Sexual behaviours and sexually transmitted infections among MSM living with HIV followed at a university hospital in Istanbul,Turkey

Abstract

Background

Men sex with men (MSM) are accepted as a hidden key population in the dissemination of HIV in Turkey. Understanding sexual behaviours and Sexually Transmitted Infections (STI) frequency in MSM living with HIV is important to provide appropriate health and control policies.

Methods

Sexual anamnesis including 5Ps were taken with triple-site (urine, pharyngeal and rectal swab) screening tests, which were performed according to the recommendations in the HIV follow up guidelines, from 45 MSM living with HIV, who were followed and consecutively attended to their control visit Marmara University Pendik Education and Training Hospital, in Istanbul, in 2018.

Results

24.4 % and 26.7 % of participants tested positive for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), respectively. This ratio decreased to 6.7% if urine was the only sample taken to be tested. Syphilis seropositivity increased from 18% to 34% during the HIV diagnosis to triple testing time, which is a median period of 28 months.

Conclusion

The data obtained emphasizes the screening and reimbursement of triple testing in key population groups.

Keywords

HIV (Human immunodeficiency virus) < viral disease sexual behaviour < other Chlamydia (Chlamydia trachomatis) < bacterial disease gonorrhea (Neisseria gonorrhoeae) < bacterial disease screening < other

Introduction

In Turkey, Human Immunodeficiency Virus (HIV), syphilis, Neisseria gonorrhoeae (NG), and Chlamydia trachomatis (CT) infections are notifiable diseases under national legislation. Due to the increasing case numbers, these sexually transmitted infections (STIs) have become a major public health concern in last few decades.

From 2010 to 2021, the number of new HIV infections declined in sub-Saharan Africa but increased in Eastern Europe, Central Asia, the Middle East, North Africa, and Latin America, as well as in Turkey.¹ Epidemiologically, Turkey is classified within the World Health Organization (WHO) Central Europe region due to its geographic and demographic characteristics, while also being in close proximity to the Middle East and North Africa. In 2023, Poland and Turkey together accounted for 70% of all HIV diagnoses reported in the Central Europe region. Moreover, these two countries reported the highest proportions of HIV diagnoses with an unknown transmission mode—78% in Poland and 71% in Turkey.² According to official records from the Turkish Ministry of Health, 45,835 HIV cases were reported between 1985 and November 2024.³ The annual number of new diagnoses has been rising rapidly, nearly doubling from 3213 cases in 2020 to 6329 cases in 2023.^3,4 In Turkey, several key HIV prevention measures remain under-implemented, including the identification of key populations, indicator condition–guided testing, condom distribution, sexual education for youth, and access to pre-exposure prophylaxis (PrEP), as documented in existing national policy reports.^3,5,6

Globally, men who have sex with men (MSM) are recognized as a key population for both HIV and syphilis, with HIV acquisition rates estimated to be 26 times higher than in the general population and syphilis prevalence reaching up to 19.6% in certain countries.⁷ MSM are disproportionately affected by STIs due to multiple risk factors, including having multiple sexual partners, condomless intercourse reported in up to 61% of encounters, engagement in chemsex in up to 15% of individuals, and a high frequency of sexual activity.^5,8–10 Male sex workers constitute a hidden key population in STI transmission and are diagnosed with STIs approximately 6.5 times more frequently than female sex workers.¹¹

Among individuals with high-risk sexual behaviors and frequent STI episodes, there is strong interest in, and willingness to use, HIV PrEP and doxycycline prophylaxis—both of which should be integral components of a comprehensive HIV and STI prevention strategy. Although awareness of, and willingness to use, PrEP are high among MSM in Turkey, actual access remains limited, with only 2.5% reporting PrEP use in the past 12 months, primarily due to lack of reimbursement.^12–14

Triple-site testing (urogenital/urine, rectal, and pharyngeal) is a key component of asymptomatic STI screening among MSM, enabling early detection and treatment prior to symptom onset or the development of complications. This approach also helps interrupt transmission chains, thereby reducing STI incidence and prevalence at the population level.¹⁵ Taking a detailed sexual history to identify all anatomical sites at risk, followed by routine screening of these sites, is also cost-effective in high-risk populations.¹⁶ Studies have shown that urogenital-only screening can miss the majority of rectal and pharyngeal NG and CT infections, with up to two-thirds of cases remaining undetected in the absence of extragenital testing.¹⁷

International guidelines emphasize the importance of regular STI screening among MSM, particularly those at elevated risk.^15,16,18 While these guidelines strongly advocate for comprehensive screening, there is ongoing debate regarding the lack of clear evidence for individual- or public health–level benefits from screening for CT and NG. Although urogenital CT and NG infections can cause serious complications—including pelvic inflammatory disease, perihepatitis, and adverse pregnancy outcomes—the clinical significance of asymptomatic oropharyngeal and rectal infections remains uncertain.¹⁹ Unlike systemic infections such as syphilis and HIV, CT and NG are frequently asymptomatic, self-limiting mucosal infections capable of spontaneous clearance, with similar host–pathogen interaction patterns.^20,21 Intensive screening may interrupt the development of protective immune responses, thereby increasing susceptibility to re-infection—a concept known as the “arrested immunity hypothesis,” supported by animal, clinical, and epidemiological evidence for CT.^21–23 Observations of higher rates of symptomatic disease in settings with more frequent screening for asymptomatic infection are consistent with this hypothesis.^23,24

Regarding screening frequency, UK guidelines recommend annual testing for asymptomatic individuals and following any change in sexual partner, with a maximum frequency of every 3 months for sexually active individuals. Triple-site testing is advised for all sexually active MSM. For those at higher risk—such as PrEP users, individuals reporting more than 10 partners in the past year, those with multiple or anonymous partners since their last test, individuals engaging in sexualized drug use (including chemsex), or those diagnosed with a bacterial STI within the previous year—testing every 3 months is recommended.¹⁸

The U.S. Centers for Disease Control and Prevention (CDC) recommends quarterly screening for NG, CT, and syphilis in sexually active MSM.¹⁶ The World Health Organization (WHO) advises periodic testing for urethral and rectal NG and CT, as well as serologic testing for syphilis, in asymptomatic MSM who access health-care services at least annually or every 6 months. Screening frequency should balance cost, case detection yield, and the potential consequences of not screening, taking into account rates of partner change and sexual exposure.¹⁵

In Turkey, there is no guideline specifically addressing MSM and no national guideline dedicated solely to STIs. Two documents provide recommendations relevant to HIV follow-up and STI screening: the HIV/AIDS Diagnosis, Monitoring, and Treatment Handbook—an official publication of the Turkish HIV/AIDS Platform—and the Ministry of Health’s HIV/AIDS Diagnosis and Treatment Guide. One document recommends specimen-specific collection strategies, such as rectal swabs for CT in MSM, urine samples for heterosexual men, and site-specific sampling for NG based on clinical suspicion. The other emphasizes the high risk of reinfection and advises retesting for NG or CT three months after a positive diagnosis.^25,26

In Turkey, multiplex PCR testing for CT and NG has been primarily available in tertiary hospitals and laboratories in major urban centers since 2022. However, reimbursement has recently been restricted to a single specimen type, and comprehensive national data on overall test utilization are lacking.²⁷

Among new HIV diagnoses in Turkey, the proportion attributed to MSM has been increasing significantly, and this group is considered the most hidden key population in the country.^3,28,29

In Turkey, infectious diseases outpatient clinics function de facto as sexual health services. The HIV outpatient clinic at Marmara University Pendik Training and Research Hospital—where 35.7% of people living with HIV under follow-up have self-identified as MSM—is one of the oldest patient-centered, friendly environment clinics in the country. Since the beginning of the HIV epidemic, it has strived to provide care in accordance with international standards.^2,30,31

According to the European AIDS Clinical Society (EACS) guidelines, STI screening should be offered to all sexually active individuals at the time of HIV diagnosis, annually thereafter, whenever STI symptoms are reported, and during pregnancy. More frequent screening at 3-month intervals is recommended for individuals at particularly high risk of STIs, including those with multiple or anonymous partners. Frequent HIV screening is also essential for individuals on PrEP.³² The British Association for Sexual Health and HIV further recommends three-monthly testing for individuals engaging in sexualized drug use, including chemsex, and for those within 1 year of a bacterial STI diagnosis.¹⁸

Although antiretroviral therapy is reimbursed in Turkey, triple-site testing is not covered by the national insurance system.^16,27,32 To our knowledge, only one study from Turkey has evaluated STI screening in people living with HIV, and this was limited to urine samples; no studies have examined MSM or MSM living with HIV using the recommended triple-site approach.³³

The present study aimed to describe the sociodemographic characteristics, sexual behaviors, and associated STIs—detected through triple-site testing—among MSM living with HIV followed in our clinic, representing a small segment of the key HIV population in İstanbul.

Methods

Data collection

Among MSM living with HIV who consecutively attended our clinic and had been followed by a single physician since diagnosis, those reporting multiple sexual partners underwent triple-site testing for CT, NG, and Trichomonas vaginalis (TV) after providing a comprehensive sexual history. The history was obtained using the “5 Ps” framework—Partners, Practices, Protection from STIs, Past history of STIs, and Prevention of Pregnancy—as outlined in the STI guidelines, and was incorporated as a routine component of follow-up from March 2018 to February 2019.^16,34 In addition, open-ended questions were used, in accordance with guideline recommendations, to allow participants to describe their experiences and perspectives more freely. The sexual behaviors assessed included partner-finding methods, condom use habits, rectal irrigation practices, alcohol consumption, chemsex and other drug use, engagement in transactional sex, having multiple sexual partners, and preferred sexual role identity (receptive, insertive, or versatile).

Urine samples were also tested for Ureaplasma urealyticum (UU), Ureaplasma parvum (UP), Mycoplasma hominis (MH), and Mycoplasma genitalium (MG).

Urine, rectal, and pharyngeal swab samples were collected using the BD MAX™ UVE Specimen Collection Kit and transported to the laboratory under appropriate conditions. For rectal and pharyngeal samples, initial testing was performed by pooling the two specimens in equal proportions; if a pooled sample tested positive, a second round of testing was conducted separately for each site. DNA extraction and real-time polymerase chain reaction (PCR) for CT, NG, and TV were performed on the BD MAX™ System using the BD MAX™ CT/GC/TV kit, following the manufacturer’s instructions. First-void urine specimens were used for the detection of MG, MH, UU, and UP DNA. Testing was performed by multiplex PCR using the BioGX Sample-Ready™ kit on the BD MAX™ System, following the manufacturer’s instructions. At our center, syphilis screening is performed using a treponemal test–based reverse sequence algorithm. When a positive result is obtained on the initial treponemal screening test, the laboratory reflexively performs a standard quantitative non-treponemal test with titer to guide management decisions. If the non-treponemal test is negative, a second treponemal test—based on different antigens from the initial test—is conducted to adjudicate the initial result. If the second treponemal test is positive but the non-treponemal test remains negative, the patient is managed for latent syphilis. If the second treponemal test is negative, no further evaluation or treatment is indicated.¹⁶

In this study, syphilis screening was performed using a chemiluminescence immunoassay (CLIA) as the initial treponemal test, Treponema pallidum hemagglutination assay (TPHA) as the second treponemal test, and rapid plasma reagin (RPR) as the non-treponemal test. Participants in the cohort were screened for syphilis at the time of HIV diagnosis as baseline. Thereafter, syphilis screening was performed annually during HIV follow-up visits, irrespective of participants’ number of sexual partners or engagement in unprotected sexual activity. While triple-site PCR testing was included in this study, syphilis screening was also performed to identify new syphilis cases among participants after their HIV diagnosis.

Although the commercial multiplex PCR assays used in this study were capable of detecting TV, MH, UU, and UP, routine screening for MH, UU, and UP is not recommended; therefore, results for these organisms are not presented. Similarly, because there is no current recommendation for screening MSM for TV due to uncertain benefit, these data are also not reported.^35,36

Statistical analysis

Categorical data were summarized as frequencies and percentages. The Chi-square test was used to evaluate associations between categorical variables. For continuous variables, descriptive statistics (median, minimum, and maximum values) were calculated, and normality was assessed using the Kolmogorov–Smirnov test. As the data were not normally distributed, non-parametric tests were applied. A p value of <.05 was considered statistically significant.

Results

Forty-five asymptomatic MSM living with HIV attending routine follow-up visits were included in this study. The mean age of participants was 38.2 ± 11.1 years (median: 35.0 years; range: 22–68 years). Sociodemographic characteristics are presented in Table 1. Of all participants, 44.3% (n = 20) resided on the Asian side of İstanbul, while 33.3% (n = 15) lived on the European side.

Table 1.

Socio-demographic and sexual behavioural characteristics of participants.

Characteristics	N	%
Age (median, min-max)	35 years, (22–68 years)
Sexual orientation
Bisexual	12	26.7
Homosexual	33	73.3
Origin
Turkey	43	95.6
Other (China, USA)	2	4.4
Education level
Primary school	2	4.4
Secondary school	3	6.7
High school	6	13.3
Vocational school	3	6.7
University	24	53.3
Master’s degree	4	8.9
PhD degree	3	6.7
City of residence
İstanbul	35	77.8
Anatolian (Asia) side	20	57.1
European side	15	42.9
Kocaeli	7	15.6
Yalova	2	4.4
Tekirdağ	1	2.2
Marital status
Single	34	75.6
Married with a woman	5	11.1
Divorced from a woman	5	11.1
Living with a same gender partner	1	2.2
Parental status
1 child	4	8.9
2 children	2	4.4
3 children	1	2.2
No child	38	84.5
Professional activity
White-collar	23	51.1
Blue-collar	11	24.4
Retired	5	11.2
Medical doctor	3	6.7
Student	2	4.4
Unemployed	1	2.2
Monthly income (median, min-max)	931.0$, (0–10.000$)
Circumcision status
Yes	43	95.6
No	2	4.4
HPV vaccination
Yes	4	8.9
No	41	91.1
Smoking
Yes	24	53.3
No	21	46.7
Alcohol consumption
Yes	25	55.6
No	20	44.4
Drug/chemsex use^a
No	27	60.0
Amphetamine	3	6.7
Ecstasy (MDMA)	8	17.8
Heroin	1	2.2
Cocaine	2	4.4
Marijuana	10	22.2
Poppers	13	28.9
GHB (Gamma-Hydroxybutyrate)	1	2.2
The last drug usage time, months ago (median, min-max)	2.5 months, (1–24 months)
Sildenafil use
Yes	6	13.3
No	39	86.7
Testosterone use
Yes	2	4.4
No	43	95.6
Antibiotic consumption in the last 3 months
Yes	22	48.9
No	23	51.1
Antibiotics
Beta lactam	15	33.3
Macrolide	3	6.7
Doxycycline	2	4.4
Quinolone	3	6.7
Fosfomycin	1	2.2
Metronidazole	2	4.4
Trimethoprim-sulfamethoxazole	1	2.2
The duration of antibiotic usage in the last 3 months (median, min-max)^b	3 days, (1–30 days)
Months of HIV diagnosis (median, min-max)	28 months, (1–276 months)
ART duration (median, min-max)	3 months, (1–254 months)
Co-morbidity
Yes^c	19	42.2
No	26	57.8
Medications/supplements used regularly other than ART
Yes	18	40.0
No	27	60.0
Medications/supplements^a
Vitamin D	7	15.6
Selective Serotonin Reuptake Inhibitor	4	8.9
Antiplatelet	4	8.9
Antihypertensive	6	13.3
Antihistamine	1	2.2
Oral Antidiabetic	1	2.2
Alpha blocker	2	4.4
STI history
Yes	27	60.0
No	18	40.0
Travel history in the last 12 months
Yes	24	53.3
No	21	46.7
Travelled locations
Domestic	13
International	14
International locations^a
Asia	6
Europe	7
Africa	1
Number of lifetime sexual partners
≤20 partners	9	20.0
≥21 partners	36	80.0
Total number of lifetime sexual partners (median, range)	100 partners, (8–1000 partners)
Number of sexual partners in the last 3 months
≤5 partners	27	60.0
≥6 partners	18	40.0
Number of sexual partners in last 3 months (median, min-max)	4 partners, (0–30 partners)
Venues where sexual partners met
Mobile application	33	73.3
Internet	10	22.2
Through friends	2	4.4
Beaches/ parks	3	6.7
Gay bars	3	6.7
Turkish bath	1	2.2
Roadside	1	2.2
HIV status of the sexual partners
Unknown	39	86.7
Negative	1	2.2
Positive	5	11.1
Having multi partners
Yes	39	86.7
No	6	13.3
Partners’ STI status
Yes	5	11.1
No	8	17.8
Unknown	32	71.1
Transactional sex
Yes	10	22.2
No	35	77.8
Type of sexual partner relationship in last 3 months
Steady (median, range)	0, 0–10
Anonymous^d (median, range)	3, 0–30
Commercial (median, range)	0, 0–6
Casual^e (median, range)	1, 0–20
Group sex (median, range)	0, 0–6
Sexual role in oral intercourse
None	3	6.7
Receptive	3	6.7
Insertive	5	11.1
Both receptive and insertive	34	75.5
Sexual role in anal intercourse
None	3	6.7
Receptive	13	28.9
Insertive	4	8.9
Both receptive and insertive	25	55.6
Use of enemas in anal sex
Yes	27	60.0
No	18	40.0
Alcohol use during sex
Yes	16	35.6
No	29	64.4
Drug use during sex
Yes	13	28.9
No	32	71.1

^aMultiple responses were given.

^bThe antibiotic used for the longest duration by participants was doxycycline (max: 30 days), while the shortest duration was for beta-lactam antibiotics (1 day).

^c4 hypertension, 2 diabetes mellitus, 2 asthma, 2 depression, 2 osteoporosis, 2 anal fissure, 1 Kaposi’s sarcoma, 1 peptic ulcer, 1 kidney disease, 4 cardiovascular disease, 1 retinitis pigmentosa, 1 chronic sinusitis, 1 leukocytoclastic vasculitis.

^dAn anonymous sex partner was defined as a person who “you do not know, or you just got to know”.^66–68.

^eA casual sex partner was described as a person with whom “you have regular sex but not a steady relationship, but who is not anonymous”.^66–68.

Laboratory results

Rectal samples

Among the 45 rectal samples, 15.6% (n = 7) tested positive for CT and 17.8% (n = 8) for NG (Figure-1). Of the seven patients with rectal CT positivity, two also had concurrent pharyngeal CT positivity, while none had concurrent urinary CT positivity. Among the eight patients with rectal NG positivity, four had concurrent pharyngeal NG positivity, and two had concurrent urinary NG positivity (Table 2).

Figure 1.

PCR positivities according to anatomic sites.

Table 2.

Rectal CT/NG PCR test results and sexual activities in the last 3 months.

	Rectal CT PCR		p value	Rectal NG PCR		p value
	+ (n, %)	- (n, %)	p value	+ (n, %)	- (n, %)	p value
Receptive anal sex with condom use	5 (16.7)	25 (83.3)	.771	6 (20.0)	24 (80.0)	.581
Receptive anal sex without condom use	5 (21.7)	18 (78.3)	.242	6 (26.1)	17 (73.9)	.136
Insertive anal sex with condom use	3 (11.1)	24 (89.9)	.314	6 (22.2)	21 (77.8)	.340
Insertive anal sex without condom use	4 (23.5)	13 (76.5)	.250	5 (29.4)	12 (70.6)	.112

Pharyngeal samples

Among the 45 pharyngeal samples, 6.7% (n = 3) were positive for CT and 11.1% (n = 5) for NG (Figure-1).

Urinary samples

Similarly, among the 45 urinary samples, 6.7% (n = 3) tested positive for CT and 6.7% (n = 3) for NG (Figure-1).

Overall positivity across sample types

Considering urine, rectal, and pharyngeal samples collectively, 24.4% (n = 11) were positive for NG and 26.7% (n = 12) for CT. Overall, 35.7% (n = 16) of participants tested positive for at least one of the infections screened. MG was investigated only in first-void urine, with PCR positivity detected in 2.2% (n = 1) of participants.

At the time triple-site PCR testing was requested, syphilis serology was positive in 15 participants (34.1%), compared with eight individuals (18.2%) who had tested positive at the time of HIV diagnosis.

No statistically significant associations were observed between NG or CT PCR positivity and age, educational level, place of residence, marital or parental status, occupation, monthly income, cigarette, alcohol, drug, or sildenafil use, presence of comorbidities, history of any STI, travel within the past 12 months, or type of sexual partnership (steady, casual, or commercial) in the past 3 months (p > .05).

Because the number of uncircumcised and non-Turkish participants was only two, and only four MSM living with HIV had received HPV vaccination and two reported testosterone use, no statistical analysis was performed for these variables.

Antibiotic use within the past 3 months was significantly associated with lower rectal and pharyngeal NG PCR positivity (4.5% vs 30.4%, p = .047; 5.4% vs 21.7%, p = .049), but showed no significant association with rectal or pharyngeal CT PCR positivity (p = .728 and p = .608, respectively) or with urinary NG and CT PCR positivity (p = .947 and p = .489, respectively).There was no significant association between the number of sexual partners in the past 3 months and rectal NG (p = .694), rectal CT (p = .867), pharyngeal CT (p = .329), pharyngeal NG (p = .978) PCR positivity, or syphilis seropositivity (p = .131). Among MSM living with HIV in this study, 60.0% (27/45) reported enema or rectal douching prior to receptive anal intercourse. This practice was significantly associated with a higher rate of CT/NG PCR positivity compared with non-users (55.6% vs 25.9%, p = .045). Rectal and pharyngeal CT and NG PCR positivity rates by sexual practices in the past 3 months are presented in Tables 2 and 3. Rectal CT and NG positivity rates were higher among individuals engaging in receptive and insertive anal sex without condom use (21.0% and 23.5%, and 26.0% and 29.4%, respectively) compared with those reporting condom use (16.7% and 11.1%, and 20.0% and 22.0%, respectively), although these differences were not statistically significant. Pharyngeal NG positivity was significantly associated with insertive oral sex without condom use, whereas CT positivity did not demonstrate a similar association. At the time of HIV diagnosis, individuals with positive syphilis serology (tested a median of 28 months earlier) had a significantly higher prevalence of rectal NG PCR positivity on current testing compared with those with negative syphilis serology (50.0% vs 8.3%; p = .004). Similarly, individuals with current positive syphilis serology also had a significantly higher prevalence of rectal NG positivity compared with those with negative serology (33.3% vs 6.9%; p = .023).

Table 3.

Pharyngeal CT/NG PCR test results and sexual activities in last 3 months.

	Pharyngeal CT PCR		p value	Pharyngeal NG PCR		p value
	+ (n, %)	- (n, %)	p value	+ (n, %)	- (n, %)	p value
Receptive oral sex with condom use	1 (12.5)	7 (87.5)	.466	1 (12.5)	7 (87.5)	.890
Receptive oral sex without condom use	3 (8.1)	34 (91.9)	.404	3 (8.1)	34 (91.9)	.168
Insertive oral sex with condom use	0 (0.0)	7 (100.0)	a	2 (28.6)	5 (71.4)	.110
Insertive oral sex without condom use	2 (5.7)	33 (94.3)	.632	2 (5.7)	33 (94.3)	.031

^aChi-square test could not be performed due to zero values in the data.

Open-ended questions

About STI prevention

When participants were asked about measures they took to prevent STIs, 25 reported using condoms. Additional measures mentioned by individual participants included avoiding anal sex, using an antibacterial oral spray, having a single partner, washing after intercourse, abstaining from intercourse if there was an open wound, and avoiding ejaculation in the mouth during oral sex.

About condom use

Only three participants reported always using condoms. When asked about reasons for not using condoms, the responses included: trusting their partners (n = 5), inability to find or think of a condom at the time of intercourse (n = 5), belief that oral sex is not risky (n = 5), partner’s unwillingness to use condoms (n = 5), belief that condoms do not prevent STIs (n = 4), dislike of condoms (n = 3), perception that condoms diminish sexual experience (n = 1), lack of habit (n = 1), belief that condom materials are harmful (n = 1), belief that HIV transmission is not possible due to HIV RNA negativity (n = 1), and concern that condom use would hinder erection (n = 1). When asked about reasons for occasional condom use, participants reported using them with new or unfamiliar partners (n = 11), during anal sex when requested by their partner (n = 14), and when they believed there was a risk of STI transmission (n = 3).

Discussion

This is the first study in Turkey to investigate sexual behaviors and triple-site STI screening among asymptomatic MSM living with HIV. Turkey is a secular country with a predominantly Muslim population.^37,38 While same-gender marriages are not legally recognized, same-sex sexual activity is not criminalized—unlike in many other Muslim-majority countries.³⁹

In this study, 22% of MSM living with HIV were currently or previously married to women, with a median of one child, and 80% of these individuals held a university degree or higher. Except for one participant from China, none of the female spouses were aware of their husbands’ sexual orientation, although they had been informed of their HIV diagnosis. Despite a cultural tradition of tolerance rooted in the humanist philosophies of Mevlana and Yunus Emre, widespread social intolerance in Turkey makes it difficult to openly express same-sex relationships.^40,41 Even among well-educated men, some marry women to avoid stigma and conform to social norms—a pattern also reported in China, India, and other Muslim-majority countries, consistent with our findings.^4,42–44

Recent epidemiological analyses have shown a significant rise in HIV incidence among younger males in Turkey, primarily driven by MSM populations.⁴ This trend is consistent with our findings of high rates of syphilis and rectal gonorrhea among MSM living with HIV, suggesting that ongoing bacterial STI transmission may be contributing to the trajectory of the HIV epidemic. These observations underscore the urgent need for targeted STI screening and prevention strategies in this key population.

In this study, only 6.7% of participants sought partners in physical locations such as gay bars, parks, bathhouses, or roadside areas, whereas 95% used geosocial networking applications. These findings are consistent with previous studies demonstrating the limited public visibility and hidden status of MSM in Turkey.²⁹ Given that mobile application use is common worldwide, HIV and STI interventions should be adapted for digital platforms to effectively reach this hard-to-access population.^45,46

NG and CT PCR positivity at any anatomical site (pharyngeal, rectal, or urine) was detected in 24% and 27% of participants, respectively, whereas urine samples alone accounted for only 6.7% of detections. This highlights the importance of triple-site testing in asymptomatic MSM living with HIV. In previous triple-site sampling studies among MSM living with HIV, CT/NG positivity rates of 20% in Israel and 19.8%/21.7% in Portugal were reported, which are comparable to our findings.^47,48

A study from Ankara, Turkey, investigated behavioral risk factors and STI PCR positivity among heterosexual and homosexual men living with HIV using urine samples only.³³ NG and CT were detected in 3.1% and 2.5% of participants, respectively. In comparison, in our study, positivity rates for both pathogens were 6.7%. This difference may be explained by the fact that our study population consisted exclusively of MSM living with HIV, a group considered at higher risk for CT and NG colonization.³³ Our findings are also consistent with previous reports showing that reliance on urine testing alone, compared with triple-site screening, may result in missed diagnoses in up to 84% of cases.^47,48

In our study, among 35 participants who reported insertive oral sex without condom use, two tested positive for NG, whereas among 37 participants engaging in receptive oral sex without a condom, three were NG positive (Table 3). Although this difference appeared statistically significant, separating exposures is challenging because multiple oral sites are often involved simultaneously during the same sexual encounter. Previous research has shown that sexual behavior combinations are diverse and not limited to penile insertion.⁴⁹ Indeed, some studies have reported that oropharyngeal gonorrhea incidence among casual sexual partners may be nearly significantly associated with kissing alone and increases with the number of kissing partners.^50,51 These findings suggest that different sexual practices may confer varying transmission risks for pharyngeal gonorrhea.

In our study, although a statistically significant difference in pharyngeal NG positivity was observed among participants practicing insertive oral sex, the small number of positive cases warrants cautious interpretation. Further studies with larger sample sizes are needed to clarify these associations.

The single participant who tested positive for MG was bisexual, reported condomless vaginal, oral, and anal sex, had used beta-lactam antibiotics in the preceding 3 months, and was seronegative for syphilis. Antibiotic use may have masked NG detection in this case. MG has also been reported among asymptomatic MSM in countries such as China, Japan, and Portugal, with prevalence rates varying across studies.^47,52

In a study conducted in Australia between 2016 and 2017 that included 1001 asymptomatic MSM, the prevalence of NG, CT, and MG was reported as 6.7%, 9.6%, and 9.5%, respectively; however, MG prevalence decreased to 2.7% when only urine samples were tested.⁵³ In a 2022 study from Vietnam, MG prevalence was 12.8%, with detection rates of 9.2% in the rectum, 2.8% in the pharynx, and 3.1% in the urethra.⁵⁴ In our study, MG testing was performed solely on urine samples, whereas CT and NG testing included urine as well as pharyngeal and rectal swabs. This difference in sampling strategy may explain the higher detection rates for CT and NG. Of the 45 urine samples tested for MG, only one was positive, a rate consistent with those reported in the Australian and Vietnamese studies when considering urine-only testing.^53,54

In our study, rectal douching prior to receptive anal intercourse was reported by 60.0% (27/45) of participants and was significantly associated with higher CT/NG PCR positivity compared with non-users (55.6% vs 25.9%, p = .045), consistent with previous evidence of its independent association with rectal NG/CT infection.^55–57 Rectal douching and the use of saliva have also been identified as STI risk behaviors among MSM due to their associations with mucosal disruption and condomless receptive anal intercourse.^55–58 Taken together, these data emphasize the role of rectal douching in STI transmission dynamics and suggest that avoiding enema use during anal sex may be associated with a lower risk of STI, potentially serving as a protective factor.

In this study, syphilis serology was positive in 18.2% of participants at HIV diagnosis, increasing to 34.1% during follow-up, indicating ongoing syphilis transmission over a median follow-up of 28 months. Rectal NG positivity was significantly more common among individuals with syphilis seropositivity. These findings are consistent with previous studies reporting high syphilis rates among people living with HIV, including data from Turkey showing seropositivity of 24.9% among people living with HIV and up to 30.1% among MSM living with HIV.^31,32 International studies have also demonstrated similar increases in syphilis seropositivity over time, with rates ranging from 25% to 60%.^59–61 The frequent co-occurrence of bacterial STIs, particularly rectal NG, in syphilis-seropositive individuals is also in line with previous research highlighting the overlapping nature of these infections in MSM populations.⁶²

Antibiotic use within the past 3 months (median duration: 3 days) was significantly associated with lower rectal and pharyngeal NG PCR positivity, possibly reflecting the high overall antibiotic consumption—particularly beta-lactam use—among participants.

In a comparable study conducted in South Africa, the prevalence of NG and CT in rectal samples was reported as 42% and 72%, respectively, whereas in our study these rates were 17.8% and 15.6%. One possible explanation for this discrepancy is the high frequency of antibiotic use in Turkey for various indications.⁶³

High daily antibiotic consumption in Turkey, combined with the WHO’s classification of NG resistance to cephalosporins and quinolones as a high-priority public health concern, underscores the urgent need for resistance surveillance of circulating NG strains among high-risk MSM populations in the country.^64,65

Responses to the open-ended questions indicated gaps in sexual health knowledge: 14 participants reported using condoms only if requested by their partner, while four did not believe in their protective efficacy. These findings highlight the need to provide sexual health education at every clinical follow-up visit for people living with HIV.

A major strength of this study is that it represents the first collection of detailed sexual behavior data—including residence location, partner characteristics, sexual practices, prevention methods, and STI history—integrated with triple-site STI screening among MSM living with HIV in Turkey. Limitations include its single-center design, small sample size, and the absence of HPV PCR screening. Another limitation was the inability to perform lymphogranuloma venereum testing on CT–positive samples due to limited diagnostic capacity.

Conclusions

This study demonstrates, for the first time in Turkey, that adding rectal and pharyngeal samples to urine-based screening substantially improves STI detection among asymptomatic MSM living with HIV. Given that national health insurance reimburses only one PCR test, pooled triple-site sampling—as applied in this study—may represent a practical and cost-effective approach consistent with international guidelines.

Our findings—including the high detection rates of CT/NG through triple-site testing, the increased STI risk associated with rectal douching, and the concentration of MSM in specific urban districts—underscore the need for targeted, behavior-informed, and location-specific strategies to prevent HIV and STI transmission among MSM in Turkey. Such strategies could inform policy development and guide public health interventions by national authorities.

Footnotes

Acknowledgements

The authors would like to express their immense gratitude to all the men who have sex with men (MSM) living with HIV who are followed up at the HIV outpatients clinics of Marmara University Pendik Training and Research Hospital.

Ethical approval

Ethical approval was obtained from the Marmara University Faculty of Medicine Clinical Research Ethics Committee [09.2023.1389].

Ethical considerations

The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Marmara University Faculty of Medicine (09.2023.1389) on November 3rd, 2023 with the need for written informed consent waived.

Author Contributions

Designed the study: DYC, RC, GS, VK, MBA.

Collected and synthesized the data: DYC, RC, DME, FBD.

Interpreted the data: DYC, FBD, RC, LMD, US, GS, VK, Aİ.

Prepared the first draft of this manuscript: DYC.

All authors read and approved the first and final drafts of this manuscript.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Dilek Yagci-Caglayik

Fatma Burcu Doganc

Rabia Can

Dogu Mert Ersoy

Guner Soyletir

Uluhan Sili

Lutfiye Mulazimoglu

Burak Aksu

Arzu İlki

Volkan Korten

References

Nachega

Musoke

Kilmarx

, et al.

Global HIV control: is the glass half empty or half full?

Lancet HIV 2023; 10(9): e617–e622.

WHO Regional Office for Europe, European Centre for Disease Prevention and Control . HIV/AIDS surveillance in Europe 2024 – 2023 data. https://www.ecdc.europa.eu/en/publications-data/hiv-aids-surveillance-europe-2024-2023-data (2024, accessed 9 August 2025).

TC Sağlık Bakanlığı . Halk Sağlığı Genel Müdürlüğü. HIV/AIDS İstatistikleri. https://hsgm.saglik.gov.tr/depo/birimler/bulasici-hastaliklar-ve-erken-uyari-db/Dokumanlar/Istatistikler/Ek_HIV-AIDS_Istatistikleri.pdf (accessed 8 August 2025).

Derin

. Gender and age trends in HIV incidence in Turkey between 1990 and 2021: Joinpoint and age-period-cohort analyses. Medicina (Kaunas) 2024; 60(8): 1357.

European Centre for Disease Prevention and Control . HIV and STI prevention among men who have sex with men. Stockholm. https://www.ecdc.europa.eu/sites/default/files/media/en/publications/Publications/hiv-sti-prevention-among-men-who-have-sex-with-men-guidance.pdf (2015, accessed 8 August 2025).

TC Sağlık Bakanlığı . Stratejik planı 2024 - 2028. https://dosyamerkez.saglik.gov.tr/Eklenti/47452/0/saglik-bakanligi-stratejik-plan-2024-2028pdf.pdf?_tag1=7B2A9834832BF7DCF36F2C7E5607D8543752A372, (accessed 8 August 2025).

World Health Organization . Global HIV, hepatitis and STIs Programmes. https://www.who.int/teams/global-hiv-hepatitis-and-stis-programmes/overview, (accessed 8 August 2025).

European Centre for Disease Prevention and Control . EMIS-2017 - the European men-who-have-sex-with-men internet survey. Key findings from 50 countries, 2019. https://www.ecdc.europa.eu/sites/default/files/documents/European-MSM-internet-survey-2017-findings.pdf (accessed 9 August 2025).

Jansen

Steffen

Potthoff

, et al. STI in times of PrEP: high prevalence of chlamydia, gonorrhea, and mycoplasma at different anatomic sites in men who have sex with men in Germany. BMC Infect Dis 2020; 20(1): 110.

10.

Yang

Wei

, et al. HIV risk and influence factors among MSM who had sought sexual partners in core venues: a continuous sentinel surveillance in 2010-2022. Front Public Health 2024; 12: 1476642.

11.

Verhaegh-Haasnoot

Dukers-Muijrers

Hoebe

. High burden of STI and HIV in male sex workers working as internet escorts for men in an observational study: a hidden key population compared with female sex workers and other men who have sex with men. BMC Infect Dis 2015; 15: 291.

12.

Nazli

Garner

Gokengin

. Awareness of HIV pre-exposure prophylaxis among men who have sex with men using apps for sexual encounters in Turkiye. Int J STD AIDS 2022; 33(13): 1124–1133.

13.

Gökengin

Noori

Alemany

, et al. Prevention strategies for sexually transmitted infections, HIV, and viral hepatitis in Europe. Lancet Reg Health Eur 2023; 34: 100738.

14.

Saunders

Deering

Dewsnap

, et al. British Association for Sexual Health and HIV (BASHH) UK national guideline for the use of doxycycline post-exposure prophylaxis (DoxyPEP) for the prevention of syphilis, 2025. Int J STD AIDS 2025: 9564624251352053.

15.

World Health Organization . Guidelines for the management of asymptomatic sexually transmitted infections. Geneva: Licence: CC BY-NC-SA 3.0 IGO, 2025. https://iris.who.int/bitstream/handle/10665/381533/9789240104907-eng.pdf?sequence=1 (accessed 9 August 2025).

16.

Workowski

Bachmann

Chan

, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep (Morb Mortal Wkly Rep) 2021; 70(4): 1–187.

17.

Koedijk

van Bergen

Dukers-Muijrers

, et al. The value of testing multiple anatomic sites for gonorrhoea and chlamydia in sexually transmitted infection centres in The Netherlands, 2006-2010. Int J STD AIDS 2012; 23(9): 626–631.

18.

Harry Coleman

Soni

Murchie

, et al. BASHH summary guidance on testing for sexually transmitted infections. https://www.bashh.org/_userfiles/pages/files/resources/bashh_summary_guidance_on_stis_testing_2023.pdf (2023, accessed 9 August 2025).

19.

Kojima

Klausner

. Patients may accurately self-collect pharyngeal and rectal specimens for Neisseria gonorrhoeae and Chlamydia trachomatis infection: but is there benefit? Clin Infect Dis 2021; 73(9): e3181–e3182.

20.

Kenyon

Herrmann

Hughes

, et al. Management of asymptomatic sexually transmitted infections in Europe: towards a differentiated, evidence-based approach. Lancet Reg Health Eur 2023; 34: 100743.

21.

Geisler

. Duration of untreated, uncomplicated Chlamydia trachomatis genital infection and factors associated with chlamydia resolution: a review of human studies. J Infect Dis 2010; 201(Suppl 2): S104–S113.

22.

Vanbaelen

Tsoumanis

Florence

, et al. Effect of screening for Neisseria gonorrhoeae and Chlamydia trachomatis on incidence of these infections in men who have sex with men and transgender women taking HIV pre-exposure prophylaxis (the Gonoscreen study): results from a randomised, multicentre, controlled trial. Lancet HIV 2024; 11(4): e233–e244.

23.

Marcus

Mirandola

Schink

, et al.

Changes in the prevalence of self-reported sexually transmitted bacterial infections from 2010 and 2017 in two large European samples of men having sex with men-is it time to re-evaluate STI-screening as a control strategy?

PLoS One 2021; 16(3): e0248582.

24.

Williams

Williamson

Hocking

. Frequent screening for asymptomatic chlamydia and gonorrhoea infections in men who have sex with men: time to re-evaluate? Lancet Infect Dis 2023; 23(12): e558–e566.

25.

Gökengin

Kurtaran

Korten

, et al. HIV/AIDS Tanı İzlem ve Tedavi El Kitabı. İstanbul: Nobel Tıp Yayıncılığı, 2024. https://www.ekmud.org.tr/files/uploads/files/HIV_AIDS-El-Kitabi-V2.pdf?v1 (accessed 3 August 2025).

26.

TC Sağlık Bakanlığı, Halk Sağlığı Genel Müdürlüğü . HIV/AIDS Tanı Tedavi Rehberi. Sağlık Bakanlığı Yayın No:1113, Ankara, 2019. https://hsgm.saglik.gov.tr/depo/birimler/bulasici-hastaliklar-ve-erken-uyari-db/Dokumanlar/Rehberler/HIV-AIDS_Tani-Tedavi_Rehberi_2019.pdf (accessed 3 August 2025).

27.

Resmi Gazete . Sosyal Güvenlik Kurumu Sağlik Uygulama Tebliğinde Değişiklik Yapılmasına Dair Tebliğ. 21 Nisan 2024 Sayı:32524. https://www.sgk.gov.tr/Download/DownloadFile?f=ed544b52-5df2-4852-8a88-b6fb2487cf35.pdf&d=fa049c02-7d15-412e-8fb8-430c4f4f8694 (accessed 10 August 2025).

28.

Erdinc

Dokuzoguz

Unal

, et al. Temporal trends in the epidemiology of HIV in Turkey. Curr HIV Res 2020; 18(4): 258–266.

29.

Gokengin

Aybek

Aral

, et al. Programmatic mapping and size estimation of female sex workers, transgender sex workers and men who have sex with men in İstanbul and Ankara, Turkey. Sex Transm Infect 2021; 97(8): 590–595.

30.

European Centre for Disease Prevention and Control . Continuum of HIV care. Monitoring implementation of the Dublin Declaration on partnership to fight HIV/AIDS in Europe and Central Asia: 2022 progress report. Stockholm: ECDC, 2023. https://www.ecdc.europa.eu/sites/default/files/documents/CoC_HIV_0.pdf (accessed 4 August 2025).

31.

Yağcı Çağlayık

Sili

Tükenmez Tigen

, et al. Marmara Üniversitesi Pendik Eğitim ve Araştırma Hastanesi’nde takip edilen HIV ile yaşayan erişkin bireylerde sifiliz seropozitifliğinin araştırılması, 2024. Turk Hij Den Biyol Derg 2024; 81(4): 431–438.

32.

European AIDS Clinical Society . European Guidelines for treatment of HIV-positive adults in Europe. European AID Clinical Society, 2024. Version 12.1. December 2024 [Internet]. Available from: https://eacs.sanfordguide.com/eacs-part1/eacs-section4/sexual-reproductive-health/copy_of_sexual-transmission-hiv (accessed 13 March 2025).

33.

Ayaz

ÇM

Karakaplan

İnkaya

AÇ

, et al. Investigation of the frequency of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium in men living with HIV in terms of sociodemographic characteristics and behavioral risk factors. Mikrobiyoloji Bulteni 2023; 57(3): 378–389. Turkish.

34.

Centers for Disease Control and Prevention . Sexually transmitted infections (STIs). Guide to taking a sexual history, 2024. https://www.cdc.gov/sti/hcp/clinical-guidance/taking-a-sexual-history.html (accessed 7 March 2025).

35.

Centers for Disease Control and Prevention . Sexually transmitted infections treatment guidelines. Trichomoniasis, 2021. https://www.cdc.gov/std/treatment-guidelines/trichomoniasis.htm (accessed 8 August 2025).

36.

Horner

Donders

Cusini

, et al. Should we be testing for urogenital Mycoplasma hominis, Ureaplasma parvum and Ureaplasma urealyticum in men and women? - a position statement from the European STI Guidelines Editorial Board. J Eur Acad Dermatol Venereol 2018; 32(11): 1845–1851.

37.

United States of America, Department of State . Turkey (Turkey) 2022 international religious freedom report. https://www.state.gov/reports/2022-report-on-international-religious-freedom/turkey/, (accessed 3 March 2025).

38.

Wikipedia, Turkey . https://en.wikipedia.org/wiki/Turkey, accessed 3 March 2025.

39.

BBC . Homosexuality: The countries where it is illegal to be gay. https://www.bbc.com/news/world-43822234 (2023, accessed 16 March 2025).

40.

Este’Lami

. Rumi and the Universality of his message. Islam Christian-Muslim Relat 2003; 14(4): 429–524.

41.

Toker

. Love as reflected in the poetry of Jalaluddin Rumi and Yunus Emre. Agathos: An International Review of the Humanities & Social Sciences 2024; 15(2): 177–193.

42.

Anonymous . Muslim and gay: seeking identity coherence in New Zealand. Cult Health Sex 2016; 18(3): 280–293.

43.

Bakacak

Oktem

. Homosexuality in Turkey: strategies for managing heterosexism. J Homosex 2014; 61(6): 817–846.

44.

Dai

Zhong

Peng

, et al. Socio-demographics, sexual behaviours, and use of HIV prevention services among men who have sex with men and women in Western China. Int J STD AIDS 2016; 27(2): 133–140.

45.

Aafln

Sousa

ÁFL

Araújo

TME

, et al. High rates of unprotected receptive anal sex and vulnerabilities to HIV infection among Brazilian men who have sex with men. Int J STD AIDS 2021; 32(4): 368–377.

46.

Zhang

Jia

Chen

, et al. Prevalence and the associated risk factors of HIV, STIs and HBV among men who have sex with men in Kunming, China. Int J STD AIDS 2017; 28(11): 1115–1123.

47.

Minetti

Rocha

Duque

, et al. Orogenital and anal infection by Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and other sexually transmitted infections in men who have sex with men in Lisbon. Int J STD AIDS 2024; 35(5): 379–388.

48.

Zucker

Gaisa

Sigel

, et al. Triple site sexually transmitted infection testing as a crucial component of surveillance for men who have sex with men: a prospective cohort study. Int J STD AIDS 2022; 33(2): 114–122.

49.

Rosenberger

Reece

Schick

, et al. Sexual behaviors and situational characteristics of most recent male-partnered sexual event among gay and bisexually identified men in the United States. J Sex Med 2011; 8(11): 3040–3050.

50.

Chow

EPF

Vodstrcil

Williamson

, et al. Incidence and duration of incident oropharyngeal gonorrhoea and chlamydia infections among men who have sex with men: prospective cohort study. Sex Transm Infect 2021; 97(6): 452–457.

51.

Cornelisse

Walker

Phillips

, et al. Risk factors for oropharyngeal gonorrhoea in men who have sex with men: an age-matched case-control study. Sex Transm Infect 2018; 94(5): 359–364.

52.

Ando

Mizushima

Takano

, et al. High prevalence of circulating dual-class resistant Mycoplasma genitalium in asymptomatic MSM in Tokyo, Japan. JAC Antimicrob Resist 2021; 3(2): dlab091.

53.

Read

TRH

Murray

Danielewski

, et al. Symptoms, sites, and significance of Mycoplasma genitalium in men who have sex with men. Emerg Infect Dis 2019; 25(4): 719–727.

54.

Nguyen

Adamson

Bui

, et al. Mycoplasma genitalium infections among participants in an HIV pre-exposure prophylaxis Program in Hanoi, Vietnam. Sex Transm Dis 2024; 51(11): 750–755.

55.

Yuan

Fitzpatrick

, et al. Association between rectal douching and HIV and other sexually transmitted infections among men who have sex with men: a systematic review and meta-analysis. Sex Transm Infect 2019; 95(6): 428–436.

56.

Hassan

Blumenthal

Dube

, et al. Effect of rectal douching/enema on rectal gonorrhoea and chlamydia among a cohort of men who have sex with men on HIV pre-exposure prophylaxis. Sex Transm Infect 2018; 94(7): 508–514.

57.

Carballo-Diéguez

Bauermeister

Ventuneac

, et al. The use of rectal douches among HIV-uninfected and infected men who have unprotected receptive anal intercourse: implications for rectal microbicides. AIDS Behav 2008; 12(6): 860–866.

58.

Lee

Gaither

Langston

, et al. Lubrication practices and receptive anal sex: implications for STI transmission and prevention. Sex Med 2021; 9(3): 100341.

59.

Schuettfort

Groh

Kann

, et al. Sexually transmitted diseases in people living with HIV after implementation of cost coverage of HIV pre-exposure prophylaxis by statutory health insurance in Germany. HIV Med 2023; 24(2): 163–169.

60.

Lemmet

Cotte

Allavena

, et al. High syphilis prevalence and incidence in people living with HIV and Preexposure Prophylaxis users: a retrospective review in the French Dat'AIDS cohort. PLoS One 2022; 17(5): e0268670.

61.

Kenyon

Osbak

Apers

. Repeat syphilis is more likely to Be asymptomatic in HIV-infected individuals: a retrospective cohort analysis with important implications for screening. Open Forum Infect Dis 2018; 5(6): ofy096.

62.

Malekinejad

Barker

Merai

, et al. Risk of HIV acquisition among men who have sex with men infected with bacterial sexually transmitted infections: a systematic review and meta-analysis. Sex Transm Dis 2021; 48(10): e138–e148.

63.

Le Roux

Ngwenya

Nemarude

, et al. Sexually transmitted infections and sexual behaviour among men having sex with men from Tshwane, South Africa. Int J STD AIDS 2023; 34(3): 183–190.

64.

World Health Organization . Antimicrobial resistance surveillance in Europe 2023 - 2021 data. Stockholm: European Centre for Disease Prevention and Control and World Health Organization, 2023. https://www.ecdc.europa.eu/sites/default/files/documents/AntimicrobiaresistancesurveillanceinEurope2023-2021data.pdf (accessed date:10 March 2025).

65.

World Health Organization . Bacterial Priority Pathogens List, 2024: bacterial pathogens of public health importance to guide research, development and strategies to prevent and control antimicrobial resistance. Geneva: World Health Organization, 2024. Licence: CC BY-NC-SA 3.0 IGO. https://iris.who.int/bitstream/handle/10665/376776/9789240093461-eng.pdf?sequence=1 (accessed date:10 March 2025).

66.

Stockman

Hayashi

Barnes

, et al.

Recent partner violence, sexual relationship power, and STIs among women who use methamphetamine: does type of sexual partner matter?

J Urban Health 2020; 97: 387–394.

67.

Rotsaert

Smekens

Vuylsteke

, et al. Patterns of PrEP and condom use among PrEP users in Belgium: a web-based longitudinal study. BMC Public Health 2023; 23: 970.

68.

European Centre for Disease Prevention and Control . Public health benefits of partner notification for sexually transmitted infections and HIV. Stockholm: ECDC, 2013. https://www.ecdc.europa.eu/sites/default/files/media/en/publications/Publications/Partner-notification-for-HIV-STI-June-2013.pdf (accessed 8 August 2025).