High frequency of HIV-1 infections with multiple HIV-1 strains in men having sex with men (MSM) in Senegal.

Circulating and unique recombinant HIV-1 strains continue to be identified and their number increases over time, suggesting that co-infection with multiple HIV-1 is frequent. In this study we analyzed to what extent dual infections with different HIV-1 variants occur in a population group with high risk behaviour, high HIV-1 prevalence and in an area where multiple HIV-1 subtypes and Circulating Recombinant Forms (CRFs) co-circulate. We studied 69 MSM with our recently developed multi-region hybridization assay (MHA), based on fluorescent probe detection for eight common variants circulating in West and West Central Africa. At least 11 (15.9%) of the 69 patients were simultaneously infected with two different HIV-1 subtypes and/or CRFs. Among the 29 samples identified as subtype C by MHA in gag, 15 (57.7%) reacted with both C1 and C2 probes. Sequence analysis suggests that the majority of the samples reactive with C1 and C2 probes are most likely infected with two different subtype C clades. Single genome amplification and DNA dilutions confirmed dual infection with subtype D and C for MSM1193, triple infection with two different C subtype strains and one CRF02_AG strain in MSM1157 and showed that MSM3017 is at least co-infected with CRF06_cpx and CRF02_AG and another strain that could not be classified. Comparison of all subtype C sequences from the MSM population and from the general population from this and previous studies confirmed the intermixing of HIV-1 variants between low-risk women and high-risk men as shown by the intermixing of subtype C variants from MSM1157 and a female patient (02SN-HALD478). Comparison of dual infection rates between the general population and MSM in Senegal, show also clearly the importance of high HIV prevalence and high risk behavior in dual infections and subsequent intermixing of HIV-1 variants which can lead to emergence and spread of new recombinants (CRFs).

Surprisingly high prevalence of subtype C and specific HIV-1 subtype/CRF distribution in men having sex with men in Senegal.

BACKGROUND: Recent reports showed the high vulnerability for HIV infection of men who have sex with men (MSM) in Africa. Here, we report the HIV-1 variants that circulate among MSM in Senegal. METHODS: HIV-1 subtype/circulating recombinant form (CRF) was determined in an 1800-base pair fragment of pol for 70 HIV-1-positive samples from MSM. Phylogenetic trees were constructed using the neighbor-joining method with CLUSTALX. Similarity and bootstrap plots were then done for recombination analysis. The maximum likelihood approach was used for the identification of transmission clusters. RESULTS: Sixty-seven samples (95%) were from Senegalese MSM, 90% unmarried with a median age of 30 years. Fifty-five MSM had regular male partners, but 39 of 70 had also a regular female partner. The overall subtype/CRF distribution was as follows: 28 C (40%), 17 CRF02_AG (24.3%), 13 B (18.6%), 6 G (8.6%), 3 CRF09_cpx (4.3%), and 3 (4.3%) unique recombinants. In addition, 47 sequences (67.15%) were segregated into 15 transmission clusters. CONCLUSIONS: These variants circulate also among the general population or female sex workers, but the proportions are significantly different. Despite the massive stigma, the majority (80%) of MSM recognized having sex with women and could serve as a bridge for intermixing of HIV-1 variants between high-risk men and low-risk women.

Quantitation of HIV-1 RNA in dried blood spots by the real-time NucliSENS EasyQ HIV-1 assay in Senegal.

Measurement of viral load in plasma remains the best marker for the follow-up of antiretroviral therapy. However, its use is limited in developing countries due to the lack of adequate facilities and equipment, and cryopreservation of plasma during storage and transportation. Practical and reliable methods adapted to field conditions for the collection, transportation and accurate measurement of HIV-1 viral load are needed for the optimum use of antiretroviral therapy in resource-limited countries. This study evaluated the use of dried blood spots (DBS) for the real-time quantitation of HIV-1 RNA levels with the NucliSENS EasyQ((R)) HIV-1 assay (bioMérieux, Lyon, France) under field conditions in Senegal (Africa). Dried blood spots and plasma from 41 patients living in suburban Dakar were used for determination of HIV-1 RNA concentrations and stability at 37 degrees C. Analysis was performed at the Dakar University Hospital laboratory. Extraction was done with the bioMérieux NucliSENS((R)) miniMAGtrade mark, and real-time detection was done with the bioMérieux NucliSENS((R)) EasyQ system. HIV-1 RNA concentrations in plasma were compared with concentrations in dried blood spots after 8 and 15 days at 37 degrees C. The study showed a strong concordance in RNA levels between plasma and dried blood spots, which appear to be very stable over time with no apparent degradation observed after 2 weeks at 37 degrees C (mean difference 0.065logIU/ml). These results suggest that the use of dried blood spots in combination with the NucliSENS EasyQ HIV-1 assay is well adapted for HIV-1 RNA level monitoring in centralized laboratories in developing countries.

HIV infection and sexually transmitted infections among men who have sex with men in Senegal.

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.