Articles tagged as "Combination prevention"

Study finds rectal gel to be safe in men, but not as acceptable for daily use

MTN-017: a rectal phase 2 extended safety and acceptability study of tenofovir reduced-glycerin 1% gel.

Cranston RD, Lama JR, Richardson BA, Carballo-Dieguez A, Kunjara Na Ayudhya RP, Liu K, Patterson KB, Leu CS, Galaska B, Jacobson CE, Parikh UM, Marzinke MA, Hendrix CW, Johnson S, Piper JM, Grossman C, Ho KS, Lucas J, Pickett J, Bekker LG, Chariyalertsak S, Chitwarakorn A, Gonzales P, Holtz TH, Liu AY, Mayer KH, Zorrilla C, Schwartz JL, Rooney J, McGowan I; MTN-017 Protocol Team. Clin Infect Dis. 2016 Dec 16. pii: ciw832. [Epub ahead of print]

Background: HIV disproportionately affects men who have sex with men (MSM) and transgender women (TGW). Safe and acceptable topical HIV prevention methods that target the rectum are needed.

Methods: MTN-017 was a Phase 2, three-period, randomized sequence, open-label, expanded safety and acceptability crossover study comparing rectally applied reduced-glycerin (RG) 1% tenofovir (TFV) and oral emtricitabine/TFV disoproxil fumarate (FTC/TDF). In each 8-week study period participants were randomized to RG-TFV rectal gel daily; or RG-TFV rectal gel before and after receptive anal intercourse (RAI) (or at least twice weekly in the event of no RAI); or daily oral FTC/TDF.

Results: MSM and TGW (n=195) were enrolled from 8 sites in the United States, Thailand, Peru, and South Africa with mean age of 31.1 years (range 18-64). There were no differences in Grade 2 or higher adverse event rates in participants using daily gel (Incidence Rate Ratio (IRR): 1.09, p=0.59) or RAI gel (IRR: 0.90, p=0.51) compared to FTC/TDF. High adherence (≥80% of prescribed doses as assessed by unused product return and SMS reports) was less likely in the daily gel regimen (Odds Ratio (OR): 0.35, p<0.001) and participants reported less likelihood of future daily gel use for HIV protection compared to FTC/TDF (OR: 0.38, p<0.001).

Conclusions: Rectal application of RG TFV gel was safe in MSM and TGW. Adherence and product use likelihood were similar for the intermittent gel and daily oral FTC/TDF regimens, but lower for the daily gel regimen.

Abstract access  

Editor’s notes: While microbicide gel to prevent HIV in women has not been consistently shown to be effective, scientific efforts to develop a rectal microbicide gel have continued in the hopes of finding a safe and effective product for HIV prevention in men. This paper presents a phase II clinical trial in which gay men and other men who have sex with men across four different countries were randomly assigned to one of three arms: oral pre-exposure prophylaxis (‘daily oral’), topical gel administered before and after receptive anal intercourse (‘RAI’), and topical gel administered daily (‘daily rectal’). The authors found that the rectal gel was safe to use, and was acceptable to participants, although the daily rectal application had lower acceptability and lower adherence than daily oral or the RAI.  This safety, adherence, and acceptability seen in this Phase II study supports further development of the gel as a rectal microbicide candidate, although consideration will need to be given to dosing regimens to maximize adherence. 

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Rape and ARV uptake/adherence

Impact of sexual trauma on HIV care engagement: perspectives of female patients with trauma histories in Cape Town, South Africa.

Watt MH, Dennis AC, Choi KW, Ciya N, Joska JA, Robertson C, Sikkema KJ. AIDS Behav. 2016 Nov 19. [Epub ahead of print]

South African women have disproportionately high rates of both sexual trauma and HIV. To understand how sexual trauma impacts HIV care engagement, we conducted in-depth qualitative interviews with 15 HIV-infected women with sexual trauma histories, recruited from a public clinic in Cape Town. Interviews explored trauma narratives, coping behaviors and care engagement, and transcripts were analyzed using a constant comparison method. Participants reported multiple and complex traumas across their lifetimes. Sexual trauma hindered HIV care engagement, especially immediately following HIV diagnosis, and there were indications that sexual trauma may interfere with future care engagement, via traumatic stress symptoms including avoidance. Disclosure of sexual trauma was limited; no woman had disclosed to an HIV provider. Routine screening for sexual trauma in HIV care settings may help to identify individuals at risk of poor care engagement. Efficacious treatments are needed to address the psychological and behavioral sequelae of trauma.

Abstract access  

Editor’s notes: Few studies have examined the impact of violence exposure on ART uptake and adherence. There is also a paucity of studies from low- and middle-income countries. South African women face a dual burden of HIV and violence risk, especially in areas characterized by extreme poverty, substance abuse and gender inequality. This study used qualitative interviews with 15 women living with HIV with histories of sexual trauma and attending an HIV-treatment clinic. The authors explore the intersections between sexual trauma experience, HIV infection and engagement with HIV care services.

Women reported complex sexual trauma histories, with repeated abuse from childhood into adulthood. This abuse was usually from family members or ‘lovers’. Sexual violence was usually accompanied by physical and emotional abuse. Women described symptoms of post-traumatic stress disorder and depression. Many associated their HIV infection with their sexual trauma / abusive relationship(s). For some, the HIV diagnosis and taking treatment reminded them of their rape and triggered feelings of shame. Women described their sexual violence experience as more stressful and shameful than their HIV status. None had disclosed their trauma history to their HIV care provider. The findings from this study suggest that women with a sexual trauma history may have poorer uptake and adherence to ARVs than women without. Additional research is necessary in low- and middle-income countries to explore this further. There is insufficient support and counselling services for women who have experienced sexual trauma and other abuse. Implementing such services may relieve symptoms of post-traumatic stress disorder and depression and support ART uptake and adherence. 

Africa
South Africa
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Conditional cash transfers had no effect on HIV in high school attendance setting

The effect of a conditional cash transfer on HIV incidence in young women in rural South Africa (HPTN 068): a phase 3, randomised controlled trial.

Pettifor A, MacPhail C, Hughes JP, Selin A, Wang J, Gomez-Olive FX, Eshleman SH, Wagner RG, Mabuza W, Khoza N, Suchindran C, Mokoena I, Twine R, Andrew P, Townley E, Laeyendecker O, Agyei Y, Tollman S, Kahn K. Lancet Glob Health. 2016 Dec;4(12):e978-e988. doi: 10.1016/S2214-109X(16)30253-4. Epub 2016 Nov 1.

Background: Cash transfers have been proposed as an intervention to reduce HIV-infection risk for young women in sub-Saharan Africa. However, scarce evidence is available about their effect on reducing HIV acquisition. We aimed to assess the effect of a conditional cash transfer on HIV incidence among young women in rural South Africa.

Methods: We did a phase 3, randomised controlled trial (HPTN 068) in the rural Bushbuckridge subdistrict in Mpumalanga province, South Africa. We included girls aged 13-20 years if they were enrolled in school grades 8-11, not married or pregnant, able to read, they and their parent or guardian both had the necessary documentation necessary to open a bank account, and were residing in the study area and intending to remain until trial completion. Young women (and their parents or guardians) were randomly assigned (1:1), by use of numbered sealed envelopes containing a randomisation assignment card which were numerically ordered with block randomisation, to receive a monthly cash transfer conditional on school attendance (≥80% of school days per month) versus no cash transfer. Participants completed an Audio Computer-Assisted Self-Interview (ACASI), before test HIV counselling, HIV and herpes simplex virus (HSV)-2 testing, and post-test counselling at baseline, then at annual follow-up visits at 12, 24, and 36 months. Parents or guardians completed a Computer-Assisted Personal Interview at baseline and each follow-up visit. A stratified proportional hazards model was used in an intention-to-treat analysis of the primary outcome, HIV incidence, to compare the intervention and control groups. This study is registered at ClinicalTrials.gov (NCT01233531).

Findings: Between March 5, 2011, and Dec 17, 2012, we recruited 10 134 young women and enrolled 2537 and their parents or guardians to receive a cash transfer programme (n=1225) or not (control group; n=1223). At baseline, the median age of girls was 15 years (IQR 14-17) and 672 (27%) had reported to have ever had sex. 107 incident HIV infections were recorded during the study: 59 cases in 3048 person-years in the intervention group and 48 cases in 2830 person-years in the control group. HIV incidence was not significantly different between those who received a cash transfer (1.94% per person-years) and those who did not (1.70% per person-years; hazard ratio 1.17, 95% CI 0.80-1.72, p=0.42).

Interpretation: Cash transfers conditional on school attendance did not reduce HIV incidence in young women. School attendance significantly reduced risk of HIV acquisition, irrespective of study group. Keeping girls in school is important to reduce their HIV-infection risk. 

Abstract  Full-text [free] access 

Editor’s notes: Cash transfers to vulnerable household and/or individuals have been used successfully in a variety of settings as a means to reduce poverty, improve health and achieve other development-associated outcomes. Cash transfers can help address structural drivers of HIV, such as economic and gender inequalities and low levels of education, and have been proposed as a potentially important addition to HIV prevention efforts. However, the evidence of their effectiveness in the context of HIV prevention is mixed. This study is the first randomized controlled trial to examine the effect of cash transfers conditional on school attendance with HIV incidence in adolescent girls and young women in sub-Saharan Africa. The trial found no evidence that receipt of the conditional cash transfer reduced HIV or HSV-2 incidence.

Staying in education has been highlighted as a key factor for reducing the risk of HIV infection in girls and young women. In this setting, school attendance based on attendance registers was high in both trial arms (95%). This is much higher than in South Africa overall, and higher than in Mpumalanga Province (the study area). Eligibility for the trial was restricted to girls and young women who were currently enrolled in school, so the trial participants may have been more motivated to attend school than those who were not eligible. Interestingly, 75% of individuals who were screened for the trial were found to be ineligible, although the reasons for their exclusion are not given, and it is difficult to know how generalizable the results are. South Africa has a strong social protection system for poor families, and 80% of the study participants were from households that were receiving child support grants. The benefits of additional cash transfers in areas with high coverage of social protection may be minimal. Cash transfers to girls and young women for HIV prevention are likely to have a greater effect in settings with low school attendance and more limited social protection coverage.

Consistent with other studies, the trial found that staying in school was associated with a reduced risk of HIV, irrespective of trial arm. The cash transfer was also associated with a strongly reduced risk of intimate partner violence, and a small effect on reducing some sexual risk behaviours. Cash transfers may work both directly and indirectly, through a variety of different pathways that are likely to vary between settings and between populations. The high-recorded school attendance in both trial arms will have limited the ability to examine education as a pathway through which the cash transfer may have influenced HIV risk. A better understanding of these pathways and how they are affected by the setting may help inform the conditions under which cash transfers may be an effective component of an HIV prevention programme.

Africa
South Africa
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No evidence of an increased risk of female-male HIV transmission with hormonal contraception in Zambia

Hormonal contraceptive use among HIV-positive women and HIV transmission risk to male partners, Zambia, 1994-2012.

Wall KM, Kilembe W, Vwalika B, Ravindhran P, Khu NH, Brill I, Chomba E, Johnson BA, Haddad LB, Tichacek A, Allen S. J Infect Dis. 2016 Oct 1;214(7):1063-71. doi: 10.1093/infdis/jiw322. Epub 2016 Jul 26.

Background: Evidence on the association between female-to-male human immunodeficiency virus (HIV) transmission risk and hormonal contraception is sparse and conflicting.

Methods: Heterosexual HIV-discordant couples from Lusaka, Zambia, were followed longitudinally at 3 month-intervals from 1994 to 2012. The impact of hormonal contraception on time to HIV transmission from HIV-positive women to their HIV-negative male partners (M-F+) was evaluated.

Results: Among 1601 M-F+ couples, 171 genetically linked HIV transmissions occurred in men over 3216 couple-years (5.3 transmissions/100 couple-years; 95% confidence interval [CI], 4.5-6.2). In multivariable Cox models, neither injectable (adjusted hazard ratio [aHR], 0.6; 95% CI, .4-1.2), oral contraceptive pill (aHR, 0.8; 95% CI, .3-2.1), nor implant (aHR, 0.8; 95% CI, .5-1.4) use was associated with HIV transmission, relative to nonhormonal methods, after controlling for the man's age at baseline and time-varying measures of pregnancy, self-reported unprotected sex with the study partner, sperm present on a vaginal swab wet mount, genital inflammation of either partner, genital ulceration of the man, and first follow-up interval. Sensitivity analyses, including marginal structural modeling and controlling for viral load and fertility intentions available in a subset of couples, led to similar conclusions.

Conclusions: Our findings suggest null associations between hormonal contraception and risk of female-to-male HIV transmission. We support efforts to increase the contraceptive method mix for all women, regardless of HIV serostatus, along with reinforced condom counseling for HIV-serodiscordant couples.

Abstract  Full-text [free] access 

Editor’s notes: Evidence suggests that certain injectable hormonal contraceptives (particularly depot medroxyprogesterone acetate [DMPA]) may increase HIV risk in women. However, few studies have assessed whether hormonal contraception increases the risk of female-male transmission. This paper presents results from an 18-year prospective follow-up study in Zambia. In the study, the investigators were able to analyse biologically linked results of serodiscordant couples and multiple methods of contraception. Their findings suggest no evidence of an increased risk of HIV transmission from women living with HIV to their male partners. In fact, couples with a linked transmission were less likely to use injectable contraceptives than women using non-hormonal methods (not statistically significant). This is encouraging; however, there are potential confounding factors in this study, such as high circumcision rates among men and low viral loads among women. The results also conflict with two earlier studies that found an increased risk of female-male transmission associated with hormonal contraception. More research is therefore necessary to provide evidence on this topic and enable recommendations on the use of hormonal contraception among serodiscordant couples.

Africa
Zambia
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Migrations, even over short distances, substantially increase the risk of HIV acquisition in rural South Africa

Space-time migration patterns and risk of HIV acquisition in rural South Africa: a population-based cohort study.

Dobra A, Barnighausen T, Vandormael A, Tanser F. AIDS. 2016 Oct 14. [Epub ahead of print]

Objective: To quantify the space-time dimensions of human mobility in relationship to the risk of HIV acquisition.

Methods: We used data from the population cohort located in a high HIV-prevalence, rural population in KwaZulu-Natal, South Africa (2000 - 2014). We geolocated 8006 migration events (representing 1 028 782 km travelled) for 17 743 individuals (≥15 years of age) who were HIV-negative at baseline and followed-up these individuals for HIV acquisition (70 395 person-years). Based on the complete geolocated residential history of every individual in this cohort, we constructed two detailed time-varying migration indices. We then used interval-censored Cox proportional hazards models to quantify the relationship between the migration indices and the risk of HIV acquisition.

Results: 17.4% of participants migrated at least once outside the rural study community during the period of observation (median migration distance = 107.1 km, IQR 18.9-387.5). The two migration indices were highly predictive of hazard of HIV acquisition (p < 0.01) in both men and women. Holding other factors equal, the risk of acquiring HIV infection increased by 50% for migration distances of 40 km (men) and 109 km (women). HIV acquisition risk also increased by 50% when participants spent 44% (men) and 90% (women) of their respective time outside the rural study community.

Conclusion: This in-depth analysis of a population cohort in a rural sub-Saharan African population has revealed a clear non-linear relationship between distance migrated and HIV acquisition. Our findings show that even relatively short distance migration events confer substantial additional risk of acquisition.

Abstract access  

Editor’s notes: Many studies in sub-Saharan African settings have illustrated that migrants have a greater risk of HIV infection and subsequent HIV-associated mortality than their non-migrant peers. The causal mechanisms underlying this enhanced risk and the temporal sequence of the migration and HIV acquisition events are less well understood. This study conducted in rural KwaZulu-Natal in South Africa is a longitudinal analysis linking data on migration episodes and the results of repeated HIV tests for individuals who were HIV negative at baseline. The two places of residence associated with the migration event were geo-coded, enabling the associations between spatiotemporal aspects of the migration and the risk of HIV acquisition to be explored. Two migration indices were calculated - one measuring the length of time spent outside the home residence and the other measuring the sum of the distances associated with the migrations. Both migration indices were significantly associated the risk of HIV acquisition. The association with distance was non-linear, with the risk of acquisition increasing by 50% at relatively short distances (approximately 55km), and the rates of increase of risk declined as the distance of migration increased further. The magnitude of this effect was similar for both sexes. By contrast the effect of time spent away from home on the risk of acquisition of HIV was significantly greater for men than women.

There are likely to be a number of mechanisms explaining the increased risks for migrants. These include an increase in the number of sexual partners, adoption of higher risk sexual behaviour and a detachment from the social support networks that exist in the home community. Further qualitative studies are necessary to explore these more fully. The authors also recommend that such studies are replicated in other settings to assess the generalisability of the findings. Having established these causal pathways, novel HIV prevention approaches focused towards these highly vulnerable migrant populations will need to be developed as part of efforts to achieve the UNAIDS 90:90:90 treatment target.

Africa
South Africa
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Near elimination of HIV transmission with combined ART and PrEP

Integrated delivery of antiretroviral treatment and pre-exposure prophylaxis to HIV-1-serodiscordant couples: a prospective implementation study in Kenya and Uganda.

Baeten JM, Heffron R, Kidoguchi L, Mugo NR, Katabira E, Bukusi EA, Asiimwe S, Haberer JE, Morton J, Ngure K, Bulya N, Odoyo J, Tindimwebwa E, Hendrix C, Marzinke MA, Ware NC, Wyatt MA, Morrison S, Haugen H, Mujugira A, Donnell D, Celum C. PLoS Med. 2016 Aug 23;13(8):e1002099. doi: 10.1371/journal.pmed.1002099. eCollection 2016.

Background: Antiretroviral-based interventions for HIV-1 prevention, including antiretroviral therapy (ART) to reduce the infectiousness of HIV-1 infected persons and pre-exposure prophylaxis (PrEP) to reduce the susceptibility of HIV-1 uninfected persons, showed high efficacy for HIV-1 protection in randomized clinical trials. We conducted a prospective implementation study to understand the feasibility and effectiveness of these interventions in delivery settings.

Methods and findings: Between November 5, 2012, and January 5, 2015, we enrolled and followed 1013 heterosexual HIV-1-serodiscordant couples in Kenya and Uganda in a prospective implementation study. ART and PrEP were offered through a pragmatic strategy, with ART promoted for all couples and PrEP offered until 6 mo after ART initiation by the HIV-1 infected partner, permitting time to achieve virologic suppression. One thousand thirteen couples were enrolled, 78% of partnerships initiated ART, and 97% used PrEP, during a median follow-up of 0.9 years. Objective measures of adherence to both prevention strategies demonstrated high use (≥85%). Given the low HIV-1 incidence observed in the study, an additional analysis was added to compare observed incidence to incidence estimated under a simulated counterfactual model constructed using data from a prior prospective study of HIV-1-serodiscordant couples. Counterfactual simulations predicted 39.7 HIV-1 infections would be expected in the population at an incidence of 5.2 per 100 person-years (95% CI 3.7-6.9). However, only two incident HIV-1 infections were observed, at an incidence of 0.2 per 100 person-years (95% CI 0.0-0.9, p < 0.0001 versus predicted). The use of a non-concurrent comparison of HIV-1 incidence is a potential limitation of this approach; however, it would not have been ethical to enroll a contemporaneous population not provided access to ART and PrEP.

Conclusions: Integrated delivery of time-limited PrEP until sustained ART use in African HIV-1-serodiscordant couples was feasible, demonstrated high uptake and adherence, and resulted in near elimination of HIV-1 transmission, with an observed HIV incidence of <0.5% per year compared to an expected incidence of >5% per year.

Abstract  Full-text [free] access 

Editor’s notes: Long-term follow-up of the landmark HPTN-052 trial of ART for prevention of HIV transmission between HIV serodiscordant couples was covered in a recent issue of HIV This Month. In that trial, of the few transmission events that did occur, half were during the first few months of ART use in the HIV-positive partner, before viral load suppression. This study from Kenya and Uganda now suggests that offering pre-exposure prophylaxis (PrEP) to the HIV-negative partner to bridge the gap until virologic suppression may be an effective way to almost eliminate the risk of transmission.

In this study there were significant delays in ART initiation in the HIV-positive partner. At the start of the study the recommendation for ART initiation was a CD4+ cell count <350, and only half of the HIV-positive partners had initiated ART by six months. PrEP uptake by the HIV-negative partner was high during this time period and high levels of adherence were sustained, suggesting that this was a feasible and acceptable strategy for discordant couples.

The activities were delivered using specific clinical research facilities and staff, so the logical next step would be to demonstrate scalability with delivery through routine health systems and through more innovative community-based systems.  

Africa
Kenya, Uganda
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The power of soccer to increase voluntary medical male circumcision uptake in adolescents

A sport-based intervention to increase uptake of voluntary medical male circumcision among adolescent male students: results from the MCUTS 2 cluster-randomized trial in Bulawayo, Zimbabwe.

Kaufman ZA, DeCelles J, Bhauti K, Hershow RB, Weiss HA, Chaibva C, Moyo N, Mantula F, Hatzold K, Ross DA. J Acquir Immune Defic Syndr. 2016 Aug 15;72 Suppl 4:S292-8. doi: 10.1097/QAI.0000000000001046.

Background: Mathematical models suggest that 570 000 HIV infections could be averted between 2011 and 2025 in Zimbabwe if the country reaches 80% voluntary medical male circumcision (VMMC) coverage among 15- to 49-year-old male subjects. Yet national coverage remains well below this target, and there is a need to evaluate interventions to increase the uptake.

Methods: A cluster-randomized trial was conducted to assess the effectiveness of Make-The-Cut-Plus (MTC+), a single, 60-minute, sport-based intervention to increase VMMC uptake targeting secondary school boys (14-20 years). Twenty-six schools in Bulawayo, Zimbabwe, were randomized to either receive MTC+ at the start (intervention) or end (control) of a 4-month period (March to June 2014). VMMC uptake over these 4 months was measured via probabilistic matching of participants in the trial database (n = 1226 male participants; age, 14-20 years; median age, 16.2 years) and the registers in Bulawayo's 2 free VMMC clinics (n = 5713), using 8 identifying variables.

Results: There was strong evidence that the MTC+ intervention increased the odds of VMMC uptake by approximately 2.5 fold (odds ratio = 2.53; 95% confidence interval, 1.21 to 5.30). Restricting to participants who did not report being already circumcised at baseline, MTC+ increased VMMC uptake by 7.6% (12.2% vs 4.6%, odds ratio = 2.65; 95% confidence interval, 1.19 to 5.86). Sensitivity analyses related to the probabilistic matching did not change these findings substantively. The number of participants who would need to be exposed to the demand creation intervention to yield one additional VMMC client was 22.7 (or 13.2 reporting not already being circumcised). This translated to approximately US dollar 49 per additional VMMC client.

Conclusions: The MTC+ intervention was an effective and cost-effective strategy for increasing VMMC uptake among school-going adolescent male subjects in Bulawayo.

Abstract access  

Editor’s notes: WHO and UNAIDS have stressed the importance of focusing on schools and sports to increase uptake of voluntary medical male circumcision (VMMC) among adolescent males. Adolescents have the maximum potential gain from VMMC in terms of prevented infections, and the paper illustrates that the soccer-based ‘Make The Cut’ programme significantly increased VMMC in school-based adolescents. This follows an earlier trial of the programme in adult men in which the proportion accepting VMMC was 4.8% compared with 0.5% in the control arm.

The programme was designed to be brief and low cost. A trained, recently circumcised young male ‘coach’ led a one hour soccer-themed session in school. After the session the coach contacted participants who expressed an interest in VMMC, and arranged transport to a VMMC clinic. The trial team faced the common problem that the clinics where they collected outcome data used a handwritten register rather than electronic records. To address this, the team linked the clinic records to trial participants using probabilistic matching of names and contact details.

Both the prevalence and background incidence of circumcision were higher than expected. Almost half of participants (48%) said they were already circumcised at the beginning of the trial (the authors anticipated 20%), reflecting the recent increased uptake in VMMC in Zimbabwe. Although the trial illustrates significant increase in VMMC, the absolute uptake remained relatively low in the programme arm (12.2%), and a combination of successful VMMC demand creation activities (for example including monetary or non-monetary incentives) are necessary to reach global targets. 

Africa
Zimbabwe
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The HIV prevention cascade – a new approach to guide HIV prevention programmes

Providing a conceptual framework for HIV prevention cascades and assessing feasibility of empirical measurement with data from east Zimbabwe: a case study.

Garnett GP, Hallett TB, Takaruza A, Hargreaves J, Rhead R, Warren M, Nyamukapa C, Gregson S. Lancet HIV. 2016 Jul;3(7):e297-306. doi: 10.1016/S2352-3018(16)30039-X.

Background: The HIV treatment cascade illustrates the steps required for successful treatment and is a powerful advocacy and monitoring tool. Similar cascades for people susceptible to infection could improve HIV prevention programming. We aim to show the feasibility of using cascade models to monitor prevention programmes.

Methods: Conceptual prevention cascades are described taking intervention-centric and client-centric perspectives to look at supply, demand, and efficacy of interventions. Data from two rounds of a population-based study in east Zimbabwe are used to derive the values of steps for cascades for voluntary medical male circumcision (VMMC) and for partner reduction or condom use driven by HIV testing and counselling (HTC).

Findings: In 2009 to 2011 the availability of circumcision services was negligible, but by 2012 to 2013 about a third of the population had access. However, where it was available only 12% of eligible men sought to be circumcised leading to an increase in circumcision prevalence from 3.1% to 6.9%. Of uninfected men, 85.3% did not perceive themselves to be at risk of acquiring HIV. The proportions of men and women tested for HIV increased from 27.5% to 56.6% and from 61.1% to 79.6%, respectively, with 30.4% of men tested self-reporting reduced sexual partner numbers and 12.8% reporting increased condom use.

Interpretation: Prevention cascades can be populated to inform HIV prevention programmes. In eastern Zimbabwe programmes need to provide greater access to circumcision services and the design and implementation of associated demand creation activities. Whereas, HTC services need to consider how to increase reductions in partner numbers or increased condom use or should not be considered as contributing to prevention services for the HIV-negative adults.

Abstract  Full-text [free] access 

Editor’s notes: UNAIDS has set an ambitious goal of reducing new adult HIV infections below 500 000 per year by 2020. Achieving this goal relies on increased coverage of primary HIV prevention programmes, including pre-exposure prophylaxis and voluntary medical male circumcision (VMMC). The HIV treatment cascade is a well known tool to monitor the performance of services for people living with HIV, and to identify gaps in care. An HIV prevention cascade could provide a similarly useful tool to inform prevention programmes. The tool would define the steps necessary for an effective HIV prevention programme, estimating the proportion of people lost at each step, and hence identifying the barriers to effective HIV prevention in populations. The authors propose a framework for HIV prevention cascades, differentiating between availability, uptake, adherence, and efficacy.  The framework would estimate the proportion of the population protected by a given strategy or combination of strategies. Population survey data from rural Zimbabwe are used to illustrate the prevention cascade for VMMC and behaviour change driven by HIV testing and counselling (HTC). These data are used to highlight the barriers impacting on reducing HIV incidence. As the authors acknowledge, there are limitations to the cascade approach for HIV prevention. The cascade is more difficult to define and to estimate for HIV prevention than for HIV treatment. In order for the cascade to be useful, it is necessary to have a good understanding of who is at risk of acquiring HIV.  However, the prevention needs of HIV negative adults change over time as people move in and out of risk. Although the authors illustrate the use of the cascade for an individual programme, it is more difficult to assess the combined effect of several prevention strategies. Still, the cascade approach may provide a useful tool to help guide HIV prevention efforts, by identifying gaps and prioritising areas for action.

Africa
Zimbabwe
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Demand-side activities are essential for achieving population level impact of HIV prevention tools

Interventions to strengthen the HIV prevention cascade: a systematic review of reviews.

Krishnaratne S, Hensen B, Cordes J, Enstone J, Hargreaves JR. Lancet HIV. 2016 Jul;3(7):e307-17. doi: 10.1016/S2352-3018(16)30038-8.

Background: Much progress has been made in interventions to prevent HIV infection. However, development of evidence-informed prevention programmes that translate the efficacy of these strategies into population effect remain a challenge. In this systematic review, we map current evidence for HIV prevention against a new classification system, the HIV prevention cascade.

Methods: We searched for systematic reviews on the effectiveness of HIV prevention interventions published in English from Jan 1, 1995, to July, 2015. From eligible reviews, we identified primary studies that assessed at least one of: HIV incidence, HIV prevalence, condom use, and uptake of HIV testing. We categorised interventions as those seeking to increase demand for HIV prevention, improve supply of HIV prevention methods, support adherence to prevention behaviours, or directly prevent HIV. For each specific intervention, we assigned a rating based on the number of randomised trials and the strength of evidence.

Findings: From 88 eligible reviews, we identified 1964 primary studies, of which 292 were eligible for inclusion. Primary studies of direct prevention mechanisms showed strong evidence for the efficacy of pre-exposure prophylaxis (PrEP) and voluntary medical male circumcision. Evidence suggests that interventions to increase supply of prevention methods such as condoms or clean needles can be effective. Evidence arising from demand-side interventions and interventions to promote use of or adherence to prevention tools was less clear, with some strategies likely to be effective and others showing no effect. The quality of the evidence varied across categories.

Interpretation: There is growing evidence to support a number of efficacious HIV prevention behaviours, products, and procedures. Translating this evidence into population impact will require interventions that strengthen demand for HIV prevention, supply of HIV prevention technologies, and use of and adherence to HIV prevention methods.

Abstract  Full-text [free] access

Editor’s notes: Demand, supply and use of programmes are crucial for the uptake and effective use of HIV prevention strategies. This paper presents an impressive undertaking in which the authors conducted a review of systematic reviews on the evidence for the effectiveness of HIV prevention programmes across the multiple steps in an HIV prevention cascade. This particular prevention cascade allocates programmes into demand-side, supply-side, adherence, and direct HIV prevention technologies. This was published in a separate paper in conjunction with this review. The review found that there is strong evidence with regards to which direct HIV prevention technologies are efficacious, as well as maps where adherence and supply-side programmes have been effective. A primary gap was noted on the demand-side of the cascade (e.g. information, education and communication, and peer-based activities to increase demand for medical male circumcision) where studies have not resulted in reducing HIV incidence or prevalence. There remains a need to understand why, despite supply, there is low uptake of some HIV prevention strategies, and for evaluation of novel activities to increase demand.  

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A booster dose of HIV prevention

Adolescent HIV risk reduction in the Bahamas: results from two randomized controlled intervention trials spanning elementary school through high school.

Stanton B, Dinaj-Koci V, Wang B, Deveaux L, Lunn S, Li X, Rolle G, Brathwaite N, Marshall S, Gomez P. AIDS Behav. 2016 Jun;20(6):1182-96. doi: 10.1007/s10461-015-1225-5.

To address global questions regarding the timing of HIV-prevention efforts targeting youth and the possible additional benefits of parental participation, researchers from the USA and The Bahamas conducted two sequential longitudinal, randomized trials of an evidence-based intervention spanning the adolescent years. The first trial involved 1360 grade-6 students and their parents with three years of follow-up and the second 2564 grade-10 students and their parents with two years of follow-up. Through grade-12, involvement in the combined child and parent-child HIV-risk reduction interventions resulted in increased consistent condom-use, abstinence/ protected sex, condom-use skills and parent-child communication about sex. Receipt of the grade-6 HIV-prevention intervention conferred lasting benefits regarding condom-use skills and self-efficacy. Youth who had not received the grade-six intervention experienced significantly greater improvement over baseline as a result of the grade-10 intervention. The HIV-risk reduction intervention delivered in either or both grade-6 and grade-10 conferred sustained benefits; receipt of both interventions appears to confer additional benefits.

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Editor’s notes: Prevention of HIV infection in adolescents is key to combating HIV. In the Bahamas, two school-based programmes for adolescents were evaluated to answer key questions about the effect of school-based activities at different ages in adolescence, and the effect of including parental participation. This paper focused on the additional effect of a programme in mid-adolescence (age 15 to16) following an earlier programme (at age 10 to11). The early- and mid-adolescent programmes were similar. There were eight-sessions based on Protection Motivation Theory, using discussion and role play to increase knowledge and skills regarding sexual-risk avoidance, with the aim of changing behaviour. Both included a component for parents and children together, and both were effective at improving HIV knowledge, and reported condom-use skills and intentions.

Results illustrated that the early-adolescent programme had sustained effects throughout the following six years, and the mid-adolescent programme acted as a ‘booster’, conferring additional benefits including increased rates of reported consistent condom use and abstinence/protected sexual intercourse and increased condom-use skills. Participants who did not receive the early-adolescent programme gained more benefit from the mid-adolescent programme but had lower scores than youth who had both. Parental involvement was important, especially regarding condom-use skills. Although the results are promising, there is potential for biased reporting of self-reported behavioural outcomes, and it would be good to confirm these findings with biological outcomes including unplanned pregnancy and HSV-2 infection. 

Latin America
Bahamas
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