HPV Vaccine Misperceptions Among Hispanics/Latinos in Southern California

BACKGROUND

Cervical and other vaccine-preventable HPV-associated cancers disproportionately impact Hispanic/Latinos in the USA. HPV vaccine uptake may be impacted by community agreement with common HPV vaccine misperceptions. It is unknown whether Hispanics/Latinos have a greater agreement with these misperceptions relative to non-Hispanic whites.

METHODS

HPV vaccine misperceptions were assessed through a 12-item Likert scale included in a population health assessment mailed to households in the southwest United States. Linear regression models assessed the association between identifying as Hispanic/Latino and summed misperception score.

RESULTS

Among the 407 individuals in the analytic sample, 111 (27.3%) were Hispanic/Latino and 296 (72.7%) were non-Hispanic white. On average, Hispanics/Latinos had a 3.03-point higher HPV vaccine misperception sum score relative to non-Hispanic whites, indicating greater agreement with misperceptions (95% confidence interval: 1.16-4.88; p < 0.01).

DISCUSSION

Culturally relevant interventions are needed to address HPV vaccine misperceptions among Hispanics/Latinos as part of efforts toward HPV-associated cancer health equity.

Long-acting Injectable PrEP Interest and General PrEP Awareness among People who Inject Drugs in the San Diego-Tijuana Border Metroplex

Long-acting injectable HIV pre-exposure prophylaxis (LAI-PrEP) could help overcome multilevel challenges to HIV prevention for people who inject drugs (PWID), including those in the binational San Diego-Tijuana metroplex. Yet, general PrEP awareness and interest in LAI-PrEP remain underexplored among PWID. From 2020 to 2021, 562 HIV-negative PWID in San Diego and Tijuana completed surveys assessing general PrEP awareness and interest in oral and LAI-PrEP. Modified Poisson regression examined factors associated with general PrEP awareness. Multinomial logistic regression assessed factors associated with interest in both oral and LAI-PrEP, oral PrEP only, LAI-PrEP only, or neither. General PrEP awareness was low (18%) and associated with experiencing unsheltered homelessness (adjusted prevalence ratio [APR] = 1.50, 95% confidence interval [CI]: 0.96-2.33), past 6-month fentanyl injection (APR = 1.53, 95% CI: 1.04-2.25), and transactional sex (APR = 1.71, 95% CI: 1.06-2.76). Interest in oral PrEP only was most common (44%), followed by LAI-PrEP only (25%) and neither (16%). Compared to the odds of being interested in LAI-PrEP only, the odds of being interested in oral PrEP only were lower among those who were stopped by police (AOR = 0.38, 95% CI: 0.22-0.65), reported past 6-month fentanyl injection (AOR = 0.33, 95% CI: 0.20-0.56), polydrug use (AOR = 0.48, 95% CI: 0.27-0.86), injecting multiple times daily (AOR = 0.26, 95% CI: 0.14-0.46), receptive syringe use (AOR = 0.30, 95% CI: 0.19-0.49), and higher perceived HIV risk (AOR = 0.24, 95% CI: 0.15-0.39). Interest in LAI-PrEP was more common among PWID reporting social and structural factors that could interfere with oral PrEP adherence, suggesting LAI-PrEP implementation could increase PrEP coverage among those most vulnerable to HIV.

Health, harm reduction, and social service providers' perspectives on the appropriateness and feasibility of peer distribution of HIV self-test kits among people who use drugs

BACKGROUND

People who use drugs (PWUD) experience elevated HIV risk and numerous barriers to facility-based HIV testing. HIV self-testing (HIVST) could circumvent many of those barriers and is acceptable among PWUD, yet HIVST implementation for PWUD is limited. Service providers' perspectives on specific HIVST delivery strategies could help increase availability for PWUD.

METHODS

From April-November 2021, we interviewed 16 health, harm reduction, and social service providers working with PWUD in San Diego, CA. Interviews and rapid thematic analysis explored perspectives on HIVST's utility and appropriateness, as well as the feasibility of and anticipated challenges with specific HIVST delivery strategies, including peer or secondary distribution.

RESULTS

Participants viewed HIV as a significant threat to PWUD health and confirmed the presence of numerous barriers to local facility-based HIV testing. Participants viewed HIVST as a promising and potentially empowering solution. Based on community familiarity with secondary distribution of harm reduction supplies (i.e., naloxone) and information, participants viewed secondary distribution of HIVST kits as an appropriate and feasible strategy for increasing the reach of HIVST, but also described potential barriers (e.g., engaging socially disconnected individuals, ensuring linkages to services following HIVST) and provided suggestions for alternative HIVST kit delivery models (e.g., harm reduction vending machines).

CONCLUSIONS

Service providers viewed secondary distribution of HIVST kits among PWUD as promising, appropriate, and feasible, yet specialized efforts may be needed to reach the most marginalized individuals and ensure consistent provision of educational information and referral supports that maximize the impact of this approach.

The Gender Minority Stress and Resilience Measure: Psychometric Validity for Use in Spanish

Purpose

Stigma is a fundamental driver of HIV disparities among transgender women (TW). The gender minority stress and resilience (GMSR) measure has not been validated in Spanish-speaking, resource-limited settings. We examined the psychometric properties of a translated and abbreviated GMSR among TW in Tijuana, Mexico.

Methods

From 2020 to 2021, 152 participants were recruited through social media and venue-based sampling. We collected information on the abbreviated GMSR, psychosocial factors (e.g., depressive symptoms), and sociodemographics. The abbreviated GMSR assessed 7 factors (Discrimination, Rejection, Internalized Transphobia, Negative Expectations, Nondisclosure, Pride, and Community Connectedness). Confirmatory factor analysis, Cronbach's alphas, and McDonald's omegas assessed structural validity. Pearson's partial correlations assessed criterion, convergent, and discriminant validities.

Results

The 7-factor structure solution had acceptable fit (root mean square error of approximation [95% confidence interval]=0.05 [0.05-0.06]; comparative fit index/Tucker-Lewis index=0.92/0.91); and internal reliability (α=0.62-0.89; ω=0.62-0.89). Depressive (r=0.22-0.43; p<0.001-0.007), post-traumatic stress disorder (PTSD; r=0.20-0.34; p<0.001-0.017) symptoms, and perceived stress (r=0.19-0.41; p≤0.001-0.030) were all positively associated with all stress factors (e.g., Discrimination, Rejection, Internalized Transphobia, Negative Expectations, and Nondisclosure). The resilience factor Pride was associated with fewer PTSD symptoms (r=-0.18; p=0.027), lower perceived life stress (r=-0.21; p=0.012), and greater general resilience (r=0.26; p=0.002). The Community Connectedness resilience factor was associated with fewer depressive symptoms (r=-0.22; p=0.007). Constructs were conceptually distinct with factor correlations below 0.60.

Conclusion

Findings suggest that the Spanish-translated, abbreviated GMSR is a reliable and valid measure. These data expand the usability of the GMSR to TW in a Latin American, Spanish-speaking context.

Determinants of HIV Pre-Exposure Prophylaxis (PrEP) Retention among Transgender Women: A Sequential, Explanatory Mixed Methods Study

Transgender women (TW) face inequities in HIV and unique barriers to PrEP, an effective biomedical intervention to prevent HIV acquisition. To improve PrEP retention among TW, we examined factors related to retention using a two-phase, sequential explanatory mixed methods approach. In Phase I, we used data from a trial of 170 TW who were provided oral PrEP to examine predictors of 24-week retention. In Phase II, we conducted 15 in-depth interviews with PrEP-experienced TW and used thematic analysis to explain Phase I findings. In Phase I, more participants who were not retained at 24 weeks reported sex work engagement (18% versus 7%) and substantial/severe drug use (18% versus 8%). In Phase II, participants reported drug use as a barrier to PrEP, often in the context of sex work, and we identified two subcategories of sex work. TW engaged in "non-survival sex work" had little difficulty staying on PrEP, while those engaged in "survival sex work" struggled to stay on PrEP. In Phase I, fewer participants not retained at 24 weeks reported gender-affirming hormone therapy (GAHT) use (56% versus 71%). In Phase II, participants prioritized medical gender affirmation services over PrEP but also described the bidirectional benefits of accessing GAHT and PrEP. TW who engaged in "survival sex work" experience barriers to PrEP retention (e.g., unstable housing, drug use) and may require additional support to stay in PrEP care.

Willingness to use and distribute HIV self-testing kits among people who inject drugs in the San Diego-Tijuana border region

BACKGROUND

HIV self-testing (HIVST) could increase HIV testing access among people who inject drugs (PWID), and secondary distribution (i.e., peer-delivery) of HIVST kits in PWID social networks could further expand coverage. We assessed willingness to use and distribute HIVST kits among PWID in the San Diego-Tijuana border region.

METHODS

From 2020 to 2021, HIV-negative PWID in San Diego, USA, and Tijuana, Mexico, completed surveys and provided data on individual (N = 539) and social network (N = 366) characteristics. We used modified Poisson regression to examine the effects of individual and social network characteristics on willingness to use and distribute HIVST kits.

RESULTS

Most participants were willing to use (81%) and distribute (81%) HIVST kits. At the individual level, prior HIV testing was positively associated with willingness to use (adjusted prevalence ratio [aPR] = 1.24, 95% confidence interval [CI] 1.10-1.40) and distribute (aPR = 1.27, 95% CI 1.12-1.43) HIVST kits, while perceiving oneself to be at higher HIV risk than others was negatively associated with willingness to use HIVST kits (aPR = 0.83, 95% CI 0.74-0.93). At the network level, willingness to distribute HIVST kits was positively associated with network size (aPR = 1.04 per member, 95% CI 1.01-1.08) and greater proportions of one's network encouraging them to use drugs (aPR = 1.29, 95% CI 1.16-1.44) and having a history of homelessness (aPR = 1.51, 95% CI 1.31-1.74) or detention/arrest (aPR = 1.57, 95% CI 1.36-1.82), and negatively associated with a greater proportion of one's network including "very close" persons (aPR = 0.80, 95% CI 0.69-0.94).

CONCLUSIONS

We found high potential for HIVST kits and their secondary distribution to increase HIV testing among PWID who face the greatest barriers to facility-based testing.

Unit costs of needle and syringe program provision: a global systematic review and cost extrapolation

BACKGROUND

Needle and syringe programs (NSPs) are effective at preventing HIV and hepatitis C virus (HCV) among people who inject drugs (PWID), yet global coverage is low, partly because governments lack data on the cost and cost-effectiveness of NSP in their countries to plan and fund their responses. We conducted a global systematic review of unit costs of NSP provision to inform estimation of cost drivers and extrapolated costs to other countries.

METHODS

We conducted a systematic review to extract data on the cost per syringe distributed and its cost drivers. We estimated the impact of country-level and program-level variables on the cost per syringe distributed using linear mixed-effects models. These models were used to predict unit costs of NSP provision, with the best performing model used to extrapolate the cost per syringe distributed for 137 countries. The total cost for a comprehensive NSP (200 syringes per PWID/year) was also estimated for 68 countries with PWID population size estimates.

RESULTS

We identified 55 estimates of the unit cost per syringe distributed from 14 countries. Unit costs were extrapolated for 137 countries, ranging from $0.08 to $20.77 (2020 USD) per syringe distributed. The total estimated spend for a high-coverage, comprehensive NSP across 68 countries with PWID size estimates is $5 035 902 000 for 10 887 500 PWID, 2.1-times higher than current spend.

CONCLUSION

Our review identified cost estimates from high-income, upper-middle-income, and lower-middle-income countries. Regression models may be useful for estimating NSP costs in countries without data to inform HIV/HCV prevention programming and policy.

Correlates of impulsivity among female sex workers in Mexico

Impulsivity is a trait characteristic that is associated with sexual risk behavior. We examined correlates of impulsivity among 602 female sex workers (FSWs) enrolled in a sexual risk reduction intervention in Mexico (2016-2020). Impulsivity was positively associated with condomless sex with clients. Higher levels of impulsivity were associated with greater use of alcohol and heavy drugs, use of illicit drugs with clients, sexual/physical abuse history, and clinical depression. Global public health policy that supports free substance abuse treatment in combination with psychotherapeutic treatments (e.g. regulation management skills) and behavioral-focused therapy may help to reduce HIV/STI incidence in this vulnerable population.

"A lotta people switched playing hard ball to playing Russian roulette": Experiences with rising overdose incidence caused by drug supply changes during the COVID-19 pandemic in the San Diego-Tijuana border metroplex

Background

People who use drugs (PWUD) in the San Diego, USA and Tijuana, Mexico metroplex face high overdose risk related to historic methamphetamine use and relatively recent fentanyl introduction into local drug supplies. The personal overdose experiences of PWUD in this region are understudied, however, and may have been influenced by the COVID pandemic.

Methods

From September-November 2021, we conducted 28 qualitative interviews among PWUD ≥18 years old sampled from an ongoing cohort study in the San Diego-Tijuana metroplex. Interviews explored overdose experiences and changes in the drug supply. Thematic analysis of coded interview transcripts explored overdose experiences, perspectives on drug supply changes, interactions with harm reduction services, and naloxone access.

Results

Among 28 participants, 13 had experienced an overdose. Participants discussed rising levels of fentanyl in local drug supplies and increasing overdose incidents in their social networks. Participants discussed a general shift from injecting heroin to smoking fentanyl in their networks. Participants' most common concerns included having consistent access to a safe and potent drug supply and naloxone.

Conclusion

Participants prioritized adapting to drug supply changes and preventing overdose compared to other health concerns, such as HIV and COVID-19. Efforts to address overdose in this region could benefit from drug checking services and expanded, equitable delivery of naloxone.

COVID-19 vaccination acceptability and experiences among people who inject drugs in San Diego County

Background

People who inject drugs (PWID) face increased risk of SARS-CoV-2 acquisition and severe disease, yet COVID-19 vaccine uptake has been suboptimal. To inform vaccination interventions tailored for the needs of this population, we explored COVID-19 vaccination acceptability and experiences among PWID in San Diego County, USA.

Methods

From September-November 2021, we conducted qualitative interviews with PWID aged ≥18 years who were participating in a prospective study of infectious disease risks in San Diego. Thematic analysis of coded interview transcripts focused on identifying barriers and facilitators to COVID-19 vaccination.

Results

Of 28 participants, 15 reported having had ≥1 dose of COVID-19 vaccine, primarily received through community health centers, pharmacies, jails, and homeless shelters. We identified three key barriers to COVID-19 vaccination: (1) low perceived risk of COVID-19 (or belief in natural immunity), (2) institutional distrust (e.g., of pharmaceutical companies and government agencies that "rushed" vaccine development, approval, and distribution), and (3) conflicting information from news, social media, and peers. We also identified three key facilitators of vaccination, including (1) heightened personal and interpersonal safety concerns, (2) health service outreach efforts to make vaccines more accessible, and (3) tailored information delivered by trusted sources (e.g., outreach or community health workers).

Conclusions

Tailored intervention strategies to increase acceptability and uptake of COVID-19 vaccination among PWID should involve efforts to increase vaccine literacy and motivation while decreasing institutional distrust and structural barriers to access.

Long-Acting Injectable Human Immunodeficiency Virus Pre-Exposure Prophylaxis Preferred Over Other Modalities Among People Who Inject Drugs: Findings from a Qualitative Study in California

People who inject drugs (PWID) have extraordinarily low uptake of human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) despite high levels of need. Long-acting PrEP modalities hold promise for HIV prevention among PWID, but product preferences remain poorly understood. From September to November 2021, we conducted qualitative interviews with 28 HIV-negative, adult (≥18 years) PWID in San Diego County, CA, to explore their perspectives on daily oral PrEP pills and long-acting PrEP modalities (i.e., injections, implants, intravaginal rings, and broadly neutralizing antibodies), which we explained using standard scripts. Thematic analysis identified variations in PrEP modality interest and acceptability. We identified three key factors across the 28 interviews that appeared to influence PrEP modality preferences: perceived convenience of use, invasiveness, and familiarity (based on past experience). Overall, most participants preferred injectable PrEP over other modalities because they viewed injectable medications as convenient, noninvasive, and familiar. While injectable PrEP was recently approved for use in the United States and was most the acceptable PrEP modality in this sample, our findings suggest that intervention and implementation research is urgently needed to improve our understanding of strategies that could support access, uptake, and sustained adherence to longer-acting PrEP for PWID.

Psychometric Evaluation of the Personal Feelings Questionnaire-2 (PFQ-2) Shame Subscale Among Spanish-Speaking Female Sex Workers in Mexico

Shame may increase HIV risk among stigmatized populations. The Personal Feelings Questionnaire-2 (PFQ-2) measures shame, but has not been validated in Spanish-speaking or nonclinical stigmatized populations disproportionately affected by HIV in resource-limited settings. We examined the psychometric properties of the Spanish-translated PFQ-2 shame subscale among female sex workers in two Mexico-U.S. border cities. From 2016 to 2017, 602 HIV-negative female sex workers in Tijuana and Ciudad Juarez participated in an efficacy trial evaluating a behavior change maintenance intervention. Interviewer-administered surveys collected information on shame (10-item PFQ-2 subscale), psychosocial factors, and sociodemographics. Item performance, confirmatory factor analysis, internal consistency, differential item functioning by city, and concurrent validity were assessed. Response options were collapsed to 3-point responses to improve item performance, and one misfit item was removed. The revised 9-item shame subscale supported a single construct and had good internal consistency (Cronbach's α = .86). Notable differential item functioning was found but resulted in a negligible effect on overall scores. Correlations between the revised shame subscale and guilt (r = .79, p < .01), depression (r = .69, p < .01), and emotional support (r = -.28, p < .01) supported concurrent validity. The revised PFQ-2 shame subscale showed good reliability and concurrent validity in our sample, and should be explored in other stigmatized populations.

Prevalence of bacterial sexually transmitted infections and coinfection with HIV among men who have sex with men and transgender women in Tijuana, Mexico

We estimated the prevalence of syphilis and Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections, as well as human immunodeficiency virus (HIV) coinfection among cisgender men who have sex with cisgender men (MSM) and transgender women (TW) in Tijuana, Mexico. MSM and TW (N = 212) recruited via respondent-driven and venue-based sampling for HIV testing underwent sexually transmitted infection (STI) testing and completed interviewer-administered surveys in this study (2017-2018). Treponemal rapid tests were used at the point-of-care with positives undergoing confirmatory testing following the reverse syphilis-testing algorithm. Nucleic acid amplification testing of urine and swabs (rectal and pharyngeal) was used to detect CT/NG at three anatomic sites. Chi-squared tests were used to compare STI prevalence by HIV status. Sexually transmitted infection prevalence was 39.6% overall but higher for newly diagnosed HIV-positive (55.7%; N = 88) than HIV-negative (28.2%; N = 124) participants (p-value < 0.0001). Among newly diagnosed HIV-positive participants, the prevalence of syphilis was 35.2% (31/88), CT infection was 27.3% (24/88; nine urethral; 16 rectal; four pharyngeal), and NG infection was 26.1% (23/88; six urethral; 19 rectal; nine pharyngeal). Among HIV-negative participants, the prevalence of syphilis was 12.1% (15/124), CT infection was 13.7% (17/124; seven urethral; nine rectal; two pharyngeal), and NG infection was 9.7% (12/124; three urethral; seven rectal; seven pharyngeal). Over 60% of all CT (25/41) and NG (26/35) infections in the full sample occurred extragenitally in the absence of urethral infections, and over 80% of rectal (30/37) and pharyngeal (16/18) infections were asymptomatic. The high prevalence of syphilis, CT, and NG infections among MSM and TW in Tijuana suggests STI screening that includes extragenital tests, particularly at HIV diagnosis, may help curb HIV/STI transmission.

A comparison of the effectiveness of respondent-driven and venue-based sampling for identifying undiagnosed HIV infection among cisgender men who have sex with men and transgender women in Tijuana, Mexico

BACKGROUND

Efforts to increase HIV testing, diagnosis and care are critical to curbing HIV epidemics among cisgender men who have sex with men (MSM) and transgender women (TW) in low- and middle-income countries (LMIC). We compared the effectiveness of respondent-driven sampling (RDS) and venue-based sampling (VBS) for identifying previously undiagnosed HIV infection among MSM and TW in Tijuana, Mexico.

METHODS

Between March 2015 and December 2018, we conducted RDS within the social networks of MSM and TW and VBS at venues frequented by MSM and TW to socialize and meet sexual partners. Those reached by RDS/VBS who reported at least 18 years of age, anal sex with MSM or TW, and no previous HIV diagnosis were eligible for HIV testing.

RESULTS

Of those screened following recruitment via RDS (N = 1232; 98.6% MSM; 1.3% TW), 60.8% (749/1232) were eligible for HIV testing and 97.5% (730/749) were tested for HIV infection, which led to the identification of 36 newly diagnosed HIV infections (4.9%). Of those screened following recruitment via VBS (N = 2560; 95.2% MSM; 4.6% TW), 56.5% (1446/2560) were eligible for HIV testing and 92.8% (1342/1446) were tested for HIV infection, which led to the identification of 82 newly diagnosed HIV infections (6.1%). The proportion of new HIV diagnoses did not differ by recruitment method (ratio = 0.81, 95% confidence interval: 0.55 to 1.18). Compared to those recruited via RDS, those tested following recruitment via VBS were younger, more likely to identify as gay, and more likely to identify as TW. Compared to those recruited via VBS, those newly diagnosed with HIV infection following recruitment via RDS reported higher levels of internalized stigma and were more likely to report injection drug use and a history of deportation from the United States.

CONCLUSIONS

Despite RDS and VBS being equally effective for identifying undiagnosed HIV infection, each recruitment method reached different subgroups of MSM and TW in Tijuana. Our findings suggest that there may be benefits to using both RDS and VBS to increase the identification of previously undiagnosed HIV infection and ultimately support HIV care engagement among MSM and TW in Mexico and other similar LMIC.

Dynamics and Dispersal of Local HIV Epidemics Within San Diego and Across The San Diego-Tijuana Border

BACKGROUND

Evolutionary analyses of well-annotated HIV sequence data can provide insights into viral transmission patterns and associated factors. Here, we explored the transmission dynamics of the HIV-1 subtype B epidemic across the San Diego (US) - Tijuana (Mexico) border region to identify factors that could help guide public health policy.

METHODS

HIV pol sequences were collected from people with HIV in San Diego County and from Tijuana between 1996-2018. A multistep phylogenetic approach was used to characterize the dynamics of spread. The contribution of geospatial factors and HIV risk group to the local dynamics were evaluated.

RESULTS

Phylogeographic analyses of the 2,034 sequences revealed an important contribution of local transmission in sustaining the epidemic, as well as a complex viral migration network across the region. Geospatial viral dispersal between San Diego communities occurred predominantly among men-who-have-sex with-men with central San Diego being the main source (34.9%) and recipient (39.5%) of migration events. HIV migration was more frequent from San Diego county towards Tijuana than vice versa. Migrations were best explained by driving time between locations.

CONCLUSION

The US-Mexico border may not be a major barrier to the spread of HIV, which may stimulate coordinated transnational intervention approaches. Whereas a focus on central San Diego has the potential to avert most spread, the substantial viral migration independent of central San Diego shows that county-wide efforts will be more effective. Combined, this work shows that epidemiological information gleaned from pathogen genomes can uncover mechanisms that underlie sustained spread and, in turn, can be a building block of public health decision making.

Recent HIV Infection among men who have sex with men and transgender women in Tijuana

OBJECTIVE To characterize recent HIV infections among newly diagnosed men who have sex with men and transgender women in Tijuana. METHODS Limiting Antigen (LAg)-Avidity testing was performed to detect recent HIV infection within a cohort of newly-diagnosed men who have sex with men and transgender women in Tijuana. Logistic regression was used to determine characteristics associated with recent infection. A partial transmission network was inferred using HIV-1 pol sequences. Tamura-Nei 93 genetic distances were measured between all pairs of sequences, and the network was constructed by inferring putative transmission links (genetic distances ≤ 1.5%). We assessed whether recent infection was associated with clustering within the inferred network. RESULTS Recent infection was detected in 11% (22/194) of newly-diagnosed participants. Out of the participants with sequence data, 60% (9/15) with recent infection clustered compared with 31% (43/139) with chronic infection. Two recent infections belonged to the same cluster. In adjusted analyses, recent infection was associated with years of residence in Tijuana (OR = 1.5; 95%CI 1.01-1.09), cocaine use (past month) (OR = 8.50; 95%CI 1.99-28.17), and ever experiencing sexual abuse (OR = 2.85; 95%CI 1.03-7.85). DISCUSSION A total of 11% of men newly diagnosed with HIV who have sex with men and transgender women in Tijuana were recently infected. The general lack of clustering between participants with recent infection suggests continued onward HIV transmission rather than an outbreak within a particular cluster.

Perceived barriers to pre-exposure prophylaxis use and the role of syndemic factors among female sex workers in the Mexico-United States border region: a latent class analysis

Female sex workers (FSWs) experience syndemic factors (e.g., polydrug use, hazardous alcohol consumption, client-perpetrated violence, depression, and sexually transmitted infections) that often heighten vulnerability to HIV and limit healthcare utilization. We hypothesized that syndemic factors will limit FSWs' uptake of pre-exposure prophylaxis (PrEP). From 2016 to 2017, 295 HIV-negative FSWs were enrolled in a behavioral HIV prevention trial in Tijuana and Ciudad Juarez, Mexico, underwent STI testing, and completed surveys on syndemic factors and perceived barriers to PrEP use. Syndemic scores (0-5) were calculated by summing syndemic factors. Latent class analysis (LCA) was used to identify homogeneous classes with respect to perceived barriers to PrEP use. We identified four classes: (1) perceived healthcare access barriers (8.3%), (2) perceived financial barriers (18.7%), (3) high level of perceived barriers (19.9%), and (4) low level of perceived barriers (53.0%) to PrEP use. Those experiencing three (adjusted odds ratio [aOR] = 3.63, 95% confidence interval [CI] = 1.24-10.67) and four or five (aOR = 6.30, 95% CI = 1.70-23.35) syndemic factors had a higher odds of membership in the class characterized by a high level of perceived barriers than in the class characterized by a low level of perceived barriers. Addressing syndemic factors may maximize PrEP's impact among FSWs along Mexico's northern border.

Stigma and Web-Based Sex Seeking Among Men Who Have Sex With Men and Transgender Women in Tijuana, Mexico: Cross-Sectional Study

BACKGROUND

Stigma toward sexual and gender minorities is an important structural driver of HIV epidemics among men who have sex with men (MSM) and transgender women (TW) globally. Sex-seeking websites and apps are popular among MSM and TW. Interventions delivered via Web-based sex-seeking platforms may be particularly effective for engaging MSM and TW in HIV prevention and treatment services in settings with widespread stigma toward these vulnerable populations.

OBJECTIVE

To assess the potential utility of this approach, the objectives of our study were to determine the prevalence of Web-based sex seeking and examine the effect of factors that shape or are influenced by stigma toward sexual and gender minorities on Web-based sex seeking among MSM and TW in Tijuana, Mexico.

METHODS

From 2015 to 2018, 529 MSM and 32 TW were recruited through venue-based and respondent-driven sampling. Interviewer-administered surveys collected information on Web-based sex seeking (past 4 months) and factors that shape or are influenced by stigma toward sexual and gender minorities (among MSM and TW: traditional machismo, internalized stigma related to same-sex sexual behavior or gender identity, and outness related to same-sex sexual behavior or gender identity; among MSM only: sexual orientation and history of discrimination related to same-sex sexual behavior). A total of 5 separate multivariable logistic regression models were used to examine the effect of each stigma measure on Web-based sex seeking.

RESULTS

A total of 29.4% (165/561) of our sample reported seeking sex partners on the Web. Web-based sex seeking was negatively associated with greater endorsement of traditional machismo values (adjusted odds ratio [AOR] 0.36, 95% CI 0.19 to 0.69) and greater levels of internalized stigma (AOR 0.96, 95% CI 0.94 to 0.99). Web-based sex seeking was positively associated with identifying as gay (AOR 2.13, 95% CI 1.36 to 3.33), greater outness (AOR 1.17, 95% CI 1.06 to 1.28), and a history of discrimination (AOR 1.83, 95% CI 1.08 to 3.08).

CONCLUSIONS

Web-based sex-seeking is relatively common among MSM and TW in Tijuana, suggesting that it may be feasible to leverage Web-based sex-seeking platforms to engage these vulnerable populations in HIV prevention and treatment services. However, HIV interventions delivered through Web-based sex-seeking platforms may have limited reach among those most affected by stigma toward sexual and gender minorities (ie, those who express greater endorsement of traditional machismo values, greater levels of internalized stigma, lesser outness, and nongay identification), given that within our sample they were least likely to seek sex on the Web.

Perceived barriers to pre-exposure prophylaxis use among HIV-negative men who have sex with men in Tijuana, Mexico: A latent class analysis

BACKGROUND

Given the slow uptake of PrEP among cisgender men who have sex with men (MSM) in high-income countries, efforts to roll-out PrEP in low- and middle-income countries (LMIC) should address barriers to PrEP use to facilitate its more rapid uptake. To inform PrEP programs in LMIC, we examined patterns of perceived barriers to PrEP use among HIV-negative MSM in Tijuana, Mexico.

METHODS

From 03/2016-09/2017, 364 MSM completed interviewer-administered surveys assessing perceived barriers to PrEP use across 4 domains: PrEP attribute, individual, interpersonal, and structural. Latent class analysis was performed to identify distinct classes with respect to perceived barriers to PrEP use. Multinomial logistic regression was used to identify factors associated with class membership.

RESULTS

We identified three classes characterized by (1) high levels of perceived barriers across domains (12%), (2) low levels of perceived barriers across domains (43%), and (3) perceived PrEP attribute barriers (i.e., side-effects and cost) (45%). Membership in the high level of perceived barriers class (vs. the low level of perceived barriers class) was positively associated with having a history of incarceration (AOR: 2.44; 95% CI: 1.04, 5.73) and negatively associated with more social support (AOR: 0.99; 95% CI: 0.98, 1.00). Membership in the perceived PrEP attribute barriers class was positively associated with having seen a healthcare provider in the past year (AOR: 2.78; 95% CI: 1.41, 5.45) and negatively associated with having any HIV-positive or status unknown partners (AOR: 0.56; 95% CI: 0.31, 1.01).

CONCLUSIONS

Since most participants were in either the low level of perceived barriers class or the perceived PrEP attribute barriers class, future PrEP uptake may be high among MSM in Tijuana. However, these findings suggest that achieving sufficient PrEP uptake and adherence among MSM in Tijuana may require a range of comprehensive HIV prevention interventions.

Hazardous Alcohol Consumption Moderates the Relationship Between Safer Sex Maintenance Strategies and Condomless Sex With Clients Among Female Sex Workers in Mexico

Understanding the relationship between cognitive and behavioral processes and long-term behavior change is critical to developing behavior change maintenance interventions. We examined the relationship between cognitive and behavioral safer sex maintenance strategies and condomless vaginal/anal sex with clients among female sex workers (FSWs) in Mexico. We hypothesized a moderating effect of hazardous alcohol use, such that the relationship between the use of safer sex maintenance strategies and condomless sex would be weaker among FSWs who meet criteria for hazardous alcohol consumption. Data were gathered from 602 FSWs enrolled in a sexual risk reduction intervention with a text messaging maintenance component. Seven cognitive and behavioral strategies purported to be critical in sustaining long-term behavior change were measured (e.g., maintenance self-efficacy). The relationship between FSWs’ use of safer sex maintenance strategies and condomless vaginal/anal sex with clients was moderated by hazardous alcohol consumption. The association was weaker among FSWs who met criteria for hazardous alcohol consumption. Among FSWs who met criteria for hazardous alcohol consumption, maintenance self-efficacy was associated with fewer condomless sex acts with clients ( b = −0.35, p < .001). Among FSWs who did not meet criteria for hazardous alcohol consumption, recovery self-efficacy ( b = −0.21, p < .05) and self-monitoring ( b = −0.34, p < .001) were associated with fewer acts of condomless sex. Results indicate the importance of examining the multidimensional nature of safer sex maintenance strategies and of exploring subgroup differences in their associations with behavioral outcomes. Interventions that address safer sex maintenance strategies in the context of alcohol treatment should be developed for this subgroup of FSWs.

Maternal role strain and depressive symptoms among female sex workers in Mexico: the moderating role of sex work venue

Stressors that arise in parenting are likely to have an adverse impact on the psychological well-being of female sex workers (FSWs), particularly in low- to middle-income countries (LMIC). This study examined the association between maternal role strain and depressive symptoms among 426 FSW mothers with dependent-age children (aged < 18 years) in Tijuana and Cd. Juarez, Mexico (2016-2017). Four dimensions of maternal role strain (e.g., child emotional and behavioral problems) were examined in relation to maternal depressive symptoms. We also investigated whether the relationship between maternal role strain and depressive symptoms was modified by venue of sex work. Compared to indoor/establishment-based FSWs, street-based FSWs reported significantly more child-related financial strain. In multiple regression analysis, having more depressive symptoms was associated with identifying as a street-based FSW, greater use of drugs, lower emotional support, more child-related financial strain and more emotional and behavioral problems in children. A significant interaction was identified such that the association between maternal role strain and depressive symptoms was stronger for indoor/establishment-based compared to street-based FSWs. These findings suggest the need to address parenting strain and type of sex work venue in the development of counseling programs to improve the mental health of FSWs in LMIC.

Impact of time perspectives on texting intervention to reduce HIV/STI transmission among female sex workers in Tijuana and Ciudad Juarez, Mexico

Text messages may sustain post-counseling gains in behavioral improvements and reduce HIV/STI incidence. However, their effectiveness may depend on the messages' time perspective and characteristics of the individual. We evaluated the impact of time perspective on a text messaging intervention designed to maintain improvements in safer sex practices among drug-using and non-drug-using female sex workers (FSWs) in Tijuana (n = 141) and Cd. Juarez (n = 129), Mexico. FSWs received the efficacious Mujer Segura intervention, and were randomized to receive safer sex maintenance text messages with either a short-term or future-oriented time perspective. The outcome was HIV/STI incidence rate over 6-month follow-up. In Tijuana, combined HIV/STI incidence density was lower among FSWs in the FUTURE group (31.67 per 100 py) compared to women in the SHORT-TERM group (62.40 per 100 py). Conversely, in Cd. Juarez, HIV/STI incidence density was lower (although non-significant) among FSWs in the SHORT-TERM group (19.80 per 100 py) compared to those in the FUTURE group (35.05 per 100 py). These findings suggest that future-oriented text messages may sustain post-counseling improvements in sexual risk behavior among FSWs, but findings may vary by FSWs' characteristics (e.g., drug use), and by region and context.

Oral and vaginal HIV pre-exposure prophylaxis product attribute preferences among female sex workers in the Mexico-US border region

To assess the potential uptake of HIV pre-exposure prophylaxis (PrEP) products among female sex workers (FSWs) vulnerable to HIV infection, we examined the influence of product attributes on willingness to use products among 271 HIV-negative FSWs in Tijuana and Ciudad Juarez, Mexico (2016-2017). Via five-point Likert scale ratings, participants indicated their willingness to use hypothetical products with six attributes: formulation (pill, gel, liquid, or ring), frequency of use (daily, on-demand, or monthly), cost per use (10 or 200 pesos), effectiveness (40% or 80%), side effects (none or mild), and access point (healthcare clinic or non-governmental organization). Conjoint analysis was used to determine the impact of attributes on product ratings and identify preferred product attributes. Multinomial logistic regression was used to identify factors associated with formulation preferences. In both cities, formulation and frequency of use had the greatest impact on ratings. Participants in Ciudad Juarez indicated a strong preference for oral pills, whereas participants in Tijuana indicated roughly equal preferences for oral pills and vaginal gels. Monthly product use was preferred in both cities. Compared to preferring oral pills (38%), preferring vaginal gels (28%) was associated with practicing vaginal lubrication (adjusted odds ratio = 2.08; 95% confidence interval: 1.07-4.04). Oral PrEP may be acceptable to many FSWs in Tijuana and Ciudad Juarez; however, continued development of behaviorally-congruent vaginal PrEP products may also facilitate uptake and ensure sufficient coverage.

Factors in the HIV risk environment associated with bacterial vaginosis among HIV-negative female sex workers who inject drugs in the Mexico-United States border region

Background

Bacterial vaginosis (BV) is the most common cause of vaginitis among women worldwide and is associated with increased susceptibility to sexually transmitted infections (STIs), including HIV. We aimed to determine the impact of the HIV risk environment on BV among female sex workers who inject drugs (FSW-PWIDs) in Tijuana and Ciudad Juarez, Mexico.

Methods

We performed a cross-sectional analysis utilizing baseline data from a randomized controlled trial evaluating a behavioral HIV prevention intervention. Participants underwent testing for BV using the OSOM BVBlue® Rapid Test (Genzyme Diagnostics, San Diego, CA) and completed a survey eliciting information on the HIV risk environment, sexual risk behaviors, and substance use. We applied logistic regression to identify correlates of BV in the physical, social, economic, and political HIV risk environments stratified by study site (Ciudad Juarez vs. Tijuana).

Results

In total, 584 HIV-negative FSW-PWIDs (300 Ciudad Juarez; 284 Tijuana) were enrolled. The prevalence of BV was 39% (n = 228), which was higher in Ciudad Juarez (56.7%) compared to Tijuana (20.4%). In both cities, micro-level components of the physical HIV risk environment were associated with BV. In Ciudad Juarez, BV was associated with past experiences or threats of physical violence in response to proposed condom use (adjusted odds ratio [aOR] = 3.66, 95% confidence interval [CI]: 1.74–7.69, p = 0.001) and lifetime residence in Ciudad Juarez (aOR = 1.74, 95% CI: 1.05–2.87, p = 0.031). In Tijuana, BV was associated with the number of hours spent on the street daily in the past six months looking for, using, or dealing drugs, engaging in other income generating activities, or sleeping (aOR = 1.05, 95% CI: 1.001–1.097, p = 0.045).

Conclusions

Our findings suggest that FSW-PWIDs’ risk of BV may be shaped by the microphysical HIV risk environment. Addressing components of the physical risk environment, including interventions to reduce gender-based violence, may alleviate the burden of BV and subsequent susceptibility to HIV/STIs among FSW-PWIDs in the Mexico/US border region.

Trial registration

National Institute of Health (NIH) Clinical Trials Identifier NCT00840658, and date of NIH trial registration February 7, 2009.

Vaginal washing and lubrication among female sex workers in the Mexico-US border region: implications for the development of vaginal PrEP for HIV prevention

Background

To assess the potential acceptability and inform the development of behaviorally-congruent vaginal douche- or gel-based HIV pre-exposure prophylaxis (PrEP) products, we examined vaginal washing and lubrication practices among female sex workers (FSWs) in Tijuana and Ciudad Juarez, two northern Mexico cities bordering the United States (US).

Methods

Two hundred and ninety-five HIV-negative FSWs (145 Tijuana; 150 Ciudad Juarez) enrolled in a behavioral HIV prevention intervention trial completed surveys assessing vaginal washing and lubrication practices, as well as motivators and barriers to performing each practice. Logistic regression was used to identify potential predictors of each practice in the past month.

Results

In the past month, vaginal washing was performed by 56 and 22% of FSWs in Tijuana and Ciudad Juarez (p <  0.0001), respectively, while vaginal lubrication was performed by 64 and 45% of FSWs in Tijuana and Ciudad Juarez (p = 0.001), respectively. Vaginal washing was positively associated with living in Tijuana (adjusted odds ratio [AOR] = 4.35, 95% confidence interval [CI]: 2.60–7.30), older age (AOR = 1.04 per year, 95% CI: 1.01–1.06), and vaginal lubrication (AOR = 2.99, 95% CI: 1.67–5.35), while it was negatively associated with being born in the same state as the study site (AOR = 0.50, 95% CI: 0.31–0.82), earning a monthly income ≥3500 pesos (AOR = 0.53, 95% CI: 0.28–1.00), and hazardous alcohol consumption (AOR = 0.56, 95% CI: 0.33–0.95). Vaginal lubrication was positively associated with living in Tijuana (AOR = 2.21, 95% CI: 1.37–3.54) and vaginal washing (AOR = 2.91, 95% CI: 1.64–5.18), while it was negatively associated with being born in the same state as the study site (AOR = 0.47, 95% CI: 0.29–0.75).

Conclusions

The moderate and high prevalence of vaginal washing and lubrication, respectively, suggest behaviorally-congruent, multi-purpose, vaginal douche- and gel-based PrEP products that simultaneously address FSWs’ needs and prevent HIV infection may be acceptable to many FSWs along the Mexico-US border. Future product development and implementation should also consider the link between vaginal washing and lubrication to ensure existing practices do not undermine vaginal PrEP product effectiveness.

Trial registration

ClincialTrials.gov (NCT02447484).

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5946-z) contains supplementary material, which is available to authorized users.

Uptake of a Partner Notification Model for HIV Among Men Who Have Sex With Men and Transgender Women in Tijuana, Mexico

Undiagnosed HIV infection is common among men who have sex with men (MSM) and transgender women (TW) in Latin America. We examined uptake of a partner notification (PN) model among MSM and TW in Tijuana, Mexico. Forty-six HIV-positive MSM/TW enrolled as index patients, and reported 132 MSM/TW sexual partners for PN. Of notified partners (90/132), 39% declined eligibility screening or participation, 39% tested for HIV, and of those 28% were newly-diagnosed HIV-positive. Partners who were seen by the index patient more than once in the past 4 months and those who primarily had sex with the index patient in one of their homes were more likely to be notified via PN (76% vs. 50%; p = 0.01 and 86% vs. 64%, p = 0.02, respectively). Lower than expected PN uptake was associated with problems identifying index patients, obtaining reliable partner contact information, and engaging notified partners.

Sexual Partner Concurrency Among Partners Reported by MSM with Recent HIV Infection

We examined concurrency among sexual partners reported by men who have sex with men (MSM) with recent (acute or early) HIV infection in San Diego, California (2002-2015). Partners overlapping in time in the past 3 months were considered concurrent. Logistic generalized linear mixed models were used to identify factors associated with concurrency at the partner-level. 56% (388/699) of partners were concurrent to ≥1 other partner. The odds of concurrency were higher among partners >10 years younger than the participant (vs. within 10 years of age) [adjusted odds ratio (AOR) = 2.22, 95% confidence interval (CI) 1.09-4.52], longer term partners (AOR per month = 1.02, 95% CI 1.01-1.03), and partners met online (AOR = 1.56, 95% CI 0.98-2.48). Concurrency is common among partners of recently HIV-infected MSM. Tailored HIV prevention strategies for MSM with older partners, longer term partners, and partners met online may help minimize the potential impact of concurrency on HIV transmission.

HIV testing among men who have sex with men in Tijuana, Mexico: a cross-sectional study

OBJECTIVES

HIV testing is critical to the delivery of comprehensive HIV prevention and care services, yet coverage of sexual minorities by HIV testing programmes remains insufficient in many low- and middle-income countries, including Mexico. The objective of this study was to identify the prevalence and correlates of HIV testing among men who have sex with men (MSM) in Tijuana, Mexico.

METHODS

We conducted a cross-sectional study (2012-2013) among 189 MSM recruited via respondent-driven sampling (RDS). RDS-weighted logistic regression was used to identify correlates of prior HIV testing.

RESULTS

RDS-adjusted prevalence of prior and recent (≤ 12 months) HIV testing was 63.5% (95% CI 51.9% to 73.5%) and 36.8% (95% CI 25.4% to 46.4%), respectively. Prior HIV testing was positively associated with older age (adjusted OR (AOR)=1.09, 95% CI 1.04 to 1.15), being born in Tijuana (AOR=2.68, 95% CI 1.05 to 6.86), higher levels of education (AOR=2.65, 95% CI 1.08 to 6.53), identifying as homosexual or gay (AOR=3.73, 95% CI 1.48 to 9.42), being more 'out' about having sex with men (AOR=1.28, 95% CI:1.02 to 1.62), and a history of sexual abuse (AOR=3.24, 95% CI 1.06 to 9.86). Prior HIV testing was negatively associated with reporting more condomless anal intercourse acts (past 2 months) (AOR=0.95, 95% CI 0.92 to 0.98) and greater internalised homophobia (AOR=0.92, 95% CI 0.86 to 0.99).

CONCLUSIONS

Our findings indicate an urgent need for expanded HIV testing services for MSM in Tijuana. Innovative, non-stigmatising, confidential HIV testing interventions targeted at young, less educated, migrant and non-gay identifying MSM may facilitate HIV testing and timely linkage to HIV care and treatment within this population.

Incidence and Predictors of HIV and Sexually Transmitted Infections Among Female Sex Workers and Their Intimate Male Partners in Northern Mexico: A Longitudinal, Multilevel Study

Preventing human immunodeficiency virus (HIV) infection and other sexually transmitted infections (STIs) requires an understanding of sexual relationship factors beyond the individual level. We estimated HIV/STI incidence and identified time-varying predictors of STI acquisition in a prospective cohort study of female sex workers and their intimate (noncommercial) male partners in northern Mexico. From 2010 to 2013, couples underwent behavioral and biological assessments biannually for 24 months. Among 413 initially HIV-uninfected participants, 8 seroconverted during follow-up. Incidence of HIV (1.12 cases/100 person-years (PY)), chlamydia (9.47 cases/100 PY), active syphilis (4.01 cases/100 PY), and gonorrhea (1.78 cases/100 PY) was higher among women than among men (HIV: P = 0.069; all STIs combined: P < 0.001). In multivariable conditional logistic regression with individual fixed effects and correlated error terms within couples, risk of STI acquisition was significantly higher among women who had recently used cocaine, crack, or methamphetamine (adjusted odds ratio (OR) = 2.13, 95% confidence interval (CI): 1.07, 4.28). STI risk was lower among women who reported physically assaulting their male partners (adjusted OR = 0.44, 95% CI: 0.22, 0.86) and among men whose female partners had regular sex-work clients (adjusted OR = 0.38, 95% CI: 0.14, 1.03). Improving vulnerable couples' sexual health will require addressing the contexts in which drug use, interpersonal conflict, and economic vulnerability converge.

Incident syphilis infection among people who inject drugs in Tijuana, Mexico

Given that syphilis is associated with HIV infection among people who inject drugs (PWID), we examined syphilis incidence among PWID in Tijuana, Mexico. From 2006 to 2007, 940 PWID (142 women and 798 men) were recruited via respondent-driven sampling and followed for 18 months. At semi-annual visits, participants were tested for syphilis and completed surveys, which collected information on socio-demographics, sexual behaviours, substance use and injection behaviours. Poisson regression was used to estimate syphilis incidence rates (IRs), incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Twenty-one participants acquired syphilis during follow-up (IR = 1.57 per 100 person-years, 95% CI: 1.02-2.41). In a multivariate analysis, syphilis incidence was higher among women (IRR = 3.90, 95% CI: 1.37-11.09), HIV-positive participants (IRR = 4.60, 95% CI: 1.58-13.39) and those who reported ever exchanging sex for drugs, money, or other goods (IRR = 2.74, 95% CI: 0.97-7.76), while syphilis incidence was lower among those living in Tijuana for a longer duration (IRR = 0.95 per year, 95% CI: 0.91-1.00) and those reporting at least daily injection drug use (past 6 months) (IRR = 0.22, 95% CI: 0.09-0.54). Our findings suggest interventions that address the destabilising conditions associated with migration and integrate sexual and drug-related risk reduction strategies may help reduce syphilis incidence among PWID along the Mexico-US border.

STI/HIV test result disclosure between female sex workers and their primary, non-commercial male partners in two Mexico-US border cities: a prospective study

OBJECTIVES

Disclosure of sexually transmitted infections (STI)/HIV diagnoses to sexual partners is not mandated by public health guidelines in Mexico. To assess the feasibility of couples-based STI/HIV testing with facilitated disclosure as a risk-reduction strategy within female sex workers' (FSW) primary partnerships, we examined STI/HIV test result disclosure patterns between FSWs and their primary, non-commercial male partners in two Mexico-US border cities.

METHODS

From 2010 to 2013, 335 participants (181 FSWs and 154 primary male partners) were followed for 24 months. At semiannual visits, participants were tested for STIs/HIV and reported on their disclosure of test results from the previous visit. Multilevel logistic regression was used to identify individual-level and partnership-level predictors of cumulative (1) non-disclosure of ≥1 STI test result and (2) non-disclosure of ≥1 HIV test result within couples during follow-up.

RESULTS

Eighty-seven percent of participants reported disclosing all STI/HIV test results to their primary partners. Non-disclosure of ≥1 STI test result was more common among participants who reported an STI diagnosis as part of the study (adjusted OR=3.05, 95% CI 1.13 to 8.25), while non-disclosure of ≥1 HIV test result was more common among participants in longer-duration partnerships (AOR=1.15 per year, 95% CI 1.03 to 1.28). Drug use before/during sex within partnerships was associated with non-disclosure of both STI (AOR=5.06, 95% CI 1.64 to 15.62) and HIV (AOR=4.51, 95% CI: 1.32 to 15.39) test results.

CONCLUSIONS

STI/HIV test result disclosure was highly prevalent within FSWs' primary partnerships, suggesting couples-based STI/HIV testing with facilitated disclosure may be feasible for these and potentially other high-risk, socially marginalised couples.

Commercial lubricant use among HIV-negative men who have sex with men in Los Angeles: implications for the development of rectal microbicides for HIV prevention

To inform the development and assess potential use of rectal microbicide gels for HIV prevention among men who have sex with men (MSM), we examined the dynamics and contexts of commercial lubricant use during receptive anal intercourse (RAI) within this population. From 2007 to 2010, 168 HIV-negative MSM living in Los Angeles who practice RAI completed computer-assisted self-interviews, which collected information on their last sexual event with ≤3 recent partners, at baseline, three months, and one-year study visits. Logistic generalized linear mixed models were used to identify individual- and sexual event-level characteristics associated with commercial lubricant use during RAI at the last sexual event within 421 partnerships reported by participants over the course of follow-up. During RAI at their last sexual event, 57% of partnerships used a condom and 69% used commercial lubricant. Among partnerships that used commercial lubricant, 56% reported lubricant application by both members of the partnership, 66% first applied lubricant during sex, but before penetration, and 98% applied lubricant at multiple locations. The relationship between substance use and commercial lubricant use varied by condom use (interaction p-value = 0.01). Substance use was positively associated with commercial lubricant use within partnerships that did not use condoms during RAI at their last sexual event (AOR = 4.47, 95% [corrected] [CI]: 1.63-12.28), but no association was observed within partnerships that did use condoms (AOR = 0.66, 95% CI: 0.23-1.85). Commercial lubricant use during RAI was also positively associated with reporting more sexual partners (AOR = 1.18, 95% CI: 1.05-1.31), while older age (units = 5 years; AOR = 0.75, 95% CI: 0.61-0.94), homelessness (past year; AOR = 0.32, 95% CI: 0.13-0.76), and having sex with an older (>10 years) partner (AOR = 0.37, 95% CI: 0.14-0.95) were negatively associated with commercial lubricant use. These factors should be considered in the development of rectal microbicide gels to enhance their acceptability and use among MSM.

Acceptability of potential rectal microbicide delivery systems for HIV prevention: a randomized crossover trial

We assessed the acceptability of three of over-the-counter products representative of potential rectal microbicide (RM) delivery systems. From 2009 to 2010, 117 HIV-uninfected males (79 %) and females (21 %) who engage in receptive anal intercourse participated in a 6-week randomized crossover acceptability trial. Participants received each of three products (enema, lubricant-filled applicator, suppository) every 2 weeks in a randomized sequence. CASI and T-ACASI scales assessed product acceptability via Likert responses. Factor analysis was used to identify underlying factors measured by each scale. Random effects models were fit to examine age and gender effects on product acceptability. Three underlying factors were identified: Satisfaction with Product Use, Sexual Pleasure, and Ease of Product Use. For acceptability, the applicator ranked highest; however, differences between product acceptability scores were greatest among females and younger participants. These findings indicate that RM delivery systems impact their acceptability and should be considered early in RM development to enhance potential use.

Use of the location-based social networking application GRINDR as a recruitment tool in rectal microbicide development research

Mobile phone social networking applications such as GRINDR are potential tools for recruitment of men who have sex with men (MSM) for HIV prevention research. Demographics and sexual risk behaviors of men recruited through GRINDR and through traditional media were compared. GRINDR participants were younger (mean age 31 vs. 42, p < 0.0001), more White identified (44 vs. 30 %, p < 0.01), and had more sex partners in the previous 14 days (1.88 vs. 1.10, p < 0.05) than other recruits. Email responses were less successful for enrollment than phone calls (5 vs. 50 %). This approach resulted in successful recruitment of younger and more educated, White identified MSM.