• mycoplasma
• chlamydia trachomatis
• HIV

Chlamydia trachomatis had long been working its quiet mischief before scientific advances identified it as the responsible organism. All that time symptoms and conditions would no doubt have been misattributed, and management would have been largely symptomatic. It is tempting to see the emergence of the latest ‘hidden’ STI—Mycoplasma genitalium (MG)—as following the same pattern. It is a relatively common infection; fears of its potential impact on reproductive health remain troublingly ill-defined; symptomatic treatment raises the spectre of emerging antibiotic resistance. Also as with chlamydia, the scope and impact of the new awareness is genuinely international. In the UK, interest was galvanised in 2015 by data from the third National Survey of Health Attitudes and Lifestyles (NATSAL 3). But studies brought together of STI show us how identical issues are having to be addressed in Australia1 and two regions of the US.2 3 Everywhere there is the same challenge of defining universal standards for screening and management. Fundamental to this will be research like this to establish prevalence and the clinical and risk correlates. Taylor et al 3 pursue the implications of MG for women’s reproductive health, analysing the association with histological endometritis, an a signal of pelvic inflammatory disease. Couldwell et al 1 address antibiotic resistance in an Australian MSM population, investigating mutations of the organism linked to macrolide resistance.

A second theme is HIV prevention, and the use of clever interventions to engage ‘hard-to-reach’ populations. ‘Clever’ in this context means culturally tailored, and the studies have, in different ways, required researchers to seek to understand the worlds of those they wish to influence. The sexual health implications of the use by MSM of smartphone networking apps have been frequently discussed. So has the possibility of employing these apps to promote awareness, so transforming the cause of the problem into its solution. The innovation discussed in Chow’s editorial4 and an original research study by Gutierrez et al 5 is to abandon the idea of stand-alone health awareness apps—never popular—in favour of adopting existing popular apps, like Grindr or Hornet, to promote awareness and testing. Rather more curious, however, is a customised Singaporean educational intervention reported by Wong et al 6 that required researchers to explore the world of Vietnamese and Thai entertainment workers. Finally, and closer to home for our BASHH subscribers, Saigal’s educational article7 explores practical issues relating to a different kind of cultural barrier that can impede access to the ‘hard-to-reach’, the law surrounding criminal liability for HIV transmission in the UK.

Other themes include tuberculosis/HIV co-infection8 9 and PrEP.10 11 Siqueira and colleagues estimate the enormous cost-burden to the Brazilian health system of each active TB/HIV co-infection as compared with an HIV or latent TB/HIV case, while Cevik et al 9 consider the complexities of combining rifampicin-based TB therapy with Dolutegravir. On PrEP, Beymer returns to the old problem of risk-compensation, comparing the incidence of STI before and after PrEP initiation in a cohort of MSM from Los Angeles. Gillespie considers the related question of how introduction of pre-exposure prophylaxis has had an impact on the recourse among Scottish MSM to post-exposure prophylaxis for sexual exposure.11

So much for the major themes. In addition to these, Brook’s editorial12 considers the challenges to developing countries seeking to meet UNAIDS 90:90:90 targets by poor access to viral-load testing, and the potential for these to be addressed by point-of-care (POCT) viral-load testing, if this ever becomes available at reasonable cost and the technology proves serviceable in these contexts. Other studies explores the relative psychological impact on men and women of diagnosis with chlamydia13; the development of azithromycin resistance in relation to earlier treatment with the drug for STIs14; the social determinants of condomless anal intercourse in Swedish MSM15 and the prevalence of HPV in China by region, sexual orientation and HIV status.16

Last but not least, our clinical readers will want to turn to this month’s Clinical Roundup17 and a column by Ceri Evans on the relationship between BASHH and sexual health advisers.18