Prevalence and risk factors for HPV seropositivity and anogenital DNA positivity among men who have sex with men: a repeated cross-sectional study.

OBJECTIVES: This study aimed to assess associations of potential risk factors with human papillomavirus (HPV) seropositivity among men who have sex with men (MSM) and compare these to risk factors for anal and penile (HPV) deoxyribonucleic acid (DNA)-positivity in the same study population. METHODS: Seropositivity and anal and penile HPV DNA-positivity were determined for seven high-risk HPV genotypes for MSM aged 16-24 years participating in Papillomavirus Surveillance among STI clinic Youngsters in the Netherlands (PASSYON) 2009-2021. Logistic regression models were conducted to assess risk factors for seropositivity, anal and penile HPV DNA-positivity. RESULTS: Overall, 1019 MSM were included. HPV-16 and -18 were most common for serology, and anal and penile HPV DNA-positivity. Although no clear similarities were observed for most risk factors for HPV seropositivity and anal or penile DNA positivity, receptive anal intercourse (RAI) was the strongest associated risk factor for both seropositivity ('RAI ever' adjusted odds ratio [aOR] 3.50, 95% confidence interval [CI] 1.56-7.88; 'RAI previous 6 months' aOR 2.17, 95% CI 1.44-3.26) and anal DNA-positivity ('RAI previous 6 months' aOR 1.67, 95% CI 1.09-2.56). CONCLUSIONS: Our study is suggestive of site-specific immune response after HPV infection; RAI might lead to anal HPV infections and consequently to seroconversion. Finally, as the two genotypes that are most oncogenic and preventable by all HPV vaccines were most common, our results underline the importance of gender-neutral vaccination.

Diagnostic accuracy of HPV16 early antigen serology for HPV-driven oropharyngeal cancer is independent of age and sex.

A growing proportion of head and neck cancer (HNC), especially oropharyngeal cancer (OPC), is caused by human papillomavirus (HPV). There are several markers for HPV-driven HNC, one being HPV early antigen serology. We aimed to investigate the diagnostic accuracy of HPV serology and its performance across patient characteristics. Data from the VOYAGER consortium was used, which comprises five studies on HNC from North America and Europe. Diagnostic accuracy, that is, sensitivity, specificity, Cohen's kappa and correctly classified proportions of HPV16 E6 serology, was assessed for OPC and other HNC using p16INK4a immunohistochemistry (p16), HPV in situ hybridization (ISH) and HPV PCR as reference methods. Stratified analyses were performed for variables including age, sex, smoking and alcohol use, to test the robustness of diagnostic accuracy. A risk-factor analysis based on serology was conducted, comparing HPV-driven to non-HPV-driven OPC. Overall, HPV serology had a sensitivity of 86.8% (95% CI 85.1-88.3) and specificity of 91.2% (95% CI 88.6-93.4) for HPV-driven OPC using p16 as a reference method. In stratified analyses, diagnostic accuracy remained consistent across sex and different age groups. Sensitivity was lower for heavy smokers (77.7%), OPC without lymph node involvement (74.4%) and the ARCAGE study (66.7%), while specificity decreased for cases with <10 pack-years (72.1%). The risk-factor model included study, year of diagnosis, age, sex, BMI, alcohol use, pack-years, TNM-T and TNM-N stage. HPV serology is a robust biomarker for HPV-driven OPC, and its diagnostic accuracy is independent of age and sex. Future research is suggested on the influence of smoking on HPV antibody levels.

Global Type-Specific Genital Human Papillomavirus Prevalence in Men, by Sexual Orientation: A Systematic Review and Meta-Analysis.

BACKGROUND: Knowledge on genital type-specific human papillomavirus (HPV) prevalence among men is important for prevention of HPV-related cancers and other diseases. Men who have sex with men (MSM) have higher anal prevalence than men who have sex with women only (MSW) but for genital HPV this is unclear. We performed a systematic review and meta-analysis of type-specific genital HPV prevalence among men, by sexual orientation. METHODS: MEDLINE and Embase were used for searching publications reporting on male genital HPV prevalence with data from November 2011 onwards. A random-effects meta-analysis was conducted estimating pooled type-specific and grouped external genital and urethral HPV prevalence. Subgroup analyses were conducted for sexual orientation. RESULTS: Twenty-nine studies were eligible. Of those, 13 studies reported prevalence among MSM, 5 among MSW, and 13 studies did not stratify by sexual orientation. The most common genotypes were HPV-6 and HPV-16 for both anatomical locations, although heterogeneity was high. HPV prevalence was similar among studies reporting on MSW, MSM, and men with unknown sexual orientation. CONCLUSIONS: Genital HPV is common among men, with HPV-6 and HPV-16 being the most common genotypes. Type-specific HPV genital prevalence appears to be similar among MSM and MSW, which contrasts with earlier findings on anal HPV.

Determinants of frequent and infrequent STI testing and STI diagnosis related to test frequency among men who have sex with men in the eastern part of the Netherlands: a 6-year retrospective study.

OBJECTIVE: Men who have sex with men (MSM) remain vulnerable to sexually transmitted infections (STIs) and are advised to be tested at least twice a year. The aim of this study was to assess the determinants of test frequency and their associations with an STI diagnosis. DESIGN: A 6-year retrospective study. SETTING: 5 STI clinics in the eastern part of the Netherlands. PARTICIPANTS: MSM whose mean test interval was 6 months or more were grouped as 'infrequently tested' (n=953), and those with a mean test interval less than 6 months were grouped as 'frequently tested' (n=658). PRIMARY AND SECONDARY OUTCOME MEASURES: Test frequency and STI diagnosis and determinants. RESULTS: MSM who were ever diagnosed with an STI (OR=1.4, 95% CI 1.1 to 1.7), MSM who had never had STI symptoms (OR=0.8, 95% CI 0.6 to 1.0), and MSM who had ever had sex with both men and women (OR=0.6, 95% CI 0.5 to 0.8) were more often frequently tested. Moreover, in both groups, MSM who had ever been notified by a partner (OR=2.2, 95% CI 1.7 to 2.9 infrequently tested; OR=2.0, 95% CI 1.4 to 2.9 frequently tested), MSM who had ever had STI symptoms (OR=1.6, 95% CI 1.2 to 2.1 infrequently tested; OR=1.8, 95% CI 1.3 to 2.6 frequently tested) and MSM who were ever diagnosed with HIV (OR=2.7, 95% CI 1.5 to 4.6 infrequently tested; OR=6.8, 95% CI 2.6 to 17.5 frequently tested) were more likely to be diagnosed with an STI. CONCLUSIONS: Among MSM visiting STI clinics, those who were ever diagnosed with HIV were more often diagnosed with an STI, but did not visit STI clinics more frequently than HIV-negative MSM. This highlights the necessity of encouraging MSM who are diagnosed with HIV to have STI tests more frequently.

Frequency and determinants of consistent STI/HIV testing among men who have sex with men testing at STI outpatient clinics in the Netherlands: a longitudinal study.

OBJECTIVES: Men who have sex with men (MSM) are at highest risk for STIs and HIV infections in the Netherlands. However, official guidelines on STI testing among MSM are lacking. They are advised to test for STIs at least every six months, but their testing behaviour is not well known. This study aimed to get insight into the proportion and determinants of consistent 6-monthly STI testing among MSM testing at STI outpatient clinics in the Netherlands. METHODS: This study included longitudinal surveillance data of STI consultations among MSM from all 26 STI outpatient clinics in the Netherlands between 1 June 2014 and 31 December 2015. Multinomial logistic regression analysis was used to identify determinants of consistent 6-monthly testing compared with single testing and inconsistent testing. Determinants of time between consultations among men with multiple consultations were analysed using a Cox Prentice-Williams-Peterson gap-time model. RESULTS: A total of 34 605 STI consultations of 18 634 MSM were included. 8966 (48.1%) men had more than one consultation, and 3516 (18.9%) men tested consistently 6-monthly. Indicators of high sexual risk behaviour, including having a history of STI, being HIV positive and having more than 10 sex partners, were positively associated with both being a consistent tester and returning to the STI clinic sooner. Men who were notified by a partner or who reported STI symptoms were also more likely to return to the STI clinic sooner, but were less likely to be consistent testers, identifying a group of event-driven testers. CONCLUSIONS: The proportion of consistent 6-monthly testers among MSM visiting Dutch STI outpatient clinics was low. Testing behaviour was associated with sexual risk behaviour, but exact motives to test consistently remain unclear. Evidence-based testing guidelines are needed to achieve optimal reductions in STI transmission in the future.

Repeated STI and HIV testing among HIV-negative men who have sex with men attending a large STI clinic in Amsterdam: a longitudinal study.

OBJECTIVE: In the Netherlands, men who have sex with men (MSM) are advised via informal guidelines to test for STI at least annually. We estimated the proportion of HIV-negative MSM testing repeatedly at 12-month or smaller intervals at a large STI clinic in the Netherlands. In addition, we explored whether repeated testing is related to risk behaviour. DESIGN AND METHODS: Longitudinal data of HIV-negative MSM visiting the Amsterdam STI clinic between 2009 and 2012 were analysed. To estimate the timing of repeated testing, Kaplan-Meier methods were used. Determinants for repeated testing (distinguishing testing at 12-month or smaller intervals and less than 12-monthly testing, with single testers as reference group) were identified using multivariate multinomial logistic regression analyses. RESULTS: In total, 19,479 consultations of 9174 HIV-negative MSM were identified. Of these MSM, 35% (95% CI 33% to 36%) were estimated to return to the STI clinic within 1 year following baseline consultation. Among 1767 men with at least two consultations and at least 2 years between baseline and last consultation, 43% tested repeatedly at 12-month or smaller intervals in those first 2 years. Repeated testers reported higher sexual risk behaviour (ie, only casual or both casual and steady sex partners, higher numbers of sex partners) at baseline compared with single testers. This effect tended to be slightly stronger for men testing repeatedly at 12-month or smaller intervals. CONCLUSIONS: The proportion of MSM testing for STI annually is low. MSM testing repeatedly had higher baseline levels of risk behaviour. Strategies to motivate MSM to test annually should be explored.

Direct and indirect effects of screening for Chlamydia trachomatis on the prevention of pelvic inflammatory disease: a mathematical modeling study.

BACKGROUND: Pelvic inflammatory disease (PID) results from the ascending spread of microorganisms, including Chlamydia trachomatis, to the upper genital tract. Screening could improve outcomes by identifying and treating chlamydial infections before they progress to PID (direct effect) or by reducing chlamydia transmission (indirect effect). METHODS: We developed a compartmental model that represents a hypothetical heterosexual population and explicitly incorporates progression from chlamydia to clinical PID. Chlamydia screening was introduced, with coverage increasing each year for 10 years. We estimated the separate contributions of the direct and indirect effects of screening on PID cases prevented per 100,000 women. We explored the influence of varying the time point at which clinical PID could occur and of increasing the risk of PID after repeated chlamydial infections. RESULTS: The probability of PID at baseline was 3.1% by age 25 years. After 5 years, the intervention scenario had prevented 187 PID cases per 100,000 women and after 10 years 956 PID cases per 100,000 women. At the start of screening, most PID cases were prevented by the direct effect. The indirect effect produced a small net increase in PID cases, which was outweighed by the effect of reduced chlamydia transmission after 2.2 years. The later that progression to PID occurs, the greater the contribution of the direct effect. Increasing the risk of PID with repeated chlamydial infection increases the number of PID cases prevented by screening. CONCLUSIONS: This study shows the separate roles of direct and indirect PID prevention and potential harms, which cannot be demonstrated in observational studies.

Individual and population level effects of partner notification for Chlamydia trachomatis.

Partner notification (PN or contact tracing) is an important aspect of treating bacterial sexually transmitted infections (STIs), such as Chlamydia trachomatis. It facilitates the identification of new infected cases that can be treated through individual case management. PN also acts indirectly by limiting onward transmission in the general population. However, the impact of PN, both at the level of individuals and the population, remains unclear. Since it is difficult to study the effects of PN empirically, mathematical and computational models are useful tools for investigating its potential as a public health intervention. To this end, we developed an individual-based modeling framework called Rstisim. It allows the implementation of different models of STI transmission with various levels of complexity and the reconstruction of the complete dynamic sexual partnership network over any time period. A key feature of this framework is that we can trace an individual's partnership history in detail and investigate the outcome of different PN strategies for C. trachomatis. For individual case management, the results suggest that notifying three or more partners from the preceding 18 months yields substantial numbers of new cases. In contrast, the successful treatment of current partners is most important for preventing re-infection of index cases and reducing further transmission of C. trachomatis at the population level. The findings of this study demonstrate the difference between individual and population level outcomes of public health interventions for STIs.

Uptake of regular chlamydia testing by U.S. women: a longitudinal study.

BACKGROUND: Routine chlamydia screening is a recommended preventive intervention for sexually active women aged

Transmission dynamics of Chlamydia trachomatis affect the impact of screening programmes.

To assess the impact of screening programmes in reducing the prevalence of Chlamydia trachomatis, mathematical and computational models are used as a guideline for decision support. Unfortunately, large uncertainties exist about the parameters that determine the transmission dynamics of C. trachomatis. Here, we use a SEIRS (susceptible-exposed-infected-recovered-susceptible) model to critically analyze the turnover of C. trachomatis in a population and the impact of a screening programme. We perform a sensitivity analysis on the most important steps during an infection with C. trachomatis. Varying the fraction of the infections becoming symptomatic as well as the duration of the symptomatic period within the range of previously used parameter estimates has little effect on the transmission dynamics. However, uncertainties in the duration of temporary immunity and the asymptomatic period can result in large differences in the predicted impact of a screening programme. We therefore analyze previously published data on the persistence of asymptomatic C. trachomatis infection in women and estimate the mean duration of the asymptomatic period to be longer than anticipated so far, namely 433 days (95% CI: 420-447 days). Our study shows that a longer duration of the asymptomatic period results in a more pronounced impact of a screening programme. However, due to the slower turnover of the infection, a substantial reduction in prevalence can only be achieved after screening for several years or decades.