HIV-1 heterosexual transmission and association with sexually transmitted infections in the era of treatment as prevention

Abstract

Objectives: HIV-1 heterosexual transmission among individuals on antiretroviral treatment (ART) with undetectable viremia is extremely rare. The aim of this study was to evaluate the risk of sexual HIV-1 transmission and other sexually transmitted infections (STIs) in HIV-1 serodifferent couples while the index partner is on ART. Methods: HIV transmission was evaluated in 200 HIV-1 heterosexual serodifferent couples in a stable relationship (≥3 months). All HIV-positive individuals had been on ART for ≥3 months and had been followed up for a median preceding time of 4.5 years (range 0.3–16years) at the HIV couples clinic at Hospital Nossa Senhora da Conceição in Porto Alegre, Brazil. Following written informed consent, participants responded to demographic/behavioral questionnaires. Quantitative PCR for HIV RNA, T-cell subsets, and STI testing (syphilis, herpes, human papillomavirus, gonorrhea, and bacterial vaginosis) were performed. Self-collected vaginal swabs were obtained for quantitative HIV genital viral load testing. Results: Among 200 couples, 70% of index partners were female. Five seroconversions were observed; the HIV infection incidence was 2.5% (95% confidence interval 0.8% to 5.7%). Mean plasma viral load results were higher in HIV transmitters compared to non-transmitters (p = 0.02). The presence of STIs was significantly greater in couples who seroconverted (60.0% vs. 13.3%; odds ratio 9.75, 95% confidence interval 1.55–61.2; p = 0.023). The duration of undetectable HIV viremia and presence of STIs were associated with HIV transmission. Conclusions: Undetectable viremia was the main factor associated with non-transmissibility of HIV in this setting.

Transmitted drug resistance among HIV-1 drug-naïve patients in Greece

“…Information on all newly diagnosed HIV patients with available genotypic resistance testing in Greece were included; however, heterosexual patients were underrepresented due to their limited linkage to clinical care. This underrepresentation of heterosexuality in HIV infection has also been reported in previous studies (Knauth et al, 2020;Leal et al, 2015;Melo et al, 2019) and should be acknowledged when interpreting the results of this study in terms of the relative risk of TDR. In addition, a high percentage of individuals had an unknown route of transmission.…”

The Importance of Regulation in Natural Immunity to HIV

“…Even though they cause such trouble, some STIs, such as Chlamydia trachomatis and Neisseria gonorrhoeae , are difficult to diagnose because of the lack of symptoms in infected women. Studies have reported that there is a greater than three-fold higher risk of contracting HIV when the person already has an STI [ 86 ].…”

HIV-1 Entry and Prospects for Protecting against Infection

“…STIs typically result in the destruction of the mucosal barriers, which leads to activation and recruitment of HIV target cells at the site of infection [ 112 ]. It has been reported that having one STI resulted in a threefold increased risk of HIV acquisition, whereas having two or more STIs increased the risk of HIV acquisition to more than sixfold [ 119 ]. In addition, women are also predisposed to HIV through asymptomatic STIs such as Chlamydia trachomatis , Neisseria gonorrhea , amongst other bacterial STIs that can sometimes be difficult to diagnose [ 120 ].…”