Generational analysis of trends in unprotected sex in France among men who have sex with men: The major role of context-driven evolving patterns

<div><p>Objective</p><p>Using a generational approach, this study analyses how unprotected anal intercourse has evolved since 1991 in France across different generations of men who have sex with men (MSM) whose sexual lives began at different periods in the history of the HIV epidemic.</p><p>Design</p><p>Data were collected from 18–59 year-old respondents to the French Gay Press surveys <i>Enquêtes Presse Gay</i>, conducted repeatedly between 1991 and 2011 (N = 32,196) using self-administered questionnaires distributed in gay magazines and over the internet.</p><p>Methods</p><p>Trends in unprotected anal intercourse (i.e. condomless anal sex) with casual partners of unknown or different HIV serostatus (hereafter “UAId” in this manuscript) were studied. Responses were analysed according to year and then reorganised for age-cohort analyses by generation, based on the year respondents turned 18.</p><p>Results</p><p>UAId rates fell from 1991 to 1997, and then rose from 13.4% in 1997 to 25.5% in 2011 among seronegative respondents, and from 24.8% to 63.3%, respectively, among seropositive respondents. Both in seropositive and seronegative respondents, UAId increased over time for all generations, indicative of a strong period effect.</p><p>Conclusion</p><p>Analyses of data from several generations of MSM who started their sexual lives at different time points in the HIV epidemic, revealed very similar trends in UAId between generations, among both seropositive and seronegative respondents. This strong period effect suggests that sexual behaviours in MSM are influenced more by contextual than generational factors. The fact that prevention practices are simultaneously observed in different generations and that there are most likely underlying prevention norms among MSM, suggests that PrEP could become widely accepted by all generations of MSM exposed to the risk of HIV.</p></div

Social and demographic characteristics, HIV status and UAI in the previous 12 months with casual partners, among respondents to the Gay Press surveys.

<p>Social and demographic characteristics, HIV status and UAI in the previous 12 months with casual partners, among respondents to the Gay Press surveys.</p

Longitudinal changes from 1997 to 2011 in the percentage of respondents who reported at least one episode of UAId. (A) seronegative respondents; (B) seropositive respondents.

<p>The dotted curves link the points obtained during the same survey year. UAId: unprotected anal intercourse in the 12 months before the survey with a casual partner of unknown or different HIV serostatus. Looking at Fig 2 we see that the generation of HIV seronegative MSM who turned 18 between 1984 and 1987 is represented by the green curve in Fig 2A. When responding to the 1997 Gay Press survey this generation's mean age was 29.6 years, and 13.2% reported having UAId at least once during the previous year. When this generation responded to the 2000 survey, the mean age was 32.5 years, and 16.0% reported having UAId at least once during the previous year. In 2004 and 2011, with mean ages of 36.5 years and 43.5 years, respectively, 18.3% and 24.0% of the seronegative MSM from this generation who responded to the surveys, reported having UAId at least once during the preceding year. Similarly, in Fig 2B, the green curve represents the generation of seropositive MSM that turned 18 years old between 1984 and 1987. This generation's mean age when they responded to the 1997 Gay Press survey was 29.9 years, and 21.3% reported having UAId at least once during the previous year. This generation’s mean age when they responded to the 2000 survey was 32.7 years, and 37.3% reported having UAId at least once during the previous year. In 2004 and 2011, with mean ages of 36.6 years and 43.5 years, respectively, 48.0% and 58.8% of the seropositive MSM this generation reported at least one episode of UAId during the preceding year.</p

Trends in the percentage of respondents reporting at least one episode of UAId, as a function of HIV serostatus, in the Gay Press surveys from 1991 to 2011.

<p>UAId: unprotected anal intercourse in the 12 months before the survey with a casual partner of unknown or different HIV serostatus.</p

Photomicrographs of sagittal sections of sciatic nerves (A-D,I-L) or intraplantar skins (E-H) dissected from (VEH_crem + VEH_hpc)(A,E,I)-, (PAC + VEH_hpc)(B,F,J)-, (VEH_crem + 3α-DIOL)(C,G,K)- or (PAC + 3α-DIOL)(D,H,L)-treated rats.

<p>Nerve sections were labeled with the monoclonal NF200 antibody (<b>A</b>-<b>D</b>) or with the monoclonal anti-CNPase (<b>I</b>-<b>L</b>) revealed with Alexa-488-conjugated donkey anti-mouse. (<b>E</b>-<b>H</b>) Intraplantar skin sections were labeled with the polyclonal anti-PGP9.5 revealed with FITC-conjugated goat anti-rabbit. White arrows indicated intraepidermal nerve fibers. Scale bar, 50 µm.</p

Effects of 3α-DIOL (4 mg/kg/2 days) corrective (A-E) or prophylactic (F-J) treatment on PAC-induced neuropathic pain symptoms.

<p>(<b>A</b>-<b>C</b>,<b>F</b>-<b>H</b>) Action of 3α-DIOL against PAC-induced mechanical allodynia (<b>A</b>,<b>F</b>) and hyperalgesia (<b>B</b>,<b>C</b>,<b>G</b>,<b>H</b>). Chartbars show the mean + SEM of the percentages of paw withdrawal responses to mechanical stimulation by von Frey filament 4 g (<b>A</b>,<b>F</b>), 15 g (<b>B</b>,<b>G</b>) or 26 g (<b>C</b>,<b>H</b>) (n=8 per group). (<b>D</b>,<b>I</b>) Effect of 3α-DIOL against PAC-evoked cold-allodynia. (<b>E</b>,<b>J</b>) 3α-DIOL effects on the heat thermal nociceptive thresholds of vehicle- and PAC-treated rats. Each bar represents the mean + SEM of 6 observations in each of 8 rats. Non-parametric Mann-Whitney <i>U</i> test was used for the analysis of the von Frey test results and two-way repeated measures ANOVAs followed by Newman-Keuls <i>post </i><i>hoc</i> comparisons were used for acetone and Plantar Tests. Statistical differences between controls and each treatment group at each testing day are shown. * <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.005. * vs (VEH_crem + VEH_hpc), # vs (PAC + VEH_hpc).</p

Curative effects of 3α-DIOL against PAC-induced reduction of sciatic nerve action potential parameters (CV_latency: A; CV_peak: B and peak amplitude: C).

<p>Histograms of normalized CV_latency and CV_peak show their reduction by PAC and recovery by 3α-DIOL treatment (<b>A</b>,<b>B</b>). Mean CV values were calculated as % of the mean CV obtained from vehicle-treated rats. (<b>C</b>) Recovery from PAC-induced NAP peak amplitude decrease by 3α-DIOL treatment. Each value is the mean (+SEM) of NAP peak amplitude obtained from 8 rat sciatic nerves per each group investigated. ** <i>p</i><0.01, *** <i>p</i><0.005. * vs (VEH_crem + VEH_hpc), # vs (PAC + VEH_hpc).</p

Effect of PAC treatment on the rat mechanical (A-C) and thermal (D, E) nociceptive threshold.

<p>(<b>A</b>-<b>C</b>) Time-course of mechanical allodynia (<b>A</b>) and hyperalgesia (<b>B</b>,<b>C</b>) induced by PAC treatment. Graphs show the mean + SEM of the percentages of paw withdrawal responses to mechanical stimulation by von Frey filament 4 g (<b>A</b>), 15 g (<b>B</b>) or 26 g (<b>C</b>) (n=8 per group). (<b>D</b>,<b>E</b>) Effects of PAC treatment on rat cold (<b>D</b>) or heat (<b>E</b>) thermal nociceptive threshold assessed by acetone (<b>D</b>) or Plantar (<b>E</b>) tests. Each point represents the mean + SEM of 6 observations in each of 8 rats. Non-parametric Mann-Whitney <i>U</i> test was used for the analysis of the von Frey test results and one-way repeated measures ANOVAs followed by Newman-Keuls <i>post </i><i>hoc</i> comparisons were used for acetone and Plantar tests. Statistical differences between control and paclitaxel group on each testing day are shown. * <i>p</i><0.05, *** <i>p</i><0.005. </p

Dose- and injection frequency-dependent effects of corrective 3α-DIOL treatment on the mechanical nociceptive thresholds of control- and PAC-treated rats.

<p>Corrective treatment every 2- (<b>A</b>) or 4-days (<b>B</b>) consisted in starting 3α-DIOL (2 or 4 mg/kg) or VEH_hpc i.p. administrations 2 days after the end of PAC treatment. Threshold values represent responses to 26 g von Frey filament (% ± SEM). Non-parametric Mann-Whitney <i>U</i> test was used. Statistical differences between controls and each treatment group at each testing day are shown. n=6 per group; * <i>p</i><0.05. * compared to VEH_crem+VEH_hpc; # compared to PAC+VEH_hpc.</p

Photomicrographs of sagittal sections of sciatic nerves (A,B,E,F) or hind paw intraplantar skins (C,D) dissected from vehicle (A,C,E)- and PAC (B,D,F)-treated rats.

<p>Nerve sections were labeled with the monoclonal NF200 antibody (<b>A</b>,<b>B</b>) or with the monoclonal anti-CNPase (<b>E</b>,<b>F</b>) revealed with Alexa-488-conjugated donkey anti-mouse. (<b>C</b>,<b>D</b>) Intraplantar skin sections were labeled with the polyclonal anti-PGP9.5 revealed with FITC-conjugated goat anti-rabbit. White arrows indicated intraepidermal nerve fibers. Scale bar=50µm.</p