The HepTestContest: a global innovation contest to identify approaches to hepatitis B and C testing.

BACKGROUND: Innovation contests are a novel approach to elicit good ideas and innovative practices in various areas of public health. There remains limited published literature on approaches to deliver hepatitis testing. The purpose of this innovation contest was to identify examples of different hepatitis B and C approaches to support countries in their scale-up of hepatitis testing and to supplement development of formal recommendations on service delivery in the 2017 World Health Organization hepatitis B and C testing guidelines. METHODS: This contest involved four steps: 1) establishment of a multisectoral steering committee to coordinate a call for contest entries; 2) dissemination of the call for entries through diverse media (Facebook, Twitter, YouTube, email listservs, academic journals); 3) independent ranking of submissions by a panel of judges according to pre-specified criteria (clarity of testing model, innovation, effectiveness, next steps) using a 1-10 scale; 4) recognition of highly ranked entries through presentation at international conferences, commendation certificate, and inclusion as a case study in the WHO 2017 testing guidelines. RESULTS: The innovation contest received 64 entries from 27 countries and took a total of 4 months to complete. Sixteen entries were directly included in the WHO testing guidelines. The entries covered testing in different populations, including primary care patients (n = 5), people who inject drugs (PWID) (n = 4), pregnant women (n = 4), general populations (n = 4), high-risk groups (n = 3), relatives of people living with hepatitis B and C (n = 2), migrants (n = 2), incarcerated individuals (n = 2), workers (n = 2), and emergency department patients (n = 2). A variety of different testing delivery approaches were employed, including integrated HIV-hepatitis testing (n = 12); integrated testing with harm reduction and addiction services (n = 9); use of electronic medical records to support targeted testing (n = 8); decentralization (n = 8); and task shifting (n = 7). CONCLUSION: The global innovation contest identified a range of local hepatitis testing approaches that can be used to inform the development of testing strategies in different settings and populations. Further implementation and evaluation of different testing approaches is needed.

Changes in health in England, with analysis by English regions and areas of deprivation, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

BACKGROUND: In the Global Burden of Disease Study 2013 (GBD 2013), knowledge about health and its determinants has been integrated into a comparable framework to inform health policy. Outputs of this analysis are relevant to current policy questions in England and elsewhere, particularly on health inequalities. We use GBD 2013 data on mortality and causes of death, and disease and injury incidence and prevalence to analyse the burden of disease and injury in England as a whole, in English regions, and within each English region by deprivation quintile. We also assess disease and injury burden in England attributable to potentially preventable risk factors. England and the English regions are compared with the remaining constituent countries of the UK and with comparable countries in the European Union (EU) and beyond. METHODS: We extracted data from the GBD 2013 to compare mortality, causes of death, years of life lost (YLLs), years lived with a disability (YLDs), and disability-adjusted life-years (DALYs) in England, the UK, and 18 other countries (the first 15 EU members [apart from the UK] and Australia, Canada, Norway, and the USA [EU15+]). We extended elements of the analysis to English regions, and subregional areas defined by deprivation quintile (deprivation areas). We used data split by the nine English regions (corresponding to the European boundaries of the Nomenclature for Territorial Statistics level 1 [NUTS 1] regions), and by quintile groups within each English region according to deprivation, thereby making 45 regional deprivation areas. Deprivation quintiles were defined by area of residence ranked at national level by Index of Multiple Deprivation score, 2010. Burden due to various risk factors is described for England using new GBD methodology to estimate independent and overlapping attributable risk for five tiers of behavioural, metabolic, and environmental risk factors. We present results for 306 causes and 2337 sequelae, and 79 risks or risk clusters. FINDINGS: Between 1990 and 2013, life expectancy from birth in England increased by 5·4 years (95% uncertainty interval 5·0-5·8) from 75·9 years (75·9-76·0) to 81·3 years (80·9-81·7); gains were greater for men than for women. Rates of age-standardised YLLs reduced by 41·1% (38·3-43·6), whereas DALYs were reduced by 23·8% (20·9-27·1), and YLDs by 1·4% (0·1-2·8). For these measures, England ranked better than the UK and the EU15+ means. Between 1990 and 2013, the range in life expectancy among 45 regional deprivation areas remained 8·2 years for men and decreased from 7·2 years in 1990 to 6·9 years in 2013 for women. In 2013, the leading cause of YLLs was ischaemic heart disease, and the leading cause of DALYs was low back and neck pain. Known risk factors accounted for 39·6% (37·7-41·7) of DALYs; leading behavioural risk factors were suboptimal diet (10·8% [9·1-12·7]) and tobacco (10·7% [9·4-12·0]). INTERPRETATION: Health in England is improving although substantial opportunities exist for further reductions in the burden of preventable disease. The gap in mortality rates between men and women has reduced, but marked health inequalities between the least deprived and most deprived areas remain. Declines in mortality have not been matched by similar declines in morbidity, resulting in people living longer with diseases. Health policies must therefore address the causes of ill health as well as those of premature mortality. Systematic action locally and nationally is needed to reduce risk exposures, support healthy behaviours, alleviate the severity of chronic disabling disorders, and mitigate the effects of socioeconomic deprivation. FUNDING: Bill & Melinda Gates Foundation and Public Health England.

Surveillance systems for sexually transmitted infections: a global review.

PURPOSE OF REVIEW: Sexually transmitted infections (STIs) continue to exert a substantial public health burden globally but surveillance remains a challenge, especially in the developing world. We reviewed STI surveillance systems in various regions globally and used available data to provide an overview of recent trends in STI epidemiology. RECENT FINDINGS: STI surveillance systems in the developing world are often limited and restricted to ad hoc cross-sectional surveys; however, available data suggest that these areas are disproportionately affected by STIs, with a higher burden in marginalized groups such as sex workers. Developed countries typically have established surveillance systems. Recent reports suggest many of these countries are experiencing rising diagnoses of STIs in men who have sex with men (MSM) and an increasing contribution of HIV-positive MSM to STI epidemics. SUMMARY: There is considerable variability in the surveillance for STIs globally, ranging from active or passive, to sentinel, laboratory or clinic-based systems. Given different levels of resources and patterns of healthcare provision, it is difficult to compare surveillance data across regions; however, available data suggest that considerable inequality in STI burden exists. In resource-limited settings, syndromic surveillance with periodic laboratory assessments is recommended to monitor trends in STIs.

UK health performance: findings of the Global Burden of Disease Study 2010.

BACKGROUND: The UK has had universal free health care and public health programmes for more than six decades. Several policy initiatives and structural reforms of the health system have been undertaken. Health expenditure has increased substantially since 1990, albeit from relatively low levels compared with other countries. We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to examine the patterns of health loss in the UK, the leading preventable risks that explain some of these patterns, and how UK outcomes compare with a set of comparable countries in the European Union and elsewhere in 1990 and 2010. METHODS: We used results of GBD 2010 for 1990 and 2010 for the UK and 18 other comparator nations (the original 15 members of the European Union, Australia, Canada, Norway, and the USA; henceforth EU15+). We present analyses of trends and relative performance for mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE). We present results for 259 diseases and injuries and for 67 risk factors or clusters of risk factors relevant to the UK. We assessed the UK's rank for age-standardised YLLs and DALYs for their leading causes compared with EU15+ in 1990 and 2010. We estimated 95% uncertainty intervals (UIs) for all measures. FINDINGS: For both mortality and disability, overall health has improved substantially in absolute terms in the UK from 1990 to 2010. Life expectancy in the UK increased by 4·2 years (95% UI 4·2-4·3) from 1990 to 2010. However, the UK performed significantly worse than the EU15+ for age-standardised death rates, age-standardised YLL rates, and life expectancy in 1990, and its relative position had worsened by 2010. Although in most age groups, there have been reductions in age-specific mortality, for men aged 30-34 years, mortality rates have hardly changed (reduction of 3·7%, 95% UI 2·7-4·9). In terms of premature mortality, worsening ranks are most notable for men and women aged 20-54 years. For all age groups, the contributions of Alzheimer's disease (increase of 137%, 16-277), cirrhosis (65%, ?15 to 107), and drug use disorders (577%, 71-942) to premature mortality rose from 1990 to 2010. In 2010, compared with EU15+, the UK had significantly lower rates of age-standardised YLLs for road injury, diabetes, liver cancer, and chronic kidney disease, but significantly greater rates for ischaemic heart disease, chronic obstructive pulmonary disease, lower respiratory infections, breast cancer, other cardiovascular and circulatory disorders, oesophageal cancer, preterm birth complications, congenital anomalies, and aortic aneurysm. Because YLDs per person by age and sex have not changed substantially from 1990 to 2010 but age-specific mortality has been falling, the importance of chronic disability is rising. The major causes of YLDs in 2010 were mental and behavioural disorders (including substance abuse; 21·5% [95 UI 17·2-26·3] of YLDs), and musculoskeletal disorders (30·5% [25·5-35·7]). The leading risk factor in the UK was tobacco (11·8% [10·5-13·3] of DALYs), followed by increased blood pressure (9·0 % [7·5-10·5]), and high body-mass index (8·6% [7·4-9·8]). Diet and physical inactivity accounted for 14·3% (95% UI 12·8-15·9) of UK DALYs in 2010. INTERPRETATION: The performance of the UK in terms of premature mortality is persistently and significantly below the mean of EU15+ and requires additional concerted action. Further progress in premature mortality from several major causes, such as cardiovascular diseases and cancers, will probably require improved public health, prevention, early intervention, and treatment activities. The growing burden of disability, particularly from mental disorders, substance use, musculoskeletal disorders, and falls deserves an integrated and strategic response. FUNDING: Bill & Melinda Gates Foundation.

Common roots: a contextual review of HIV epidemics in black men who have sex with men across the African diaspora.

Pooled estimates from across the African diaspora show that black men who have sex with men (MSM) are 15 times more likely to be HIV positive compared with general populations and 8·5 times more likely compared with black populations. Disparities in the prevalence of HIV infection are greater in African and Caribbean countries that criminalise homosexual activity than in those that do not criminalise such behaviour. With the exception of US and African epidemiological studies, most studies of black MSM mainly focus on outcomes associated with HIV behavioural risk rather than on prevalence, incidence, or undiagnosed infection. Nevertheless, black MSM across the African diaspora share common experiences such as discrimination, cultural norms valuing masculinity, concerns about confidentiality during HIV testing or treatment, low access to HIV drugs, threats of violence or incarceration, and few targeted HIV prevention resources.

Comparisons of disparities and risks of HIV infection in black and other men who have sex with men in Canada, UK, and USA: a meta-analysis.

BACKGROUND: We did a meta-analysis to assess factors associated with disparities in HIV infection in black men who have sex with men (MSM) in Canada, the UK, and the USA. METHODS: We searched Embase, Medline, Google Scholar, and online conference proceedings from Jan 1, 1981, to Dec 31, 2011, for racial comparative studies with quantitative outcomes associated with HIV risk or HIV infection. Key words and Medical Subject Headings (US National Library of Medicine) relevant to race were cross-referenced with citations pertinent to homosexuality in Canada, the UK, and the USA. Data were aggregated across studies for every outcome of interest to estimate overall effect sizes, which were converted into summary ORs for 106,148 black MSM relative to 581,577 other MSM. FINDINGS: We analysed seven studies from Canada, 13 from the UK, and 174 from the USA. In every country, black MSM were as likely to engage similarly in serodiscordant unprotected sex as other MSM. Black MSM in Canada and the USA were less likely than other MSM to have a history of substance use (odds ratio, OR, 0·53, 95% CI 0·38-0·75, for Canada and 0·67, 0·50-0·92, for the USA). Black MSM in the UK (1·86, 1·58-2·18) and the USA (3·00, 2·06-4·40) were more likely to be HIV positive than were other MSM, but HIV-positive black MSM in each country were less likely (22% in the UK and 60% in the USA) to initiate combination antiretroviral therapy (cART) than other HIV-positive MSM. US HIV-positive black MSM were also less likely to have health insurance, have a high CD4 count, adhere to cART, or be virally suppressed than were other US HIV-positive MSM. Notably, despite a two-fold greater odds of having any structural barrier that increases HIV risk (eg, unemployment, low income, previous incarceration, or less education) compared with other US MSM, US black MSM were more likely to report any preventive behaviour against HIV infection (1·39, 1·23-1·57). For outcomes associated with HIV infection, disparities were greatest for US black MSM versus other MSM for structural barriers, sex partner demographics (eg, age, race), and HIV care outcomes, whereas disparities were least for sexual risk outcomes. INTERPRETATION: Similar racial disparities in HIV and sexually transmitted infections and cART initiation are seen in MSM in the UK and the USA. Elimination of disparities in HIV infection in black MSM cannot be accomplished without addressing structural barriers or differences in HIV clinical care access and outcomes. FUNDING: None.

Enhancing HIV/AIDS, viral hepatitis, sexually transmitted disease, and tuberculosis prevention in the United States through program collaboration and service integration: the case for broader implementation.

HIV infection, viral hepatitis, sexually transmitted diseases, and tuberculosis in the United States remain major public health concerns. The current disease-specific prevention approach oftentimes has led to narrow success and missed opportunities for increasing program capacity, leveraging resources, addressing social and structural determinants, and accelerating health impact-suggesting a need for greater innovation to prevent related diseases. The National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention's Program Collaboration and Service Integration (PCSI) strategic priority aims to strengthen collaborative engagement across these disease areas and to integrate services at the client level. In this review, we articulate the 5 principles of PCSI-appropriateness, effectiveness, flexibility, accountability, and acceptability. Drawing upon these principles and published literature, we discuss the case for change that underlies PCSI, summarize advances in the field since 2007, and articulate key next steps. Although formal evaluation is needed to fully assess the health impact of PCSI, available evidence suggests that this approach is a promising tool to advance prevention goals.

The effect of combination prevention strategies on HIV incidence among gay and bisexual men who have sex with men in the UK: a model-based analysis.

BACKGROUND: In the UK, the number of new HIV diagnoses among gay and bisexual men who have sex with men (GBMSM) has decreased substantially. We aimed to understand the contribution of different interventions in reducing HIV incidence so far; to estimate future HIV incidence with continuation of current policies and with further scaling up of current interventions; and to estimate the maximum additional annual cost that should be spent towards these interventions for them to offer value for money. METHODS: We calibrated a dynamic, individual-based, stochastic simulation model, the HIV Synthesis Model, to multiple sources of data on HIV among GBMSM aged 15 years or older in the UK. Primarily these were routine HIV surveillance data collected by the UK Health Security Agency. We compared HIV incidence in 2022 with the counterfactual incidence: if HIV testing rates stopped increasing in 2012 and the policy of antiretroviral therapy (ART) at diagnosis was not introduced in mid-2015; if pre-exposure prophylaxis (PrEP) was not introduced; if condom use was low from 2012 in all GBMSM, at levels similar to those observed in 1980; and in the first and second scenario combined. We also projected future outcomes under the assumption of continuation of current policies and considering increases in PrEP and HIV testing uptake and a decrease in condomless sex. FINDINGS: Our model estimated a 77% (90% uncertainty interval [UI] 61-88) decline in HIV incidence since around 2014, with an estimated 597 infections ([90% UI 312-956]; 1·1 per 1000 person-years [90% UI 0·6-1·8]) in men aged 15-64 years in 2022. Both PrEP introduction and increased HIV testing with ART initiation at diagnosis each had a substantial effect on HIV incidence. Without PrEP introduction, we estimate there would have been 2·16 times the number of infections that actually occurred (90% UI 1·06-3·75) between 2012 and 2022; without increased HIV testing and ART initiation at diagnosis there would have been 2·18 times the number of infections that actually occurred (1·18-3·60), and if condomless sex was at the levels before the HIV epidemic, there would have been 2·27 times the number of infections that actually occurred (0·9-5·4). If rates of testing, ART use, and PrEP use remain as they are currently, there is a predicted decline in incidence to 388 HIV infections in 2025 (90% UI 226-650) and to 263 (137-433) in 2030. Increases in HIV testing and PrEP use were predicted to accelerate the decline in HIV incidence. Given the quality-adjusted life-year (QALY) benefit and a cost-effectiveness threshold of £30 000 per QALY gained, in order to be cost-effective an additional £1·62 million could be spent per year to increase testing levels by 34% (90% UI 25-46) and PrEP use by 55% (10-107). To achieve that, a 16% reduction in the cost of delivery of testing and PrEP would be required. INTERPRETATION: Combination prevention, including a PrEP strategy, played a major role in the reduction in HIV incidence observed so far in the UK among GBMSM. Continuation of current activities should lead to a continued decline; however, it is unlikely to lead to reaching the target of fewer than 50 HIV infections per year among GBMSM by 2030. It will be important to reduce costs for testing and PrEP for their continued expansion to be cost-effective. FUNDING: National Institute for Health Research under its Programme Grants for Applied Research Programme and Medical Research Council-UK Research and Innovation.

Epidemiology of, and behavioural risk factors for, sexually transmitted human papillomavirus infection in men and women in Britain.

OBJECTIVES: Persistent infection with high-risk sexually transmitted human papillomaviruses (HR-HPVs) can lead to development of cervical and other cancers, while low-risk types (low-risk HPV) may cause genital warts. We explored the epidemiology of different HPV types in men and women and their association with demographic and behavioural variables. METHODS: We analysed data collected for the British National Survey of Sexual Attitudes and Lifestyles, a cross-sectional survey undertaken in 1999-2001. Half of all sexually experienced male and female respondents aged 18-44 years were invited to provide a urine sample. We tested 3123 stored urine samples using an in-house Luminex-based HPV genotyping system. RESULTS: HPV DNA was detected in 29.0% (95% CI 26.7% to 31.3%) of samples from women and 17.4% (95% CI 15.1% to 19.8%) from men. Any of 13 HR-HPV types was detected in 15.9% (95% CI 14.1% to 17.8%) of women and 9.6% (95% CI 8.0% to 11.6%) of men. HPV types 16/18 were found in 5.5% (95% CI 4.5% to 6.8%) of women and 3.0% (95% CI 2.1% to 4.3%) of men; and types 6/11 in 4.7% (95% CI 1.8% to 5.9%) of women and 2.2% (95% CI 1.5% to 3.1%) of men. In multivariate analysis, HR-HPV was associated with new partner numbers, in women with younger age, single status and partner concurrency, and in men with number of partners without using condom(s) and age at first intercourse. CONCLUSIONS: HPV DNA was detectable in urine of a high proportion of the sexually active British population. In both genders, HR-HPV was strongly associated with risky sexual behaviour. The minority of HPV infections were of vaccine types. It is important to monitor HPV prevalence and type distribution following the introduction of vaccination of girls.

Free HIV self-test for identification and linkage to care of previously undetected HIV infection in men who have sex with men in England and Wales (SELPHI): an open-label, internet-based, randomised controlled trial.

BACKGROUND: High levels of HIV testing in men who have sex with men remain key to reducing the incidence of HIV. We aimed to assess whether the offer of a single, free HIV self-testing kit led to increased HIV diagnoses with linkage to care. METHODS: SELPHI was an internet-based, open-label, randomised controlled trial that recruited participants via sexual and social networking sites. Eligibility criteria included being a man or trans woman (although trans women are reported separately); being resident in England or Wales, UK; being aged 16 years or older; having had anal intercourse with a man; not having a positive HIV diagnosis; and being willing to provide name, email address, date of birth, and consent to link to national HIV databases. Participants were randomly allocated (3:2) by computer-generated number sequence to receive a free HIV self-test kit (BT group) or to not receive this free kit (nBT group). Online surveys collected data at baseline, 2 weeks after enrolment (BT group only), 3 months after enrolment, and at the end of the study. The primary outcome was confirmed (linked to care) new HIV diagnosis within 3 months of enrolment, analysed by intention to treat. Those assessing the primary outcome were masked to allocation. This study is registered with the ISRCTN Clinical Trials Register, number ISRCTN20312003. FINDINGS: 10 111 participants (6049 in BT group and 4062 in nBT group) enrolled between Feb 16, 2017, and March 1, 2018. The median age of participants was 33 years (IQR 26-44 years); 9000 (89%) participants were White; 8118 (80%) participants were born in the UK; 81 (1%) participants were transgender men; 4706 (47%) participants were university educated; 1537 (15%) participants had never been tested for HIV; and 389 (4%) participants were taking pre-exposure prophylaxis. At enrolment, 7282 (72%) participants reported condomless anal sex with at least one male partner in the previous 3 months. In the BT group, of the 4511 participants for whom HIV testing information was available, 4263 (95%) reported having used the free HIV self-test kit within 3 months.Within 3 months of enrolment there were 19 confirmed new HIV diagnoses (0·31%) in 6049 participants in the BT group and 15 (0·37%) of 4062 in the nBT group (p=0·64). INTERPRETATION: The offer of a single, free HIV self-test did not lead to increased rates of new HIV diagnoses, which could reflect decreasing HIV incidence rates in the UK. Nonetheless, the offer of a free HIV self-testing kit resulted in high HIV testing rates, indicating that self-testing is an attractive testing option for a large group of men who have sex with men. FUNDING: UK National Institute for Health and Care Research.

Sexual health, HIV, and sexually transmitted infections among gay, bisexual, and other men who have sex with men in the United States.

The sexual health of gay, bisexual, and other men who have sex with men (MSM) in the United States is not getting better despite considerable social, political and human rights advances. Instead of improving, HIV and sexually transmitted infections (STIs) remain disproportionately high among MSM and have been increasing for almost two decades. The disproportionate and worsening burden of HIV and other STIs among MSM requires an urgent re-assessment of what we have been doing as a nation to reduce these infections, how we have been doing it, and the scale of our efforts. A sexual health approach has the potential to improve our understanding of MSM's sexual behavior and relationships, reduce HIV and STI incidence, and improve the health and well-being of MSM.

A review of the Centers for Disease Control and Prevention's response to the HIV/AIDS crisis among Blacks in the United States, 1981-2009.

Among US racial/ethnic groups, Blacks are at the highest risk of acquiring HIV/AIDS. In response, the Centers for Disease Control and Prevention (CDC) has launched the Heightened National Response to Address the HIV/AIDS Crisis Among African Americans, which seeks to engage public and nonpublic partners in a synergistic effort to prevent HIV among Blacks. The CDC also recently launched Act Against AIDS, a campaign to refocus attention on the domestic HIV/AIDS crisis. Although the CDC's efforts to combat HIV/AIDS among Blacks have achieved some success, more must be done to address this crisis. New initiatives include President Obama's goal of developing a National HIV/AIDS Strategy to reduce HIV incidence, decrease HIV-related health disparities, and increase access to care, especially among Blacks and other disproportionately affected populations.

Use of contraceptive services in Britain: findings from the second National Survey of Sexual Attitudes and Lifestyles (Natsal-2).

OBJECTIVE: To describe contraceptive service use and identify demographic and sexual behavioural characteristics associated with use (and non-use) of different services. METHODS: Probability survey sample of men and women aged 16-44 years, resident in Britain. Participants comprised 3369 men and 4375 women reporting vaginal intercourse in the last year (excluding those reporting exclusive use of sterilisation or medical investigations for infertility). Main outcome measures were use of contraceptive services, grouped as: general practice, community contraceptive clinics, retail services and nonuse of services. RESULTS: General practice was the most commonly reported source of contraceptive supplies for women (59.2%), while retail services were most frequently reported by men (42.7%). 16.3% of women and 7.3% of men reported using more than one type of service. 20.7% of women and 45.1% of men had used no service in the last year, and amongst 16-17-year-olds the proportions reporting non-use of services was 13.8% and 31.2%, respectively. Use of community contraceptive clinics was associated with being younger, childless, single and reporting more heterosexual partners in the last year. CONCLUSIONS: There was relatively little 'shopping around' between different services, suggesting that choice of contraceptive providers ensures a range of needs is met for most people. While general practice is the most commonly used source of supplies, community contraceptive clinics are seeing those potentially at higher sexual health risk, particularly the young and those with multiple partners. Ways of improving young people's access to services for contraceptive supplies need to be addressed.

Control measures used during lymphogranuloma venereum outbreak, Europe.

To assess the response to the reemergence of lymphogranuloma venereum, we conducted a cross-sectional survey by administering a structured questionnaire to representatives from 26 European countries. Responses were received from 18 countries. The ability to respond quickly and the measures used for outbreak detection and control varied. Evidence-based criteria were not consistently used to develop recommendations. We did not develop criteria to determine the effectiveness of the recommendations. The degree of preparedness for an unexpected outbreak, as well as the ability of countries to respond quickly to alerts, varied, which indicates weaknesses in the ability to control an outbreak. More guidance is needed to implement and evaluate control measures used during international outbreaks.

Infectious syphilis in high-income settings in the 21st century.

In high-income countries after World War II, the widespread availability of effective antimicrobial therapy, combined with expanded screening, diagnosis, and treatment programmes, resulted in a substantial decline in the incidence of syphilis. However, by the turn of the 21st century, outbreaks of syphilis began to occur in different subpopulations, especially in communities of men who have sex with men. The reasons for these outbreaks include changing sexual and social norms, interactions with increasingly prevalent HIV infection, substance abuse, global travel and migration, and underinvestment in public-health services. Recently, it has been suggested that these outbreaks could be the result of an interaction of the pathogen with natural immunity, and that syphilis epidemics should be expected to intrinsically cycle. We discuss this hypothesis by examining long-term data sets of syphilis. Today, syphilis in western Europe and the USA is characterised by low-level endemicity with concentration among population subgroups with high rates of partner change, poor access to health services, social marginalisation, or low socioeconomic status.