Rectal Douching Associated with Receptive Anal Intercourse: A Literature Review

Rectal Douche as HIV Pre-Exposure Prophylaxis for Receptive Anal Intercourse: An End User Tenofovir Powder Sachet Preparation Feasibility Study (DREAM-04)

BACKGROUND

Unprotected receptive anal intercourse carries the highest sexual HIV transmission risk. The need for diverse pre-exposure prophylaxis (PrEP) options has encouraged the development of on-demand, topical PrEP products for those preferring nonsystemic or occasional PrEP. We assessed end users' proficiency in preparing tenofovir douches from sachets containing 2 different powder types, lyophilized and spray dried, and evaluated their experience.

METHODS

Cisgender adult men with a history of RAI-related douching were consented, screened, and randomized 1:1 to the order of the powder type prepared. All participants prepared at least 3 enema bottles of each powder type. Aliquots from each prepared douche bottle were analyzed for tenofovir (TFV) concentration, osmolality, and pH. User experience and likelihood of future product use were assessed by questionnaire.

RESULTS

Twenty-one eligible participants were enrolled. Most participants reported both products as easy or very easy to prepare and likely or very likely to be used. Participants preferred the lyophilized product. The lyophilized and spray-dried douche bottles prepared met the osmolality specifications 89% and 61% of the time and TFV content specifications 81% and 29% of the time, respectively. Questionnaires indicated the most common challenges were tearing open the sachets and transferring the spray-dried product.

CONCLUSIONS

Most participants reported the douches were easy to prepare and indicated likely future use. Although the lyophilized sachets were prepared sufficiently to establish preparation feasibility, the spray-dried sachets often fell outside specifications. Failure analysis provided insights to guide product modifications to improve the proficiency of douche preparation and future product use.

Acceptability of a rectal microbicide douche for HIV prevention: a mixed-methods analysis of a first-in-human formulation pilot study

OBJECTIVES

DREAM-01 was an open label, dose-escalation and variable osmolarity study to identify a tenofovir HIV-prevention douche/enema that could achieve protective colon tissue cell concentrations and high acceptability. To assess impact on sexual enjoyment, iso-osmolar and hypo-osmolar placebo douches were provided for at-home use before receptive anal sex (RAS).

METHODS

Eighteen HIV-uninfected men who have RAS were administered three tenofovir douches at the research clinic: Product A, an iso-osmolar dose; Product B, an iso-osmolar escalation dose; and Product C, a hypo-osmolar escalation dose. Following Products A and C, participants were given a saline douche of matching osmolarity to use at home before RAS. Participants reported acceptability via a computer-assisted self-interview and in-depth interview in this mixed-methods study.

RESULTS

All three products were rated acceptable by 17 (95%) of the participants. A majority (94%) would be likely or very likely to use any of the three products before RAS. Of those who used the saline douches before RAS and then rated their sexual enjoyment, most reported that their sexual enjoyment was not affected. Interview data revealed that participants found the product easy to incorporate into their regular routine, but would prefer to use more liquid for cleansing.

CONCLUSIONS

These findings indicate that the hypo-osmolar Product C, which also provides the most rapid delivery of tenofovir for HIV prevention, is acceptable for future safety trials and that our sample reports high likelihood of using a rectal microbicide douche for HIV prevention. Our findings support continued pursuit of a tenofovir rectal microbicide douche.

TRIAL REGISTRATION NUMBER

NCT02750540.

Phase I Dose Volume Escalation of Rectally Administered PC-1005 to Assess Safety, Pharmacokinetics, and Antiviral Pharmacodynamics as a Multipurpose Prevention Technology (MTN-037)

BACKGROUND

On demand, topical PrEP is desired by those preferring episodic, nonsystemic PrEP. PC-1005 gel (MIV-150, zinc, and carrageenan) exhibits in vitro antiviral HIV-1, human papillomavirus (HPV), and herpes simplex virus type 2 (HSV-2) activity, attractive for a multipurpose prevention technology candidate. We evaluated the safety, pharmacokinetics, and antiviral effect of rectally applied PC-1005.

METHODS

HIV-uninfected adults received a series of 3 rectal PC-1005 doses-4, 16, and 32 mL separated by 2-week washout periods. Following each dose, plasma, rectal fluid and tissue, and vaginal fluid were collected over 48 hours.

RESULTS

Thirteen adults enrolled; 12 completed all 3 doses. All 13 adverse events reported were grade 1 or 2; 5 were judged study drug related. Plasma MIV-150 peaked 1-2 h after dosing with a median peak concentrations range of 0.07-0.23 ng/mL and median half-life range of 4.9-7.4 hours across dose volumes; median concentrations were below assay quantitation limits (BLQ) 24 hours after dosing. Rectal tissue MIV-150 peaked 0.5-1 hours after dosing at 1.4 ng/g (ng/mL) (0.8, 1.9), 46.0 (30.7, 831.0), and 79.7 (11.9, 116.0), respectively, after each dose volume; median tissue concentrations were BLQ beyond 5 hours for all doses. All vaginal fluid samples were BLQ. Ex vivo antiviral assays showed 5 hours of antiviral HPV and HSV effects but no anti-HIV activity.

CONCLUSIONS

MIV-150 rectal tissue concentrations were below the 100 ng/g target concentration and transient. Ex vivo assays demonstrated antiviral HSV and HPV effects but not against HIV. PC-1005 requires a more potent antiviral and longer-lasting formulation for further consideration as a multipurpose prevention technology candidate.

CLINICAL TRIALS

NCT03408899.

History of Rectal Product Use and Country of Residence Influence Preference for Rectal Microbicide Dosage Forms Among Young Sexual and Gender Minorities: A Multi-country Trial Comparing Placebo Douche, Suppository, and Insert Products

The DESIRE Study (MTN-035) explored product preference among three placebo rectal microbicide (RM) formulations, a rectal douche (RD), a suppository, and an insert, among 210 sexually active transgender people and men who have sex with men in five counties: the United States, Peru, Thailand, South Africa, and Malawi. Participants used each product prior to receptive anal sex (RAS) for 1 month, following a randomly assigned sequence, then selected their preferred product via computer assisted self-interview. In-depth interviews examined reasons for preference. We compared product preference and prior product use by country to explore whether geographic location and experience with the similar products impacted preference. A majority in the United States (56%) and Peru (58%) and nearly half in South Africa (48%) preferred the douche. Most in Malawi (59%) preferred the suppository, while half in Thailand (50%) and nearly half in South Africa (47%) preferred the insert. Participants who preferred the douche described it as quick and easy, already routinized, and serving a dual purpose of cleansing and protecting. Those who preferred the insert found it small, portable, discreet, with quick dissolution. Those who preferred the suppository found the size and shape acceptable and liked the added lubrication it provided. Experience with product use varied by country. Participants with RD experience were significantly more likely to prefer the douche (p = 0.03). Diversifying availability of multiple RM dosage forms can increase uptake and improve HIV prevention efforts globally.

Pleasurable and problematic receptive anal intercourse and diseases of the colon, rectum and anus

The ability to experience pleasurable sexual activity is important for human health. Receptive anal intercourse (RAI) is a common, though frequently stigmatized, pleasurable sexual activity. Little is known about how diseases of the colon, rectum, and anus and their treatments affect RAI. Engaging in RAI with gastrointestinal disease can be difficult due to the unpredictability of symptoms and treatment-related toxic effects. Patients might experience sphincter hypertonicity, gastrointestinal symptom-specific anxiety, altered pelvic blood flow from structural disorders, decreased sensation from cancer-directed therapies or body image issues from stoma creation. These can result in problematic RAI - encompassing anodyspareunia (painful RAI), arousal dysfunction, orgasm dysfunction and decreased sexual desire. Therapeutic strategies for problematic RAI in patients living with gastrointestinal diseases and/or treatment-related dysfunction include pelvic floor muscle strengthening and stretching, psychological interventions, and restorative devices. Providing health-care professionals with a framework to discuss pleasurable RAI and diagnose problematic RAI can help improve patient outcomes. Normalizing RAI, affirming pleasure from RAI and acknowledging that the gastrointestinal system is involved in sexual pleasure, sexual function and sexual health will help transform the scientific paradigm of sexual health to one that is more just and equitable.

Tenofovir Douche as HIV Preexposure Prophylaxis for Receptive Anal Intercourse: Safety, Acceptability, Pharmacokinetics, and Pharmacodynamics (DREAM 01)

BACKGROUND

Despite highly effective HIV preexposure prophylaxis (PrEP) options, no options provide on-demand, nonsystemic, behaviorally congruent PrEP that many desire. A tenofovir-medicated rectal douche before receptive anal intercourse may provide this option.

METHODS

Three tenofovir rectal douches-220 mg iso-osmolar product A, 660 mg iso-osmolar product B, and 660 mg hypo-osmolar product C-were studied in 21 HIV-negative men who have sex with men. We sampled blood and colorectal tissue to assess safety, acceptability, pharmacokinetics, and pharmacodynamics.

RESULTS

The douches had high acceptability without toxicity. Median plasma tenofovir peak concentrations for all products were several-fold below trough concentrations associated with oral tenofovir disoproxil fumarate (TDF). Median colon tissue mucosal mononuclear cell (MMC) tenofovir-diphosphate concentrations exceeded target concentrations from 1 hour through 3 to 7 days after dosing. For 6-7 days after a single product C dose, MMC tenofovir-diphosphate exceeded concentrations expected with steady-state oral TDF 300 mg on-demand 2-1-1 dosing. Compared to predrug baseline, HIV replication after ex vivo colon tissue HIV challenge demonstrated a concentration-response relationship with 1.9 log10 maximal effect.

CONCLUSIONS

All 3 tenofovir douches achieved tissue tenofovir-diphosphate concentrations and colorectal antiviral effect exceeding oral TDF and with lower systemic tenofovir. Tenofovir douches may provide a single-dose, on-demand, behaviorally congruent PrEP option, and warrant continued development. Clinical Trials Registration . NCT02750540.

A conjoint experiment of three placebo rectal products used with receptive anal sex: results from MTN-035

INTRODUCTION

End-user perspectives are vital to the design of new biomedical HIV prevention products. Conjoint analysis can support the integration of end-user perspectives by examining their preferences of potential pre-exposure prophylaxis (PrEP) products. The Microbicides Trial Network (MTN) 035 protocol examined three placebo rectal dosage forms (insert, enema and suppository) that could deliver PrEP prior to receptive anal sex (RAS).

METHODS

Between April 2019 and July 2020, we enrolled 217 HIV-negative, cisgender men who have sex with men (MSM; n = 172; 79.3%) and transgender people (n = 47; 20.7%) ages 18-35 into a randomized cross-over trial across Malawi, Peru, South Africa, Thailand and the United States. Participants used each product prior to RAS over 4-week periods. Participants completed a conjoint experiment where they selected between random profiles using seven features (dosage form, timing of use before sex, side effects, duration of protection, effectiveness, frequency of use and need for a prescription).

RESULTS

Effectiveness was the strongest determinant of choice (30.4%), followed by modality (18.0%), potential side effects (17.2%), frequency of use (10.8%), duration of protection (10.4%), timing of use before sex (7.4%) and need for a prescription (5.9%). Relative utility scores indicated that the most desirable combination of attributes was a product with 95% efficacy, used 30 minutes before sex, offering a 3- to 5-day protection window, used weekly, having no side effects, in the form of an enema and available over-the-counter.

CONCLUSIONS

Choice in next-generation PrEP products is highly desired by MSM and transgender people, as no one-size-fits-all approach satisfies all the preferences. MTN-035 participants weighed product features differently, recognizing the need for diverse, behaviourally congruent biomedical options that fit the needs of intended end-users.

A latent trajectory analysis of young sexual and gender minorities' adherence to three rectal microbicide placebo formulations (MTN-035; a randomized crossover trial)

BACKGROUND

Rectal microbicides (RM) are biomedical HIV prevention products that aim to prevent or reduce the transmission of HIV and other sexually transmitted infections (STIs). RM modalities may be beneficial for populations who have complex lifestyles, difficulties adhering to pre-exposure prophylaxis (PrEP) regimens, and/or have limited access to care. MTN-035 (DESIRE; Developing and Evaluating Short-Acting Innovations for Rectal Use), a randomized crossover trial, aimed to evaluate the safety and acceptability of, and adherence to, three placebo RM modalities (douche, insert, and suppository) prior to receptive anal intercourse.

METHODS

We conducted latent trajectory analysis to identify clusters of individuals who shared similar trajectories in acceptability and adherence for each product (douche, insert, and suppository) over time. We analyzed weekly short messaging service (SMS) use reports for each modality as reported by enrolled sexual and gender minority (SGM) participants.

RESULTS

Two trajectories for each product were identified: a "protocol compliant" trajectory (i.e., at least one product use occasion per week) and "high use" trajectory (i.e., more than three product use occasions per week). Participants with high use were more likely to lack access to PrEP and have higher intentions to utilize RM modalities compared to those who were protocol compliant.

CONCLUSIONS

This study highlighted high adherence to RM modalities among SGM. As research into viable HIV prevention modalities continues to evolve, tailored intervention strategies are needed to support the uptake of and adherence to alternative prevention modalities that are behaviorally congruent with targeted users.

TRIAL REGISTRATION

NCT03671239 (14/09/2018).

Sexual health and treatment-related sexual dysfunction in sexual and gender minorities with prostate cancer

Prostate cancer treatment has substantial effects on sexual health and function. Sexual function is a vital aspect of human health and a critical component of cancer survivorship, and understanding the potential effects of different treatment modalities on sexual health is crucial. Existing research has extensively described the effects of treatment on male erectile tissues necessary for heterosexual intercourse; however, evidence regarding their effects on sexual health and function in sexual and gender minority populations is minimal. These groups include sexual minority - gay and bisexual - men, and transgender women or trans feminine people in general. Such unique effects in these groups might include altered sexual function in relation to receptive anal and neovaginal intercourse and changes to patients' role-in-sex. Sexual dysfunctions following prostate cancer treatment affecting quality of life in sexual minority men include climacturia, anejaculation, decreased penile length, erectile dysfunction, and problematic receptive anal intercourse, including anodyspareunia and altered pleasurable sensation. Notably, clinical trials investigating sexual outcomes after prostate cancer treatment do not collect sexual orientation and gender identity demographic data or outcomes specific to members of these populations, which perpetuates the uncertainty regarding optimal management. Providing clinicians with a solid evidence base is essential to communicate recommendations and tailor interventions for sexual and gender minority patients with prostate cancer.

A randomized trial of safety, acceptability and adherence of three rectal microbicide placebo formulations among young sexual and gender minorities who engage in receptive anal intercourse (MTN-035)

Efforts to develop a range of HIV prevention products that can serve as behaviorally congruent viable alternatives to consistent condom use and oral pre-exposure prophylaxis (PrEP) remain crucial. MTN-035 was a randomized crossover trial seeking to evaluate the safety, acceptability, and adherence to three placebo modalities (insert, suppository, enema) prior to receptive anal intercourse (RAI). If participants had no RAI in a week, they were asked to use their assigned product without sex. We hypothesized that the modalities would be acceptable and safe for use prior to RAI, and that participants would report high adherence given their behavioral congruence with cleansing practices (e.g., douches and/or enemas) and their existing use to deliver medications (e.g., suppositories; fast-dissolving inserts) via the rectum. Participants (N = 217) were sexual and gender minorities enrolled in five different countries (Malawi, Peru, South Africa, Thailand, and the United States of America). Mean age was 24.9 years (range 18-35 years). 204 adverse events were reported by 98 participants (45.2%); 37 (18.1%) were deemed related to the study products. The proportion of participants reporting "high acceptability" was 72% (95%CI: 65% - 78%) for inserts, 66% (95%CI: 59% - 73%) for suppositories, and 73% (95%CI: 66% - 79%) for enemas. The proportion of participants reporting fully adherent per protocol (i.e., at least one use per week) was 75% (95%CI: 69% - 81%) for inserts, 74% (95%CI: 68% - 80%) for suppositories, and 83% (95%CI: 77% - 88%) for enemas. Participants fully adherent per RAI-act was similar among the three products: insert (n = 99; 58.9%), suppository (n = 101; 58.0%) and enema (n = 107; 58.8%). The efficacy and effectiveness of emerging HIV prevention drug depends on safe and acceptable delivery modalities that are easy to use consistently. Our findings demonstrate the safety and acceptability of, and adherence to, enemas, inserts, and suppositories as potential modalities through which to deliver a rectal microbicide.

Hypo-osmolar rectal douche tenofovir formulation prevents simian/human immunodeficiency virus acquisition in macaques

In spite of the rollout of oral pre-exposure prophylaxis (PrEP), the rate of new HIV infections remains a major health crisis. In the United States, new infections occur predominantly in men having sex with men (MSM) in rural settings where access to PrEP can be limited. As an alternative congruent with MSM sexual behavior, we have optimized and tested tenofovir (TFV) and analog-based iso-osmolar and hypo-osmolar (HOsm) rectal douches for efficacy against rectal simian/human immunodeficiency virus (SHIV) infection of macaques. Single TFV HOsm high-dose douches achieved peak plasma TFV levels similar to daily oral PrEP, while other formulations yielded lower concentrations. Rectal tissue TFV-diphosphate (TFV-DP) concentrations at the portal of virus entry, however, were markedly higher after HOsm douching than daily oral PrEP. Repeated douches led to significantly higher plasma TFV and higher TFV-DP concentrations in rectal tissue at 24 hours compared with single douches, without detectable mucosal or systemic toxicity. Using stringent repeated intrarectal SHIV exposures, single HOsm high-dose douches delivered greater protection from virus acquisition for more than 24 hours compared with oral PrEP. Our results demonstrate a rapid delivery of protective TFV doses to the rectal portal of virus entry as a potential low-cost and safe PrEP alternative.

Twinks, Jocks, and Bears, Oh My! Differing subcultural appearance identifications among gay men and their associated eating disorder psychopathology

Gay men have increased risk of body dissatisfaction and disordered eating compared to heterosexual men, and it is unclear what differentiates their risk for thinness- and muscularity-oriented eating psychopathology. Differing subcultural appearance identifications (SAIs) among gay men are one potential factor that may relate to varied eating psychopathology, but this has not been studied. We examined gay men's SAIs: twinks, jocks, and bears; any "other" self-identified SAI; or no SAI, as well as the relationship between men's SAIs and traditional eating psychopathology and unhealthy dieting (both facets of thinness-oriented psychopathology), and muscularity-oriented psychopathology using univariate ANOVAs controlling for participant age. 264 U.S. gay-identified participants self-reported sexual orientation, SAIs, and eating psychopathology. Self-identified twinks did not report higher traditional eating psychopathology or unhealthy dieting than other SAIs or those without a SAI, as hypothesized. Self-identified twinks, jocks, and bears all reported greater muscularity-oriented eating pathology than those without a SAI. Self-identified jocks also reported higher muscularity-oriented disordered eating than those with an "other" self-identified SAI and bears. Thus, having a SAI may increase risk for disordered eating; specifically, identifying as a twink, jock or bear may confer greater risk for muscularity-oriented eating pathology.

More than just oral PrEP: exploring interest in rectal douche, dissolvable implant, removable implant and injection HIV prevention approaches among racially diverse men who have sex with men in the Northeast Corridor

OBJECTIVES

HIV scholars and practitioners have worked to expand strategies for prevention among marginalised populations who are disproportionately impacted by the epidemic, such as racial minority men who have sex with men (MSM). Given this urgency, the objective of this study was to assess interest in biomedical prevention strategies.

METHODS

This exploratory and cross-sectional study investigated interest in four biomedical prevention tools-rectal douche, dissolvable implant, removable implant and injection-among a racially diverse sample of MSM from the Northeast Corridor region between Philadelphia and Trenton. Data were collected as part of screening for Connecting Latinos en Pareja, a couples-based HIV prevention intervention for Latino MSM and their partners.

RESULTS

A total of 381 individuals participated in the screener and provided information about their interest in bio tools. Approximately 26% of participants identified as black, 28% as white and 42% as 'other' or multiracial; 49% identified as Latino. Majority (54%) reported some form of child sexual abuse. Of the participants who reported being in a primary relationship (n=217), two-thirds reported unprotected anal sex within that relationship over the past 90 days (n=138, 64%) and approximately half (n=117, 54%) reported unprotected anal sex outside of the relationship in this period. Majority of participants reported interest in all bio tools assessed, including dissolvable implants (60%), removable implants (64%), rectal douching (79%) and injection (79%). Although interest in bio tools was broadly unassociated with demographics and sexual risk behaviours, analyses revealed significant associations between reports of child sexual abuse and interest in implant and injection methods.

CONCLUSIONS

The authors recommend investing in these prevention methods, particularly rectal douching and injection, as a means of preventing HIV among racial minority MSM. Given the interest in biomedical prevention tools, future studies should explore potential strategies for adherence.

Getting Clear About Rectal Douching Among Men Who Have Sex With Men

Receptive anal sex is the primary means through which HIV is transmitted among men who have sex with men (MSM). Recently, researchers have begun investigating the role that rectal douching may play in amplifying risk for transmission. Yet, there is limited research on the frequency with which MSM douche, the products they use, and how this may vary across sociodemographic characteristics. A U.S. national sample of 4745 MSM completed an online survey that assessed their douching behavior, demographic characteristics, sexual behavior, and their anal sexual positioning (i.e., top, bottom, versatile). Nearly two-thirds (65.8%) had engaged in rectal douching in the last three months. Among those who douched, water was commonly reported (84.2%) and 20.1% reported using commercial enemas (e.g., Fleet), as well as water and soap (15.0%)-numbers exceed 100% as some participants reported more than one. Men who douched reported significantly more receptive and insertive condomless anal sex acts in the prior 3 months. One-in-ten men reported rectal bleeding after douching. Compared to HIV-negative participants who had not taken PrEP, participants had higher odds of reporting douching in the past 3 months if they were HIV-negative and currently on PrEP (AOR = 1.82), HIV-negative and previously used PrEP (AOR = 1.58), and HIV-positive (AOR = 1.83). Douching was common in this sample. Given that douching could amplify risk for HIV transmission, healthcare providers should discuss douching safety with their patients, with a focus on harm reduction (e.g., reduce risk of bleeding, as opposed to abstinence from douching).

Rectal Douching and Anal Human Papillomavirus Among Young Men Who Have Sex With Men in China

BACKGROUND

Young men who have sex with men (YMSM) are particularly at increased risk for human papillomavirus (HPV) infection and related malignancies. Rectal douching, commonly practiced among MSM, has been associated with HIV, chlamydia, gonorrhea, and viral hepatitis in cross-sectional studies. We conducted this study to understand the association between self-reported rectal douching and anal HPV among YMSM in China.

METHODS

Between September 2018 and March 2019, MSM aged 15 to 24 years who ever engaged in receptive anal intercourse over the last 3 months were recruited via community-based organizations and centers for disease control located in 4 cities in China. Participants were asked to complete an online survey. We performed multivariate logistic regression adjusted for potential confounders to examine the association between self-reported rectal douching and anal HPV.

RESULTS

Among 273 MSM with a median age of 20 years (interquartile range, 19-21 years) included in this study, 130 (47.6%) practiced rectal douching during the preceding 3 months and 96 (36.2%) were infected with anal HPV. Self-reported rectal douching was found to be associated with increased odds of anal HPV infection (odds ratio, 2.16; 95% confidence interval, 1.22-3.82) among YMSM, after adjusting for age, sexual debut, sex with alcohol or drugs, and HIV testing history.

CONCLUSIONS

Self-reported rectal douching is associated with higher odds of anal HPV infection independent of sexual behaviors among YMSM. More prospective studies to ascertain this association are needed. Health education materials should inform men of the potential risk of rectal douching. Research on safer rectal douching procedures is warranted.

The use of inappropriate anal douching tool associates with increased HIV infection among men who have sex with men: a cross-sectional study in Shenyang, China

Background

Rectal douching (RD) is widely practiced by men who have sex with men (MSM), and is associated with increased risk of HIV infection. However, the mechanism of how RD increases the risk of HIV infection is not well understood, and there is limited data on RD behavior in MSM practicing anal sex in China. We examine the purpose of RD, its timing in relation to anal sex, the types of RD products used, and risky sexual behaviors among MSM reporting anal sex.

Methods

Between August 2017 and December 2018, a cross-sectional study was conducted among adult MSM in Shenyang, China. Data were collected on demographics, sexual behaviors, and RD for the most recent sexual intercourse by means of interviewer-administered face-to-face questionnaires. Blood samples were collected to test for antibodies to HIV and syphilis. Multivariable logistic regression models were used to assess the risk factors associated with HIV infection.

Results

A total of 515 eligible MSM participated in this survey (median age: 31 years). During the most recent anal intercourse, 28.3% (146/515) had condomless receptive anal intercourse (CRAI), 21.4% (110/515) practiced serosorting, and more than half (61.6%, 317/515) reported RD before or after anal sex. Of those practicing RD, 96.8% (307/317) conducted RD before sex, while 62.5% (198/317) conducted RD after sex. The douching devices used were primarily shower hoses (85.3%, 262/307), and relatively few MSM used commercial RD products (8.1%, 25/307) before sex. The prevalence of HIV-1 and syphilis was 11.7% and 13.2%, respectively. HIV infection was positively associated with RD, practicing RD before sex, the interaction between RD and CRAI using a shower hose for RD and other risk factors, practicing RD after sex, CRAI, using nitrite inhalants, main sexual role with males as bottom and syphilis infection.

Conclusions

RD is popular among Chinese MSM. Improper noncommercial RD tools use (such as shower hose), the interaction effect between RD and CRAI associated with HIV infection. Public health workers and the MSM community should publicize scientific knowledge and prevention approaches relating to RD and HIV transmission to MSM. We recommend that further studies should be conducted to understand the detailed mechanism between RD and increased HIV prevalence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10276-z.

Rectal douching in a community sample of men and women

Rectal douching (RD) may be a vector for sexually transmitted infection (STI) acquisition. The aim of this study was to describe the relationship between RD, and the prevalence of various STIs and sexual behaviors in a sample of women and men in Long Beach, California. Five hundred and forty-seven men (mean age 42.8 years) and 530 women (mean age 37 years) recruited from a community-based setting between April 2010 and August 2014 completed the Risk Behavior Assessment and a questionnaire eliciting information on use of lubricants and enemas for vaginal intercourse (VI) and anal intercourse (AI). Participants were screened for high-risk behaviors for human immunodeficiency virus infection including injection drug use. Bivariate analyses were conducted separately for women and men. Based on the empirical results, separate logistic regression models for women and men were constructed. Sensitivity analysis was conducted to assess model fit for reduced samples of only those men and women who reported AI. For men, RD was associated with a lower odds of being hepatitis C antibody positive, greater odds of being positive for hepatitis B virus surface antigen, syphilis, and using lubricants for receptive anal intercourse (RAI). RD in women was associated with higher odds of a positive test for syphilis, ever vaginally douching for VI, and using lubricants for RAI. Men and women who practice RD report positive syphilis test results and use of lubricants for RAI. RD should not be perceived as preventing STIs.

Lubricants and rectal douching: associations with rectal gonorrhea, chlamydia, and/or syphilis infection among men who have sex with men

Despite widespread prevalence of lubricant use and rectal douching for receptive anal intercourse (RAI) among men who have sex with men (MSM), research evaluating the association of these behaviors with sexually transmitted infections (STIs) is limited. This is an observational analysis of a longitudinal cohort of predominantly Black/Latino MSM in Los Angeles. Every six months from August 2014 to January 2018, participants received STI screening and surveys evaluating lubricant use, douching, substance use, and sexual risk behaviors. General estimating equations evaluated the association between consistent lubricant use and douching for RAI with positive rectal Neisseria gonorrhoeae, Chlamydia trachomatis, and/or syphilis (positive STI). Among 313 participants across 552 study visits, 16.5% (91/552) had positive STI. Consistent lubricant use was reported in 52.7% (243/552) and rectal douching in 57.6% (318/552) of study visits. Consistent lubricant use was associated with STI diagnosis (adjusted OR [AOR] 1.81; 95% CI 1.11-2.96; p = 0.018). Each episode of rectal douching before RAI was associated with 2% increased odds of positive STI (AOR 1.02; 95% CI 1.00-1.04; p = 0.041). Among this cohort of HIV-positive and high-risk HIV-negative MSM, lubricant use and douching was common and independently associated with an STI, suggesting the utility of prevention messaging around barrier methods/condoms for sexual encounters involving douching/lubricant use.

Prevalence and Correlates of Rectal Douching and Enema Use Among Black Sexual Minority Men and Black Transwomen in the Deep South

HIV/STI disparities are highest among Black sexual minority men (BSMM) and Black transwomen (BTW) in the Deep South. Exploring the prevalence and correlates of rectal douching and enema use could provide insights into risk factors and HIV/STI prevention opportunities among these groups. This study explored the prevalence and correlates of rectal douching and enema using Poisson regression models among 375 BSMM and BTW in Jackson, MS, and Atlanta GA. Approximately 95% reported their gender as male/man; 5.6% self-identified as transwomen. Most reported being single (73.1%) and were unemployed (56.0%); 36.1% were previously diagnosed with HIV. In multivariable models, BSMM and BTW who reported that their typical sexual position during anal sex was "bottom" (aPR = 2.39, 95% CI = 1.48, 3.84) or "versatile" (aPR = 2.46, 95% CI = 1.44, 4.17) had a higher prevalence of rectal douching and enema use than those who reported "top." Deeper understanding of the contexts of rectal douching, enema use, and sexual positioning practices is needed.

Rectal Douching and Microbicide Acceptability among Young Men who Have Sex with Men

Men who have sex with men (MSM) commonly report engaging in rectal douching (RD) practices prior to receptive anal intercourse. Researchers are interested in the possibility of designing a RD with a microbicide component. In our analyses, we examined whether YMSM who engaged in RD behaviors differ in HIV prevention behaviors from their non-RD peers. We then examined whether RD frequency was associated with rectal microbicide acceptability. Half the participants (47.8%) reported having ever douched. Participants were more likely to douche if they were racial/ethnic minorities (AOR = 2.24, p = 0.02) and had recently tested for HIV (AOR = 1.96, p = 0.04). Greater douching frequency was associated with racial/ethnic minorities (β = 0.20, p = 0.009) and recent HIV testing (β = 0.19, p < 0.01). Participants who reported frequently douching indicated greater microbicide acceptability (β = 0.32, p < 0.001). Designing behaviorally congruent products remains a priority in next generation Pre-Exposure Prophylaxis (PrEP) and a rectal douche might be an additional tool if found to be efficacious.

Anogenital Dermatitis in Men Who Have Sex with Men

Evaluation of anogenital dermatitis requires a detailed history, including a sexual history. Men who have sex with men have different risk of certain infectious causes compared with men who have sex with women. Infectious causes of balanitis and anal dermatitis are easily treatable once identified. Irritant contact dermatitis is a common cause of balanitis, and avoidance of irritants, including decreased soap washing, helps many patients improve. Detailed histories of the personal products used by the patient and partner(s), including soaps, lotions, perfumes, lubricants, condoms, topical medications, hygiene sprays, personal wipes, and laundry detergent, may reveal possible irritants or contact allergens.

Rectal Douching Practices Associated with Anal Intercourse: Implications for the Development of a Behaviorally Congruent HIV-Prevention Rectal Microbicide Douche

Tenofovir administration via rectal douching results in higher rectal-mucosa drug concentration than oral administration. Many who engage in receptive anal intercourse (RAI) use cleansing rectal douches. To inform development of a behaviorally-congruent tenofovir douche, 4751 individuals ≥ 18 years-old, born male, from all US states/territories, who engaged in anal intercourse responded to an online survey. Of those who reported RAI in the prior 3 months, 80% douched beforehand, 82% within 1 h, mean 2.9 consecutive applications; 27% douched afterwards, 83% within 1 h, mean 1.7 consecutive applications. Among multidose users, 78% applied doses within 2 min, and 76% retained liquid < 1 min. Most used tap water (89%) in an enema bottle (50%) or rubber bulb (43%), and douched for cleanliness (97%), to avoid smelling bad (65%), and to enhance pleasure (24%). 98% reported high likelihood of using an HIV-prevention douche. An ideal product will protect within a user's typical number of applications, within 1 h, and be dissolvable in tap water.

Association between rectal douching and HIV and other sexually transmitted infections among men who have sex with men: a systematic review and meta-analysis

BACKGROUND

Men who have sex with men (MSM) are disproportionately affected by HIV and other STIs worldwide. Rectal douching, which is commonly used by MSM in preparation for anal sex, may increase the risk of HIV and other STIs by injuring the rectal mucosa. Results from individual studies reporting associations between rectal douching and HIV and other STIs among MSM are inconsistent. We performed a systematic review and meta-analysis to estimate the association between rectal douching and HIV and other STIs among MSM.

METHODS

We searched PubMed, Embase, Scopus and Web of Science for studies published from January 1970 to November 2018. Studies that reported ORs and 95% CIs of associations between rectal douching and infection with HIV/STIs, or reported enough data to calculate these estimates, were included. We assessed risk of bias using the Newcastle-Ottawa Scale. ORs were pooled using a random effects model.

RESULTS

Twenty-eight eligible studies were identified in our review, of which 24 (20 398 participants) were included in the meta-analysis. Rectal douching was associated with increased odds of infection with HIV (OR 2.80, 95% CI 2.32 to 3.39), and any STI other than HIV (including hepatitis B virus (HBV), hepatitis C virus (HCV), chlamydia, gonorrhoea, syphilis and human papillomavirus) (OR 2.46, 95% CI 1.95 to 3.11) among MSM. For specific STIs, douching was associated with increased odds of viral hepatitis (HBV, HCV) (OR 3.29, 95% CI 2.79 to 3.87), and chlamydia or gonorrhoea (OR 3.25, 95% CI 2.02 to 5.23). These associations remained significant in studies that adjusted for potential confounders.

CONCLUSION

Rectal douching may put MSM at increased risk for infection with HIV and other STIs. Longitudinal studies are needed to clarify this association, and health education materials should inform men of the potential for increased risk of infection with rectal douching.

Fecal Coliform Bacterial Detection to Assess Enema Adherence in HIV Prevention Clinical Studies

Evaluating the efficacy of any HIV prevention strategy is dependent on ensuring and objectively monitoring adherence to the intervention. Medicated rectal enemas are a potential method for providing topical, episodic HIV prophylaxis during receptive anal intercourse. Assessing adherence to recommended enema dosing regimens is essential in evaluating the utility of this strategy. We utilized fecal coliform bacteria on used enema tips as a marker for enema use. Enema tip coliforms were tested by repurposing a microtiter plate-based water quality test designed to detect fecal contamination of water. Coliform detection occurred with 100% sensitivity and specificity when tips were assayed on day of use. The assay performed well post-7 day sample storage at room temperature, yielding a sensitivity of 80% and specificity of 93%. All (n = 64) samples collected in a subset of the DREAM-01 rectal microbicide enema clinical trial tested positive, even when tips were evaluated > 7 days post-reported use. The coliform-based enema tip assay allows monitoring of adherence in interventions involving rectal enemas in a sensitive, specific and inexpensive manner. The test performs well in clinical trial settings.

HIV Antiretroviral Pre-Exposure Prophylaxis: Development Challenges and Pipeline Promise

The US Food and Drug Administration (FDA) approved oral daily tenofovir/emtricitabine (Truvada) for pre-exposure prophylaxis of human immunodeficiency virus (HIV) infection in 2012 on the basis of two randomized controlled trials (RCTs), one in men who have sex with men (MSM) and another in HIV serodiscordant heterosexual couples. Subsequently, even greater efficacy has been demonstrated in MSM with rapid population-level incidence reductions in some locations. In contrast, studies of antiretroviral pre-exposure prophylaxis (PrEP) in heterosexual women showed only modest or no efficacy, largely attributed to low adherence. The mixed results of antiretroviral-based PrEP bear witness to unique drug development challenges at this complicated intersection of sexual behavior, public health, and drug development. Multiple innovative methods and formulation strategies followed to address unmet medical needs of persons struggling with daily oral PrEP adherence or preference for nonsystemic PrEP options. Clinical pharmacology plays essential roles throughout this PrEP development process, especially in early product development and through pharmacologically informed enhancement and interpretation of clinical trials.

Correlates of Rectal Douching Practices Among Men Who Have Sex With Men in Kenya

BACKGROUND

Among men who have sex with men (MSM), rectal douching (RD) has been associated with increased prevalence of human immunodeficiency virus and other sexually transmitted infections. Substances commonly used for RD, especially water-based solutions, could disrupt the rectal epithelium and increase susceptibility to infection. The few existing reports on RD among MSM are primarily in middle- and high-income settings, and to date, no study has focused on RD among MSM in Africa.

METHODS

We conducted a secondary data analysis of programmatic data from key population service centers in western Kenya. Data were extracted from records of clients who identified as MSM and accessed services between January 1, 2014, and September 1, 2016. We compared demographic and behavioral characteristics of men who did and did not practice RD. Logistic regression assessed associations with RD.

RESULTS

Of the 202 MSM in this analysis, 63% engaged in RD. All who engaged in RD used water-based substances. Those who engaged in receptive anal intercourse in the last 3 months were more likely to report RD (odds ratio, 3.19; 95% confidence interval, 1.67-6.07). Among MSM who engaged in sex work, those who practiced RD reported more regular clients per week (2.8 clients vs. 1.3 clients, P = 0.01). Rectal douching practices did not vary by other sexual risk practices.

CONCLUSIONS

Rectal douching is common in this population of Kenyan MSM, especially among those who have recently engaged in receptive anal intercourse, suggesting that a rectal douche that delivers microbicides could be a potential intervention to reduce human immunodeficiency virus/sexually transmitted infection within this population.

Development of rectal enema as microbicide (DREAM): Preclinical progressive selection of a tenofovir prodrug enema

HIV pre-exposure prophylaxis (PrEP) strategies have the potential to prevent millions of incident HIV infections each year. However, the efficacy of PrEP strategies has been plagued by issues of non-adherence, likely because of the difficulty in motivating otherwise healthy people to adhere to treatment regimens that require significant behavioral changes and daily discipline. An alternative approach to PrEP is to focus on strategies that fit in to normal, and even desirable, sexual behaviors, such as the use of cleansing enemas by men who have sex with men (MSM) prior to receptive anal intercourse (RAI). Here, we describe preclinical efforts toward optimizing a tenofovir (TFV)-based enema formulation for rectal PrEP. Using a murine model, we compared the plasma and tissue pharmacokinetics of TFV and various TFV prodrugs, including tenofovir disoproxil fumarate (TDF), tenofovir alafenamide (TAF), and hexadecyloxypropyl tenofovir (CMX157), after dosing as enema formulations with varying osmolality and ion content. We observed that the enema vehicle composition played a more important role than the TFV prodrug properties in achieving rapid and therapeutically relevant tenofovir diphosphate (TFV-DP) concentrations in mouse colorectal tissue. Our results support the next steps, which are further preclinical (non-human primate) and clinical development of a hypo-osmolar TFV enema product for rectal PrEP.