This month’s journal is rich in articles exploring uncertainties and encouraging reflection on clinical practice and research methods. Three papers address the vexed question of the significance of Mycobacterium genitalium in various populations. Gaydos et al (see p 438) report a prevalence of 15.2% in urethritis, while Bradshaw’s group (see p 432) report its asymptomatic character in the rectum and urethra of men who have sex with men (MSM), and absence from the pharynx. Ross et al (see p 436) report a prevalence of 4.5% in asymptomatic clinic attendees. Clearly some definitive, well-designed research studies will be necessary if we are to answer fundamental questions about this organism.

Some tricky clinical cases of missed gonococcal septicaemia in a patient with lupus (see p 441), and syphilis masquerading as warts (see p 484) provide useful clinical reminders. Other clinical highlights include the continuing evolution of herpes simplex, with an increasing proportion of first episodes due to herpes simplex virus type …