672 research outputs found
Oral human papillomavirus (HPV) infection in men who have sex with men: prevalence and lack of anogenital concordance.
To estimate the prevalence of oral detectable human papillomavirus (HPV) DNA in HIV-negative men who have sex with men (MSM) attending a sexual health clinic in London and concordance with anogenital HPV infection. Such data are important to improve our understanding of the epidemiology of oral HPV and the potential use of vaccines to prevent oropharyngeal cancers
Testing for sexually transmitted infections in a population-based sexual health survey: development of an acceptable ethical approach
Population-based research is enhanced by biological
measures, but biological sampling raises complex ethical
issues. The third British National Survey of Sexual
Attitudes and Lifestyles (Natsal-3) will estimate the
population prevalence of five sexually transmitted
infections (STIs) (Chlamydia trachomatis, Neisseria
gonorrhoeae, human papillomavirus (HPV), HIV and
Mycoplasma genitalium) in a probability sample aged
16e44 years. The present work describes the
development of an ethical approach to urine testing for
STIs, including the process of reaching consensus on
whether to return results. The following issues were
considered: (1) testing for some STIs that are treatable
and for which appropriate settings to obtain free testing
and advice are widely available (Natsal-3 provides all
respondents with STI and healthcare access
information), (2) limits on test accuracy and timeliness
imposed by survey conditions and sample type, (3)
testing for some STIs with unknown clinical and public
health implications, (4) how a uniform approach is easier
to explain and understand, (5) practical difficulties in
returning results and cost efficiency, such as enabling
wider STI testing by not returning results. The agreed
approach, to perform voluntary anonymous testing with
specific consent for five STIs without returning results,
was approved by stakeholders and a research ethics
committee. Overall, this was acceptable to respondents
in developmental piloting; 61% (68 of 111) of
respondents agreed to provide a sample. The
experiences reported here may inform the ethical
decision making of researchers, research ethics
committees and funders considering population-based
biological sampling
Human papillomavirus DNA in men who have sex with men: type-specific prevalence, risk factors and implications for vaccination strategies.
BACKGROUND: Human papillomavirus (HPV) vaccination of girls will have relatively little effect on HPV-related disease in men who have sex with men (MSM). We determined HPV prevalence and risk factors in MSM to inform the potential effectiveness of vaccinating MSM. METHODS: Cross-sectional study of 522 MSM aged 18-40 attending a London sexual health clinic who completed a computer-assisted self-interview. Urine and two swabs (anal and penile/scrotal/perianal) were collected and tested using an in-house Luminex-based HPV genotyping system. RESULTS: Prevalence of DNA of the vaccine-preventable HPV types in ano-genital specimens of men was 87/511 (17.0%), 166/511 (32.5%) and 232/511 (45.4%) for the bivalent (HPV16/18), quadrivalent (HPV6/11/16/18) and nonavalent (HPV6/11/16/18/31/33/45/52/58) vaccine types, respectively. A total of 25.1% had one of the quadrivalent types, and 7.4% had 2+ types. Median age at first anal sex was 19 (IQR 17-23) and at first clinic attendance was 24 (IQR 20-27). The increase in the odds of any HPV infection per year of age was 4.7% (95% CI 1.2-8.4). CONCLUSIONS: On the basis of the current infection status, most MSM, even among a high-risk population attending a sexual health clinic, are not currently infected with the vaccine-type HPV. A targeted vaccination strategy for MSM in the UK could have substantial benefits
Spatiotemporal Evolution of Runaway Electron Momentum Distributions in Tokamaks
Novel spatial, temporal, and energetically resolved measurements of bremsstrahlung hard-x-ray (HXR) emission from runaway electron (RE) populations in tokamaks reveal nonmonotonic RE distribution functions whose properties depend on the interplay of electric field acceleration with collisional and synchrotron damping. Measurements are consistent with theoretical predictions of momentum-space attractors that accumulate runaway electrons. RE distribution functions are measured to shift to a higher energy when the synchrotron force is reduced by decreasing the toroidal magnetic field strength. Increasing the collisional damping by increasing the electron density (at a fixed magnetic and electric field) reduces the energy of the nonmonotonic feature and reduces the HXR growth rate at all energies. Higher-energy HXR growth rates extrapolate to zero at the expected threshold electric field for RE sustainment, while low-energy REs are anomalously lost. The compilation of HXR emission from different sight lines into the plasma yields energy and pitch-angle-resolved RE distributions and demonstrates increasing pitch-angle and radial gradients with energy.United States. Department of Energy (DE-FC02-04ER54698)United States. Department of Energy (DE-FG02-07ER54917)United States. Department of Energy (DE-AC05-00OR22725)United States. Department of Energy (DE-FC02-99ER54512)United States. Department of Energy (DE-SC0016268
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Human papillomavirus (HPV) vaccination and oropharyngeal HPV in ethnically diverse, sexually active adolescents: community-based cross-sectional study.
OBJECTIVES: Oropharyngeal squamous cell carcinoma is the most common human papillomavirus (HPV)-associated cancer in the UK, but little is known about the prevalence of oropharyngeal HPV in sexually active teenagers. We investigated reported HPV vaccination coverage (in females) and prevalence of oropharyngeal HPV in sexually active students attending six technical colleges in London, UK. METHODS: In 2017, we obtained mouthwash samples and questionnaires from male and female students taking part in the 'Test n Treat' chlamydia screening trial. Samples were subjected to HPV genotyping. RESULTS: Of 232 participants approached, 202 (87%) provided a mouthwash sample and questionnaire. Participants' median age was 17 years and 47% were male. Most (73%) were from black and minority ethnic groups, 64% gave a history of oral sex, 52% reported having a new sexual partner in the past 6 months, 33% smoked cigarettes, 5.9% had concurrent genitourinary Chlamydia trachomatis infection and 1.5% Neisseria gonorrhoeae and 5.0% were gay or bisexual. Only 47% (50/107) of females reported being vaccinated against HPV 16/18, of whom 74% had received ≥2 injections. HPV genotyping showed three mouthwash samples (1.5%, 95% CI 0.3% to 4.3%) were positive for possible high-risk human papillomavirus (HR-HPV), one (0.5%, 0.0% to 2.7%) for low-risk HPV 6/11, but none (0.0%, 0.0% to 1.8%) for HR-HPV. Four samples (2.0%, 0.5% to 5.0%) were positive for HPV16 using a HPV16 type-specific quantitative PCR, but these were at a very low copy number and considered essentially negative. CONCLUSIONS: Despite the high prevalence of oral sex and genitourinary chlamydia and low prevalence of HPV vaccination, the prevalence of oropharyngeal HR-HPV in these adolescents was negligible
Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)
In the context of widespread opportunistic chlamydia screening among young adults, we aimed to quantify chlamydia testing and diagnosis among 16-24 year olds in Britain in relation to risk factors for prevalent chlamydia infection
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