Screening for gonorrhoea using samples collected through the English National Chlamydia Screening Programme and risk of false positives: a national survey of Local Authorities

OBJECTIVES: To investigate use of dual tests for Chlamydia trachomatis and Neisseria gonorrhoeae on samples collected through the National Chlamydia Screening Programme (NCSP) in England. DESIGN AND SETTING: During May-July 2013, we delivered an online survey to commissioners of sexual health services in the 152 upper-tier English Local Authorities (LAs) who were responsible for commissioning chlamydia screening in people aged 15-24 years. MAIN OUTCOME MEASURES: (1) The proportion of English LAs using dual tests on samples collected by the NCSP; (2) The estimated number of gonorrhoea tests and false positives from samples collected by the NCSP, calculated using national surveillance data on the number of chlamydia tests performed, assuming the gonorrhoea prevalence to range between 0.1% and 1%, and test sensitivity and specificity of 99.5%. RESULTS: 64% (98/152) of LAs responded to this national survey; over half (53% (52/98)) reported currently using dual tests in community settings. There was no significant difference between LAs using and not using dual tests by chlamydia positivity, chlamydia diagnosis rate or population screening coverage. Although positive gonorrhoea results were confirmed with supplementary tests in 93% (38/41) of LAs, this occurred after patients were notified about the initial positive result in 63% (26/41). Approximately 450-4500 confirmed gonorrhoea diagnoses and 2300 false-positive screens might occur through use of dual tests on NCSP samples each year. Under reasonable assumptions, the positive predictive value of the screening test is 17-67%. CONCLUSIONS: Over half of English LAs already commission dual tests for samples collected by the NCSP. Gonorrhoea screening has been introduced alongside chlamydia screening in many low prevalence settings without a national evidence review or change of policy. We question the public health benefit here, and suggest that robust testing algorithms and clinical management pathways, together with rigorous evaluation, be implemented wherever dual tests are deployed

Teenagers’ understandings of and attitudes towards vaccines and vaccine-preventable diseases: a qualitative study

<p>Background: To examine immunisation information needs of teenagers we explored understandings of vaccination and vaccine-preventable diseases, attitudes towards immunisation and experiences of immunisation. Diseases discussed included nine for which vaccines are currently offered in the UK (human papillomavirus, meningitis, tetanus, diphtheria, polio, whooping cough, measles, mumps and rubella), and two not currently included in the routine UK schedule (hepatitis B and chickenpox).</p> <p>Methods Twelve focus groups conducted between November 2010 and March 2011 with 59 teenagers (29 girls and 30 boys) living in various parts of Scotland.</p> <p>Results Teenagers exhibited limited knowledge and experience of the diseases, excluding chickenpox. Measles, mumps and rubella were perceived as severe forms of chickenpox-like illness, and rubella was not associated with foetal damage. Boys commonly believed that human papillomavirus only affects girls, and both genders exhibited confusion about its relationship with cancer. Participants considered two key factors when assessing the threat of diseases: their prevalence in the UK, and their potential to cause fatal or long-term harm. Meningitis was seen as a threat, but primarily to babies. Participants explained their limited knowledge as a result of mass immunisation making once-common diseases rare in the UK, and acknowledged immunisation's role in reducing disease prevalence.</p> <p>Conclusions While it is welcome that fewer teenagers have experienced vaccine-preventable diseases, this presents public health advocates with the challenge of communicating benefits of immunisation when advantages are less visible. The findings are timely in view of the Joint Committee on Vaccination and Immunisation's recommendation that a booster of meningitis C vaccine should be offered to teenagers; that teenagers did not perceive meningitis C as a significant threat should be a key concern of promotional information. While teenagers’ experiences of immunisation in school were not always positive, they seemed enthusiastic at the prospect of introducing more vaccines for their age group.</p&gt

Planetary population synthesis

In stellar astrophysics, the technique of population synthesis has been successfully used for several decades. For planets, it is in contrast still a young method which only became important in recent years because of the rapid increase of the number of known extrasolar planets, and the associated growth of statistical observational constraints. With planetary population synthesis, the theory of planet formation and evolution can be put to the test against these constraints. In this review of planetary population synthesis, we first briefly list key observational constraints. Then, the work flow in the method and its two main components are presented, namely global end-to-end models that predict planetary system properties directly from protoplanetary disk properties and probability distributions for these initial conditions. An overview of various population synthesis models in the literature is given. The sub-models for the physical processes considered in global models are described: the evolution of the protoplanetary disk, the planets' accretion of solids and gas, orbital migration, and N-body interactions among concurrently growing protoplanets. Next, typical population synthesis results are illustrated in the form of new syntheses obtained with the latest generation of the Bern model. Planetary formation tracks, the distribution of planets in the mass-distance and radius-distance plane, the planetary mass function, and the distributions of planetary radii, semimajor axes, and luminosities are shown, linked to underlying physical processes, and compared with their observational counterparts. We finish by highlighting the most important predictions made by population synthesis models and discuss the lessons learned from these predictions - both those later observationally confirmed and those rejected.Comment: 47 pages, 12 figures. Invited review accepted for publication in the 'Handbook of Exoplanets', planet formation section, section editor: Ralph Pudritz, Springer reference works, Juan Antonio Belmonte and Hans Deeg, Ed

Massive black hole science with eLISA

The evolving Laser Interferometer Space Antenna (eLISA) will revolutionize our understanding of the formation and evolution of massive black holes (MBHs) along cosmic history, by probing massive black hole binaries (MBHBs) in the 10(3) - 10(7) M-circle dot range out to redshift z greater than or similar to 10. High signal-to-noise ratio detections of similar to 10 - 100 MBHB coalescences per year will allow accurate measurements of the parameters of individual MBHBs (such as their masses, spins and luminosity distance), and a deep understanding of the underlying cosmic MBH parent population. This wealth of unprecedented information can lead to breakthroughs in many areas of physics, including astrophysics, cosmology and fundamental physics. We review the current status of the field, recent progress and future challenges

Giant Planet Formation and Migration

© 2018, The Author(s). Planets form in circumstellar discs around young stars. Starting with sub-micron sized dust particles, giant planet formation is all about growing 14 orders of magnitude in size. It has become increasingly clear over the past decades that during all stages of giant planet formation, the building blocks are extremely mobile and can change their semimajor axis by substantial amounts. In this chapter, we aim to give a basic overview of the physical processes thought to govern giant planet formation and migration, and to highlight possible links to water delivery.S.-J. Paardekooper is supported by a Royal Society University Research Fellowship. A. Johansen is supported by the Knut and Alice Wallenberg Foundation, the Swedish Research Council (grant 2014-5775) and the European Research Council (ERC Starting Grant 278675-PEBBLE2PLANET)