclusion Blood and seminal plasma viral load were both associated with human immunodeficiency virus type 1 transmission, but blood plasma viral load was the stronger predictor in this cohort. Herpes simplex virus 2 coinfection was associated with the risk of transmission but not acquisition of human immunodeficiency virus type 1.

Associations between Virologic and Immunologic Dynamics in Blood and in the Male Genital Tract

“…(i) Overall. Similar to previous studies (13,39,56,69,72), we found a positive trend between HIV RNA levels in blood and semen (P ϭ 0.07), while no correlations were found between seminal HIV and CMV levels (P ϭ 0.35) or between seminal HSV and CMV levels (P ϭ 0.39). Activation levels (RA-CD38 ϩ ) of CD4 ϩ and CD8 ϩ subsets in blood were highly correlated with each other (P Ͻ 0.001) and with activation of CD8 ϩ T cells in semen (P Ͻ 0.01).…”

“…uman immunodeficiency virus 1 (HIV) RNA viral loads in blood (31,59) and semen (7,13) of HIV-infected individuals correlate with the risk of sexual transmission (15,28,44). Although HIV RNA levels in blood roughly correlate with levels in seminal plasma (13,39,56,69,72), local genital factors, particularly concomitant sexually transmitted infections (STI), can increase HIV shedding in semen (38,39,61).…”

“…Although HIV RNA levels in blood roughly correlate with levels in seminal plasma (13,39,56,69,72), local genital factors, particularly concomitant sexually transmitted infections (STI), can increase HIV shedding in semen (38,39,61). Common bacterial STI can also increase the number of immune cells in the genital tract (9,52), and elevated counts of white blood cells in semen are associated with higher seminal HIV shedding (3,4,69,80).…”

“…For HSV-2, among HIV-infected people, the seroprevalence is ϳ70 to 90% (50,76), and seminal shedding of HSV is associated with higher HIV RNA genital levels (8,53,64). Also, HSV-2 seropositivity of the source partners is associated with HIV transmission among men who have sex with men (MSM) (13); however, the use of acyclovir for chronic HSV infection among HIVinfected individuals does not reduce HIV transmission to their partners (14). The seroprevalence of CMV among HIV-infected men is even higher at 95 to 100% (20,60), and CMV is associated with HIV disease progression in both treated and untreated individuals (18,21,24,25,37,58,70,75).…”

Human Immunodeficiency Virus Transmission

“…Ma et al (2010) reported that the probability of unprotected heterosexual transmission may vary with population and be influenced by many factors, these could include: the type of sex (Mastro et al, 1994: De Vincenzi, 1994Varghese et al, 2002); bleeding during intercourse (Royce et al, 1997), semen viral load (Gupta et al, 1997;Tachet et al, 1999;Kalichman et al, 2008;Butler et al, 2008), stage of HIV infection (Mastro et al, 1994;Fauci et al, 1996;Wawer et al, 2005), comorbid sexually transmitted diseases (Royce et al, 1997), vaginal or anal canal, co-occurring psychosocial risk factors . Sexual forms of transmission are seen as a major portal of entry of HIV as 10-30% of seminal/vaginal fluids have transmissible virus (Royce et al, 1997;Henin et al, 1993).…”