Awareness and willingness toward doxycycline post-exposure prophylaxis use for bacterial sexually transmitted infections among men who have sex with men
Yi-Ting Chen
A , Kuan-Yin Lin A B , Hsin-Yun Sun B , Yu-Shan Huang B , Wang-Da Liu B C , Yu-Chung Chuang B , Po-Hsien Kuo D , Sung-Hsi Huang D , Kai-Hsiang Chen D , Aristine Cheng B , Wang-Huei Sheng B , Szu-Min Hsieh B , Sung-Ching Pan A B , Un-In Wu B C , Szu-Ting Huang D , Tzong-Yow Wu E , Wen-Chun Liu B , Pei-Ying Wu A , Yu-Zhen Luo A , Hsi-Yen Chang A , Ling-Ya Chen A , An-Ting Peng F , Pei-Yu Wang F , Guei-Chi Li B and Chien-Ching Hung B E G *
A
B
C
D
E
F
G
Abstract
Doxycycline post-exposure prophylaxis (doxy-PEP) has shown efficacy in preventing bacterial sexually transmitted infections (STIs) among men who have sex with men (MSM). We aimed to investigate the awareness and willingness toward doxy-PEP among MSM in the real-world setting.
From October 2023 to March 2024, we enrolled MSM aged ≥18 years, including people with HIV and PrEP users in Taiwan. Participants completed a questionnaire interview on sexual behaviors, STI history, and awareness and willingness to use doxy-PEP. Factors associated with willingness and doxy-PEP prescription were identified.
Of 1100 participants (median age, 36 years), 75.5% were people with HIV and 24.5% were PrEP users. Among them, 29.8% (328/1100) had heard of doxy-PEP. After education and counseling, 85.9% (945/1100) expressed willingness to use doxy-PEP and 45.6% (431/945) received prescriptions for doxy-PEP. In multivariable analysis, willingness to use doxy-PEP was associated with engaging in anal sex (AOR 2.98, 95% CI 1.01–8.78), having fixed sexual partners (AOR 0.53, 95% CI 0.34–0.82), using recreational drugs (AOR 1.59, 95% CI 1.01–2.50) and receiving suggestions from healthcare providers (AOR 1.89, 95% CI 1.22–2.91). Starting doxy-PEP was associated with having a bachelor’s degree or higher (AOR 1.47, 95% CI 1.03–2.09), more than five sexual partners (AOR 1.97, 95% CI 1.18–3.27), chlamydia history (AOR 1.92, 95% CI 1.23–2.99), suggestions from healthcare providers (AOR 1.64, 95% CI 1.10–2.45) and information from scientific research papers (AOR 1.34, 95% CI 1.01–1.79).
MSM in Taiwan had high willingness toward doxy-PEP, which was correlated with their at-risk sexual behavior. Understanding factors influencing willingness and counseling from healthcare providers may guide doxy-PEP implementation.
Keywords: chlamydia, gonorrhea, health literacy, people with HIV, pre-exposure prophylaxis, syphilis, tetracycline, unprotected sex.
Introduction
The global burden of sexually transmitted infections (STIs) is on the rise. In 2020, an estimated 374 million new cases of treatable STIs, such as chlamydia, gonorrhea, syphilis and trichomoniasis, were reported worldwide.1,2 Although the risk of HIV transmission has significantly decreased due to advancements in antiretroviral therapy and the adoption of pre-exposure prophylaxis (PrEP) for HIV, the rates of other bacterial STIs continue to increase, particularly in populations at higher risk of STIs, such as gay, bisexual, and other cisgender men who have sex with men (MSM) and transgender women.3,4 Among people with HIV and MSM using PrEP for HIV, coinfection with bacterial STIs is not uncommon. This is likely linked to changes in sexual behaviors, and the use of biomedical HIV treatment and prevention.5,6
Doxycycline, a broad-spectrum tetracycline antibiotic, is commonly recommended for the treatment of chlamydia and syphilis due to its safety, cost-effectiveness and minimal drug interactions. Doxycycline post-exposure prophylaxis (doxy-PEP) has been demonstrated to be efficacious in preventing bacterial STIs among MSM in clinical trials, reducing the occurrences of chlamydia and syphilis by 70–85%, and gonorrhea by approximately 50%.7,8 Recognizing the potential of doxy-PEP as a transformative STI prevention strategy, the US Centers for Disease Control and Prevention, and the Australasian Society for HIV, Viral Hepatitis, and Sexual Health Medicine advocate for its consideration in at-risk MSM and transgender women.9,10 In contrast, the British Association of Sexual Health and HIV does not endorse its use because of concerns about the potential long-term impact on antimicrobial resistance and microbiome.11
Although the long-term implications of doxy-PEP remain unclear due to limited availability of long-term follow-up data, previous studies have indicated varying acceptance rates of doxy-PEP among MSM, ranging from 60% to 84%.12–14 Higher acceptance rates were observed among individuals engaged in condomless sex and those with prior STIs. The proportion of MSM receiving doxy-PEP ranged from 2.2% to 23%.15–18 These studies primarily included MSM without HIV infection in Western countries. In this study, we aimed to assess the awareness and willingness of Asian MSM, irrespective of their HIV status, to use doxy-PEP, and to evaluate the subsequent prescriptions after providing information, education and counseling.
Materials and methods
Study design and participants
From October 2023 to March 2024, a multicenter, cross-sectional survey was conducted at the infectious disease clinics of National Taiwan University Hospital, National Taiwan University Hospital Hsin-Chu Branch, and National Taiwan University Cancer Center in northern Taiwan. The study consecutively included MSM aged ≥18 years, including people with HIV and HIV PrEP users, during their clinic visits. According to the national guidelines for HIV treatment, people with HIV undergo regular serologic tests for syphilis and viral hepatitis every 3–6 months and annually, respectively.19 HIV PrEP users undergo routine serologic tests for syphilis and bacterial STIs screening every 3 months.20 Additionally, individuals who presented with symptoms suggestive of STIs tested for bacterial STIs using multiplex real-time PCR assay (Allplex™ STI Essential Assay; Seegene, Seoul, Republic of Korea) of oral rinse, urethral swab and rectal swab specimens to detect Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium. Since late 2023, doxycycline has been prescribed out-of-pocket to MSM and transgender women with elevated STI risks in clinical practice, based on substantial supporting evidence.7,8
Measures
Participants were provided by clinicians with a link to access a self-administered questionnaire using smartphones during their clinic visits. Data from the questionnaire were collected using the REDCap platform, a clinical research electronic data capture system developed by Vanderbilt University. The questionnaire covered the sections on demographics (age, education, employment and income), sexual behavior practices in the previous year (engaging in anal or oral sex, having fixed or casual sex partners, number of sexual partners and condom use), recreational drug use in the previous year (ecstasy, ketamine, methamphetamine, gamma-hydroxybutyrate and amyl nitrate), history of STIs in the previous year (including syphilis, gonorrhea, chlamydia, genital herpes, genital warts and viral hepatitis), frequency of STI testing in the previous year, awareness of using doxy-PEP (‘yes/no’ question), along with information sources, willingness to use doxy-PEP (‘yes/no’ question) with reasons for the willingness, factors influencing doxy-PEP use and perceived STI risk. The factors influencing doxy-PEP use were hypothetical, and included suggestions from healthcare providers, scientific research papers, experiences from friends, media news coverage and suggestions from community opinion leaders. Willingness was assessed in two scenarios: when having sex with fixed sexual partners and when having sex with casual sexual partners. During the questionnaire interview, we first assessed participants’ awareness of doxy-PEP use, after which educational leaflets (either paper or online) containing doxy-PEP information were distributed. The leaflet (see Supplementary material Fig. S1) provided detailed information about doxy-PEP, including the targeted diseases (syphilis and chlamydia infection), the intended population (MSM at risk for STIs), and the recommended dosing and precautions. It also included figures to illustrate the dosing instructions for different scenarios. Willingness for doxy-PEP use was evaluated post-education, and prescriptions were provided out-of-pocket by clinicians after eligibility assessment and counseling. Participants who received doxy-PEP were followed every 3 months to monitor for adverse effects and the occurrence of STIs. Perceptions of sexual health were assessed based on participants’ agreement with five statements: (1) ‘Using condoms is the most effective method to prevent STIs,’ (2) ‘I believe I am at a higher risk of contracting STIs compared to others,’ (3) ‘My current lifestyle makes me more likely than others to get STIs,’ (4) ‘I don’t believe it’s possible for me to get STIs,’ and (5) ‘I currently have control over my sexual health’. Responses were measured using 5-point Likert scale questions, ranging from 1 (strongly disagree) to 5 (strongly agree), to indicate different levels of agreement.
Statistical analyses
The survey data collected from REDCap were downloaded into an encrypted Excel file for consolidation, and analyzed using the SPSS ver. 25.0 statistical software package (IBM Corporation). Descriptive statistics summarized participant characteristics, using percentage for categorical variables and median with interquartile range (IQR) for non-normally distributed continuous variables. Logistic regression analyses were performed to identify the factors associated with the willingness to use doxy-PEP and the receipt of prescriptions. Factors showing significance at P < 0.05 in the univariable analysis were included in the multivariable analysis, and a backward selection was applied to refine the final model. For variables with multiple response options (e.g. income, number of sexual partners and frequency of STI testing), we converted them into dummy variables and selected a reference group for comparison. For a history of specific STIs in the previous year, we considered it as binary independent variables. Results were presented as unadjusted and adjusted odds ratios (AOR) with 95% confidence intervals (CIs). The analyses were further stratified by people with HIV and PrEP users, as they represent distinct groups. For more precise interpretation, modified Poisson regression analyses were performed to identify associated factors, presented as unadjusted and adjusted prevalence ratios. Statistical significance was set at P < 0.05 (two-tailed).
Results
Characteristics of the participants
A total of 1111 participants were enrolled in the study, with 1100 completing the questionnaire interview, resulting in a completion rate of 99.0%. Among the 1100 participants, 830 (75.5%) were people with HIV, 270 (24.5%) were HIV PrEP users and the median age was 36 years (32–43 years; Table 1). In the previous year, 1001 participants (91.0%) reported engaging in anal sex, and 957 (87.0%) reported engaging in oral sex. Of the 561 participants (51.0%) who reported having fixed sexual partners, 470 (83.8%) indicated inconsistent condom use. Similarly, among 668 participants (60.7%) with casual sexual partners, 571 (85.5%) reported inconsistent condom use. Approximately 41.3% of the participants reported having two to five partners, and 27.4% more than five partners. The most prevalent STIs reported in the past year were syphilis (25.6%), followed by chlamydia (12.2%) and gonorrhea (10.5%). Most participants reported testing for STIs every 3–6 months (69.7%), followed by testing due to symptoms or annually (23.7%), with only 6.5% never having tested for STIs.
| Variable | All participants (n = 1100) | |
|---|---|---|
| Basic demographic information | ||
| Age (years), median (IQR), years | 36 (32–43) | |
| Bachelor’s degree or higher, n (%) | 847 (77.0) | |
| Full-time or part-time employment, n (%) | 1019 (92.6) | |
| Monthly salary, n (%) | ||
| <US$999 | 130 (11.8) | |
| US$999–2333 | 759 (69.0) | |
| >US$2333 | 211 (19.2) | |
| People with HIV, n (%) | 830 (75.5) | |
| HIV PrEP users, n (%) | 270 (24.5) | |
| Sexual behavior practices in the previous year | ||
| Having anal sex, n (%) | 1001 (91.0) | |
| Having oral sex, n (%) | 957 (87.0) | |
| Having fixed sexual partners A, n (%) | 561 (51.0) | |
| Having casual sexual partners A, n (%) | 668 (60.7) | |
| No. of sexual partners, n (%) | ||
| Having 1 sexual partner | 263 (23.9) | |
| Having 2–5 sexual partners | 454 (41.3) | |
| Having >5 sexual partners | 301 (27.4) | |
| Recreational drug use in the previous year, n (%) | 348 (31.6) | |
| History of STIs in the previous year | ||
| Syphilis, n (%) | 282 (25.6) | |
| Chlamydia, n (%) | 134 (12.2) | |
| Gonorrhea, n (%) | 115 (10.5) | |
| Others B, n (%) | 96 (8.7) | |
| Frequency of STI testing in the previous year | ||
| Never, n (%) | 72 (6.5) | |
| Having symptoms or annually, n (%) | 261 (23.7) | |
| Every 3–6 months, n (%) | 767 (69.7) | |
| Awareness of doxy-PEP | ||
| Having ever heard of doxy-PEP, n (%) | 328 (29.8) | |
| Sources of information regarding doxy-PEP, n (%) | ||
| Healthcare providers | 166 (15.1) | |
| Television or social media | 131 (11.9) | |
| Friends or sexual partners | 94 (8.5) | |
| Medical literature | 52 (4.7) | |
| Willingness to use doxy-PEP | ||
| Being willing to use doxy-PEP, n (%) | 945 (85.9) | |
| Factors influencing doxy-PEP use, n (%) | ||
| Suggestions from healthcare providers | 918 (83.5) | |
| Scientific research papers | 601 (54.6) | |
| Experiences from friends | 433 (39.4) | |
| Media news coverage | 152 (13.8) | |
| Suggestions from community opinion leaders | 115 (10.5) | |
doxy-PEP, doxycycline post-exposure prophylaxis; IQR, interquartile range; PrEP, pre-exposure prophylaxis; STI, sexually transmitted infection.
Awareness and willingness to use doxy-PEP
Among the 1100 participants, only 328 (29.8%) had heard of doxy-PEP, and the information sources included healthcare providers (15.1%), television or social media (11.9%), friends or sexual partners (8.5%) and medical literature (4.7%; Table 1). After education, 945 (85.9%) expressed their willingness to use doxy-PEP. Factors influencing doxy-PEP use included suggestions from healthcare providers (83.5%), scientific research papers (54.6%), experiences shared by friends (39.4%), media news coverage (13.8%) and advice from community opinion leaders (10.5%). Among the participants with fixed sexual partners and those with casual partners, the main reasons for the willingness to use doxy-PEP were the fear of contracting STIs (75.7% and 80.8%, respectively) and concerns about transmitting STIs to others (69.7% and 71.7%, respectively; Fig. 1a). In contrast, the primary reason for unwillingness included only having sex with fixed sexual partners (67.1% and 20.9%, respectively), infrequent sexual activity (21.2% and 25.6%, respectively) and concerns about antimicrobial resistance (17.1% and 7.0%, respectively; Fig. 1b).
Top 5 reasons for (a) considering and (b) not considering taking doxy-PEP after unprotected sex among participants in scenarios involving fixed sexual partners and casual sexual partners in Taiwan, from October 2023 to March 2024. doxy-PEP, doxycycline post-exposure prophylaxis; STI, sexually transmitted infection; CI, confidence interval.
Factors associated with willingness to use doxy-PEP
Of the 1100 participants, 945 (85.9%) were willing to use doxy-PEP. Compared with the participants not willing to use doxy-PEP, those who expressed willingness to use doxy-PEP were more likely to have engaged in anal sex (98.7% vs 95.9%), have casual sexual partners (62.3% vs 51.0%) as opposed to fixed sexual partners (48.7% vs 65.2%), a higher number of sexual partners (42.3% vs 34.8% for 2–5 sexual partners; 27.9% vs 23.9% for >5 sexual partners), recreational drug use (33.4% vs 20.6%), a prior history of syphilis (26.9% vs 18.1%), to undergo STI testing every 3–6 months (70.6% vs 64.5%) and to receive suggestions from healthcare providers (84.9% vs 74.8%; all P < 0.05). In the multivariable analysis, the willingness to use doxy-PEP was associated with engaging in anal sex (AOR 2.98, 95% CI 1.01–8.78), having fixed sexual partners (AOR 0.53, 95% CI 0.34–0.82), using recreational drugs (AOR 1.59, 95% CI 1.01–2.50) and receiving suggestions from healthcare providers (AOR 1.89, 95% CI 1.22–2.91; Table 2). The adjusted prevalence ratios are presented in Supplementary Table S2. Among people with HIV, the associated factors include having anal sex, having fixed sexual partners, receiving information from friends or sexual partners and receiving suggestions from healthcare providers. In contrast, no associated factors were identified among PrEP users (Tables S4–S5).
| Variable | Willing to use (n = 945) | Unwilling to use (n = 155) | Univariate analysis | Multivariate analysis A | |||
|---|---|---|---|---|---|---|---|
| OR (95% CI) | P | AOR (95% CI) | P | ||||
| Age (years), median (IQR), per 1-year increase | 37 (32–43) | 35 (32–42) | 1.01 (0.99–1.03) | 0.114 | |||
| Bachelor’s degree or higher, n (%) | 733 (77.6) | 114 (73.5) | 1.24 (0.84–1.83) | 0.271 | |||
| Full-time or part-time employment, n (%) | 879 (93.0) | 140 (90.3) | 1.42 (0.79–2.57) | 0.236 | |||
| Monthly salary, n (%) | |||||||
| >US$999 | 107 (11.3) | 23 (14.8) | Reference | ||||
| US$999–2333 | 658 (69.6) | 101 (65.2) | 1.40 (0.85–2.30) | 0.184 | |||
| >US$2333 | 180 (19.0) | 31 (20.0) | 1.24 (0.69–2.52) | 0.462 | |||
| People with HIV, n (%) | 720 (76.2) | 110 (71.0) | 1.30 (0.89–1.91) | 0.162 | |||
| HIV PrEP users, n (%) | 225 (23.8) | 45 (29.0) | 0.76 (0.52–1.11) | 0.162 | |||
| Having anal sex, n (%) | 861 (98.7) | 140 (95.9) | 3.36 (1.22–9.22) | 0.019 | 2.98 (1.01–8.78) | 0.046 | |
| Having oral sex, n (%) | 823 (94.4) | 134 (91.8) | 1.50 (0.78–2.90) | 0.223 | |||
| Having fixed sexual partners B, n (%) | 460 (48.7) | 101 (65.2) | 0.49 (0.34–0.72) | <0.001 | 0.53 (0.34–0.82) | 0.005 | |
| Having casual sexual partners B, n (%) | 589 (62.3) | 79 (51.0) | 1.76 (1.23–2.51) | 0.002 | 0.91 (0.52–1.59) | 0.763 | |
| No. of sexual partners, n (%) | |||||||
| Having 1 sexual partner | 208 (22.0) | 55 (35.5) | Reference | Reference | |||
| Having 2–5 sexual partners | 400 (42.3) | 54 (34.8) | 1.95 (1.29–2.95) | 0.001 | 1.40 (0.82–2.39) | 0.210 | |
| Having >5 sexual partners | 264 (27.9) | 37 (23.9) | 1.88 (1.19–2.97) | 0.006 | 1.17 (0.62–2.23) | 0.619 | |
| Recreational drug use, n (%) | 316 (33.4) | 32 (20.6) | 1.93 (1.27–2.91) | 0.002 | 1.59 (1.01–2.50) | 0.041 | |
| History of STIs in the previous year, n (%) | |||||||
| Syphilis | 254 (26.9) | 28 (18.1) | 1.66 (1.08–2.57) | 0.021 | 1.37 (0.86–2.19) | 0.177 | |
| Chlamydia | 118 (12.5) | 16 (10.3) | 1.24 (0.71–2.15) | 0.446 | |||
| Gonorrhea | 101 (10.7) | 14 (9.0) | 1.20 (0.67–2.16) | 0.533 | |||
| Others C | 82 (8.7) | 14 (9.0) | 0.95 (0.52–1.73) | 0.885 | |||
| Frequency of STI testing, n (%) | |||||||
| Never | 56 (5.9) | 16 (10.3) | Reference | Reference | |||
| Having symptoms or annually | 222 (23.5) | 39 (15.2) | 1.62 (0.84–3.12) | 0.143 | 1.17 (0.56–2.47) | 0.664 | |
| Every 3–6 months | 667 (70.6) | 100 (64.5) | 1.90 (1.05–3.45) | 0.033 | 1.32 (0.67–2.59) | 0.420 | |
| Having ever heard of doxy-PEP, n (%) | 289 (30.6) | 39 (25.2) | 1.31 (0.88–1.93) | 0.172 | |||
| Sources of information regarding doxy-PEP, n (%) | |||||||
| Healthcare providers | 150 (15.9) | 16 (10.3) | 1.63 (0.94–2.83) | 0.076 | |||
| Television or social media | 114 (12.1) | 17 (11.0) | 1.11 (0.64–1.91) | 0.696 | |||
| Friends or sexual partners | 87 (9.2) | 7 (4.5) | 2.14 (0.97–4.72) | 0.058 | |||
| Medical literature | 44 (4.7) | 8 (5.2) | 0.89 (0.41–1.94) | 0.784 | |||
| Factors influencing doxy-PEP use, n (%) | |||||||
| Suggestions from healthcare providers | 802 (84.9) | 116 (74.8) | 1.88 (1.25–2.82) | 0.002 | 1.89 (1.22–2.91) | 0.004 | |
| Scientific research papers | 522 (55.2) | 79 (51.0) | 1.18 (0.84–1.66) | 0.323 | |||
| Experiences from friends | 375 (39.7) | 58 (37.4) | 1.10 (0.77–1.56) | 0.593 | |||
| Media news coverage | 125 (13.2) | 27 (17.4) | 0.72 (0.45–1.14) | 0.162 | |||
| Suggestions from community opinion leaders | 94 (9.9) | 21 (13.5) | 0.70 (0.42–1.17) | 0.176 | |||
AOR, adjusted odds ratios; CI, confidence interval; doxy-PEP, doxycycline post-exposure prophylaxis; PrEP, pre-exposure prophylaxis; STI, sexually transmitted infection.
Factors associated with receiving doxy-PEP
Of the 945 participants expressing willingness to use doxy-PEP, 431 (45.6%) received prescriptions of doxycycline. Compared with participants who did not start doxy-PEP, those who started doxy-PEP tended to have a Bachelor’s degree or higher (81.7% vs 74.1%), casual sexual partners (73.1% vs 53.3%) rather than fixed sexual partners (45.5% vs 51.4%), a higher number of sexual partners (43.6% vs 41.2% for 2–5 sexual partners; 36.9% vs 20.4% for >5 sexual partners), recreational drug use (38.1% vs 29.6%), a history of STIs in the previous year (syphilis, 31.6% vs 23.0%; chlamydia, 13.2% vs 8.6%; gonorrhea, 17.6% vs 8.2%), undergone STI testing when symptomatic or annually (25.3% vs 22.0%), and received suggestions from healthcare providers (87.9% vs 82.3%) and information from scientific research papers (59.4% vs 51.8%; all P < 0.05). In the multivariable analysis, starting doxy-PEP was associated with having a Bachelor’s degree or higher (AOR 1.47, 95% CI 1.03–2.09), having more than five sexual partners (AOR 1.97, 95% CI 1.18–3.27), having a history of chlamydia (AOR 1.92, 95% CI 1.23–2.99), and receiving suggestions from healthcare providers (AOR 1.64, 95% CI 1.10–2.45) and information from scientific research papers (AOR = 1.34; 95% CI = 1.01–1.79; Table 3). The adjusted prevalence ratios are presented in Table S3. Among people with HIV, the associated factors include a history of chlamydia, receiving information from television or social media, receiving suggestions from healthcare providers and information from scientific research papers. In contrast, no associated factors were identified among PrEP users (Tables S6–S7).
| Variable | Receiving doxy-PEP (n = 431) | Not receiving doxy-PEP (n = 514) | Univariate analysis | Multivariate analysis A | |||
|---|---|---|---|---|---|---|---|
| OR (95% CI) | P | AOR (95% CI) | P | ||||
| Age (years), median (IQR), per 1-year increase | 36 (31–43) | 38 (32–44) | 0.99 (0.97–1.00) | 0.308 | |||
| Bachelor’s degree or higher, n (%) | 352 (81.7) | 381 (74.1) | 1.55 (1.13–2.12) | 0.006 | 1.47 (1.03–2.09) | 0.032 | |
| Full-time or part-time employment, n (%) | 394 (91.4) | 485 (94.4) | 0.63 (0.38–1.05) | 0.079 | |||
| Monthly salary, n (%) | |||||||
| <US$ 999 | 46 (10.7) | 61 (11.9) | Reference | ||||
| US$999–2333 | 297 (68.9) | 361 (70.2) | 1.09 (0.72–1.64) | 0.679 | |||
| >US$2333 | 88 (20.4) | 92 (17.9) | 1.26 (0.78–2.05) | 0.333 | |||
| People with HIV, n (%) | 316 (73.3) | 404 (78.6) | 0.74 (0.55–1.01) | 0.058 | |||
| HIV PrEP users, n (%) | 115 (26.7) | 110 (21.4) | 1.33 (0.99–1.80) | 0.058 | |||
| Having anal sex, n (%) | 410 (47.6) | 451 (52.4) | 1.10 (0.33–3.60) | 0.886 | |||
| Having oral sex, n (%) | 397 (48.2) | 426 (51.8) | 1.61 (0.88–2.92) | 0.120 | |||
| Having fixed sexual partners B, n (%) | 196 (45.5) | 264 (51.4) | 0.65 (0.50–0.85) | 0.002 | 0.88 (0.64–1.21) | 0.448 | |
| Having casual sexual partners B, n (%) | 315 (73.1) | 274 (53.3) | 2.10 (1.57–2.81) | <0.001 | 1.32 (0.87–2.01) | 0.190 | |
| No. of sexual partners, n (%) | |||||||
| Having 1 sexual partner | 68 (15.8) | 140 (27.2) | Reference | Reference | |||
| Having 2–5 sexual partners | 188 (43.6) | 212 (41.2) | 1.82 (1.28–2.59) | 0.001 | 1.30 (0.84–2.01) | 0.224 | |
| Having >5 sexual partners | 159 (36.9) | 105 (20.4) | 3.11 (2.13–4.56) | <0.001 | 1.97 (1.18–3.27) | 0.009 | |
| Recreational drug use, n (%) | 164 (38.1) | 152 (29.6) | 1.46 (1.11–1.91) | 0.006 | 1.03 (0.76–1.41) | 0.812 | |
| History of STIs in the previous year, n (%) | |||||||
| Syphilis | 136 (31.6) | 118 (23.0) | 1.54 (1.15–2.06) | 0.003 | 1.19 (0.86–1.65) | 0.278 | |
| Chlamydia | 76 (17.6) | 42 (8.2) | 2.40 (1.61–3.59) | <0.001 | 1.92 (1.23–2.99) | 0.004 | |
| Gonorrhea | 57 (13.2) | 44 (8.6) | 1.62 (1.07–2.46) | 0.022 | 0.91 (0.57–1.45) | 0.693 | |
| Others C | 42 (9.7) | 40 (7.8) | 1.27 (0.81–2.01) | 0.287 | |||
| Frequency of STI testing, n (%) | |||||||
| Never | 19 (4.4) | 37 (7.2) | Reference | Reference | |||
| Having symptoms or annually | 109 (25.3) | 113 (22.0) | 1.87 (1.01–3.46) | 0.044 | 1.43 (0.73–2.79) | 0.294 | |
| Every 3–6 months | 303 (70.3) | 364 (70.8) | 1.62 (0.91–2.87) | 0.099 | 0.97 (0.52–1.83) | 0.947 | |
| Have ever heard of doxy-PEP, n (%) | 132 (30.6) | 157 (30.5) | 1.00 (0.76–1.32) | 0.978 | |||
| Sources of information regarding doxy-PEP, n (%) | |||||||
| Healthcare providers | 73 (16.9) | 77 (15.0) | 1.15 (0.81–1.64) | 0.413 | |||
| Television or social media | 46 (10.7) | 68 (13.2) | 0.78 (0.52–1.16) | 0.230 | |||
| Friends or sexual partners | 38 (8.8) | 49 (9.5) | 0.91 (0.58–1.43) | 0.704 | |||
| Medical literature | 17 (3.9) | 27 (5.3) | 0.74 (0.39–1.37) | 0.343 | |||
| Factors influencing doxy-PEP use, n (%) | |||||||
| Suggestions from healthcare providers | 379 (87.9) | 423 (82.3) | 1.56 (1.08–2.26) | 0.017 | 1.64 (1.10–2.45) | 0.014 | |
| Suggestions from friends | 173 (40.1) | 202 (39.3) | 1.03 (0.79–1.34) | 0.793 | |||
| Scientific research papers | 256 (59.4) | 266 (51.8) | 1.36 (1.05–1.76) | 0.019 | 1.34 (1.01–1.79) | 0.040 | |
| Media news coverage | 51 (11.8) | 74 (14.4) | 0.78 (0.54–1.16) | 0.247 | |||
| Suggestions from community opinion leader | 47 (10.9) | 47 (9.1) | 1.21 (0.79–1.86) | 0.368 | |||
AOR, adjusted odds ratios; CI, confidence interval; doxy-PEP, doxycycline post-exposure prophylaxis; PrEP, pre-exposure prophylaxis; STI, sexually transmitted infection.
Perceptions of sexual health
The majority of the participants considered condom use as the most effective method to prevent STIs (56.5%), which was consistent regardless of their willingness to use doxy-PEP or to start doxy-PEP. Participants who were willing to use doxy-PEP were more likely to perceive a higher risk of contracting STIs compared with those who were unwilling to use doxy-PEP (mean sore, 3.1 vs 2.7, P < 0.001). Similarly, participants starting doxy-PEP had a higher perceived risk of STI acquisition compared with those not starting doxy-PEP (mean score, 3.3 vs 3.0, P < 0.001). Individuals who were unwilling to use doxy-PEP tended to believe in a lower likelihood of STI acquisition compared with those who were willing to use doxy-PEP (mean score, 2.5 vs 2.2, P = 0.003), whereas the participants not starting doxy-PEP felt more confident in their sense of control of their sexual health compared with those who did not start it (mean score, 4.0 vs 3.9, P = 0.038; Table S1).
Discussion
In this study investigating the awareness and willingness to use doxy-PEP among Asian MSM, we found a high proportion of participants expressing their willingness to use doxy-PEP after information dissemination, education and counseling. MSM who reported recreational drug use and lacked regular sexual partners demonstrated an increased willingness to receive doxy-PEP. Individuals with higher education achievement, multiple sexual partners and a history of STIs in the previous year were more inclined to start doxy-PEP. Both the willingness and uptake of doxy-PEP can be influenced by the healthcare providers and support from scientific research findings. Thorough assessment and counseling can help tailor the implementation of doxy-PEP to those who need it.
With the growing body of scientific evidence, there has been a notable increase in awareness regarding the utilization of doxy-PEP. A survey conducted in 2021, which targeted MSM (with 13% being people with HIV) recruited through Chinese community-based organizations, revealed that approximately 65% of the participants were familiar with PrEP for HIV, whereas only 29% were aware of doxy-PEP.21 Individuals who received information from peers and perceived an elevated risk of STIs showed higher levels of awareness. A recent survey focusing on the awareness of doxy-PEP among MSM and transgender women seeking HIV and STI services in the US indicated a substantial rise in the awareness levels. Among the participants, 50% were knowledgeable about doxy-PEP, 49% showed interest and 18% had previous experience with doxy-PEP.22 No association was observed between doxy-PEP usage and ethnic background or HIV status. Our study revealed that only 29.8% of MSM seeking care for HIV prevention and treatment were aware of doxy-PEP, which could be potentially attributed to slow uptake of the scientific data among the healthcare providers, such as general physicians and STI specialists, and a lack of perceived susceptibility to STIs among the majority of the participants. Improving awareness could be achieved through dissemination of scientific data and educational efforts targeting at-risk populations.
Prior research has demonstrated significant interest in doxy-PEP among MSM.12–14 A study including users of a gay social-networking app (with 16% being people with HIV) found that 86% expressed willingness to participate in a doxy-PEP study.12 Another survey among MSM in the US (with 16% being people with HIV) showed widespread acceptance of doxycycline PrEP and PEP, with an acceptance rate of 68% after being provided with informative materials detailing doxy-PEP.14 Factors linked to increased willingness included ethnic background (European descent compared with Asian), concerns about STI acquisition, engagement in condomless sex, a history of bacterial STI diagnosis and prior or current use of HIV PrEP.12–14 In-depth interviews suggested that participants perceived doxy-PEP as effective, offering quality-of-life benefits, such as reduced anxiety and a sense of control over sexual health.23,24 Our study also indicated a strong willingness among MSM to use doxy-PEP (85.9%), considering the approach as uncomplicated and beneficial for promoting sexual health, particularly in preventing STIs and reducing transmission risks. The reduced willingness observed among the participants who were engaged in sex with fixed partners might be attributed to exclusively unprotected sex within those partnerships or engagement in infrequent sexual activity.15,25,26
A German study on doxycycline use conducted in 2023 showed that doxycycline PEP and PrEP were already well known within the MSM community; 55% of the individuals had received therapeutic doxycycline and 23% had used doxy-PEP.17 In our study, the rate of doxy-PEP prescriptions (45.6%) exceeded that of previous studies.15–17 However, the discrepancy between the high rate of willingness and the relatively low rate of starting doxycycline prophylaxis may be related to concerns about antimicrobial resistance and potential long-term effects from both the MSM population and healthcare providers.14,27 Previous studies on doxy-PEP have demonstrated an increase in doxycycline-resistant Staphylococcus aureus and N. gonorrhoeae, which may actively select for resistance to other antimicrobials, such as ceftriaxone.8,28 The challenges could be particularly significant in regions with a high prevalence of tetracycline-resistant gonorrhea. Although awareness of antimicrobial resistance may reduce the interest in using doxy-PEP,29 education on the effectiveness of doxy-PEP and the potential risks of antimicrobial resistance should be balanced. Identifying the optimal population for doxy-PEP and minimizing unnecessary use are essential to mitigate the risk of antimicrobial resistance. Given the significant benefits of STI prevention offered by the doxy-PEP strategy, behaviors that increase the chances of contracting or transmitting STIs and previous STI history were associated with receiving doxy-PEP. Additionally, individuals with higher levels of education, and those who received education and counseling about doxy-PEP may improve both their willingness and initiation of doxy-PEP.30 Previous studies showed that lower educational attainment and income were associated with a higher risk of STIs; therefore, education and counseling may improve health literacy and help reduce this risk.31 Education and counseling may also reduce the risk of antimicrobial resistance resulting from inappropriate use of doxy-PEP, as previous studies have found that MSM populations might obtain antibiotics for STI prevention through different channels outside the hospital setting.14
This study has several limitations. First, it focused solely on MSM in hospitals in northern Taiwan, limiting the generalizability. Second, the participants were either people with HIV or PrEP users; therefore, the awareness and willingness of doxy-PEP in people without HIV or people who are not using PrEP for HIV remain unclear. Finally, the willingness to doxy-PEP was assessed with a simple yes/no question rather than a Likert-scale question, which may affect the precision and interpretability of the results. The levels of willingness to use doxy-PEP and rates of starting doxy-PEP may change with time after more real-world data accumulate regarding the emergence of antimicrobial resistance, the impact on intestinal microbiome and long-term protective effects of doxy-PEP.
Conclusion
MSM in Taiwan had a high willingness toward doxy-PEP use. Willingness toward doxy-PEP and doxy-PEP uptake were associated with behaviors that increase the chances of contracting or transmitting STIs and a STI history. Suggestions from healthcare providers and provision of scientific evidence could improve the readiness and prescription of doxy-PEP. Understanding willingness, assessing behaviors that increase the chances of contracting or transmitting STIs, and providing education and counseling are important to guide the effective implementation of doxy-PEP within the MSM community.
Data availability
All data generated or analyzed during this study are included in this published article.
Conflicts of interest
CCH has received research support from Gilead Sciences and speaker honoraria from Gilead Sciences, and served on advisory boards for Gilead Sciences. HYS and PHK have received research support from Gilead Sciences. Other authors have reported no potential conflicts of interest.
Declaration of funding
This study was supported by the Taiwan Centers for Disease Control (MOHW113-CDC-C-114-000104). The funding source played no role in study design and conduct, data collection, analysis or interpretation, writing of the manuscript, or the decision to submit it for publication.
Acknowledgements
The authors thank the HIV Care Team who assisted in the conduct of this study, including the physicians, HIV case managers, and research assistants from the National Taiwan University Hospital, the National Taiwan University Hospital Hsin-Chu Branch and the National Taiwan University Cancer Center.
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