Taking connected mobile-health diagnostics of infectious diseases to the field.

Mobile health, or 'mHealth', is the application of mobile devices, their components and related technologies to healthcare. It is already improving patients' access to treatment and advice. Now, in combination with internet-connected diagnostic devices, it offers novel ways to diagnose, track and control infectious diseases and to improve the efficiency of the health system. Here we examine the promise of these technologies and discuss the challenges in realizing their potential to increase patients' access to testing, aid in their treatment and improve the capability of public health authorities to monitor outbreaks, implement response strategies and assess the impact of interventions across the world.

Predictors of starting and stopping chemsex in men who have sex with men in England: findings from the AURAH2 prospective study.

BACKGROUND: Chemsex (the use of psychoactive drugs in sexual contexts) has been associated with HIV acquisition and other STIs, so there is benefit in identifying those most likely to start chemsex to offer risk reduction interventions such as pre-exposure prophylaxis (PrEP). To date, there have been no data from a longitudinal study analysing factors most associated with starting and stopping chemsex. METHODS: The prospective cohort study, Attitudes to and Understanding Risk of Acquisition of HIV over Time (AURAH2), collected 4 monthly and annual online questionnaire data from men who have sex with men (MSM) from 2015 to 2018. We investigate the association of sociodemographic factors, sexual behaviours and drug use with starting and stopping chemsex among 622 men who completed at least one follow-up questionnaire. Poisson models with generalised estimating equations were used to produce risk ratios (RRs) accounting for multiple starting or stopping episodes from the same individual. Multivariable analysis was adjusted for age group, ethnicity, sexual identity and university education. FINDINGS: In the multivariable analysis, the under 40 age group was significantly more likely to start chemsex by the next assessment (RR 1.79, 95% CI 1.12 to 2.86). Other factors which showed significant association with starting chemsex were unemployment (RR 2.10, 95% CI 1.02 to 4.35), smoking (RR 2.49, 95% CI 1.63 to 3.79), recent condomless sex (CLS), recent STI and postexposure prophylaxis (PEP) use in the past year (RR 2.10, 95% CI 1.33 to 3.30). Age over 40 (RR 0.71, 95% CI 0.51 to 0.99), CLS, and use of PEP (RR 0.64, 95% CI 0.47 to 0.86) and PrEP (RR 0.47, 95% CI 0.29 to 0.78) were associated with lower likelihood of stopping chemsex by the next assessment. INTERPRETATION: Knowledge of these results allows us to identify men most likely to start chemsex, thus providing an opportunity for sexual health services to intervene with a package of risk mitigation measures, especially PrEP use.

Going beyond 'regular and casual': development of a classification of sexual partner types to enhance partner notification for STIs.

OBJECTIVES: To develop a classification of sexual partner types for use in partner notification (PN) for STIs. METHODS: A four-step process: (1) an iterative synthesis of five sources of evidence: scoping review of social and health sciences literature on partner types; analysis of relationship types in dating apps; systematic review of PN intervention content; and review of PN guidelines; qualitative interviews with public, patients and health professionals to generate an initial comprehensive classification; (2) multidisciplinary clinical expert consultation to revise the classification; (3) piloting of the revised classification in sexual health clinics during a randomised controlled trial of PN; (4) application of the Theoretical Domains Framework (TDF) to identify index patients' willingness to engage in PN for each partner type. RESULTS: Five main partner types emerged from the evidence synthesis and consultation: 'established partner', 'new partner', 'occasional partner', 'one-off partner' and 'sex worker'. The types differed across several dimensions, including likely perceptions of sexual exclusivity, likelihood of sex reoccurring between index patient and sex partner. Sexual health professionals found the classification easy to operationalise. During the trial, they assigned all 3288 partners described by 2223 index patients to a category. The TDF analysis suggested that the partner types might be associated with different risks of STI reinfection, onward transmission and index patients' engagement with PN. CONCLUSIONS: We developed an evidence-informed, useable classification of five sexual partner types to underpin PN practice and other STI prevention interventions. Analysis of biomedical, psychological and social factors that distinguish different partner types shows how each could warrant a tailored PN approach. This classification could facilitate the use of partner-centred outcomes. Additional studies are needed to determine the utility of the classification to improve measurement of the impact of PN strategies and help focus resources.

Relative contribution of essential and non-essential activities to SARS-CoV-2 transmission following the lifting of public health restrictions in England and Wales.

PURPOSE: We aimed to understand which non-household activities increased infection odds and contributed greatest to SARS-CoV-2 infections following the lifting of public health restrictions in England and Wales. PROCEDURES: We undertook multivariable logistic regressions assessing the contribution to infections of activities reported by adult Virus Watch Community Cohort Study participants. We calculated adjusted weighted population attributable fractions (aPAF) estimating which activity contributed greatest to infections. FINDINGS: Among 11 413 participants (493 infections), infection was associated with: leaving home for work (aOR 1.35 (1.11-1.64), aPAF 17%), public transport (aOR 1.27 (1.04-1.57), aPAF 12%), shopping once (aOR 1.83 (1.36-2.45)) vs. more than three times a week, indoor leisure (aOR 1.24 (1.02-1.51), aPAF 10%) and indoor hospitality (aOR 1.21 (0.98-1.48), aPAF 7%). We found no association for outdoor hospitality (1.14 (0.94-1.39), aPAF 5%) or outdoor leisure (1.14 (0.82-1.59), aPAF 1%). CONCLUSION: Essential activities (work and public transport) carried the greatest risk and were the dominant contributors to infections. Non-essential indoor activities (hospitality and leisure) increased risk but contributed less. Outdoor activities carried no statistical risk and contributed to fewer infections. As countries aim to 'live with COVID', mitigating transmission in essential and indoor venues becomes increasingly relevant.

PrEP use and unmet PrEP-need among men who have sex with men in London prior to the implementation of a national PrEP programme, a cross-sectional study from June to August 2019.

BACKGROUND: Access to prevention options, including HIV pre-exposure prophylaxis (PrEP), remains a public health priority for gay, bisexual, and other men who have sex with men (MSM), especially in London. We describe PrEP use in a London community sample of MSM before the introduction of a national PrEP programme in October 2020. METHODS: From June-August 2019, MSM aged ≥ 18 recruited from London commercial venues were asked to self-complete a sexual health questionnaire and provide an oral fluid sample for anonymous HIV antibody testing. Descriptive analyses of demographic characteristics, service engagement and outcomes, as well as sexual risk and prevention behaviours were examined in the survey population and in those reporting current PrEP use. We performed sequential, multivariate analyses examining current PrEP use in MSM of self-perceived HIV-negative/unknown status with identified PrEP-need defined as the report of condomless anal sex (CAS) in the last three months, or the report of CAS (in the last year) with an HIV-positive/unknown status partner not known to be on HIV treatment, in reflection of UK PrEP guidelines. RESULTS: One thousand five hundred and thirty-fifth questionnaires were completed across 34 venues, where 1408 were analysed. One in five MSM of self-perceived HIV-negative/unknown status reported current PrEP use (19.7%, 242/1230). In men with PrEP-need, 68.2% (431/632) did not report current use. Current PrEP use was associated with age (aOR: 3.52, 95% CI: 1.76-7.02 in men aged 40-44 vs men aged 18-25) and education (aOR: 1.72, 95% CI: 1.01-2.92 in men with ≥ 2 years/still full-time vs no/ < 2 years of education since age 16). CONCLUSION: Among MSM in London, PrEP use is high but there is indication of unmet PrEP-need in men of younger age and lower levels of post-16 education. National programme monitoring and evaluation will require continued community monitoring to guide interventions ensuring equitable PrEP access and uptake in those who could most benefit from PrEP.

Opposing associations of depression with sexual behaviour: implications for epidemiological investigation among gay, bisexual and other men who have sex with men.

OBJECTIVE: The aim of this report is to investigate the nature of the relationship between depression and condomless sex (CLS) among gay, bisexual and other men who have sex with men (GBMSM). METHODS: Data are from the Antiretrovirals, Sexual Transmission Risk and Attitude (ASTRA) study of people living with HIV and attending one of eight HIV outpatient clinics in England (2011-2012) and the Attitudes to and Understanding of Risk of Acquisition of HIV (AURAH) study of HIV-negative/unknown status individuals attending one of 20 genitourinary medicine clinics in England (2013-2014). This analysis included GBMSM only. For each study, the prevalence of depressive symptoms (Patient Health Questionnaire-9 score ≥10) was presented according to three categories of sex in the past 3 months (considering anal/vaginal sex with men/women and anal sex with men in separate definitions): (1) no sex, (2) condom-protected sex only and (3) CLS. Multinomial logistic regression with 'condom-protected sex only' as the reference group was used to adjust for age and (for ASTRA participants) time since HIV diagnosis. RESULTS: There were opposing associations of depression with recent sexual behaviour: the prevalence of depression was higher among those who reported no sex and those who reported CLS, compared with those who reported condom-protected sex only. Among the 2170 HIV-positive GBMSM in ASTRA, considering anal/vaginal sex with men/women, the prevalence of depressive symptoms was 32%, 20% and 28%, respectively, among men reporting no sex (n=783), condom-protected sex only (n=551) and CLS (n=836) (global p<0.001). Among the 1477 HIV-negative GBMSM in AURAH, the prevalence of depressive symptoms was 12%, 8% and 13%, respectively, for no sex (n=137), condom-protected sex only (n=487) and CLS (n=853) (global p=0.017). Patterns were similar after adjustment and when only considering anal sex between men. CONCLUSIONS: Depression may be linked both to lack of sexual activity and to sexual risk taking. When investigating associations between depression and CLS, it is important to separate out individuals reporting condom-protected sex only from those reporting no sex.

A new transdisciplinary research model to investigate and improve the health of the public.

Transdisciplinary research approaches are being applied to today's complex health problems, including the climate crisis and widening inequalities. Diverse forms of disciplinary and experiential knowledge are required to understand these challenges and develop workable solutions. We aimed to create an updated model reflective of the strengths and challenges of current transdisciplinary health research that can be a guide for future studies. We searched Medline using terms related to transdisciplinary, health and research. We coded data deductively and inductively using thematic analysis to develop a preliminary model of transdisciplinary research. The model was tested and improved through: (i) a workshop with 27 participants at an international conference in Xiamen, China and (ii) online questionnaire feedback from included study authors. Our revised model recommends the following approach: (i) co-learning, an ongoing phase that recognizes the distributed nature of knowledge generation and learning across partners; (ii) (pre-)development, activities that occur before and during project initiation to establish a shared mission and ways of working; (iii) reflection and refinement to evaluate and improve processes and results, responding to emergent information and priorities as an ongoing phase; (iv) conceptualization to develop goals and the study approach by combining diverse knowledge; (v) investigation to conduct the research; (vi) implementation to use new knowledge to solve societal problems. The model includes linear and cyclical processes that may cycle back to project development. Our new model will support transdisciplinary research teams and their partners by detailing the necessary ingredients to conduct such research and achieve health impact.

Effect of weighting for sampling and non-response on estimates of STI prevalence in the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

OBJECTIVES: In addition to researcher-designed sampling biases, population-representative surveys for biomarker measurement of STIs often have substantial missingness due to non-contact, non-consent and other study-implementation issues. STI prevalence estimates may be biased if this missingness is related to STI risk. We investigated how accounting for sampling, interview non-response and non-provision of biological samples affects prevalence estimates in the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). METHODS: Natsal-3 was a multistage, clustered and stratified probability sample of 16-74 year-olds conducted between 2010 and 2012. Individuals were sampled from all private residential addresses in Britain; respondents aged 16-44 were further sampled to provide a urine specimen based on characteristics including self-reported sexual behaviours. We generated prevalence estimates and confidence intervals for six STIs in five stages: first without accounting for sampling or non-response, then applying inverse-probability weights cumulatively accounting for interview sampling, interview non-response, urine sampling and urine non-response. RESULTS: Interview non-completion occurred for 42.3% of interview-sampled individuals; urine non-completion occurred for 43.5% of urine-sampled individuals. Interview-sampled individuals, interview respondents, those selected for urine samples and those providing urine samples were each in turn slightly more at-risk for most STIs, leading to lower prevalence estimates after incorporating each set of weights. Researcher-controlled sampling had more impact than respondent-controlled response. CONCLUSIONS: Accounting for both sampling structures and willingness to interview or provide urine specimens can affect national STI prevalence estimates. Using both types of weights, as was done in Natsal-3, is important in reporting on population-based biomarker surveys.

Antimicrobial resistance in Mycoplasma genitalium sampled from the British general population.

BACKGROUND: Mycoplasma genitalium is a common sexually transmitted infection. Treatment guidelines focus on those with symptoms and sexual contacts, generally with regimens including doxycycline and/or azithromycin as first-line and moxifloxacin as second-line treatment. We investigated the prevalence of antimicrobial resistance (AMR)-conferring mutations in M. genitalium among the sexually-active British general population. METHODS: The third national survey of sexual attitudes and lifestyles (Natsal-3) is a probability sample survey of 15 162 men and women aged 16-74 years in Britain conducted during 2010-12. Urine test results for M. genitalium were available for 4507 participants aged 16-44 years reporting >1 lifetime sexual partner. In this study, we sequenced regions of the 23S rRNA and parC genes to detect known genotypic determinants for resistance to macrolides and fluoroquinolones respectively. RESULTS: 94% (66/70) of specimens were re-confirmed as M. genitalium positive, with successful sequencing in 85% (56/66) for 23S rRNA and 92% (61/66) for parC genes. Mutations in 23S rRNA gene (position A2058/A2059) were detected in 16.1% (95%CI: 8.6% to 27.8%) and in parC (encoding ParC D87N/D87Y) in 3.3% (0.9%-11.2%). Macrolide resistance was more likely in participants reporting STI diagnoses (past 5 years) (44.4% (18.9%-73.3%) vs 10.6% (4.6%-22.6%); p=0.029) or sexual health clinic attendance (past year) (43.8% (23.1%-66.8%) vs 5.0% (1.4%-16.5%); p=0.001). All 11 participants with AMR-conferring mutations had attended sexual health clinics (past 5 years), but none reported recent symptoms. CONCLUSIONS: This study highlights challenges in M. genitalium management and control. Macrolide resistance was present in one in six specimens from the general population in 2010-2012, but no participants with AMR M. genitalium reported symptoms. Given anticipated increases in diagnostic testing, new strategies including novel antimicrobials, AMR-guided therapy, and surveillance of AMR and treatment failure are recommended.

Epidemiology of genital warts in the British population: implications for HPV vaccination programmes.

OBJECTIVES: To estimate the prevalence of, and describe risk factors for, genital warts (GWs) in the British population, following the introduction of the bivalent (human papillomavirus (HPV)-16/18) vaccination programme in girls, and prior to the switch to quadrivalent (HPV-6/11/16/18) vaccine (offering direct protection against GWs) and compare this with GW diagnoses in the prevaccination era. METHODS: Natsal-3, a probability sample survey in Britain, conducted in 2010-2012, interviewed 9902 men and women aged 16-44. Natsal-2, conducted in 1999-2001, surveyed 11 161 men and women aged 16-44. Both surveys collected data on sexual behaviour and sexually transmitted infection diagnoses using computer-assisted interview methods. RESULTS: In Natsal-3, 3.8% and 4.6% of sexually experienced men and women reported ever having a diagnosis of GWs, with 1.3% of men and 1.7% of woman reporting a GWs diagnosis in the past 5 years. GWs were strongly associated with increasing partner numbers and condomless sex. Diagnoses were more frequent in men who have sex with men (MSM) (11.6% ever, 3.3% past 5 years) and in women reporting sex with women (10.8% ever, 3.6% past 5 years). In the age group who were eligible for vaccination at the time of Natsal-3 (16-20 years), a similar proportion of same-aged women reported a history of GWs in Natsal-2 (1.9%, 1.1-3.4) and Natsal-3 (2.6%, 1.5-4.4). CONCLUSIONS: These data provide essential parameters for mathematical models that inform cost-effectiveness analyses of HPV vaccination programmes. There was no evidence of population protection against GWs conferred by the bivalent vaccine. Even with vaccination of adolescent boys, vaccination should be offered to MSM attending sexual health clinics.

Associations of depression and anxiety symptoms with sexual behaviour in women and heterosexual men attending sexual health clinics: a cross-sectional study.

OBJECTIVE: To assess the association of symptoms of depression and anxiety with sexual risk behaviour and history, among women and heterosexual men attending genitourinary medicine (GUM) clinics. METHODS: Attitudes to and Understanding of Risk of Acquisition of HIV (AURAH) was a cross-sectional, self-administered questionnaire study recruited from 20 GUM clinics in England, 2013-2014. This analysis included women and heterosexual men. The prevalence of depression and anxiety symptoms was assessed. Modified Poisson regression was used to produce adjusted prevalence ratios (aPR) for the association of t demographic, socioeconomic and lifestyle factors with depression and anxiety, adjusted for gender, age, ethnicity, education level and study region. Among individuals reporting sex in the past 3 months, associations of depression and anxiety with sexual risk behaviour and history were assessed separately by gender, adjusted for age, ethnicity, study region, education and relationship status. RESULTS: Questionnaires were completed by 676 women and 470 heterosexual men. Depression symptoms were reported by 100 (14.8%) women and 33 men (7.0%). Anxiety symptoms were reported by 79 women (11.7%) and 21 men (4.5%). Among women reporting recent sex, those with depression symptoms were more likely to report condomless sex with a non-regular partner, aPR 1.38 (1.07-1.77) and recent condomless sex with two or more partners, 1.80 (1.25-2.59). Women with anxiety symptoms more likely to report recent condomless sex with two or more partners, 1.68 (1.13-2.50), low self-efficacy for condom use, 1.54 (1.02-2.31) and STI diagnosis in the last year 1.51 (1.04-2.20). Among heterosexual men reporting recent sex, depression and anxiety symptoms were associated with low self-efficacy with condom use, 2.32 (1.29-4.19) for depression and 2.23 (1.26-3.94) for anxiety, but not with measures of condomless sex. DISCUSSION: The associations between psychological symptoms and sexual risk behaviours highlight the importance of holistic assessment of need by both general and sexual health clinicians. We highlight the challenge in delivering holistic care associated with fragmentation of sexual health services.

Combination prevention and HIV: a cross-sectional community survey of gay and bisexual men in London, October to December 2016.

BackgroundMen who have sex with men (MSM) are at risk of HIV and are an important population to monitor and ameliorate combination prevention efforts.AimTo estimate HIV prevalence and identify factors associated with frequent HIV testing (≥ 2 HIV tests in the last year) and pre-exposure prophylaxis (PrEP) use among MSM in London.MethodsFor this cross-sectional study, MSM recruited from 22 social venues provided oral-fluid samples for anonymous HIV antibody (Ab) testing and completed a questionnaire. Factors associated with frequent HIV testing and PrEP use were identified through logistic regression.ResultsOf 767 men recruited, 545 provided an eligible oral specimen. Among these, 38 MSM (7.0%) were anti-HIV positive including five (13.2%; 5/38) who reported their status as negative. Condomless anal sex within the previous 3 months was reported by 60.1% (412/685) men. Frequent HIV testing was associated with, in the past year, a reported sexually transmitted infection (adjusted odds ratio (AOR): 5.05; 95% confidence interval (CI): 2.66-9.58) or ≥ 2 casual condomless partners (AOR 2-4 partners: 3.65 (95% CI: 1.87-7.10); AOR 5-10 partners: 3.34(95% CI: 1.32-8.49). Age ≥ 35 years was related to less frequent HIV testing (AOR 35-44 years: 0.34 (95% CI: 0.16-0.72); AOR ≥ 45 years: 0.29 (95% CI: 0.12-0.69). PrEP use in the past year was reported by 6.2% (46/744) of MSM and associated with ≥ 2 casual condomless sex partners (AOR: 2.86; 95% CI: 1.17-6.98) or chemsex (AOR: 2.31; 95% CI: 1.09-4.91).ConclusionThis bio-behavioural study of MSM found high rates of behaviours associated with increased risk of HIV transmission. Combination prevention, including frequent HIV testing and use of PrEP, remains crucial in London.

Sexual health clinic attendance and non-attendance in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

OBJECTIVES: In Britain, sexual health clinics (SHCs) are the most common location for STI diagnosis but many people with STI risk behaviours do not attend. We estimate prevalence of SHC attendance and how this varies by sociodemographic and behavioural factors (including unsafe sex) and describe hypothetical service preferences for those reporting unsafe sex. METHODS: Complex survey analyses of data from Britain's third National Survey of Sexual Attitudes and Lifestyles, a probability survey of 15 162 people aged 16-74 years, undertaken 2010-2012. RESULTS: Overall, recent attendance (past year) was highest among those aged 16-24 years (16.6% men, 22.4% women), decreasing with age (<1.5% among those 45-74 years). Approximately 15% of sexually-active 16-74 year olds (n=1002 men; n=1253 women) reported 'unsafe sex' (condomless first sex with a new partner and/or ≥2 partners and no condom use, past year); >75% of these had not attended a SHC (past year). However, of non-attenders aged 16-44 years, 18.7% of men and 39.0% of women reported chlamydia testing (past year) with testing highest in women aged <25 years. Of those aged 16-44 years reporting unsafe sex, the majority who reported previous SHC attendance would seek STI care there, whereas the majority who had not would use general practice. CONCLUSION: While most reporting unsafe sex had not attended a SHC, many, particularly younger women, had tested for chlamydia suggesting engagement with sexual health services more broadly. Effective, diverse service provision is needed to engage those at-risk and ensure that they can attend services appropriate to their needs.

Trichomonas vaginalis infection is uncommon in the British general population: implications for clinical testing and public health screening.

INTRODUCTION: Variable use of new molecular assays, asymptomatic infections and a lack of population data mean that the population burden of Trichomonas vaginalis is uncertain. We investigated the age-specific prevalence of T. vaginalis within the sexually active British general population to inform testing strategies. METHODS: Britain's third National Survey of Sexual Attitudes and Lifestyle (Natsal-3) is a probability sample survey of 15 162 individuals aged 16-74 years, undertaken during 2010-2012. Urine from 4386 participants aged 16-44 years reporting ≥1 lifetime sexual partner was tested for T. vaginalis using in-house real-time PCR. RESULTS: Urinary T. vaginalis was detected in seven women and no men providing urine samples, giving a weighted prevalence estimate of 0.3% (95% CI 0.1% to 0.5%) in sexually experienced women aged 16-44 years. Of the seven women with T. vaginalis detected, four were of black or mixed ethnicity (prevalence 2.7% (0.9% to 7.7%) in this group) and five reported recent partners of black or mixed ethnicity. Six of the women reported symptoms, and five reported sexual health clinic attendance in the past 5 years (prevalence in those reporting clinic attendance: 1.0% (0.4% to 2.3%)). The prevalence of a self-reported history of T. vaginalis (past 5 years) was 0.1% (0.0% to 0.2%) in women and 0.0% (0.0% to 0.2%) in men aged 16-44 years. CONCLUSIONS: Our British population prevalence estimates indicate that T. vaginalis is a rare infection. These data support policies that restrict asymptomatic screening for T. vaginalis and suggest deployment of molecular tests should be focused within clinical settings and guided by symptoms and local demography.

Changes in conceptions in women younger than 18 years and the circumstances of young mothers in England in 2000-12: an observational study.

BACKGROUND: In 2000, a 10-year Teenage Pregnancy Strategy was launched in England to reduce conceptions in women younger than 18 years and social exclusion in young parents. We used routinely collected data and data from Britain's National Surveys of Sexual Attitudes and Lifestyles (Natsal) to examine progress towards these goals. METHODS: In this observational study, we used random-effects meta-regression to analyse the change in conception rates from 1994-98 to 2009-13 by top-tier local authorities in England, in relation to Teenage Pregnancy Strategy-related expenditure per head, socioeconomic deprivation, and region. Data from similar probability sample surveys: Natsal-1 (1990-91), Natsal-2 (1999-2001), and Natsal-3 (2010-12) were used to assess the prevalence of risk factors and their association with conception in women younger than 18 years in women aged 18-24 years; and the prevalence of participation in education, work, and training in young mothers. FINDINGS: Conception rates in women younger than 18 years declined steadily from their peak in 1996-98 and more rapidly from 2007 onwards. More deprived areas and those receiving greater Teenage Pregnancy Strategy-related investment had higher rates of conception in 1994-98 and had greater declines to 2009-13. Regression analyses assessing the association between Teenage Pregnancy Strategy funding and decline in conception rates in women younger than 18 years showed an estimated reduction in the conception rate of 11.4 conceptions (95% CI 9.6-13.2; p<0.0001) per 1000 women aged 15-17 years for every £100 Teenage Pregnancy Strategy spend per head and a reduction of 8.2 conceptions (5.8-10.5; p<0.0001) after adjustment for socioeconomic deprivation and region. The association between conception in women younger than 18 years and lower socioeconomic status weakened slightly between Natsal-2 and Natsal-3. The prevalence of participation in education, work, or training among young women with a child conceived before age 18 years was low, but the odds of them doing so doubled between Natsal-2 and Natsal-3 (odds ratio 1.99, 95% CI 0.99-4.00). INTERPRETATION: A sustained, multifaceted policy intervention involving health and education agencies, alongside other social and educational changes, has probably contributed to a substantial and accelerating decline in conceptions in women younger than 18 years in England since the late 1990s. FUNDING: Medical Research Council, Wellcome Trust, Economic and Social Research Council, and Department of Health.

Pre-exposure prophylaxis to prevent the acquisition of HIV-1 infection (PROUD): effectiveness results from the pilot phase of a pragmatic open-label randomised trial.

BACKGROUND: Randomised placebo-controlled trials have shown that daily oral pre-exposure prophylaxis (PrEP) with tenofovir-emtricitabine reduces the risk of HIV infection. However, this benefit could be counteracted by risk compensation in users of PrEP. We did the PROUD study to assess this effect. METHODS: PROUD is an open-label randomised trial done at 13 sexual health clinics in England. We enrolled HIV-negative gay and other men who have sex with men who had had anal intercourse without a condom in the previous 90 days. Participants were randomly assigned (1:1) to receive daily combined tenofovir disoproxil fumarate (245 mg) and emtricitabine (200 mg) either immediately or after a deferral period of 1 year. Randomisation was done via web-based access to a central computer-generated list with variable block sizes (stratified by clinical site). Follow-up was quarterly. The primary outcomes for the pilot phase were time to accrue 500 participants and retention; secondary outcomes included incident HIV infection during the deferral period, safety, adherence, and risk compensation. The trial is registered with ISRCTN (number ISRCTN94465371) and ClinicalTrials.gov (NCT02065986). FINDINGS: We enrolled 544 participants (275 in the immediate group, 269 in the deferred group) between Nov 29, 2012, and April 30, 2014. Based on early evidence of effectiveness, the trial steering committee recommended on Oct 13, 2014, that all deferred participants be offered PrEP. Follow-up for HIV incidence was complete for 243 (94%) of 259 patient-years in the immediate group versus 222 (90%) of 245 patient-years in the deferred group. Three HIV infections occurred in the immediate group (1·2/100 person-years) versus 20 in the deferred group (9·0/100 person-years) despite 174 prescriptions of post-exposure prophylaxis in the deferred group (relative reduction 86%, 90% CI 64-96, p=0·0001; absolute difference 7·8/100 person-years, 90% CI 4·3-11·3). 13 men (90% CI 9-23) in a similar population would need access to 1 year of PrEP to avert one HIV infection. We recorded no serious adverse drug reactions; 28 adverse events, most commonly nausea, headache, and arthralgia, resulted in interruption of PrEp. We detected no difference in the occurrence of sexually transmitted infections, including rectal gonorrhoea and chlamydia, between groups, despite a suggestion of risk compensation among some PrEP recipients. INTERPRETATION: In this high incidence population, daily tenofovir-emtricitabine conferred even higher protection against HIV than in placebo-controlled trials, refuting concerns that effectiveness would be less in a real-world setting. There was no evidence of an increase in other sexually transmitted infections. Our findings strongly support the addition of PrEP to the standard of prevention for men who have sex with men at risk of HIV infection. FUNDING: MRC Clinical Trials Unit at UCL, Public Health England, and Gilead Sciences.

Patterns of chlamydia testing in different settings and implications for wider STI diagnosis and care: a probability sample survey of the British population.

BACKGROUND: Following widespread rollout of chlamydia testing to non-specialist and community settings in the UK, many individuals receive a chlamydia test without being offered comprehensive STI and HIV testing. We assess sexual behaviour among testers in different settings with a view to understanding their need for other STI diagnostic services. METHODS: A probability sample survey of the British population undertaken 2010-2012 (the third National Survey of Sexual Attitudes and Lifestyles). We analysed weighted data on chlamydia testing (past year), including location of most recent test, and diagnoses (past 5 years) from individuals aged 16-44 years reporting at least one sexual partner in the past year (4992 women, 3406 men). RESULTS: Of the 26.8% (95% CI 25.4% to 28.2%) of women and 16.7% (15.5% to 18.1%) of men reporting a chlamydia test in the past year, 28.4% of women and 41.2% of men had tested in genitourinary medicine (GUM), 41.1% and 20.7% of women and men respectively tested in general practice (GP) and the remainder tested in other non-GUM settings. Women tested outside GUM were more likely to be older, in a relationship and to live in rural areas. Individuals tested outside GUM reported fewer risk behaviours; nevertheless, 11.0% (8.6% to 14.1%) of women and 6.8% (3.9% to 11.6%) of men tested in GP and 13.2% (10.2% to 16.8%) and 9.6% (6.5% to 13.8%) of women and men tested in other non-GUM settings reported 'unsafe sex', defined as two or more partners and no condom use with any partner in the past year. Individuals treated for chlamydia outside GUM in the past 5 years were less likely to report an HIV test in that time frame (women: 54.5% (42.7% to 65.7%) vs 74.1% (65.9% to 80.9%) in GUM; men: 23.9% (12.7% to 40.5%) vs 65.8% (56.2% to 74.3%)). CONCLUSIONS: Most chlamydia testing occurred in non-GUM settings, among populations reporting fewer risk behaviours. However, there is a need to provide pathways to comprehensive STI care to the sizeable minority at higher risk.

Condomless sex in HIV-diagnosed men who have sex with men in the UK: prevalence, correlates, and implications for HIV transmission.

OBJECTIVE: HIV transmission is ongoing among men who have sex with men (MSM) in the UK. Sex without a condom (condomless sex, CLS) is the main risk factor. We investigated the prevalence of and factors associated with types of CLS. METHODS: Cross-sectional questionnaire study in UK HIV clinics in 2011/2012 (ASTRA). MSM diagnosed with HIV for ≥3 months reported on anal and vaginal sex, CLS with HIV-serodifferent partners (CLS-D) and CLS with HIV-seroconcordant (CLS-C) partners in the previous 3 months. Mutually exclusive sexual behaviours were as follows: (1) Higher HIV risk CLS-D (not on antiretroviral therapy (ART) or clinic-recorded viral load(VL) >50 c/mL), (2) Other CLS-D, (3) CLS-C without CLS-D, (4) Condom-protected sex only and (5) No anal or vaginal sex. Associations were examined of sociodemographic, HIV-related, lifestyle, and other sexual measures with the five categories of sexual behaviour. We examined the prevalence of higher HIV risk CLS-D incorporating (in addition to ART and VL) time on ART, ART non-adherence, and recent sexually transmitted infections (STIs). RESULTS: Among 2189 HIV-diagnosed MSM (87% on ART), prevalence of any CLS in the past 3 months was 38.2% (95% CI 36.2% to 40.4%) and that of any CLS-D was 16.3% (14.8%-17.9%). The five-category classification was as follows: (1) Higher HIV risk CLS-D: 4.2% (3.5% to 5.2%), (2) Other CLS-D: 12.1% (10.8% to 13.5%), (3) CLS-C without CLS-D: 21.9% (20.2% to 23.7%), (4) Condom-protected sex only: 25.4% (23.6% to 27.3%) and (5) No anal or vaginal sex: 36.4% (34.3% to 38.4%). Compared with men who reported condom-protected sex only, MSM who reported any CLS in the past 3 months had higher prevalence of STIs, chemsex-associated drug use, group sex, higher partner numbers, and lifetime hepatitis C. Prevalence of higher HIV risk CLS-D ranged from 4.2% to 7.5% according to criteria included. CONCLUSION: CLS was prevalent among HIV-diagnosed MSM, but CLS-D with higher HIV transmission risk was overall low. CLS-D is no longer the most appropriate measure of HIV transmission risk behaviour among people with diagnosed HIV; accounting for VL is important.

Forming new sex partnerships while overseas: findings from the third British National Survey of Sexual Attitudes & Lifestyles (Natsal-3).

OBJECTIVES: Travelling away from home presents opportunities for new sexual partnerships, which may be associated with sexually transmitted infection (STI) risk. We examined the prevalence of, and factors associated with, reporting new sexual partner(s) while overseas, and whether this differed by partners' region of residence. METHODS: We analysed data from 12 530 men and women aged 16-74 years reporting ≥1 sexual partner(s) in the past 5 years in Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), a probability survey undertaken 2010-2012. RESULTS: 9.2% (95% CI 8.3% to 10.1%) of men and 5.3% (4.8% to 5.8%) of women reported new sexual partner(s) while overseas in the past 5 years. This was strongly associated with higher partner numbers and other sexual and health risk behaviours. Among those with new partners while overseas, 72% of men and 58% of women reported partner(s) who were not UK residents. Compared with those having only UK partners while abroad, these people were more likely to identify as 'White Other' or 'Non-White' (vs White British ethnicity), report higher partner numbers, new partners from outside the UK while in the UK and paying for sex (men only) all in the past 5 years. There was no difference in reporting STI diagnosis/es during this time period. CONCLUSIONS: Reporting new partners while overseas was associated with a range of sexual risk behaviours. Advice on sexual health should be included as part of holistic health advice for all travellers, regardless of age, destination or reason for travel.

Men who have sex with men in Great Britain: comparing methods and estimates from probability and convenience sample surveys.

OBJECTIVE: To examine sociodemographic and behavioural differences between men who have sex with men (MSM) participating in recent UK convenience surveys and a national probability sample survey. METHODS: We compared 148 MSM aged 18-64 years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) undertaken in 2010-2012, with men in the same age range participating in contemporaneous convenience surveys of MSM: 15 500 British resident men in the European MSM Internet Survey (EMIS); 797 in the London Gay Men's Sexual Health Survey; and 1234 in Scotland's Gay Men's Sexual Health Survey. Analyses compared men reporting at least one male sexual partner (past year) on similarly worded questions and multivariable analyses accounted for sociodemographic differences between the surveys. RESULTS: MSM in convenience surveys were younger and better educated than MSM in Natsal-3, and a larger proportion identified as gay (85%-95% vs 62%). Partner numbers were higher and same-sex anal sex more common in convenience surveys. Unprotected anal intercourse was more commonly reported in EMIS. Compared with Natsal-3, MSM in convenience surveys were more likely to report gonorrhoea diagnoses and HIV testing (both past year). Differences between the samples were reduced when restricting analysis to gay-identifying MSM. CONCLUSIONS: National probability surveys better reflect the population of MSM but are limited by their smaller samples of MSM. Convenience surveys recruit larger samples of MSM but tend to over-represent MSM identifying as gay and reporting more sexual risk behaviours. Because both sampling strategies have strengths and weaknesses, methods are needed to triangulate data from probability and convenience surveys.