RESUMO
HIV-1 epidemics are expanding among men who have sex with men in low- and middle-income countries. To confirm and further explore preliminary data in Senegal, we aimed to determine 3 years after a first study the HIV-1 genetic diversity in three different viral regions. From 109 samples available in 2007, 93 were sequenced in gag, 77 in env, and 60 in pol. Phylogenetic analysis showed that subtype C predominated (38-52%), followed by CRF02_AG (30-40%), subtype B (13-17%), and CRF09_cpx (2.6-5%). Subsubtype A3 and strains tightly linked to CRF43_02G were identified in env and gag, respectively, and 12% of the samples were unique recombinants. Six transmission chains involving two to seven individuals were identified. Some strains carried resistance mutations inside transmission chains. This study confirmed the existence of a dual epidemic in Senegal and emphasized the need to strengthen prevention programs to avoid strains intermixing between low-risk women and high-risk men.
Assuntos
Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , Homossexualidade Masculina , Adolescente , Adulto , Sequência de Bases , Feminino , Variação Genética , Genótipo , Infecções por HIV/epidemiologia , HIV-1/isolamento & purificação , Humanos , Masculino , Epidemiologia Molecular , Filogenia , Prevalência , Senegal/epidemiologia , Análise de Sequência de RNA , Adulto Jovem , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genéticaRESUMO
BACKGROUND: No epidemiological study has been conducted on HIV and vulnerability to sexually transmitted diseases (STI) among men who have sex with men (MSM) in sub-Saharan Africa. METHOD: A survey including questionnaire, physical examination and detection of HIV and STI was carried out among 463 MSM, aged 18-52 years, recruited through the snowball technique in five urban sites throughout Senegal. RESULTS: A total of 21.5% of men were found to be infected with HIV [95% confidence interval (CI), 17.8-25.6]. Active syphilis, positive serology for herpes simplex virus (HSV)-2, and polymerase chain reaction detection in urine of Chlamydia and gonorrhea infections were recorded in 4.8, 22.3, 4.1 and 5.4% of participants, respectively. Most respondents reported sex with women (94.1%). In the month preceding the interview, 24% reported at least one unprotected insertive anal intercourse with a male partner, 20% at least one unprotected receptive anal intercourse, and 18% at least one unprotected intercourse with a female partner. Genital examination showed that 5% of participants had at least one clinical sign of STI. Factors associated with HIV infection were age group, the reporting of more than nine lifetime male partners [odds ratio (OR), 3.76; 95% CI, 1.61-8.79], being a waiter or bartender (OR, 3.33; 95% CI, 1.41-7.84), and living in Dakar (OR, 3.33; 95% CI, 1.07-3.43). CONCLUSION: Men who have sex with men in Senegal are highly infected with HIV and other STI. Intervention programs targeting this population are urgently needed, given their particular vulnerability and because infections are likely to disseminate into the general population given the high proportion of bisexual activity in this community.