Increasing frequency of self-reported orogenital HIV-1 transmission among men having sex with men: The ANRS PRIMO Cohort

Spatiotemporal dynamics of HIV-1 transmission in France (1999-2014) and impact of targeted prevention strategies

Background

Characterizing HIV-1 transmission networks can be important in understanding the evolutionary patterns and geospatial spread of the epidemic. We reconstructed the broad molecular epidemiology of HIV from individuals with primary HIV-1 infection (PHI) enrolled in France in the ANRS PRIMO C06 cohort over 15 years.

Results

Sociodemographic, geographic, clinical, biological and pol sequence data from 1356 patients were collected between 1999 and 2014. Network analysis was performed to infer genetic relationships, i.e. clusters of transmission, between HIV-1 sequences. Bayesian coalescent-based methods were used to examine the temporal and spatial dynamics of identified clusters from different regions in France. We also evaluated the use of network information to target prevention efforts. Participants were mostly Caucasian (85.9%) and men (86.7%) who reported sex with men (MSM, 71.4%). Overall, 387 individuals (28.5%) were involved in clusters: 156 patients (11.5%) in 78 dyads and 231 participants (17%) in 42 larger clusters (median size: 4, range 3–41). Compared to individuals with single PHI (n = 969), those in clusters were more frequently men (95.9 vs 83%, p < 0.01), MSM (85.8 vs 65.6%, p < 0.01) and infected with CRF02_AG (20.4 vs 13.4%, p < 0.01). Reconstruction of viral migrations across time suggests that Paris area was the major hub of dissemination of both subtype B and CRF02_AG epidemics. By targeting clustering individuals belonging to the identified active transmission network before 2010, 60 of the 143 onward transmissions could have been prevented.

Conclusion

These analyses support the hypothesis of a recent and rapid rise of CRF02_AG within the French HIV-1 epidemic among MSM. Combined with a short turnaround time for sample processing, targeting prevention efforts based on phylogenetic monitoring may be an efficient way to deliver prevention interventions but would require near real time targeted interventions on the identified index cases and their partners.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-017-0339-4) contains supplementary material, which is available to authorized users.

Sexual and prevention practices in men who have sex with men in the era of combination HIV prevention: results from the Presse Gays et Lesbiennes survey, France, 2011

To better understand the diversity of practices and behaviours to prevent HIV with casual partners, data from a large convenience sample of men who have sex with men (MSM) in France were categorised into different prevention profiles: no anal intercourse, consistent condom use during anal intercourse, risk-reduction practices (serosorting, seropositioning) and no discernible prevention practice (NDPP). Categories were applied to HIV-positive respondents with controlled (CI; n=672) and uncontrolled infection (UI; n=596), HIV-negative (n=4,734) and untested respondents (n=663). Consistent condom use was reported by 22% (n=148) of HIV-positive-CI respondents, 13% (n=79) of HIV-positives UI, 55% (2,603) of HIV-negatives, and 50% (n=329) of untested (p<0.001). Corresponding figures for NDPP were 45% (n=304), 55% (n=327), 21% (n=984) and 34% (n=227) (p<0.001). Logistic regressions showed that, regardless of respondents' serostatus, NDPP was associated with regularly frequenting dating websites, drug use, exposure to sperm during oral sex, and with HIV diagnosis after 2000 for HIV-positive respondents (CI and UI), with age <30 years for HIV-positive-CI, and with low education for HIV-negatives. Risk-taking remains high, despite implementation of risk-reduction practices. A global health approach should be central to prevention programmes for MSM, to include target behavioural intervention, promotion of condom use, and encouragement of regular HIV testing and early initiation of ART.