Choosing event‐driven and daily HIV pre‐exposure prophylaxis – data from two European PrEP demonstration projects among men who have sex with men

IntroductionDaily and event‐driven PrEP are both efficacious in reducing the risk for HIV infection. However, the practice of event‐driven PrEP (edPrEP) is less well studied, in particular when provided as an alternative to daily PrEP. We studied regimen preferences and switches, and sexually transmitted infection (STI) incidence.MethodsWe analysed pooled data from two prospective cohort studies among MSM: Be‐PrEP‐ared, Belgium and AMPrEP, the Netherlands. In both projects, participants could choose between daily and edPrEP at three‐monthly study visits, when they were also screened for sexually transmitted infections including hepatitis C (HCV). We assessed the proportion choosing each regimen, and the determinants of choosing edPrEP at baseline. Additionally, we compared the incidence rates (IRs) of HCV, syphilis and chlamydia or gonorrhoea between regimens using Poisson regression. The study period was from 3 August 2015 until 24 September 2018.Results and discussionWe included 571 MSM, of whom 148 (25.9%) chose edPrEP at baseline. 31.7% of participants switched regimen at least once. After 28 months, 23.5% used edPrEP. Older participants (adjusted odds ratio (aOR) = 1.38 per 10 years, 95% confidence interval (CI) = 1.15 to 1.64) and those unemployed (aOR = 1.68, 95% CI = 1.03 to 1.75) were more likely to initially choose edPrEP. IR of HCV and syphilis did not differ between regimens, but the IR of chlamydia/gonorrhoea was higher among daily users (adjusted incidence rate ratio = 1.61, 95% CI = 1.35 to 1.94).ConclusionsA quarter of participants chose edPrEP at baseline and at 28 months this proportion was similar. Although the IR of HCV and syphilis were similar in the two regimens, the lower incidence of chlamydia and gonorrhoea among edPrEP users may suggest that less frequent STI testing of this group could be considered.     

Increasing awareness of HIV pre‐exposure prophylaxis (PrEP) and willingness to use HIV PrEP among men who have sex with men: a systematic review and meta‐analysis of global data

IntroductionIntegrated knowledge regarding pre‐exposure prophylaxis (PrEP) awareness and willingness to use PrEP can be useful for HIV prevention in high incidence groups. This review summarizes the awareness of PrEP and willingness to use PrEP among men who have sex with men (MSM).MethodsOnline electronic databases were searched before 31 August 2021. A meta‐analysis was conducted to pool studies analysing PrEP awareness and willingness to use PrEP. LOESS regression and linear regression were applied to fit the trends over time for the proportion of MSM aware of PrEP and willing to use PrEP. Dose–response meta‐analysis (DRMA) was conducted by a restricted cubic spline model to explore the relationship between willingness to use PrEP and selected factors.Results and DiscussionA total of 156 articles involving 228,403 MSM were included. The pooled proportions of MSM aware of PrEP and willing to use PrEP were 50.0 (95% CI: 44.8–55.2) and 58.6% (95% CI: 54.8–62.4), respectively. PrEP awareness varied among countries with different economic status and different WHO regions, among different publication and research years, PrEP types and support policies. PrEP willingness differed among countries with different economic status and groups with different risks of HIV. The awareness of PrEP increased from 2007 to 2019 with a slope of 0.040260 (p<0.0001), while the proportion of MSM willing to use PrEP decreased from 2007 to 2014 (slope = –0.03647, p = 0.00390) but increased after 2014 (slope = 0.04187, p = 0.03895). The main facilitators of willingness to use PrEP were PrEP awareness, condomless sexual behaviours, high perceived risk of HIV infection and influence of social network. The main barriers were doubts about the efficacy and side effects of PrEP. DRMA results indicated that MSM with more sexual partners and lower level of education were more willing to use PrEP. No publication bias was observed.ConclusionsThe proportions of PrEP awareness and willingness to use PrEP among MSM have increased since 2014, although the awareness was low and the willingness was moderate. Improving awareness of PrEP through increasing access to PrEP‐related health education and enhancing risk perceptions of HIV infection could have positive effects on the willingness to use PrEP among MSM.     

Association between HIV PrEP indications and use in a national sexual network study of US men who have sex with men

IntroductionHIV pre‐exposure prophylaxis (PrEP) is effective in preventing HIV transmission. United States Public Health Service (USPHS) clinical practice guidelines define biobehavioral indications for initiation. To assess guideline implementation, it is critical to quantify PrEP nonusers who are indicated and PrEP users who are not indicated. We sought to estimate current PrEP use among US men who have sex with men (MSM), characterize whether their PrEP use aligned with their current indications for PrEP, and assess whether the association between PrEP indications and PrEP use differed by demography or geography.MethodsUsing data from a US web‐based sexual network study of MSM between 2017 and 2019, we measured PrEP usage and assessed whether respondents met indications for PrEP. Log‐binomial regression was used to estimate the relationship between PrEP indications and PrEP use, with adjustment for geography, age and race/ethnicity.ResultsOf 3508 sexually active, HIV‐negative MSM, 34% met indications for PrEP. The proportion with current PrEP use was 32% among MSM meeting indications and 11% among those without indications. Nearly 40% of those currently using PrEP did not meet indications for PrEP, and 68% of MSM with indications for PrEP were not currently using PrEP. After adjusting for geography and demographics, MSM with PrEP indications were about three times as likely to be currently using PrEP. This association varied slightly, but not significantly, by geographic region, age and race/ethnicity.ConclusionsIndications for PrEP strongly predicted current PrEP use among US MSM. However, we identified substantial misalignment between indications and use in both directions (indicated MSM who were not benefitting from PrEP, and MSM taking PrEP while not presently being indicated). PrEP underuse by those at greatest risk for HIV acquisition may limit the projected impact of PrEP implementation, despite reported increases in PrEP provision. This calls for further implementation efforts to improve PrEP delivery to those most in need during periods of elevated sexual risk and to close the gap between indications and uptake.     

Preference for using a variety of future HIV pre‐exposure prophylaxis products among men who have sex with men in three US cities

BackgroundDaily oral pre‐exposure prophylaxis (PrEP) is available and recommended for men who have sex with men (MSM) at risk for HIV infection. Other HIV prevention products are being developed, including long‐acting injectable (LAI) and event‐based oral and topical formulations. Understanding preferences for potential products by MSM can help direct further development of prevention messaging.MethodsWe present baseline data from HIV‐negative participants enrolled in the US Mobile Messaging for Men (M‐cubed) Study. Participants were asked their likelihood of and rank order preference for using daily oral PrEP and various potential prevention products (one‐ to ‐three‐month injections, 2‐1‐1 sexual event oral dosing, anal or penile gel, or anal suppository), and their sociodemographic characteristics. Bivariate and multivariable logistics regression assessed demographic associations with likelihood of use and rank order preference.ResultsOverall, most MSM reported a likelihood of using LAI (74%), sexual event‐based pills (67%) and penile gel (64%). Men who reported recent unprotected (condomless and PrEPless) anal sex most preferred a penile gel formulation (74%), followed closely by LAI and event‐based pills (73% each). Current PrEP users (vs. non‐users) had greater odds of reporting likelihood to use LAI (AOR = 3.29, 95% CI = 2.12 to 5.11), whereas men reporting recent unprotected anal sex had a greater odds of likelihood to use a penile gel (AOR = 1.79, 95% CI = 1.27 to 2.52) and an anal suppository (AOR = 1.48, 95% CI = 1.08 to 2.02). Hispanic/Latino (vs. White) MSM (AOR = 2.29, 95% CI = 1.40 to 3.73) and, marginally, Black MSM (AOR = 1.54, 95% CI = 1.00 to 2.38) had greater odds of reporting likelihood to use penile gel. Similar patterns were found for rank ordering preference of products, including condoms.ConclusionsMost MSM were interested in using various potential future HIV prevention products, especially LAI. However, two typologies of potential users emerged: men who prefer sexual event‐based methods (condoms, event‐based pill, sexual gels and suppositories) and men who prefer non‐sexual event‐based methods (daily pill, LAI). Men who reported recent unprotected anal sex preferred a penile gel product most, followed closely by sexual event‐based pills and LAI. Racial/ethnic differences were noted as well. These findings on product preferences can help in formulation development and messaging.     

Alcohol‐antiretroviral interactive toxicity beliefs as a potential barrier to HIV pre‐exposure prophylaxis among men who have sex with men

Introduction : Pre‐exposure prophylaxis (PrEP) offers as much as 90% protection against HIV transmission. However, the effectiveness of PrEP depends on uptake and adherence to even intermittent dosing. Along with intoxication leading to unintentional non‐adherence, believing that alcohol mixed with pharmaceuticals is harmful (i.e., interactive toxicity beliefs) may lead to poor uptake and intentional non‐adherence. Methods : HIV‐negative sexually active men who have sex with men (N = 272) at a large Gay Pride event in Atlanta, GA, completed anonymous surveys of demographic characteristics, sexual behaviour, alcohol use and PrEP‐related alcohol interactive toxicity beliefs. Results : A total of 118 (43%) men surveyed had two or more male sex partners and condomless anal sex in the previous six months. Alcohol use was reported by over 90% of men and it was common for participants to believe that mixing alcohol and antiretrovirals is toxic; 75% endorsed at least one interactive toxicity belief. Among the 118 men who had engaged in condomless anal sex and had multiple sex partners, one in three stated that they were not interested in PrEP and men not interested in PrEP were significantly more likely to binge drink and hold interactive toxicity beliefs. Conclusions : These results mirror studies that find interactive toxicity beliefs are a potent predictor of intentional antiretroviral non‐adherence among people living with HIV and suggest interactive toxicity beliefs may impede PrEP uptake and adherence. Messages to increase PrEP awareness and adherence may also take steps to counter erroneous beliefs about mixing alcohol with antiretrovirals in the context of PrEP.     

Adherence to event‐driven HIV PrEP among men who have sex with men in Amsterdam,the Netherlands: analysis based on online diary data, 3‐monthly questionnaires and intracellular TFV‐DP

IntroductionEvent‐driven pre‐exposure prophylaxis (edPrEP) with oral tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) is highly effective for preventing HIV acquisition in men who have sex with men (MSM) and is preferred over daily PrEP by some MSM. However, it is largely unknown how well MSM adhere to edPrEP. We then aimed to assess PrEP protection during CAS among MSM using edPrEP and participating in the Amsterdam PrEP demonstration project (AMPrEP).MethodsWe analysed data from participants enrolled in AMPrEP who were taking edPrEP. We measured adherence through (1) a mobile application in which sexual behaviour and PrEP‐use were recorded daily, (2) three‐monthly self‐completed questionnaires and (3) dried blood spot (DBS) samples collected around six, twelve and twenty‐four months after PrEP initiation. We assessed the proportion of days with condomless anal sex (CAS) acts that were protected by PrEP, per partner type (i.e. steady partners, known casual partners, unknown casual partners), and the proportion of three‐month periods during which PrEP was correctly used. Intracellular TFV‐diphosphate (TFV‐DP) concentrations were determined from DBS. Good adherence was defined as at least one tablet before and one tablet within 48 hours after a CAS act.ResultsBetween 11 September 2015 and 6 October 2019, 182 of 376 MSM (48.4%) used edPrEP for at least one three‐month period. Of the 8224 CAS days that were reported in the app during edPrEP‐use, we observed good protection for most CAS days involving steady partners (n = 1625/2455, 66.9%), known casual partners (n = 3216/3472, 92.6%) and unknown casual partners (n = 2074/2297, 90.3%). Men reported consistently correct PrEP‐use in 851 (81.4%) of the 1046 three‐month periods of edPrEP‐use. The median TFV‐DP concentration was 591 fmol/sample (interquartile range = 270 to 896).ConclusionsAdherence to edPrEP was high as determined from the online app and questionnaire. DBS measurements were consistent with two to three tablets per week on average.     

Imperfect adherence in real life: a prevention‐effective perspective on adherence to daily and event‐driven HIV pre‐exposure prophylaxis among men who have sex with men – a prospective cohort study in Taiwan

IntroductionBoth daily and event‐driven (ED) pre‐exposure prophylaxis (PrEP) have been demonstrated to be highly effective among men who have sex with men (MSM). Prevention‐effective adherence proposes that PrEP adherence should be aligned with the risk of HIV, which could be applied to both daily and ED PrEP adherence measurement. The objective of this study was to describe the relationship between the use of PrEP and sex events among the MSM PrEP users and identify factors associated with adherence among daily and ED MSM PrEP users.MethodsA multicentre, observational, prospective cohort study was conducted at three hospital‐based clinics in three urban cities of Taiwan from January 2018 to December 2019. MSM ages 18 years or older – at high risk of HIV acquisition and taking PrEP during the study period – were included in the analysis. MSM PrEP users were allowed to choose between daily and ED PrEP based on their preference. Data on sociodemographic characteristics, mental health, sexual behaviours, substance use and PrEP‐taking behaviours were collected at each visit.ResultsA total of 374 MSM were included in the analysis with 1,054 visits. More than half (56%) of the PrEP users chose ED at the baseline and 150 regimen switches were reported by 21% of the participants. There was only one seroconversion documented during the study period. Most (84.2%) of the MSM PrEP users were able to adhere to PrEP during the most recent anal intercourse in the past one month. Among ED PrEP users with suboptimal adherence, the majority (81.9%) missed the pre‐coital dose. In the multivariable analysis, we found that participants who switched from daily to an ED dosing regimen were associated with poorer adherence to PrEP.ConclusionsA high level of PrEP adherence was observed among the majority of MSM in a real‐world setting. On the other hand, Taiwanese MSM switching from daily to ED dosing regimens were less likely to adhere to PrEP, suggesting that novel approaches focusing on a dosing switch would be necessary for MSM to improve their adherence to PrEP.     

Comparison between daily and on‐demand PrEP (pre‐exposure prophylaxis) regimen in covering condomless anal intercourse for men who have sex with men in Hong Kong: A randomized,controlled, open‐label,crossover trial

IntroductionBoth daily and on‐demand regimens have been proven effective for pre‐exposure prophylaxis (PrEP) against HIV in men who have sex with men (MSM). We aimed to compare the two regimens on their coverage of condomless anal intercourse (CLAI) in MSM.MethodsA randomized, controlled, open‐label, crossover trial was conducted in a teaching hospital in Hong Kong. Participants were sexually active HIV‐negative MSM aged 18 years or above with normal renal function and without chronic hepatitis B infection. Oral tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg (TDF/FTC) tablets were prescribed for PrEP. After a 2‐week lead‐in with daily TDF/FTC for treatment‐naïve MSM for tolerance assessment, participants were randomly assigned in a 1:1 ratio with a block size of four to either daily‐first or on‐demand‐first arm based on the IPERGAY study, for receiving PrEP for 16 weeks, then crossed‐over to the alternative regimen for another 16 weeks. The primary outcome was the proportion of days with PrEP‐covered CLAI by intention‐to‐treat analysis. The trial is registered with the CCRB Clinical Trials Registry, CUHK, CUHK_CCRB00606, and is closed to accrual.ResultsBetween 25 August 2018 and 23 March 2019, 119 eligible participants were assigned to daily‐first arm (n = 59) and on‐demand‐first arm (n = 60) with an 87% overall completion rate (n = 103). With 96% and 54% of days on PrEP during daily and on‐demand periods, respectively, the proportion of days with PrEP‐covered CLAI between two arms were not statistically different (92% vs. 92%, p = 0.93). About half (47%) were diagnosed with at least one episode of incident sexually transmitted infection. Mild and time‐limited adverse events, including diarrhoea, headache, nausea and dizziness, were reported in 37 (31%) and 10 (8%) during the daily and on‐demand periods, respectively. At the end of the study, a similar proportion favoured daily or on‐demand regimen.ConclusionsHigh prevention‐effective adherence, as reflected from the coverage of CLAI, was achievable by either daily or on‐demand PrEP among MSM, albeit a higher number of tablets taken for daily PrEP. As both regimens were well accepted, a flexible approach adopting either or both regimens with possible switching is warranted in order to suit individual health needs.     

The cost‐effectiveness of HIV pre‐exposure prophylaxis in men who have sex with men and transgender women at high risk of HIV infection in Brazil

Introduction

Men who have sex with men (MSM) and transgender women (TGW) in Brazil experience high rates of HIV infection. We examined the clinical and economic outcomes of implementing a pre‐exposure prophylaxis (PrEP) programme in these populations.

Methods

We used the Cost‐Effectiveness of Preventing AIDS Complications (CEPAC)‐International model of HIV prevention and treatment to evaluate two strategies: the current standard of care (SOC) in Brazil, including universal ART access (No PrEP strategy); and the current SOC plus daily tenofovir/emtracitabine PrEP (PrEP strategy) until age 50. Mean age (31 years, SD 8.4 years), age‐stratified annual HIV incidence (age ≤ 40 years: 4.3/100 PY; age > 40 years: 1.0/100 PY), PrEP effectiveness (43% HIV incidence reduction) and PrEP drug costs ($23/month) were from Brazil‐based sources. The analysis focused on direct medical costs of HIV care. We measured the comparative value of PrEP in 2015 United States dollars (USD) per year of life saved (YLS). Willingness‐to‐pay threshold was based on Brazil's annual per capita gross domestic product (GDP; 2015: $8540 USD).

Results

Lifetime HIV infection risk among high‐risk MSM and TGW was 50.5% with No PrEP and decreased to 40.1% with PrEP. PrEP increased per‐person undiscounted (discounted) life expectancy from 36.8 (20.7) years to 41.0 (22.4) years and lifetime discounted HIV‐related medical costs from $4100 to $8420, which led to an incremental cost‐effectiveness ratio (ICER) of $2530/YLS. PrEP remained cost‐effective (<1x GDP) under plausible variation in key parameters, including PrEP effectiveness and cost, initial cohort age and HIV testing frequency on/off PrEP.

Conclusion

Daily tenofovir/emtracitabine PrEP among MSM and TGW at high risk of HIV infection in Brazil would increase life expectancy and be highly cost‐effective.

     

A multi‐country cross‐sectional study to assess predictors of daily versus on‐demand oral pre‐exposure prophylaxis in youth from South Africa,Uganda and Zimbabwe

IntroductionSub‐Saharan Africa (SSA) carries the burden of the HIV epidemic, especially among adolescents and young people (AYP). Little is known about pre‐exposure prophylaxis (PrEP) uptake and preferences among AYP in SSA. We describe preferences for daily and on‐demand PrEP among AYP in South Africa, Uganda and Zimbabwe.MethodsA cross‐sectional survey was conducted in 2019 among 13‐ to 24‐year olds, capturing socio‐demographics, HIV risk behaviours and preferences for daily or on‐demand PrEP. Logistic regression models were used to estimate odds ratios, adjusting for site, sex and age.Results and discussionA total of 1330 participants from Cape Town (n = 239), Johannesburg (n = 200), Entebbe (n = 491) and Chitungwiza (n = 400) were enrolled; 673 (51%) were male, and the median age was 19 years (interquartile range 17–22 years). Of 1287 participants expressing a preference, 60% indicated a preference for on‐demand PrEP with differences by site (p < 0.001), sex (p < 0.001) and age group (p = 0.003). On‐demand PrEP was most preferred in Entebbe (75%), among males (65%) versus females (54%) and in older participants (62% in 18‐ to 24‐year‐olds vs. 47% in 13‐ to 15‐year‐olds). After adjusting for site, sex and age group, preference for on‐demand PrEP decreased as sex frequency over the past month increased (p‐trend = 0.004) and varied with the number of partners in the last 6 months, being least popular among those reporting four or more partners (p = 0.02). Participants knowing further in advance that they were likely to have sex were more likely to prefer on‐demand PrEP (p‐trend = 0.02). Participants having a larger age gap with their most recent partner and participants whose last partner was a transactional sex partner or client were both less likely to prefer on‐demand compared to daily PrEP (p = 0.05 and p = 0.09, respectively). Participants who knew their most recent partner was living with HIV or who did not know the HIV status of their most recent partner were less likely to prefer on‐demand PrEP (p = 0.05).ConclusionsOur data show that AYP in four SSA communities prefer on‐demand over daily PrEP options, with differences seen by site, age and sex. PrEP demand creation needs to be reviewed, optimized and tailored to socio‐demographic differences and designed in conjunction with AYP.     

HIV self‐testing partially filled the HIV testing gap among men who have sex with men in China during the COVID‐19 pandemic: results from an online survey

IntroductionHIV self‐testing (HIVST) is a useful strategy to promote HIV testing among key populations. This study aimed to understand HIV testing behaviours among men who have sex with men (MSM) and specifically how HIVST was used during the coronavirus disease 2019 (COVID‐19) measures in China when access to facility‐based testing was limited.MethodsAn online cross‐sectional study was conducted to recruit men who have sex with men (MSM) in China from May to June of 2020, a period when COVID‐19 measures were easing. Data on socio‐demographic characteristics, sexual behaviours and HIV testing in the three months before and during COVID‐19 measures (23 January 2020) were collected. Chi‐square test and logistic regression were used for analyses.ResultsOverall, 685 MSM were recruited from 135 cities in 30 provinces of China, whose mean age was 28.8 (SD: 6.9) years old. The majority of participants self‐identified as gay (81.9%) and had disclosed their sexual orientation (66.7%). In the last three months, 69.6% ever had sex with men, nearly half of whom had multiple sexual partners (47.2%). Although the overall HIV testing rates before and during COVID‐19 measures were comparable, more MSM self‐tested for HIV during COVID‐19 measures (52.1%) compared to before COVID‐19 measures (41.6%, p = 0.038). Fewer MSM used facility‐based HIV testing during COVID‐19 measures (42.9%) compared to before COVID‐19 measures (54.1%, p = 0.038). Among 138 facility‐based testers before COVID‐19 measures, 59.4% stopped facility‐based testing during COVID‐19 measures. Among 136 self‐testers during COVID‐19 measures, 58.1% had no HIV self‐testing before COVID‐19 measures. Multivariable logistic regression showed that having sex with other men in the last three months (adjusted odds ratio, aOR = 2.04, 95% CI: 1.38 to 3.03), self‐identifying as gay (aOR = 2.03, 95% CI: 1.31 to 3.13), ever disclosing their sexual orientation (aOR = 1.72, 95% CI: 1.19 to 2.50) and tested for HIV in three months before COVID‐19 measures (aOR = 4.74, 95% CI: 3.35 to 6.70) were associated with HIV testing during COVID‐19 measures.ConclusionsFacility‐based HIV testing decreased and HIVST increased among MSM during COVID‐19 measures in China. MSM successfully accessed HIVST as substitute for facility‐based testing, with no overall decrease in HIV testing rates.     

Cost‐effectiveness of hepatitis C virus test‐and‐treat and risk reduction strategies among men who have sex with men living with HIV in France

IntroductionStudies suggest that hepatitis C virus (HCV) micro‐elimination is feasible among men who have sex with men (MSM) living with human immunodeficiency virus (HIV), through treatment‐as‐prevention and interventions aimed at reducing risk behaviours. However, their economic impact is poorly understood. The aim of this study was to assess the cost‐effectiveness of HCV screening and risk reduction strategies in France.MethodsA compartmental deterministic mathematical model was developed to describe HCV disease transmission and progression among MSM living with HIV in France. We evaluated different combinations of HCV screening frequency (every 12, 6 or 3 months) and risk reduction strategies (targeting only high‐risk or all MSM) from 2021 onwards. The model simulated the number of HCV infections, life‐expectancy (LYs), quality‐adjusted life‐expectancy (QALYs), lifetime costs and incremental cost‐effectiveness ratio (ICER) over a lifetime horizon (leading to an end of the simulation in 2065).ResultsAll strategies increased QALYs, compared with current practices, that is yearly HCV screening, with no risk reduction. A behavioural intervention resulting in a 20% risk reduction in the high‐risk group, together with yearly screening, was the least expensive strategy, and, therefore, cost‐saving compared to current practices. The ICER per QALY gained for the strategy combining risk reduction for the high‐risk group with 6‐month HCV screening, compared to risk reduction with yearly screening, was €61,389. It also prevented 398 new HCV infections between 2021 and 2065, with a cost per infection averted of €37,790. All other strategies were dominated (more expensive and less effective than some other available alternative) or not cost‐effective (ICER per QALY gained > €100,000).ConclusionsIn the French context, current HCV screening practices without risk reduction among MSM living with HIV cannot be justified on economic grounds. Risk reduction interventions targeted to high‐risk individuals—alongside screening either once or twice a year—could be cost‐effective depending on the policymaker''s willingness‐to‐pay.     

Prevalence and correlates of HIV among men who have sex with men in Tijuana,Mexico

Introduction

Men who have sex with men (MSM) in developing countries such as Mexico have received relatively little research attention. In Tijuana, Mexico, a border city experiencing a dynamic HIV epidemic, data on MSM are over a decade old. Our aims were to estimate the prevalence and examine correlates of HIV infection among MSM in this city.

Methods

We conducted a cross-sectional study of 191 MSM recruited through respondent-driven sampling (RDS) in 2012. Biological males over the age of 18 who resided in Tijuana and reported sex with a male in the past year were included. Participants underwent interviewer-administered surveys and rapid tests for HIV and syphilis with confirmation.

Results

A total of 33 MSM tested positive for HIV, yielding an RDS-adjusted estimated 20% prevalence. Of those who tested positive, 89% were previously unaware of their HIV status. An estimated 36% (95% CI: 26.4–46.5) had been tested for HIV in the past year, and 30% (95% CI: 19.0–40.0) were estimated to have ever used methamphetamine. Independent correlates of being infected with HIV were methamphetamine use (odds ratio [OR]=2.24, p=0.045, 95% CI: 1.02, 4.92) and active syphilis infection (OR=4.33, p=0.01, 95% CI: 1.42, 13.19).

Conclusions

Our data indicate that MSM are a key sub-population in Tijuana at higher risk for HIV. Tijuana would also appear to have the highest proportion among upper-middle-income countries of HIV-positive MSM who are unknowingly infected. More HIV prevention research on MSM is urgently needed in Tijuana.