WHO
estimated that nearly 1 million people become infected every day with
any of four curable sexually transmitted infections (STIs): chlamydia,
gonorrhoea, syphilis, and trichomoniasis. Despite their high global
incidence, STIs remain a neglected area of research. In this Commission,
we have prioritised five areas that represent particular challenges in
STI treatment and control. Chlamydia remains the most commonly diagnosed
bacterial STI in high-income countries despite widespread testing
recommendations, sensitive and specific non-invasive testing techniques,
and cheap effective therapy. We discuss the challenges for chlamydia
control and evidence to support a shift from the current focus on
infection-based screening to improved management of diagnosed cases and
of chlamydial morbidity, such as pelvic inflammatory disease. The
emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae
is globally recognised. We review current and potential future control
and treatment strategies, with a focus on novel antimicrobials.
Bacterial vaginosis is the most common vaginal disorder in women, but
current treatments are associated with frequent recurrence. Recurrence
after treatment might relate to evidence that suggests sexual
transmission is integral to the pathogenesis of bacterial vaginosis,
which has substantial implications for the development of effective
management approaches. STIs disproportionately affect low-income and
middle-income countries. We review strategies for case management,
focusing on point-of-care tests that hold considerable potential for
improving STI control. Lastly, STIs in men who have sex with men have
increased since the late 1990s. We discuss the contribution of new
biomedical HIV prevention strategies and risk compensation. Overall,
this Commission aims to enhance the understanding of some of the key
challenges facing the field of STIs, and outlines new approaches to
improve the clinical management of STIs and public health.