OBJECTIVES:Chlamydia trachomatis (chlamydia) infection has a variable course; most infections resolve but some lead to reproductive complications. Behavioural, immunological and host genetic factors likely influence risk. We aimed to identify predictors of complications in persons with and without chlamydia and develop prediction models for risk stratification. METHODS:We analysed data from a long-term cohort of Dutch individuals registered as female in municipal registries and previously screened for chlamydia, including demographic, behavioural, chlamydia-infection and serology variables, and 24 single nucleotide polymorphisms (SNPs). We constructed SNP sets capturing shared biological pathways. Using multivariable Cox regression, we developed and internally validated composite and outcome-specific models for reproductive complications (pelvic inflammatory disease (PID), ectopic pregnancy and tubal factor infertility) stratified by chlamydia status. Model performance was assessed. Point-based risk scores were derived from final models, estimating 15-year risks. Thresholds assessed the proportion classified as high risk and the proportion of outcomes captured. RESULTS:Among the 5704 participants (35 523 and 66 511 person-years in chlamydia-positive and chlamydia-negative groups), 7.1% and 5.4% experienced reproductive complications, respectively. Across outcomes, predictors included behavioural, sociodemographic and immune-related genetic factors, with most identified SNPs known to be involved in immune pathways. Model discrimination was modest (area under the curve ~0.65). Using a ≥15% predicted risk threshold, 54% of chlamydia-positive individuals were classified as high risk of reproductive complications, capturing 75% of composite outcomes (positive predictive value (PPV) 9.7%). For PID, 27% were classified as high risk, capturing 39% of cases (PPV 6.9%), and for ectopic pregnancy, 1.7% were classified as high risk, capturing 10% of cases (PPV 11.8%). CONCLUSIONS:Prediction models integrating behavioural, sociodemographic and host genetic factors showed modest performance, with better classification for chlamydia-positive individuals and PID than for ectopic pregnancy. Individual-level risk stratification is unlikely to be clinically useful, supporting population-level or group-level targeting of prevention and care.
OBJECTIVES:Women of black descent in England experience a disproportionate burden of HIV but remain under-represented among users of HIV pre-exposure prophylaxis (PrEP). Evidence on PrEP awareness, knowledge and acceptability in this population is limited. This study assessed these factors among women attending National Health Service (NHS) Sexual Health clinics. METHODS:An exploratory cross-sectional survey was conducted at two level 3 NHS Sexual Health services in England between August 2023 and May 2024. Women aged ≥16 years who self-identified as being of black ethnicity or descent were recruited using consecutive convenience sampling. Participants received a standardised educational leaflet on HIV and PrEP, as a brief educational intervention, before completing a structured questionnaire assessing demographics, PrEP awareness and knowledge prior to education, HIV testing awareness, sexual health behaviours, perceived HIV risk and willingness to consider PrEP following education. Data were analysed descriptively. RESULTS:Sixty-four women participated. Before receiving PrEP information, 73.0% had not previously heard of PrEP, 71.4% did not know its purpose and 80.0% were unaware of how it is taken. Following educational exposure, 72.3% reported that they would consider using PrEP ('yes' or 'maybe').Inconsistent or no condom use was reported by 78.0% of participants, and 17.3% expressed concerns about partner concurrency. One-fifth (20.0%) were unaware of where HIV testing services could be accessed. Concerns about medication side effects, daily pill-taking and potential drug interactions were the most reported barriers to PrEP use. CONCLUSIONS:Women of black descent attending NHS Sexual Health clinics demonstrated low awareness and knowledge of PrEP, representing a significant barrier to engagement. However, PrEP acceptability was generally favourable following brief educational exposure. Further community-based research is needed to explore wider determinants of PrEP uptake and support equitable HIV prevention strategies.
BACKGROUND:People using pre-exposure prophylaxis (PrEP) for HIV are at high risk of acquiring sexually transmitted infections (STIs). We aimed to assess the impact of doxycycline post-exposure prophylaxis (doxy-PEP) on the incidences of STIs among PrEP users in the real-world setting. METHODS:From February 2022 to November 2025, participants aged ≥18 years receiving HIV PrEP were prospectively enrolled. STI testing at baseline and follow-up included syphilis serology and multiplex real-time PCR assays for Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium. Beginning in November 2023, doxy-PEP was provided during follow-up visits. STI incidence rates before and after the first documented doxy-PEP prescription were compared within the same participants. RESULTS:A Total of 397 participants were included, with a median age of 32 Years. All participants were cisgender men; 90.9% Were men who have sex with men, 7.3% Were bisexual cisgender men And 1.8% Were heterosexual cisgender men. At enrolMent, 3.3% (13/397) Had reactive syphilis serology, 15.5% (60/386) Tested positive for C. trachomatis, 13.7% (53/386) For N. gonorrhoeae And 5.2% (20/386) For M. genitalium. Compared with the pre-doxy-pep period, the post-doxy-pep period had significantly lower incidence rates of syphilis (2.0 Vs 6.4 Per 100 person-years; incidence rate ratio (Irr) 0.3, 95% CI 0.1 To 0.8) And Chlamydia (8.8 Vs 31.9 Per 100 person-years; irr 0.3, 95% CI 0.2 To 0.4). No significant difference was observed for N. Gonorrhoeae Infection (21.0 Vs 26.3 Per 100 person-years; irr 0.8, 95% CI 0.6 To 1.1) Or M. genitalium Infection (12.7 Vs 9.5 Per 100 person-years; irr 1.3, 95% CI 0.8 To 2.3). CONCLUSION:In this real-world HIV PrEP cohort, doxy-PEP was associated with significant reductions of syphilis and chlamydia.
OBJECTIVES:Chlamydia trachomatis and Neisseria gonorrhoeae are established causes of pelvic inflammatory disease (PID), but up to 70% of cases with PID have neither infection detected. We determined the prevalence of and trends in Mycoplasma genitalium and bacterial vaginosis (BV) detection among women with non-C. trachomatis/N. gonorrhoeae PID to inform testing and treatment strategies. METHODS:We conducted a retrospective case series to determine the number of cases with PID (defined by presence of a minimum of uterine, adnexal or cervical motion tenderness) with C. trachomatis, N. gonorrhoeae, M. genitalium and/or BV detected between 2014 and 2024 at Melbourne Sexual Health Centre (MSHC). We examined trends in testing and detection of each infection over time and, among cases with PID tested for all four infections, determined the proportion with each infection detected. RESULTS:There were 3000 cases with PID during the study period. Over the 11 years, the proportion of cases with PID tested for C. trachomatis and N. gonorrhoeae was stable and high, with rises in their detection (range=7%-19%, Ptrend=0.021; 1%-7%, Ptrend<0.001, respectively). Both the proportion tested for BV and M. genitalium (89%-95%, 91%-97%, Ptrend=<0.001, respectively) and with BV and M. genitalium detected (22%-37%, 6%-14%, Ptrend<0.001, respectively) significantly increased over time. Among 2557 (85%) cases tested for all four infections, 927 (36%) had 1 and 256 (10%) had >1 infection detected. Among 2149 (84%) non-C. trachomatis/N. gonorrhoeae cases with PID, 26% had BV, 6% had M. genitalium and 4% were co-infected with BV and M. genitalium; >50% had none of the infections detected. CONCLUSIONS:In this retrospective study of cases with PID attending MSHC between 2014 and 2024, C. trachomatis and/or N. gonorrhoeae were detected in <20% of all cases. Among non-C. trachomatis/N. gonorrhoeae cases with PID, BV and M. genitalium detection was common and increased over time. Prospective case-control and sequencing studies are needed to determine the aetiologic contribution of BV, M. genitalium and other additional candidate organisms to PID.
OBJECTIVE:Human papillomavirus (HPV) infection is a major cause of cervical, anal and oropharyngeal cancers. Although Korea has implemented a national HPV vaccination programme since 2016, nationwide evidence on incidence trends and medical costs of HPV-related diseases remains limited. METHODS:This retrospective population-based study analysed Korean National Health Insurance Service claims data. Age-standardised incidence (ASI) rates of cervical intraepithelial neoplasia (CIN1 and CIN2/3), genital warts (GWs), and cervical, oropharyngeal and anal cancers from 2015 to 2022 were calculated using the 2022 Korean population as the standard. Trends in ASI were analysed using Joinpoint regression with a piecewise log-linear (Poisson) model. For diseases with and without statistically significant Joinpoints, trends were reported using pre-identified and post-identified segment-specific annual percentage changes (APCs) and the average annual percentage change (AAPC), respectively. Trends in total medical costs from 2015 to 2021 were evaluated using linear regression. RESULTS:ASI trends differed by sex and disease type. Cervical cancer incidence among females declined significantly during 2015-2022 (AAPC; -4.2%, p<0.001). Joinpoint regression identified significant inflection points in 2019 for both female and male GWs. Female GW incidence increased during 2015-2019 (APC; 3.7%, p=0.010) and then decreased significantly during 2019-2022 (APC; -14.0%, p<0.001). Male GW incidence increased significantly during 2015-2019 (APC; 11.3%, p<0.001) and then showed no statistically significant change during 2019-2022 (APC; 1.4%, p=0.290). CONCLUSIONS:These descriptive findings provide population-level evidence on HPV-associated disease burden in Korea but cannot establish causal attribution to vaccination, screening or other preventive interventions, necessitating continued surveillance with individual-level data linkage.
OBJECTIVES:The last decade has seen a rapid increase in online postal self-sampling (OPSS) for sexually transmitted infections (STIs) in the UK. Evaluating OPSS is important to understand its uptake and use by different populations. METHODS:We analysed pseudonymised routine data from online sexual health providers in three case study areas (CSAs) in England, conducting descriptive analysis of the OPSS testing cascade for service users aged 16+ years who submitted an online kit order (1 January 2022 to 30 November 2022). We used logistic regression to determine crude and adjusted associations by CSA between service user characteristics and progression along the cascade. RESULTS:Of 610 876 orders submitted and kits dispatched, 51.5-78.4% of STI kits across CSAs were returned. 98.5% (n=459 304/466 392) of returned STI kits contained 1+ processable swab/urine sample. Chlamydia test positivity as a proportion of kit orders ranged from 3.7% (CSA2) to 5.7% (CSA3), with gonorrhoea test positivity ranging from 1.29% (CSA1) to 1.63% (CSA2).Return of blood samples varied from 36.3% to 65.3% and return of processable blood samples varied from 22.8% to 57.9% of orders submitted. Older people (45+ years) were more likely than younger people (16-19 years) to return a processable blood sample (CSA1-adjusted OR (aOR)=1.85, CSA2-aOR=1.48, CSA3-aOR=1.43, all p<0.001) as were those in less deprived versus those in most deprived areas (CSA1-aOR=1.24; CSA2-aOR=1.10; CSA3-aOR=1.37, all p<0.001). Women, and men who did not report sex with men (respectively), were less likely than men who have sex with men to return a processable blood sample (CSA1-aOR=0.42, 0.39; CSA2-aOR=0.75, 0.87; CSA3-aOR=0.40, 0.54, all p<0.001), as were those reporting symptoms compared with those with no symptoms (CSA1=0.75; CSA2=0.81; CSA3=0.92, all p≤0.004). Positive predictive value for HIV screening via OPSS (excluding those known to be living with HIV) ranged from 4.4% (CSA2) to 7.1% (CSA3). CONCLUSION:We found consistent differences across CSAs in return of OPSS kits and processable blood samples by age, deprivation level, sex, sexual behaviour and symptom status. Interventions are needed to ensure that the testing pathways available meet the needs of all populations.
BACKGROUND:Unlike other key populations, gay, bisexual and other men who have sex with men (GBMSM) in Wales show a high uptake of HIV pre-exposure prophylaxis (PrEP), reflecting trends seen in countries where HIV incidence has historically been highest among GBMSM. Pragmatic solutions to evaluate inequity of uptake include the PrEP-to-need ratio (PnR), which was applied via the method and data triangulation approach to evaluate equity of PrEP uptake in Wales, 2023, using routine data. METHODS:PnR is redefined as the number of PrEP users divided by 'PrEP need'. Epidemiological PrEP need (represented by new HIV diagnoses) is compared with PrEP candidacy PrEP need (represented by the number of PrEP candidates among service users). PrEP candidates were retrospectively identified from the sexual health clinic (SHC) and online STI self-sampling request (Test and Post (T&P)) service users. PnRs were calculated across sociodemographic groups in Wales, 2023, and inequity ratios (magnitude of difference between two PnRs) were compared across methods. RESULTS:In 2023, 2191 people were prescribed PrEP and 76 people received a 'first new HIV diagnosis'. Of 62 711 SHC users and 71 872 T&P users, 7% and 14%-28% were identified as PrEP candidates, respectively. Relative to PrEP need, there were 2-58 times more men than women and 2-35 times more people of White than Black ethnicity prescribed PrEP (ranges reflect variation across triangulated PrEP need denominators). Smaller inequities in uptake were identified, favouring people aged 55+ and those in urban and less deprived settings. SHC data generate smaller PrEP-candidacy rates than T&P, most notably for women and people of Black ethnicity, for whom estimates differ by a magnitude of up to 72 and 10, respectively. CONCLUSIONS:This study identifies inequities in PrEP uptake across gender, ethnicity, age group, rural/urban classification and deprivation. Disparate estimates of equity gaps, most notably across gender and ethnicity, emphasise the limitations of routine data to evaluate equity of uptake. Data and method triangulation strengthen characterisation of PrEP-uptake inequities in low-incidence settings.
Background Sexually transmitted infections (STIs) have continued to rise in the USA, and doxycycline postexposure prophylaxis (doxyPEP) has shown prevention efficacy for bacterial STIs. We sought to evaluate doxyPEP interest, use and its associated factors among a national sample of eligible users. Methods Using national advertisements on a social networking application for men who have sex with men (MSM), we recruited participants to complete an anonymous cross-sectional online survey from 1 March to 30 April 2023. Analyses of doxyPEP user characteristics and factors associated with use were restricted to respondents assigned male sex at birth, residing in the USA and eligible for doxyPEP. Eligibility was defined as self-report of a bacterial STI in the past year following the US Centers for Disease Control and Prevention guidelines. A multivariate logistic regression model was used to evaluate the factors associated with doxyPEP use. Results Of 1428 respondents, only 9% reported ever using doxyPEP and 2.5% reported current use. Most respondents (88.3%) not currently on doxyPEP were interested in using it. Among the 471 eligible respondents included in the analysis, the median age was 37 years; the majority (93.6%) identified as cisgender MSM, 2.5% as transgender and 3.8% as non-binary. Most respondents were from the Southern United States (29.5%) and Western United States (37.6%). Among the eligible participants, 17.0% ever used doxyPEP. The majority received doxyPEP from their healthcare provider or STI clinic. Self-identifying as black race (adjusted OR (aOR) 3.08, 95% CI 1.31 to 7.16), reporting a higher number of sex partners (aOR 1.02, 95% CI 1.01 to 1.03), current pre-exposure prophylaxis use (aOR 3.61, 95% CI 1.55 to 9.74) and living with HIV (aOR 3.08, 95% CI 1.20 to 8.83) were associated with doxyPEP use in a multivariable model. Conclusion A national online survey among cisgender MSM, transgender and non-binary persons showed high interest but low use of doxyPEP, which was expected as there were no national guidelines in place at the time. These findings provide baseline estimates to inform future monitoring of doxyPEP uptake.
OBJECTIVES:In remote Australian First Nations communities, the burden of curable sexually transmitted infections (STIs) is highest for young women and men aged 16-29 years and for women is associated with two-fold higher rates of hospitalisations for pelvic inflammatory disease (PID) than for non-First Nations women. Following a randomised trial, decentralised community-led molecular point-of-care (POC) testing for STIs has operated in remote primary care across Australia for more than 7 years, improving uptake and timeliness of treatment for chlamydia, gonorrhoea and trichomonas infections. However, cost-effectiveness remains unknown. METHODS:A decision analytic model was devised to compare costs and outcomes associated with a POC testing programme for chlamydia, gonorrhoea and trichomonas infections in women and men aged 16-29 years seeking care, compared with standard care (laboratory-based testing). The analysis used a government payer perspective and 10-year time horizon. The primary outcome was the cost ($A) per quality-adjusted life year (QALY) gained. Sensitivity analyses examined uncertainty around the results. RESULTS:Based on a combined testing positivity rate of 36% and 29% for chlamydia, gonorrhoea and trichomonas for women and men, respectively, the POC testing programme, compared with laboratory testing, produced an estimated incremental cost per QALY ratio (ICER) of $A19 714 (95% CIs $A19 608 to $A19 821) over 10 years. Among those with an STI, the POC testing programme was predicted to reduce diagnosed PID by 30% and preterm/low birth weight babies by 17%. Sensitivity analyses indicated that the ICER was most sensitive to the probability of infection and receiving treatment within 2 days, based on a willingness-to-pay threshold of $A50 000. CONCLUSION:This health economic evaluation indicates that a scaled molecular POC testing programme for the management of STIs in remote primary care settings is cost-effective compared with standard care. Sustained POC testing in this setting is likely to improve reproductive health outcomes.
OBJECTIVES:National prevalence estimates of chlamydia and gonorrhoea are essential to inform public health strategies and support evidence-based policy development. The aim was to generate national prevalence chlamydia and gonorrhoea estimates in 2022/2023, identify associated risk factors and compare prevalence over time. METHODS:Five years after the first survey in 2016/2017, a second national cross-sectional probability sample survey about sexual health among men and women aged 16-34 years in the Netherlands was conducted between October 2022 and March 2023. Sexually active survey participants were invited to participate in the prevalence study and received a home-based sampling kit. Returned samples were tested for chlamydia and gonorrhoea in a laboratory (ie, nucleic acid amplification test). Weighting techniques were used to correct for selective non-response. Multivariable logistic regression analyses were performed to identify risk factors of infection. RESULTS:Of 6277 survey participants invited for the prevalence study, 1142 (18.2%) returned a specimen. The weighted overall chlamydia prevalence was 3.5% (95% CI 2.3% to 5.4%), and prevalence was higher in younger age groups (<25 vs ≥25 years). Due to low numbers in other groups, risk factor analysis was only possible among women aged 18-24 years, where risk factors for chlamydia included being <20 years, vocational education, no steady relationship and condomless sex. As in 2016/2017, no gonorrhoea cases were detected in 2022/2023. Chlamydia prevalence and associated risk factors did not change, except for higher prevalence among university-educated individuals in 2022/2023. DISCUSSION:Chlamydia prevalence among young sexually active men and women in the Netherlands remained stable between 2016/2017 and 2022/2023, with higher prevalence observed in younger age groups in both studies. Given recent changes in chlamydia testing guidelines in the Netherlands towards more restrictive testing of asymptomatic individuals, probability sample surveys with laboratory-confirmed STI testing are crucial for monitoring prevalence trends and evaluating public health policy.
OBJECTIVES:We aimed to characterise the genomic features, resistance determinants, plasmid content and phylogenetic relatedness of an extensively drug-resistant (XDR) Shigella sonnei isolate carrying bla CTX-M-15 identified in northern Spain. METHODS:A 31-year-old man who has sex with men (MSM) living with HIV on antiretroviral therapy with a prior history of treated syphilis presented with 1 week of bloody diarrhoea and abdominal pain. He reported multiple recent sexual partners and use of mobile dating applications and had no symptoms suggestive of urethritis or proctitis. Whole-genome sequencing was conducted and phylogenetic relatedness to international bla CTX-M-15 S. sonnei strains were assessed using single nucleotide polymorphism (SNP) based analysis. RESULTS:As symptoms persisted, the patient re-attended the emergency department and was discharged after Infectious Diseases consultation while awaiting susceptibility results. Whole-genome sequencing assigned it to ST152 and exhibited resistance to third-generation cephalosporins, aminoglycosides, ciprofloxacin, trimethoprim-sulfamethoxazole and azithromycin while retaining susceptibility to amoxicillin-clavulanic acid, nitrofurantoin and fosfomycin. Oral fosfomycin 500 mg was subsequently prescribed in primary care. A follow-up stool culture 1 month later was negative. Phylogenetic analysis demonstrated that this isolate was genetically distinct from clusters reported in England and Los Angeles and only moderately related to Spanish strains from Bilbao, suggesting an independent acquisition event. CONCLUSIONS:We describe the second report in Spain of an XDR S. sonnei harbouring bla CTX-M-15 sexually transmitted in an MSM. The coexistence of multiple resistance genes on potentially conjugative plasmids highlights the capacity of this pathogen as vehicles for resistance gene dissemination, which underscores the public health threat posed by sexually transmitted XDR S. sonnei.
Background HIV pre-exposure prophylaxis (PrEP) programmes are associated with intensified sexually transmitted infection (STI) screening and increased incidence of bacterial STIs, resulting in repeated antibiotic exposure. The ecological impact of STI-driven antimicrobial use on resistance in commensal bacteria remains insufficiently characterised, particularly in populations with high antimicrobial exposure such as men who have sex with men (MSM). Objective To evaluate differences in nasal Staphylococcus aureus antimicrobial resistance between MSM receiving PrEP and HIV-negative MSM not on PrEP and to explore behavioural and antibiotic exposure factors associated with resistance. Methods In this exploratory cross-sectional study, 153 HIV-negative MSM attending an STI clinic in Italy were enrolled (80 PrEP users; 73 controls). Participants underwent nasal swabbing for culture-based isolation and antimicrobial susceptibility testing of S. aureus . Antibiotic exposure, behavioural variables and STI history were collected via structured questionnaire. Results PrEP users reported more sexual partners in the last 6 months (p=0.0009) and higher antibiotic use in the preceding year (p=0.004). Doxycycline postexposure prophylaxis (Doxy-PEP) use was more frequent among PrEP users (16% vs 7%; p=0.08). The cumulative 2-year STI burden was higher in the PrEP group (p<0.0001), driven by Neisseria gonorrhoeae infections. S. aureus colonisation prevalence did not differ significantly between groups (p=0.17). However, erythromycin (p=0.0008), clindamycin (p=0.004) and tetracycline resistance (p=0.03) were more frequent among PrEP users. Tetracycline exposure was independently associated with tetracycline resistance (p=0.03), whereas PrEP status was not. Conclusions Among MSM, higher antimicrobial resistance in nasal S. aureus may be associated with antibiotic exposure rather than PrEP use per se. These exploratory findings should be interpreted with caution given the limited sample size and lack of detailed exposure quantification but support the need to integrate antimicrobial stewardship into PrEP and Doxy-PEP implementation frameworks. Longitudinal studies are needed to better disentangle the roles of antimicrobial exposure and transmission dynamics.
OBJECTIVE:In remote Australia, where there is a substantial burden of sexually transmitted infections (STIs) among First Nations peoples, testing and timely treatment are key to reducing prevalence. We evaluated the impact of introducing molecular point-of-care (POC) testing for chlamydia/gonorrhoea and later trichomonas on STI testing (including syphilis) and positive tests. METHODS:We conducted a retrospective interrupted time-series analysis of routinely collected data from First Nations peoples aged 15-54 years attending 20 remote/regional clinics participating in the Test, Treat and GO programme (2016-2019). We used segmented regression models to estimate the immediate level change (first month of POC) and after-period trends in monthly tests, positive tests and proportion of concurrent syphilis tests to assess sustainability. Before and after comparisons were estimated using linear regression models. RESULTS:There were 17 437 chlamydia/gonorrhoea and 14 173 trichomonas tests performed, mostly among women (69% and 64%) and individuals aged 15-34 years (72% and 68%). Following the introduction of molecular POC testing, there were immediate level increases in monthly tests: chlamydia/gonorrhoea by 26% (+154, p<0.001) and trichomonas by 21% (+116, p=0.004) and level increases of positive tests: gonorrhoea by 30% (+13, p=0.017) and trichomonas by 29% (+14, p=0.034); chlamydia was unchanged. The proportion of chlamydia/gonorrhoea tests with concurrent syphilis tests remained unchanged (-1.7%; -0.9%; p=0.531), while the proportion increased among positive chlamydia/gonorrhoea tests by 25% (+13%; p=0.013). Increased levels of testing were sustained for gonorrhoea/chlamydia (+2.7, p=0.118) and trichomonas (-3.5, p=0.400) and syphilis among those with positive chlamydia/gonorrhoea tests (-0.2%, p=0.593). CONCLUSION:Molecular POC testing led to immediate and sustained increases in STI testing and an immediate increase in positive tests in remote primary care. The use of POC testing is likely to result in earlier diagnosis and treatment and reduced onward transmission and sequelae, supporting a broader integration of POC testing in high-burden settings.
