Sexual Behaviors and Factors Associated with Condomless Sexual Practice in Colombian Men Who Have Sex with Men at High Risk of HIV Transmission.

Men who have sex with men (MSM) have a disproportionate burden of HIV infection worldwide. In Colombia, the prevalence of HIV in MSM is ~ 43 times higher than in the general population (17% vs. 0.4%). This study determined the sexual behaviors, HIV serostatus, and associated factors with condomless sexual practice with both regular and casual partners in 92 MSM from Medellín, Colombia. The subjects were recruited through a community-based approach, and the data were collected by a structured survey and in-depth interviews. Participants were classified into three groups according to the number of sexual partners in the last three months, to compare the sociodemographic conditions and sexual behaviors. Univariate analysis was described by absolute and relative frequencies; bivariate analysis and multivariate logistic regression were used to compare the groups and to explore the associated factors with condomless sexual practice. The overall HIV estimated prevalence was 4.3%, while the estimated prevalence for MSM with > 10 sexual partners in the last three months was 14.8%. This last group showed higher average age, higher percentage of subjects who have had sex with people living with HIV, and increased frequency of previous sexually transmitted infections. Having condomless sex with casual partners was associated with the number of sexual partners in the last three months. This study demonstrates that Colombian MSM continue to have a high risk of HIV infection/transmission and reinforce the need to implement adequate prevention programs, PrEP and guarantee access to treatment for people living with HIV.

Seronegative MSM at high risk of HIV-1 acquisition show an immune quiescent profile with a normal immune response against common antigens.

Human immunodeficiency virus (HIV) infection still represents a major public health problem worldwide, and its vaccine remains elusive. The study of HIV-exposed seronegative individuals (HESN) brings important information about the natural resistance to HIV, allows a better understanding of the infection, and opens doors for new preventive and therapeutic strategies. Among HESN groups, there are some men who have sex with men (MSM) with high-risk sexual behaviors, who represent an adequate cohort for HESN study because of their major HIV exposure without infection. This study aimed to compare the immunological profile of Colombian seronegative MSM with different risk sexual behaviors. This study included 60 MSM at high-risk (n = 16) and low-risk (n = 44) of HIV-1 acquisition. No sex worker nor homozygous delta 32 mutation subjects were included. All participants were negative for anti-HIV-1/2 antibodies and HIV-1 proviral DNA. A higher frequency of sexual partners in the last 3 months before the study participation (median, 30 vs. 2), lifetime sexual partners (median, 1,708 vs. 26), and unprotected anal intercourse (median 12.5 vs. 2) was determined in high-risk MSM than low-risk MSM. High-risk MSM also showed a quiescent profile of T cells and natural killer (NK) cells, with a significantly lower percentage of CD4+CD38+, CD4+HLADR-CD38+, CD4+Ki67+ T cells, and NKG2D+ NK cells (CD3-CD16+CD56+), a significantly higher percentage of CD4+HLADR-CD38-, and a tendency to show a higher percentage of CD8+HLADR+CD38- T cells than the low-risk group. Likewise, they showed higher mRNA levels of Serpin A1 from PBMCs. The results suggest that this MSM cohort could be HESN individuals and their resistance would be explained by a quiescent profile of T cells and NK cells and an increased Serpin A1 expression. Further study on MSM at high risk of exposure to HIV-1 is necessary to better understand the natural resistance to HIV.