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Nelly Mugo - One of the best experts on this subject based on the ideXlab platform.
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Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention a longitudinal analysis
Lancet Infectious Diseases, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly MugoAbstract:Summary Background Scarce data are available to assess Sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased Sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased Sexual risk behaviour. Methods We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heteroSexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of Sex—Unprotected by a condom—during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased Sexual risk behaviour. Results We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of Unprotected Sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in Unprotected Sex with outside partners after July, 2011, but the effect was small (average of 6·8 Unprotected Sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident Sexually transmitted infections or pregnancy after July, 2011. Interpretation Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk-taking Sexual behaviour by heteroSexual couples. Funding The Bill & Melinda Gates Foundation and the US National Institute of Mental Health.
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o11 2 Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention post unblinding analysis of the partners prep study
Sexually Transmitted Infections, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly Mugo, Kenneth Ngure, Elly KatabiraAbstract:Background Limited data are available to assess the potential for increased Sexual risk-taking by persons using antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention. In July 2011, the Partners PrEP Study, a randomised trial of daily oral tenofovir and emtricitabine/tenofovir PrEP among HIV-uninfected members of African heteroSexual HIV serodiscordant couples, demonstrated efficacy of PrEP for HIV prevention and use of placebo was discontinued in the trial. Follow-up of study participants on active PrEP through December 2012 provided an opportunity to evaluate risk behaviour on PrEP after efficacy was announced. Methods Among participants assigned to active PrEP pre-unblinding who continued follow-up after the placebo arm was stopped, we used zero-inflated negative binomial regression with robust standard errors and adjusted for baseline Sexual behaviour, age, gender, and secular changes to compare the frequency of Unprotected Sex up to 12 months before versus after knowledge of PrEP efficacy. Results We analysed 54,876 person-months (33,254 pre- versus 21,622 post-unblinding) from 3024 HIV-uninfected subjects (64% male). On average, the observed frequency of Unprotected Sex with the HIV-infected study partner was 58 per 100 person-months pre-unblinding versus 53 per 100 person-months post-unblinding, reflecting no immediate change or change in trend over time following unblinding (p = 0.734 and 0.264, respectively). The annual average total number of Unprotected Sex post-unblinding was 6 acts versus 5 that would have been expected in the counterfactual situation had unblinding not occurred. There was no significant increase in diagnoses of incident Sexually transmitted infections or pregnancy post- versus pre-unblinding (p > 0.05). Conclusion The transition from a blinded, placebo-controlled trial to all participants aware they were receiving active PrEP in the Partners PrEP Study provided a “natural experiment” to evaluate behavioural risk compensation. PrEP, provided as part of a comprehensive prevention package, may not result in substantial changes in risk-taking Sexual behaviour in HIV serodiscordant couples.
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daily short message service surveys to measure Sexual behavior and pre exposure prophylaxis use among kenyan men and women
Aids and Behavior, 2013Co-Authors: Kathryn Curran, Deborah Donnell, Nelly Mugo, Ann Kurth, Kenneth Ngure, Renee HeffronAbstract:Pre-exposure prophylaxis (PrEP) is a novel HIV prevention strategy which requires high adherence. We tested the use of daily short message service (i.e., SMS/text message) surveys to measure Sexual behavior and PrEP adherence in Kenya. Ninety-six HIV-uninfected adult individuals, taking daily oral PrEP in a clinical trial, received daily SMS surveys for 60 days. Most participants (96.9 %) reported taking PrEP on ≥80 % days, but 69.8 % missed at least one dose. Unprotected Sex was reported on 4.9 % of days; however, 47.9 % of participants reported Unprotected Sex at least once. Unprotected Sex was not correlated with PrEP use (OR = 0.95). Participants reporting more Sex were less likely to report PrEP non-adherence and those reporting no Sex were most likely to report missing a PrEP dose (adjusted OR = 1.87). PrEP adherence was high, missed doses were correlated with Sexual abstinence, and Unprotected Sex was not associated with decreased PrEP adherence.
Deborah Donnell - One of the best experts on this subject based on the ideXlab platform.
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Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention a longitudinal analysis
Lancet Infectious Diseases, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly MugoAbstract:Summary Background Scarce data are available to assess Sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased Sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased Sexual risk behaviour. Methods We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heteroSexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of Sex—Unprotected by a condom—during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased Sexual risk behaviour. Results We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of Unprotected Sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in Unprotected Sex with outside partners after July, 2011, but the effect was small (average of 6·8 Unprotected Sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident Sexually transmitted infections or pregnancy after July, 2011. Interpretation Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk-taking Sexual behaviour by heteroSexual couples. Funding The Bill & Melinda Gates Foundation and the US National Institute of Mental Health.
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o11 2 Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention post unblinding analysis of the partners prep study
Sexually Transmitted Infections, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly Mugo, Kenneth Ngure, Elly KatabiraAbstract:Background Limited data are available to assess the potential for increased Sexual risk-taking by persons using antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention. In July 2011, the Partners PrEP Study, a randomised trial of daily oral tenofovir and emtricitabine/tenofovir PrEP among HIV-uninfected members of African heteroSexual HIV serodiscordant couples, demonstrated efficacy of PrEP for HIV prevention and use of placebo was discontinued in the trial. Follow-up of study participants on active PrEP through December 2012 provided an opportunity to evaluate risk behaviour on PrEP after efficacy was announced. Methods Among participants assigned to active PrEP pre-unblinding who continued follow-up after the placebo arm was stopped, we used zero-inflated negative binomial regression with robust standard errors and adjusted for baseline Sexual behaviour, age, gender, and secular changes to compare the frequency of Unprotected Sex up to 12 months before versus after knowledge of PrEP efficacy. Results We analysed 54,876 person-months (33,254 pre- versus 21,622 post-unblinding) from 3024 HIV-uninfected subjects (64% male). On average, the observed frequency of Unprotected Sex with the HIV-infected study partner was 58 per 100 person-months pre-unblinding versus 53 per 100 person-months post-unblinding, reflecting no immediate change or change in trend over time following unblinding (p = 0.734 and 0.264, respectively). The annual average total number of Unprotected Sex post-unblinding was 6 acts versus 5 that would have been expected in the counterfactual situation had unblinding not occurred. There was no significant increase in diagnoses of incident Sexually transmitted infections or pregnancy post- versus pre-unblinding (p > 0.05). Conclusion The transition from a blinded, placebo-controlled trial to all participants aware they were receiving active PrEP in the Partners PrEP Study provided a “natural experiment” to evaluate behavioural risk compensation. PrEP, provided as part of a comprehensive prevention package, may not result in substantial changes in risk-taking Sexual behaviour in HIV serodiscordant couples.
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daily short message service surveys to measure Sexual behavior and pre exposure prophylaxis use among kenyan men and women
Aids and Behavior, 2013Co-Authors: Kathryn Curran, Deborah Donnell, Nelly Mugo, Ann Kurth, Kenneth Ngure, Renee HeffronAbstract:Pre-exposure prophylaxis (PrEP) is a novel HIV prevention strategy which requires high adherence. We tested the use of daily short message service (i.e., SMS/text message) surveys to measure Sexual behavior and PrEP adherence in Kenya. Ninety-six HIV-uninfected adult individuals, taking daily oral PrEP in a clinical trial, received daily SMS surveys for 60 days. Most participants (96.9 %) reported taking PrEP on ≥80 % days, but 69.8 % missed at least one dose. Unprotected Sex was reported on 4.9 % of days; however, 47.9 % of participants reported Unprotected Sex at least once. Unprotected Sex was not correlated with PrEP use (OR = 0.95). Participants reporting more Sex were less likely to report PrEP non-adherence and those reporting no Sex were most likely to report missing a PrEP dose (adjusted OR = 1.87). PrEP adherence was high, missed doses were correlated with Sexual abstinence, and Unprotected Sex was not associated with decreased PrEP adherence.
Kenneth Mugwanya - One of the best experts on this subject based on the ideXlab platform.
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Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention a longitudinal analysis
Lancet Infectious Diseases, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly MugoAbstract:Summary Background Scarce data are available to assess Sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased Sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased Sexual risk behaviour. Methods We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heteroSexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of Sex—Unprotected by a condom—during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased Sexual risk behaviour. Results We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of Unprotected Sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in Unprotected Sex with outside partners after July, 2011, but the effect was small (average of 6·8 Unprotected Sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident Sexually transmitted infections or pregnancy after July, 2011. Interpretation Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk-taking Sexual behaviour by heteroSexual couples. Funding The Bill & Melinda Gates Foundation and the US National Institute of Mental Health.
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o11 2 Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention post unblinding analysis of the partners prep study
Sexually Transmitted Infections, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly Mugo, Kenneth Ngure, Elly KatabiraAbstract:Background Limited data are available to assess the potential for increased Sexual risk-taking by persons using antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention. In July 2011, the Partners PrEP Study, a randomised trial of daily oral tenofovir and emtricitabine/tenofovir PrEP among HIV-uninfected members of African heteroSexual HIV serodiscordant couples, demonstrated efficacy of PrEP for HIV prevention and use of placebo was discontinued in the trial. Follow-up of study participants on active PrEP through December 2012 provided an opportunity to evaluate risk behaviour on PrEP after efficacy was announced. Methods Among participants assigned to active PrEP pre-unblinding who continued follow-up after the placebo arm was stopped, we used zero-inflated negative binomial regression with robust standard errors and adjusted for baseline Sexual behaviour, age, gender, and secular changes to compare the frequency of Unprotected Sex up to 12 months before versus after knowledge of PrEP efficacy. Results We analysed 54,876 person-months (33,254 pre- versus 21,622 post-unblinding) from 3024 HIV-uninfected subjects (64% male). On average, the observed frequency of Unprotected Sex with the HIV-infected study partner was 58 per 100 person-months pre-unblinding versus 53 per 100 person-months post-unblinding, reflecting no immediate change or change in trend over time following unblinding (p = 0.734 and 0.264, respectively). The annual average total number of Unprotected Sex post-unblinding was 6 acts versus 5 that would have been expected in the counterfactual situation had unblinding not occurred. There was no significant increase in diagnoses of incident Sexually transmitted infections or pregnancy post- versus pre-unblinding (p > 0.05). Conclusion The transition from a blinded, placebo-controlled trial to all participants aware they were receiving active PrEP in the Partners PrEP Study provided a “natural experiment” to evaluate behavioural risk compensation. PrEP, provided as part of a comprehensive prevention package, may not result in substantial changes in risk-taking Sexual behaviour in HIV serodiscordant couples.
Steffanie A Strathdee - One of the best experts on this subject based on the ideXlab platform.
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amar te duele love hurts Sexual relationship power intimate partner violence depression symptoms and hiv risk among female Sex workers who use drugs and their non commercial steady partners in mexico
Aids and Behavior, 2015Co-Authors: Monica D Ulibarri, Hortensia Amaro, Scott C Roesch, Gudelia M Rangel, Hugo Staines, Steffanie A StrathdeeAbstract:A significant body of research among female Sex workers (FSWs) has focused on individual-level HIV risk factors. Comparatively little is known about their non-commercial, steady partners who may heavily influence their behavior and HIV risk. This cross-sectional study of 214 FSWs who use drugs and their male steady partners aged ≥18 in two Mexico-U.S. border cities utilized a path-analytic model for dyadic data based upon the Actor-Partner Interdependence Model to examine relationships between Sexual relationship power, intimate partner violence (IPV), depression symptoms, and Unprotected Sex. FSWs' relationship power, IPV perpetration and victimization were significantly associated with Unprotected Sex within the relationship. Male partners' depression symptoms were significantly associated with Unprotected Sex within the relationship. Future HIV prevention interventions for FSWs and their male partners should address issues of Sexual relationship power, IPV, and mental health both individually and in the context of their relationship.
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mujer mas segura safer women a combination prevention intervention to reduce Sexual and injection risks among female Sex workers who inject drugs
BMC Public Health, 2012Co-Authors: Alicia Vera, Thomas L Patterson, Remedios Lozada, Daniela Abramovitz, Gudelia M Rangel, Hugo Staines, Gustavo J Martinez, Steffanie A StrathdeeAbstract:Female Sex workers who inject drugs (FSW-IDUs) are at risk of acquiring HIV, Sexually transmitted infections (STI) and blood-borne infections through Unprotected Sex and sharing injection equipment. We conducted a 2×2 factorial randomized controlled trial to evaluate combination interventions to simultaneously reduce Sexual and injection risks among FSW-IDUs in Tijuana and Ciudad Juarez, Mexico. FSW-IDUs ≥18 years reporting sharing injection equipment and Unprotected Sex with clients within the last month were randomized to one of four conditions based on an a priori randomization schedule, blinding interviewer/counselors to assignment. Due to the extreme vulnerability of this population, we did not include a control group that would deny some women access to preventive information. All women received similar information regardless of group allocation; the difference was in the way the information was delivered and the extent to which women had an interactive role. Each condition was a single 60-minute session, including either an interactive or didactic version of an injection risk intervention and Sexual risk intervention. Women underwent interviewer-administered surveys and testing for HIV, syphilis, gonorrhea, Chlamydia, and Trichomonas at baseline and quarterly for 12 months. Combined HIV/STI incidence will be the primary outcome. Secondary outcomes are proportionate reductions in sharing of injection equipment and Unprotected Sex with clients. Of 1,132 women, 548 (48.4%) were excluded (88.9% were ineligible; 11.1% refused to participate or did not return); 584 eligible women enrolled (284 in Tijuana; 300 in Ciudad Juarez). All 584 participants completed the baseline interview, provided biological samples and were randomized to one of the four groups. During follow-up, 17 participants (2.9%) were lost to follow-up, of whom 10 (58.8%) had died, leaving 567 participants for analysis. This study appears to be the first intervention to attempt to simultaneously reduce injection and Sexual risk behaviors among FSW-IDUs. The factorial design will permit analysis to determine whether the combination of the two interactive interventions and/or its respective components are effective in reducing injection and/or Sexual risks, which will have direct, tangible policy implications for Mexico and potentially other resource-poor countries. NCT00840658
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identifying the hiv transmission bridge which men are having unsafe Sex with female Sex workers and with their own wives or steady partners
Journal of Acquired Immune Deficiency Syndromes, 2012Co-Authors: Thomas L Patterson, Remedios Lozada, Shirley J Semple, Shira M Goldenberg, Tyson Volkmann, Manuel Gallardo, Christy M Anderson, Steffanie A StrathdeeAbstract:OBJECTIVE: To gain insights into bridging behaviors and their correlates among male clients of female Sex workers (FSWs). METHODS: Men aged >/=18 years who recently paid or traded for Sex with FSWs were recruited in Tijuana in 2008-2009. Participants underwent interviews and testing for HIV chlamydia syphilis and gonorrhea. Logistic regression compared "bridgers" (clients who had Unprotected Sex with FSWs and with a wife or steady partner) with men who did not. RESULTS: Of 383 men 134 (35%) had a steady partner. Half (n = 70) of those had Unprotected Sex with both FSWs and the steady partner. Prevalence of any Sexually transmitted infection or HIV was 16.5% among bridgers and 2.3% among nonbridgers. Compared with other clients bridgers were more likely to use drugs during Sex with FSWs (81.4% versus 46.9% P < 0.0001) had higher sensation-seeking (P < 0.0001) and misogyny scores (P = 0.05) and were more likely to offer FSWs extra money for Unprotected Sex (34.4% versus 1.6% P < 0.0001). Factors independently associated with bridging were as follows: using drugs during Sex with FSWs [adjusted odds ratio (AOR): 3.4 P = 0.007] sensation seeking (AOR: 4.3 per unit increase P = 0.05) and offering FSWs more money for Unprotected Sex (AOR: 24.5 P = 0.003). CONCLUSION: Sensation-seeking clients who use drugs during Sex and coerce FSWs into Unprotected Sex may be less responsive to standard risk reduction interventions. Interventions are needed that target clients rather than rely on FSWs to change behaviors that may not be under their control.
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correlates of Unprotected Sex with female Sex workers among male clients in tijuana mexico
Sexually Transmitted Diseases, 2010Co-Authors: Shira M Goldenberg, Shirley J Semple, Manuel Gallardo Cruz, Steffanie A Strathdee, Lucie Nguyen, Thomas L PattersonAbstract:BACKGROUND Tijuana, situated adjacent to San Diego, CA on the US-Mexico border, is experiencing an emerging HIV epidemic, with prevalence among female Sex workers (FSWs) having risen in recent years from <1% to 6%. Comparable data on FSWs' clients are lacking. We explored correlates of Unprotected Sex with FSWs among male clients in Tijuana. METHODS In 2008, males from San Diego (N = 189) and Tijuana (N = 211) aged 18 or older who had paid or traded for Sex with a FSW in Tijuana during the past 4 months were recruited in Tijuana's red light district. Participants underwent psychosocial interviews, and were tested for HIV, syphilis (Treponema pallidum), gonorrhea (Neisseria gonorrhoeae), and Chlamydia (Chlamydia trachomatis). RESULTS Of 394 men, median age was 36 years, 42.1% were married, and 39.3% were unemployed. Ethnic composition was 13.2% white, 79.4% Hispanic, and 7.4% black or other. Half (50.3%) reported Unprotected vaginal or anal Sex with FSWs in Tijuana in the past 4 months. High proportions reported using drugs during Sex (66%), and 36% reported frequenting the same FSW. Factors independently associated with Unprotected Sex with FSWs were using drugs during Sex, visiting the same FSW, being married, and being unemployed. CONCLUSIONS FSWs' clients represent a Sexually transmitted infections/HIV transmission "bridge" through Unprotected Sex with FSWs, wives, and other partners. Tailored interventions to promote consistent condom use are needed for clients, especially within the context of drug use and ongoing relations with particular FSWs.
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an exploration of contextual factors that influence hiv risk in female Sex workers in mexico the social ecological model applied to hiv risk behaviors
Aids Care-psychological and Socio-medical Aspects of Aids\ hiv, 2009Co-Authors: Sandra E Larios, Remedios Lozada, Shirley J Semple, Prisci Orozovich, Hortensia Amaro, Steffanie A Strathdee, Scott C Roesch, Hugo Staines, Miguel Fraga, Adela De La TorreAbstract:The present study examined the applicability of the Social Ecological Model for explaining condom use in a sample of female Sex workers (FSWs) (N=435) participating in a behavioral intervention to increase condom use in Tijuana, Mexico. Using a multigroup path analysis, we compared women who work in bar settings (n=233) to those who worked on the street (n=202) with regard to an individual factor (self-efficacy), an interpersonal factor (client financial incentives), and a structural factor (condom access). Competing models showed differential impacts of these factors in the two venue-based groups. Having access to condoms was associated with greater self-efficacy and less Unprotected Sex in women who worked in bars. Among street-based FSWs, having clients offer monetary incentives for Unprotected Sex was related to greater Unprotected Sex, while having access to condoms was not. Understanding the contextual factors associated with condom use among subgroups of FSWs has important implications for the development of HIV prevention interventions.
Patrick Ndase - One of the best experts on this subject based on the ideXlab platform.
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Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention a longitudinal analysis
Lancet Infectious Diseases, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly MugoAbstract:Summary Background Scarce data are available to assess Sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased Sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased Sexual risk behaviour. Methods We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heteroSexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of Sex—Unprotected by a condom—during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased Sexual risk behaviour. Results We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of Unprotected Sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in Unprotected Sex with outside partners after July, 2011, but the effect was small (average of 6·8 Unprotected Sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident Sexually transmitted infections or pregnancy after July, 2011. Interpretation Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk-taking Sexual behaviour by heteroSexual couples. Funding The Bill & Melinda Gates Foundation and the US National Institute of Mental Health.
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o11 2 Sexual behaviour of heteroSexual men and women receiving antiretroviral pre exposure prophylaxis for hiv prevention post unblinding analysis of the partners prep study
Sexually Transmitted Infections, 2013Co-Authors: Kenneth Mugwanya, Deborah Donnell, Connie Celum, Katherine K Thomas, Patrick Ndase, Nelly Mugo, Kenneth Ngure, Elly KatabiraAbstract:Background Limited data are available to assess the potential for increased Sexual risk-taking by persons using antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention. In July 2011, the Partners PrEP Study, a randomised trial of daily oral tenofovir and emtricitabine/tenofovir PrEP among HIV-uninfected members of African heteroSexual HIV serodiscordant couples, demonstrated efficacy of PrEP for HIV prevention and use of placebo was discontinued in the trial. Follow-up of study participants on active PrEP through December 2012 provided an opportunity to evaluate risk behaviour on PrEP after efficacy was announced. Methods Among participants assigned to active PrEP pre-unblinding who continued follow-up after the placebo arm was stopped, we used zero-inflated negative binomial regression with robust standard errors and adjusted for baseline Sexual behaviour, age, gender, and secular changes to compare the frequency of Unprotected Sex up to 12 months before versus after knowledge of PrEP efficacy. Results We analysed 54,876 person-months (33,254 pre- versus 21,622 post-unblinding) from 3024 HIV-uninfected subjects (64% male). On average, the observed frequency of Unprotected Sex with the HIV-infected study partner was 58 per 100 person-months pre-unblinding versus 53 per 100 person-months post-unblinding, reflecting no immediate change or change in trend over time following unblinding (p = 0.734 and 0.264, respectively). The annual average total number of Unprotected Sex post-unblinding was 6 acts versus 5 that would have been expected in the counterfactual situation had unblinding not occurred. There was no significant increase in diagnoses of incident Sexually transmitted infections or pregnancy post- versus pre-unblinding (p > 0.05). Conclusion The transition from a blinded, placebo-controlled trial to all participants aware they were receiving active PrEP in the Partners PrEP Study provided a “natural experiment” to evaluate behavioural risk compensation. PrEP, provided as part of a comprehensive prevention package, may not result in substantial changes in risk-taking Sexual behaviour in HIV serodiscordant couples.
