Aceitabilidade e início do uso da profilaxia pré-exposição ao HIV em populações-chave para epidemia de HIV/aids.

Abstract

Background: The HIV epidemic is a public health problem in Brazil and worldwide. It is concentrated in some population groups, such as men who have sex with men (MSM) and transgender women (TGW), also called key populations for the epidemic. HIV pre-exposure prophylaxis (PrEP) is an important technology for HIV prevention, indicates for populations at high HIV risk of infection, and in Brazil, it is part of the range of options for combined HIV prevention strategies. The acceptability and uptake of this technology differ according to populations and age groups, as well as their associated factors, and the knowledge about the steps for PrEP use among key populations in the Brazilian context is still quite limited. Overall objective: To study the acceptability and uptake of PrEP among key populations of the HIV epidemic in Brazil. Specific objectives: (1) To analyze the association between self perception of the risk of HIV infection and the acceptability of daily oral PrEP among MSM in twelve Brazilian capitals; (2) To analyze the sociodemographic and behavioral profiles of MSM and TrMT adolescents regarding the initiation of PrEP in three Brazilian capitals; (3) To describe the uptake process and analyze predictors for PrEP initiation among MSM and TrMT adolescents in three Brazilian capitals. Methods: This thesis was presented in three articles according to each specific objective. (1) In the first article, it was estimated the association between self-perception of HIV risk and acceptability of daily oral PrEP among Brazilian MSM. Respondent-driven sampling (RDS) was used for sociobehavioral and biological surveillance to recruit 4,176 MSM 18 years or over in 12 Brazilian cities in 2016. Results were weighted using Gile’s estimator for RDS studies. Adjusted odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using multivariate logistic regression. (2) In paper 2, data from the PrEP1519 study were used, a study demonstrating the use of PrEP among MSM and TGW (aMSM) and (aTGW) adolescents aged 15 to 19 years, in São Paulo, Salvador, and Belo Horizonte. In this analysis, data from participants enrolled in the PrEP1519 cohort between February/2019 to August/2021 were used. However, we observed these participants until February 2022 to analyze PrEP initiation in the follow-up. Adolescents who sought PrEP services were classified into four groups, according to PrEP eligibility (i.e., eligible or non-eligible) and individual decision to use PrEP (i.e., started, not started): i) participant with no indication of use of PrEP, not eligible; ii) eligible and started using PrEP at first visit; iii) eligible and started using PrEP after the first visit; and iv) with the indication of use of PrEP, but without initiation of PrEP. Groups were described and compared for sociodemographic and behavioral characteristics using 2 and Fisher's Exact tests. The analyzes were performed using the software R v.4.1.0, considering a level of statistical significance of 5%. (3) In article 3, baseline data from the PrEP1519 cohort of participants enrolled in the study between February/2019 to February/2021 were used. A socio-behavioral questionnaire was applied on the first visit to the PrEP service. The proportions of intention to use, eligibility for PrEP use, and initiation of PrEP use among participants linked to the clinics were described. Socio-behavioral and demographic factors associated with the initiation of PrEP were analyzed, stratified by age group 15 to 17 years old and 18 and 19 years old, using logistic regression with adjusted prevalence ratio (aPR) and 95% CI. Results referring to the first objective: Acceptability of daily oral PrEP was high (69.7%) among the 3,544 MSM available for analysis. Most participants self-reported low or moderate risk of HIV infection (67.2%) and a small proportion (9.3%) reported high risk. A dose-response relationship was observed between acceptability of PrEP and self-reported risk: PrEP acceptability was 1.88 times higher (OR 1.80; 95% CI: 1.24–2.85) among MSM whose perceived risk of HIV infection was low or moderate, and 5 times higher (OR 5.68; 95% CI: 2.54–12.73) among those who self-reported high risk compared to MSM reporting no HIV risk. Results referring to the second objective: Of the 1,254 adolescents who arrived at the PrEP1519 services, 61 (4.9%) were not indicated to use PrEP, because they had some clinical contraindication or an assessment that indicated a low risk for HIV. Of the 1,193 eligible for same-day PrEP initiation, 1,113 (93.3%) initiated PrEP [1,054 initiated PrEP in the first visit (88.3%) and 59 in subsequent visits (4.9%)], and 80 (6.7%) did not. Of these initiated PrEP during the follow-up, 50.0% started using PrEP within the first 42 days after the first visit. Adolescents who started using PrEP were at greater risk of HIV infection. Results referring to the third objective: Among recruited participants, 174 (19,2%) were aged 15-17 yo and 734 (80,8%) 18-19 yo. The rateof PrEP initiation was 78.2% and 77.4% for 15-17 yo and 18– 19 yo, respectively. Factors associated with PrEP initiation were: black or mixed race (aPR 2.31; 95%CI: 1.10 - 4.84) among the younger adolescents 15-17 yo; experienced violence and/or discrimination due to their sexual orientation or gender identity (aPR 1.21; 95%CI: 1.01 - 1.46); received money or favors in exchange for sex (aPR 1.32; 95%CI: 1.04 - 1.68);and having had between 2 to 5 sexual partners in the previous three months (aPR 1.39;95%CI: 1.15 - 1.68) among those 18-19 yo. Unprotected receptive anal intercourse in the previous 6 months was associated with PrEP initiation in both age groups (aPR 1.98; 95%CI: 1.02 - 3.85and aPR 1.45; 95%CI: 1.19 - 1.76 among 15-17 yo and 18-19 yo, respectively).Conclusion: PrEP is an effective prevention method to control the HIV epidemic among adults and adolescents of the key populations in Brazil and the world. The perceived risk of HIV infection plays an important role in the acceptability of PrEP. And to expand access to PrEP among vulnerable populations, PrEP programs must be organized, and health professionals must be prepared to identify vulnerable populations with an indication of prophylaxis use. So guide them about their risk of HIV infection and the need to use a preventive method, with PrEP as an option.