Transmitted drug resistance to antiretroviral drugs in Spain during the period 2019-2021.

To evaluate the prevalence of transmitted drug resistance (TDR) to nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTI, NNRTI), protease inhibitors (PI), and integrase strand transfer inhibitors (INSTI) in Spain during the period 2019-2021, as well as to evaluate transmitted clinically relevant resistance (TCRR) to antiretroviral drugs. Reverse transcriptase (RT), protease (Pro), and Integrase (IN) sequences from 1824 PLWH (people living with HIV) were studied. To evaluate TDR we investigated the prevalence of surveillance drug resistance mutations (SDRM). To evaluate TCRR (any resistance level ≥ 3), and for HIV subtyping we used the Stanford v.9.4.1 HIVDB Algorithm and an in-depth phylogenetic analysis. The prevalence of NRTI SDRMs was 3.8% (95% CI, 2.8%-4.6%), 6.1% (95% CI, 5.0%-7.3%) for NNRTI, 0.9% (95% CI, 0.5%-1.4%) for PI, and 0.2% (95% CI, 0.0%-0.9%) for INSTI. The prevalence of TCRR to NRTI was 2.1% (95% CI, 1.5%-2.9%), 11.8% for NNRTI, (95% CI, 10.3%-13.5%), 0.2% (95% CI, 0.1%-0.6%) for PI, and 2.5% (95% CI, 1.5%-4.1%) for INSTI. Most of the patients were infected by subtype B (79.8%), while the majority of non-Bs were CRF02_AG (n = 109, 6%). The prevalence of INSTI and PI resistance in Spain during the period 2019-2021 is low, while NRTI resistance is moderate, and NNRTI resistance is the highest. Our results support the use of integrase inhibitors as first-line treatment in Spain. Our findings highlight the importance of ongoing surveillance of TDR to antiretroviral drugs in PLWH particularly with regard to first-line antiretroviral therapy.

Absence of transmission from HIV-infected individuals with HAART to their heterosexual serodiscordant partners.

BACKGROUND: Further studies are needed to evaluate the level of effectiveness and durability of HAART to reduce the risk of HIV sexual transmission in serodiscordant couples having unprotected sexual practices. METHODS: A cross-sectional study was conducted with prospective cohort of heterosexual HIV serodiscordant couples where the only risk factor for HIV transmission to the uninfected partner (sexual partner) was the sexual relationship with the infected partner (index case). HIV prevalence in sexual partners at enrolment and seroconversions in follow-up were compared by antiretroviral treatment in the index partner, HIV plasma viral load in index cases and sexual risk exposures in sexual partners. In each visit, an evaluation of the risks for HIV transmission, preventive counselling and screening for genitourinary infections in the sexual partner was performed, as well as the determination of the immunological and virological situation and antiretroviral treatment in the index case. RESULTS: At enrolment no HIV infection was detected in 202 couples where the index case was taking HAART. HIV prevalence in sexual partners was 9.6% in 491 couples where the index case was not taking antiretroviral treatment (p<0.001). During follow-up there was no HIV seroconversion among 199 partners whose index case was taking HAART, accruing 7600 risky sexual exposures and 85 natural pregnancies. Among 359 couples whose index case was not under antiretroviral treatment, over 13,000 risky sexual exposures and 5 HIV seroconversions of sexual partners were recorded. The percentage of seroconversion among couples having risky sexual intercourse was 2.5 (95% confidence interval [CI]: 1.1-5.6) when the index case did not undergo antiretroviral treatment and zero (95% CI: 0-3.2) when the index case received HAART. CONCLUSIONS: The risk of sexual transmission of HIV from individuals with HAART to their heterosexual partners can become extremely low.

HTLV infection in persons with sexually transmitted diseases in Spain.

Background: HTLV-1 infection is a neglected disease, despite estimates of 10 million people infected worldwide and producing life-threatening illnesses in 10% of carriers. Sexual transmission is the main route of contagion. However, HTLV-1 is not listed among sexually transmitted infections (STIs). Methods: Serum from all consecutive individuals who had attended six STI clinics across Spain during the last 12 months were tested for HTLV antibodies using a commercial enzyme immunoassay (EIA). Reactive samples were confirmed by immunoblot. Results: A total of 2,524 samples were examined. The majority (1,936; 76.7%) belonged to men, of whom 676 (34.9%) were men who have sex with men (MSM) receiving HIV pre-exposure prophylaxis. Although native Spaniards predominated (1,470; 58.2%), up to 593 (23.5%) came from Latin America and 139 (5.5%) were African. A total of 26 individuals were initially EIA reactive and immunoblot confirmed 5 as HTLV-1 and 7 as HTLV-2. All but one HTLV-1+ case came from Latin America. Three were men and two were women. Among Latin Americans, the HTLV-1 seroprevalence was 0.67%. In contrast, all seven HTLV-2+ were native Spaniards and former injection drug users, and all but one were HIV+. Conclusion: The rate of HTLV infection among individuals with STIs in Spain is 0.5%, which is greater than in the general population. These results support the introduction of universal HTLV screening in persons who attend clinics for STIs.